Digital implementation of a laser frequency stabilisation technique in the telecommunications band

Science.gov (United States)

Jivan, Pritesh; van Brakel, Adriaan; Manuel, Rodolfo Martínez; Grobler, Michael

2016-02-01

Laser frequency stabilisation in the telecommunications band was realised using the Pound-Drever-Hall (PDH) error signal. The transmission spectrum of the Fabry-Perot cavity was used as opposed to the traditionally used reflected spectrum. A comparison was done using an analogue as well as a digitally implemented system. This study forms part of an initial step towards developing a portable optical time and frequency standard. The frequency discriminator used in the experimental setup was a fibre-based Fabry-Perot etalon. The phase sensitive system made use of the optical heterodyne technique to detect changes in the phase of the system. A lock-in amplifier was used to filter and mix the input signals to generate the error signal. This error signal may then be used to generate a control signal via a PID controller. An error signal was realised at a wavelength of 1556 nm which correlates to an optical frequency of 1.926 THz. An implementation of the analogue PDH technique yielded an error signal with a bandwidth of 6.134 GHz, while a digital implementation yielded a bandwidth of 5.774 GHz.

47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

Science.gov (United States)

2010-10-01

... of wideband systems within the band 5925-7250 MHz. (a) The −10 dB bandwidth of a device operating... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation of wideband systems within the band... variations in temperature and supply voltage. (b) The −10 dB bandwidth of the fundamental emission shall be...

76 FR 42567 - Reporting Requirements for U.S. Providers of International Telecommunications Services

Science.gov (United States)

2011-07-19

...] Reporting Requirements for U.S. Providers of International Telecommunications Services AGENCY: Federal... international telecommunications traffic for which the burdens on U.S. international service providers outweigh... international reporting requirements for U.S. providers of international telecommunications services. In the...

A Telecommunications Industry Primer: A Systems Model.

Science.gov (United States)

Obermier, Timothy R.; Tuttle, Ronald H.

2003-01-01

Describes the Telecommunications Systems Model to help technical educators and students understand the increasingly complex telecommunications infrastructure. Specifically looks at ownership and regulatory status, service providers, transport medium, network protocols, and end-user services. (JOW)

Anisotropic Exciton Rabi Oscillation in Single Telecommunication-Band Quantum Dot

Science.gov (United States)

Toshiyuki Miyazawa,; Toshihiro Nakaoka,; Katsuyuki Watanabe,; Naoto Kumagai,; Naoki Yokoyama,; Yasuhiko Arakawa,

2010-06-01

Anisotropic Rabi oscillation in the exciton state in a single InAs/GaAs quantum dot (QD) was demonstrated in the telecommunication-band by selecting two orthogonal polarization angles of the excitation laser. Our InAs QDs were embedded in an intrinsic layer of an n-i-Schottky diode, which provides an electric field to extract photoexcited carriers from QDs. Owing to the potential anisotropy of QDs, the fine structure splitting (FSS) energy in the exciton state in single InAs QDs was ˜110 μeV, measured by polarization-resolved photocurrent spectroscopy. The ratio between two different Rabi frequencies, which reflect anisotropic dipole moments of two orthogonal exciton states, was estimated to be ˜1.2. This demonstrates that the selective control of two orthogonal polarized exciton states is a promising technique for exciton-based-quantum information devices compatible with fiber optics.

Wireless telecommunication systems

CERN Document Server

Terré, Michel; Vivier, Emmanuelle

2013-01-01

Wireless telecommunication systems generate a huge amount of interest. In the last two decades, these systems have experienced at least three major technological leaps, and it has become impossible to imagine how society was organized without them. In this book, we propose a macroscopic approach on wireless systems, and aim at answering key questions about power, data rates, multiple access, cellular engineering and access networks architectures.We present a series of solved problems, whose objective is to establish the main elements of a global link budget in several radiocommunicati

Engaging Faculty in Telecommunications-Based Instructional Delivery Systems.

Science.gov (United States)

Swalec, John J.

In the design and development of telecommunications-based instructional delivery systems, attention to faculty involvement and training is often overlooked until the system is operational. The Waubonsee Telecommunications Instructional Consortium (TIC), in Illinois, is one network that benefited from early faculty input. Even before the first…

A year 2003 conceptual model for the U.S. telecommunications infrastructure.

Energy Technology Data Exchange (ETDEWEB)

Cox, Roger Gary; Reinert, Rhonda K.

2003-12-01

To model the telecommunications infrastructure and its role and robustness to shocks, we must characterize the business and engineering of telecommunications systems in the year 2003 and beyond. By analogy to environmental systems modeling, we seek to develop a 'conceptual model' for telecommunications. Here, the conceptual model is a list of high-level assumptions consistent with the economic and engineering architectures of telecommunications suppliers and customers, both today and in the near future. We describe the present engineering architectures of the most popular service offerings, and describe the supplier markets in some detail. We also develop a characterization of the customer base for telecommunications services and project its likely response to disruptions in service, base-lining such conjectures against observed behaviors during 9/11.

Lunar Noise-Temperature Increase Measurements at S-Band, X-Band, and Ka-Band Using a 34-Meter-Diameter Beam-Waveguide Antenna

Science.gov (United States)

Morabito, D. D.

2006-08-01

The Moon radiates energy at infrared and microwave wavelengths, in addition to reflecting sunlight at optical wavelengths. As a result, an antenna pointed at or near the Moon will cause an increase in receiver noise temperature that needs to be accounted for in telemetry, radio science, or ranging link budgets. The Deep Space Network may be required to use its antennas in future lunar robotic or human missions, and thus it is important to understand the nature of this temperature increase as a function of observing frequency, lunar phase, and angular offset of the antenna beam from the center of the lunar disk. This article quantifies such a set of measurements acquired at DSS 13, a 34-m-diameter research and development beam-waveguide antenna located at Goldstone, California, at three different telecommunication frequencies, S-band (2.3 GHz), X-band (8.4 GHz), and Ka-band (32 GHz), over a wide range of lunar phase, for both disk-centered and limb-centered positions of the antenna beam.

Implementation of the Quality Management System in the telecommunications companies

OpenAIRE

Menshikova Ekaterina; Khazanov Oleg; Styazhkin Mark

2016-01-01

This article describes the advantages of the implementing of the quality management system based on ISO 9001 in the telecommunications companies. The stages of the implementation of the quality management system in the telecommunications companies are discussed. The map of the main process and criteria of processes is developed. The expediency of implementing the quality management system based on the requirements of ISO 9001 in Telecommunications is showed.

Polarimetric and diffractive evaluation of 3.74 micron pixel-size LCoS in the telecommunications C-band

Science.gov (United States)

Wang, Mi; Martínez, Francisco J.; Márquez, Andrés.; Ye, Yabin; Zong, Liangjia; Pascual, Inmaculada; Beléndez, Augusto

2017-08-01

Liquid-crystal on Silicon (LCoS) microdisplays are one of the competing technologies to implement wavelength selective switches (WSS) for optical telecommunications. Last generation LCoS, with more than 4 megapixels, have decreased pixel size to values smaller than 4 microns, what increases interpixel cross-talk effects such as fringing-field. We proceed with an experimental evaluation of a 3.74 micron pixel size parallel-aligned LCoS (PA-LCoS) device. At 1550 nm, for the first time we use time-average Stokes polarimetry to measure the retardance and its flicker magnitude as a function of voltage. We also verify the effect of the antireflection coating when we try to characterize the PA-LCoS out of the designed interval for the AR coating. Some preliminary results for the performance for binary gratings are also given, where the decrease of modulation range with the increase in spatial frequency is shown, together with some residual polarization effects.

Telecommunications glossary of telecommunications terms

CERN Document Server

1997-01-01

This glossary contains more than 5,000 technical terms and definitions that were standardized by the federal government for use by international and U.S. government telecommunications specialists. It includes international and national terms drawn from the International Telecommunication Union, the International Organization for Standardization, the TIA, ANSI, and others.

Telecommunications, power supply, computer systems: the infrastructures of the soccer world cup; Telecommunications, electricite, informatique: les infrastructures de la Coupe du Monde

Energy Technology Data Exchange (ETDEWEB)

Anon.

1998-06-01

The 1998 edition of the soccer world cup took place in ten different stadiums in France and several related sites. This short paper gives a general overview of the infrastructures developed for this occasion in the domains of telecommunications, power supply (substations, protection systems, computerized control systems..), and computer systems. (J.S.)

Telecommunications demystified

CERN Document Server

Nassar, Carl R

2001-01-01

Carl R. Nassar, Ph.D., is professor of telecommunications at Colorado State University and director of the Research in Advanced Wireless Communications (RAWCom) laboratory there. He also consults for telecommunications firms and publishes extensively in the wireless literature.Balances a solid theoretical treatment of subjects with practical applications and examples.Covers both digital and analogue telecommunications systems, including digital modulation techniques.The CD accompanying the book includes MATLAB® tutorials that permit readers to model various telecommunications systems and an el

European Telecommunications Conference. Strategic Planning for the 1990s

Science.gov (United States)

Blackburn, J. F.

1990-06-01

The European Telecommunications Conference Strategic Planning for the 1990s provided information to delegates and their companies on strategic planning for the European market, particularly after the advent of the European Single Market at the end of 1992. The conference objective was to examine the impact of the initiatives of the European Commission (EC) and the changing attitudes to service provision by public and private sector organizations on industry and marketing. Organized by Blenheim Online and Logica, 40 delegates attended this conference, mainly from Europe, but with a few from the U.S. The papers were designed to illuminate such questions as emerging market sectors, impact of U.S telecommunications organizations in Europe, mergers and acquisition, standards, and value-added services.

Telecommunications network modelling, planning and design

CERN Document Server

Evans, Sharon

2003-01-01

Telecommunication Network Modelling, Planning and Design addresses sophisticated modelling techniques from the perspective of the communications industry and covers some of the major issues facing telecommunications network engineers and managers today. Topics covered include network planning for transmission systems, modelling of SDH transport network structures and telecommunications network design and performance modelling, as well as network costs and ROI modelling and QoS in 3G networks.

Space Telecommunications Radio System (STRS) Architecture. Part 1; Tutorial - Overview

Science.gov (United States)

Handler, Louis M.; Briones, Janette C.; Mortensen, Dale J.; Reinhart, Richard C.

2012-01-01

Space Telecommunications Radio System (STRS) Architecture Standard provides a NASA standard for software-defined radio. STRS is being demonstrated in the Space Communications and Navigation (SCaN) Testbed formerly known as Communications, Navigation and Networking Configurable Testbed (CoNNeCT). Ground station radios communicating the SCaN testbed are also being written to comply with the STRS architecture. The STRS Architecture Tutorial Overview presents a general introduction to the STRS architecture standard developed at the NASA Glenn Research Center (GRC), addresses frequently asked questions, and clarifies methods of implementing the standard. The STRS architecture should be used as a base for many of NASA s future telecommunications technologies. The presentation will provide a basic understanding of STRS.

Telecommunication system engineering

CERN Document Server

Freeman, Roger L

2004-01-01

From the review of the Third Edition:""A must for anyone in volved in the practical aspects of the telecommunications industry.""-CHOICE* Outlines the expertise essential to the successful operation and design of every type of telecommunications networks in use today* New edition is fully revised and expanded to present authoritative coverage of the important developments that have taken place since the previous edition was published* Includes new chapters on hot topics such as cellular radio, asynchronous transfer mode, broadband technologies, and network management

47 CFR 80.475 - Scope of service of the Automated Maritime Telecommunications System (AMTS).

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Scope of service of the Automated Maritime Telecommunications System (AMTS). 80.475 Section 80.475 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Automated Systems § 80.475 Scope of service of the Automated Maritime Telecommunications System (AMTS). (a...

Development of Broadband Telecommunication System for Railways using Laser Technology

Science.gov (United States)

Nakamura, Kazuki; Nakagawa, Shingo; Matsubara, Hiroshi; Tatsui, Daisuke; Seki, Kiyotaka; Haruyama, Shinichiro; Teraoka, Fumio

We developed a high-speed telecommunication system applicable to railways, to improve customer service and efficiency of operator's telecommunication between the ground facilities and trains under operations. We manufactured a mobile telecommunication system, capable of recording the transfer rate of 1Gbps in theory by applying the laser beam communication technology. We carried out a field test using trains in active service, and obtained the result of the transfer rate of approximately 700Mbps on the TCP layer between the ground and the train running at a speed of approximately 130km/h.

X-Band CubeSat Communication System Demonstration

Science.gov (United States)

Altunc, Serhat; Kegege, Obadiah; Bundick, Steve; Shaw, Harry; Schaire, Scott; Bussey, George; Crum, Gary; Burke, Jacob C.; Palo, Scott; O'Conor, Darren

2015-01-01

Today's CubeSats mostly operate their communications at UHF- and S-band frequencies. UHF band is presently crowded, thus downlink communications are at lower data rates due to bandwidth limitations and are unreliable due to interference. This research presents an end-to-end robust, innovative, compact, efficient and low cost S-band uplink and X-band downlink CubeSat communication system demonstration between a balloon and a Near Earth Network (NEN) ground system. Since communication systems serve as umbilical cords for space missions, demonstration of this X-band communication system is critical for successfully supporting current and future CubeSat communication needs. This research has three main objectives. The first objective is to design, simulate, and test a CubeSat S- and X-band communication system. Satellite Tool Kit (STK) dynamic link budget calculations and HFSS Simulations and modeling results have been used to trade the merit of various designs for small satellite applications. S- and X-band antennas have been tested in the compact antenna test range at Goddard Space Flight Center (GSFC) to gather radiation pattern data. The second objective is simulate and test a CubeSat compatible X-band communication system at 12.5Mbps including S-band antennas, X-band antennas, Laboratory for Atmospheric and Space Physics (LASP) /GSFC transmitter and an S-band receiver from TRL-5 to TRL-8 by the end of this effort. Different X-band communication system components (antennas, diplexers, etc.) from GSFC, other NASA centers, universities, and private companies have been investigated and traded, and a complete component list for the communication system baseline has been developed by performing analytical and numerical analysis. This objective also includes running simulations and performing trades between different X-band antenna systems to optimize communication system performance. The final objective is to perform an end-to-end X-band CubeSat communication system

Telecommunications Policy, High Definition Television, and U.S. Competitiveness.

Science.gov (United States)

Cohen, Robert B.; Donow, Kenneth

New policies are needed for the U.S. telecommunications industry. The continuation of current policies--which emphasize customer and convenience services to the near exclusion of developing domestically produced equipment and improving infrastructure--will constrain the domestic growth of U.S. corporations and make it difficult for smaller…

47 CFR 90.1213 - Band plan.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Band plan. 90.1213 Section 90.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND... § 90.1213 Band plan. The following channel center frequencies are permitted to be aggregated for...

Future Standardization of Space Telecommunications Radio System with Core Flight System

Science.gov (United States)

Briones, Janette C.; Hickey, Joseph P.; Roche, Rigoberto; Handler, Louis M.; Hall, Charles S.

2016-01-01

NASA Glenn Research Center (GRC) is integrating the NASA Space Telecommunications Radio System (STRS) Standard with the Core Flight System (cFS), an avionics software operating environment. The STRS standard provides a common, consistent framework to develop, qualify, operate and maintain complex, reconfigurable and reprogrammable radio systems. The cFS is a flexible, open architecture that features a plugand- play software executive called the Core Flight Executive (cFE), a reusable library of software components for flight and space missions and an integrated tool suite. Together, STRS and cFS create a development environment that allows for STRS compliant applications to reference the STRS application programmer interfaces (APIs) that use the cFS infrastructure. These APIs are used to standardize the communication protocols on NASAs space SDRs. The cFS-STRS Operating Environment (OE) is a portable cFS library, which adds the ability to run STRS applications on existing cFS platforms. The purpose of this paper is to discuss the cFS-STRS OE prototype, preliminary experimental results performed using the Advanced Space Radio Platform (ASRP), the GRC S- band Ground Station and the SCaN (Space Communication and Navigation) Testbed currently flying onboard the International Space Station (ISS). Additionally, this paper presents a demonstration of the Consultative Committee for Space Data Systems (CCSDS) Spacecraft Onboard Interface Services (SOIS) using electronic data sheets (EDS) inside cFE. This configuration allows for the data sheets to specify binary formats for data exchange between STRS applications. The integration of STRS with cFS leverages mission-proven platform functions and mitigates barriers to integration with future missions. This reduces flight software development time and the costs of software-defined radio (SDR) platforms. Furthermore, the combined benefits of STRS standardization with the flexibility of cFS provide an effective, reliable and

NATO Telecommunications Symposium

CERN Document Server

Lucas, William; Conrath, David

1978-01-01

This book contains the proceedings of the first international symposium devoted to research on the evaluation and planning of new person-to-person telecommunication systems. It was sponsored by NATO's Special Programme Panel on Systems Science and took place, in September 1977, at the University of Bergamo in the north of Italy. Telecommunication systems which provide for communication be­ tween people, rather than computers or other instruments, are of two kinds. There are mass communication systems (broadcast radio and television) and interpersonal systems (for example, the telephone and Telex) which join together individuals or small groups. Here we have included in the interpersonal category certain systems for re­ trieving information from computers, essentially those systems in which the role of the computer 1s primarily to act as a store and to identify that information which best fits a user's request. (This excludes management information systems in which the computer performs important transformat...

47 CFR 18.303 - Prohibited frequency bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Prohibited frequency bands. 18.303 Section 18.303 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT Technical Standards § 18.303 Prohibited frequency bands. Operation of ISM equipment within the...

Quality of service management efficient scheme for the universal mobile telecommunications system

Directory of Open Access Journals (Sweden)

E. Zaleta–Alejandre

2008-04-01

Full Text Available This research work proposes a new Radio Resource Management (RRM scheme in order to accomplish the Quality of Service (QoS management for the Universal Mobile Telecommunications System (UMTS. The solution is based on UMTS standardization and a performance evaluation is presented to demonstrate its efficiency.

The Case for Deep Space Telecommunications Relay Stations

Science.gov (United States)

Chandler, Charles W.; Miranda, Felix A. (Technical Monitor)

2004-01-01

Each future mission to Jupiter and beyond must carry the traditional suite of telecommunications systems for command and control and for mission data transmission to earth. The telecommunications hardware includes the large antenna and the high-power transmitters that enable the communications link. Yet future spacecraft will be scaled down from the hallmark missions of Galileo and Cassini to Jupiter and Saturn, respectively. This implies that a higher percentage of the spacecraft weight and power must be dedicated to telecommunications system. The following analysis quantifies this impact to future missions and then explores the merits of an alternative approach using deep space relay stations for the link back to earth. It will be demonstrated that a telecommunications relay satellite would reduce S/C telecommunications weight and power sufficiently to add one to two more instruments.

Nanotechnology for telecommunications

CERN Document Server

Anwar, Sohail; Qazi, Salahuddin; Ilyas, Mohammad

2010-01-01

With its unique promise to revolutionize science, engineering, technology, and other fields, nanotechnology continues to profoundly impact associated materials, components, and systems, particularly those used in telecommunications. These developments are leading to easier convergence of related technologies, massive storage data, compact storage devices, and higher-performance computing. Nanotechnology for Telecommunications presents vital technical scientific information to help readers grasp issues and challenges associated with nanoscale telecommunication system development and commerciali

Single-photon generator for optical telecommunication wavelength

International Nuclear Information System (INIS)

Usuki, T; Sakuma, Y; Hirose, S; Takemoto, K; Yokoyama, N; Miyazawa, T; Takatsu, M; Arakawa, Y

2006-01-01

We report on the generation of single-photon pulses from a single InAs/InP quantum dot in telecommunication bands (1.3-1.55 μm: higher transmittance through an optical fiber). First we prepared InAs quantum dots on InP (0 0 1) substrates in a low-pressure MOCVD by using a so-called InP 'double-cap' procedure. The quantum dots have well-controlled photo emission wavelength in the telecommunication bands. We also developed a single-photon emitter in which quantum dots were embedded. Numerical simulation designed the emitter to realize efficient injection of the emitted photons into a single-mode optical fiber. Using a Hanbury-Brown and Twiss technique has proved that the photons through the fiber were single photons

The telecommunications handbook engineering guidelines for fixed, mobile and satellite systems

CERN Document Server

Penttinen, Jyrki T J

2015-01-01

This practical handbook and reference provides a complete understanding of the telecommunications field supported by descriptions and case examples throughout Taking a practical approach, The Telecommunications Handbook examines the principles and details of all of the major and modern telecommunications systems currently available to industry and to end-users. It gives essential information about usage, architectures, functioning, planning, construction, measurements and optimisation. The structure of the book is modular, giving both overall descriptions of the architectures and functionali

Data Exchange Inventory System for Telecommunications and Systems Operations (DEXI-OTSO)

Data.gov (United States)

Social Security Administration — This Data Exchange Inventory (DEXI) for the Office of Telecommunications and System Operations, (OTSO) Network Troubleshooting is a browser-based inventory database...

Generation of optical frequencies out of the frequency comb of a femtosecond laser for DWDM telecommunication

International Nuclear Information System (INIS)

Kim, Y-J; Chun, B J; Kim, Y; Hyun, S; Kim, S-W

2010-01-01

We exploit the frequency comb of a fs laser as the frequency ruler to generate reference optical frequencies for multi-channel DWDM (dense wavelength-division-multiplexing) telecommunication. Our fiber-based scheme of single-mode extraction enables on-demand generation of optical frequencies within the telecommunication band with an absolute frequency uncertainty of 9.1×10 -13 . The linewidth of extracted optical modes is less than 1 Hz, and the instability is measured 2.3×10 -15 at 10 s averaging. This outstanding performance of optical frequency generation would lead to a drastic improvement of the spectral efficiency for the next-generation DWDM telecommunication

Control and adaptation in telecommunication systems mathematical foundations

CERN Document Server

Popovskij, Vladimir; Titarenko, Larysa

2011-01-01

This book is devoted to mathematical foundations providing synthesis and analysis of control and adaptation algorithms targeting modern telecommunication systems (TCS). The most popular technologies and network management methods are discussed.

AMIGA at the Auger observatory: the telecommunications system

International Nuclear Information System (INIS)

Platino, M; Hampel, M R; Almela, A; Sedoski, A; Lucero, A; Suarez, F; Wainberg, O; Etchegoyen, A; Fiszelew, P; Vega, G De La; Videla, M; Yelos, D; Cancio, A; Garcia, B

2013-01-01

AMIGA is an extension of the Pierre Auger Observatory that will consist of 85 detector pairs, each one composed of a surface water-Cherenkov detector and a buried muon counter. Each muon counter has an area of 30 square meters and is made of scintillator strips, with doped optical fibers glued to them, which guide the light to 64 pixel photomultiplier tubes. The detector pairs are arranged at 433 m and 750 m array spacings. In this paper we present the telecommunications system designed to connect the muon counters with the central data processing system at the observatory campus in Malarg and quot;ue. The telecommunications system consists of a point-to-multipoint radio link designed to connect the 85 muon counters or subscribers to two coordinators located at the Coihueco fluorescence detector building. The link provides TCP/IP remote access to the scintillator modules through router boards installed on each of the surface detectors of AMIGA. This setup provides a flexible LAN configuration for each muon counter connected to a WAN that links all the data generated by the muon counters and the surface detectors to the Central Data Acquisition System, or CDAS, at the observatory campus. We present the design parameters, the proposed telecommunications solution and the laboratory and field tests proposed to guarantee its functioning for the whole data traffic generated between each surface detector and muon counter in the AMIGA array and the CDAS

Study of LEO-SAT microwave link for broad-band mobile satellite communication system

Science.gov (United States)

Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

1993-01-01

In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

Service Quality Management in the ITS Telecommunications Systems

Directory of Open Access Journals (Sweden)

Tomas Zelinka

2013-12-01

Full Text Available Guaranteed selected quality of telecommunication service and wide area coverage are typical requirements of the ITS (Intelligent Transport Systems applications. Extensive range of wireless data services with reasonable coverage is provided by public wireless services operators, however, mostly no guaranteed relevant range of quality and security is available. ITS services require cost-effectively solution which can be resolved by combination of the "core" public solution with the other public as well as private services where and when it is needed. Such approach requires implementation of the relevant flexible system architecture supported by the efficient decision processes. ITS specific service security requirements would not underestimated, as well. Special situation is identified in case of the C2I (Car to Infrastructure and C2C (Car to Car communication namely if the vehicle on board unit is interconnected with the vehicle CAN (Controlled Area Network based network. Such configurations significantly increase potential of dangerous intruders´ attacks. Probability of the critical hazards appearances grows if the ITS data are accessible in the wide area networks. That is also the main reason why relevant telecommunications security support is understood as one of the crucial part of the ITS telecommunications solution.

VIP-PERSONNEL FOR TELECOMMUNICATIONS

Directory of Open Access Journals (Sweden)

Konstantin Yakovishin

2013-12-01

Full Text Available In the article the new nonconventional technology of preparation of the experts of high qualification for telecommunications is considered. The experience of teaching of discipline “Informatics” on Faculty of Telecommunication systems in National Aviation University is generalized. The following idea develops: the modern VІР-expert in telecommunications should know and be able to simulate telecommunication systems and protocols in systems of fast designing by methods of the Object- guided programming. In the article the new elements of new technology are considered – they are: the formation of knowledge and skills on modeling the telecommunication protocols, training is exclusively on the examples (projects, teaching of lectures by analogy to a method of descending designing. It is marked, that it is necessary to supplement the usual comments of the texts, photo and video from electronic lectures on a multimedia projector by start and performance of the simulating programs on the computer.

Technological advances in telecommunications for mines

Energy Technology Data Exchange (ETDEWEB)

Waye, P.M.Y.; Yewen, R. [Mine Radio Systemic Inc., Stouffville, ON (Canada)

2002-01-01

As mines utilize more automation in mining operations to improve efficiency and safety, a corresponding increasing demand is placed on the transport of information. Some of the recent technological advances in underground telecommunications are described for various data, voice and video applications. In particular, two new innovative underground communication systems are described, one with highspeed data at 30 Mbps and the other for mine-wide evacuation and safety applications. The high-speed data system incorporates state-of-the-art data networking technologies and the existing leaky-cable, narrow-band radio channels. The new system provides over the same basic infrastructure - the highspeed data network at 30 Mbps TCP/IP Ethernet with 100 Base-T interconnection, plus 32 narrow-band radio channels. The second system is a system for mine-wide evacuation with 'through-the-earth' communication infrastructure. Emergency situations can be communicated to and from all the miners within seconds through a central control location. The technology involved does not require leaky cable or any other similar transmission media installation. Many applications are possible, including warning miners of emergency situations, mine rescue operation to communicate with trapped miners, and regular reporting from miners working alone.

Telecommunications system reliability engineering theory and practice

CERN Document Server

Ayers, Mark L

2012-01-01

"Increasing system complexity require new, more sophisticated tools for system modeling and metric calculation. Bringing the field up to date, this book provides telecommunications engineers with practical tools for analyzing, calculating, and reporting availability, reliability, and maintainability metrics. It gives the background in system reliability theory and covers in-depth applications in fiber optic networks, microwave networks, satellite networks, power systems, and facilities management. Computer programming tools for simulating the approaches presented, using the Matlab software suite, are also provided"

47 CFR 90.353 - LMS operations in the 902-928 MHz band.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false LMS operations in the 902-928 MHz band. 90.353... operations in the 902-928 MHz band. LMS systems may be authorized within the 902-928 MHz band, subject to the..., scientific, and medical (ISM) devices and radiolocation Government stations that operate in the 902-928 MHz...

JPRS Report, Telecommunications

Science.gov (United States)

1987-07-07

The management puts great emphasis on its human resources sector — its de- velopment, motivation, and perform- ance. Entrepreneurship also plays...telecommunications services outside Telco’s franchise . And HCV has indicated to the Government it hopes Telco’s monopoly will be stripped when its franchise expires...under a franchised monopoly by Telco, he explained. The other telecommunications services, such as mobile telephone and radio paging, are all

Advances in X-Band and S-Band Linear Accelerators for Security, NDT, and Other Applications

CERN Document Server

Mishin, Andrey V

2005-01-01

At AS&E High Energy Systems Division, we designed several new advanced high energy electron beam and X-ray sources. Our primary focus has always been in building the world's most portable commercial X-band accelerators. Today, our X-band systems frequently exceed performance of the similar S-band machines, while they are more portable compared to the latter. The new designs of the X-band accelerators in the most practical energy range from 1 MeV to 6 MeV have been tested delivering outstanding results. Seventy 6 MeV X-band linacs systems have been produced. The most compact linac for security is used by AS&E in a self-shielded, Shaped Energy™ cargo screening system. We pioneered using the X-band linear accelerators for CT, producing high quality images of oil pipes and wood logs. An X-band linear accelerator head on a robotic arm has been used for electron beam radiation curing of an odd-shaped graphite composite part. We developed the broad-range 4 MeV to over 10 MeV energy-regulated X-band ...

Implementing Case Tools in the Inteligent Telecommunication Systems

OpenAIRE

Bahador Ghahramani; Azad Azadmanesh

2003-01-01

This paper discusses an intelligent and Internet-based Telecommunication System Specification Model (TSSM) using Computer Aided Systems Engineering tools (CASE tools). TSSM implements CASE tools to mechanize its lifecycle development maintenance and integration process. This model is developed to improve the system analysts (SA) efforts in their design and development of major software and hardware initiatives. This model also improves the SA effectiveness by guiding them through the system's...

Development of Cooling Design Technique for an Electronic Telecommunication System Using HPHE

International Nuclear Information System (INIS)

Lee, Jung Hwan; Ryoo, Seong Ryoul; Chun, Ji Hwan; Kim, Jong Man; Kim, Hyun Jun; Kim, Chul Ju; Suh, Myung Won

2007-01-01

The purpose of this study is to investigate the cooling performance of Heat Pipe Heat Exchanger(HPHE) for an electronic telecommunication system by adequate convection condition. Heat generation rates of electronic components, the temperature distributions of HPHE and surrounding air are analyzed experimentally and numerically. In order to perform the heat transfer analysis for the thermal design of telecommunication system, a program is developed. The program is useful to a user who is not familiar with an electronic telecommunication system. The simulation results showed that the HPHE were able to achieve a cooling capacity of up to 230W at the maximum temperature difference of 17.4 .deg. C. To verify the results from the numerical simulation, an experiment was conducted under the same condition as the numerical simulation, and their results were compared

36 CFR 1194.23 - Telecommunications products.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Telecommunications products... Telecommunications products. (a) Telecommunications products or systems which provide a function allowing voice... intermix speech with TTY use. (b) Telecommunications products which include voice communication...

47 CFR 90.531 - Band plan.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Band plan. 90.531 Section 90.531...-805 MHz Bands § 90.531 Band plan. This section sets forth the band plan for the 763-775 MHz and 793... and portables subject to Commission-approved regional planning committee regional plans. Transmitter...

Telecommunications and navigation systems design for manned Mars exploration missions

Science.gov (United States)

Hall, Justin R.; Hastrup, Rolf C.

1989-06-01

This paper discusses typical manned Mars exploration needs for telecommunications, including preliminary navigation support functions. It is a brief progress report on an ongoing study program within the current NASA JPL Deep Space Network (DSN) activities. A typical Mars exploration case is defined, and support approaches comparing microwave and optical frequency performance for both local in situ and Mars-earth links are described. Optical telecommunication and navigation technology development opportunities in a Mars exploration program are also identified. A local Mars system telecommunication relay and navigation capability for service support of all Mars missions has been proposed as part of an overall solar system communications network. The effects of light-time delay and occultations on real-time mission decision-making are discussed; the availability of increased local mass data storage may be more important than increasing peak data rates to earth. The long-term frequency use plan will most likely include a mix of microwave, millimeter-wave and optical link capabilities to meet a variety of deep space mission needs.

Privacy Act System of Records: EPA Telecommunications Detail Records, EPA-32

Science.gov (United States)

Learn more about the EPA Telecommunications Detail Records System, including who is covered in the system, the purpose of data collection, routine uses for the system's records, and other security procedures.

Regulatory governance of telecommunications liberalisation in Taiwan

Energy Technology Data Exchange (ETDEWEB)

Cheng, Kuo-Tai [Department of Regional Studies in Humanity and Social Sciences, National Hsin-Chu University of Education, No. 521 Nan-Da Road, Hsin-Chu 300 (China); Hebenton, Bill [School of Law, University of Manchester, M13 9PP (United Kingdom)

2008-12-15

This paper examines the changing role of government and market in regulating the telecommunications sector from since 1996 in Taiwan. It contextualises the theoretical aspects of regulatory governance for institutional design and practices, and reviews the concepts and mechanisms for appraising privatisation and regulatory systems. Using a conceptual framework for researching privatisation and regulation, it describes the process and issues pertinent to telecommunications liberalisation and privatisation in Taiwan, supported by a brief presentation of theoretical points of view as well as practitioners' views. The paper presents results concerning criteria for appraising privatisation and regulatory governance and considers policy lessons that can be learned from the experiences of the Taiwanese telecommunications sector's liberalisation. (author)

Main Directions in Ensuring Business Continuity for Information and Telecommunication Systems of High Availability

Directory of Open Access Journals (Sweden)

Boris Mikhailovich Egorov

2014-12-01

Full Text Available Enterprise Continuity Program, Information and Telecommunication System of Bank of Russia The results of the analysis of the main directions to ensure business continuity for the information and telecommunication systems of high availability in relation to expansion of the problems range, their intellectualization and the modern IT implementation are given.

47 CFR 15.713 - TV bands database.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database. 15.713 Section 15.713... TV bands database. (a) Purpose. The TV bands database serves the following functions: (1) To... databases. (b) Information in the TV bands database. (1) Facilities already recorded in Commission databases...

32 CFR 2001.50 - Telecommunications automated information systems and network security.

Science.gov (United States)

2010-07-01

... NATIONAL SECURITY INFORMATION Safeguarding § 2001.50 Telecommunications automated information systems and... identified in the Committee on National Security Systems (CNSS) issuances and the Intelligence Community Directive (ICD) 503, Intelligence Community Information Technology Systems Security Risk Management...

Implementing Case Tools in the Inteligent Telecommunication Systems

Directory of Open Access Journals (Sweden)

Bahador Ghahramani

2003-02-01

Full Text Available This paper discusses an intelligent and Internet-based Telecommunication System Specification Model (TSSM using Computer Aided Systems Engineering tools (CASE tools. TSSM implements CASE tools to mechanize its lifecycle development maintenance and integration process. This model is developed to improve the system analysts (SA efforts in their design and development of major software and hardware initiatives. This model also improves the SA effectiveness by guiding them through the system's Lifecycle Development Process (LDP. The CASE tools are used to support, integrate, and monitor all LDP functions of the system.

A 7MeV S-Band 2998MHz Variable Pulse Length Linear Accelerator System

CERN Document Server

Hernandez, Michael; Mishin, Andrey V; Saverskiy, Aleksandr J; Skowbo, Dave; Smith, Richard

2005-01-01

American Science and Engineering High Energy Systems Division (AS&E HESD) has designed and commissioned a variable pulse length 7 MeV electron accelerator system. The system is capable of delivering a 7 MeV electron beam with a pulse length of 10 nS FWHM and a peak current of 1 ampere. The system can also produce electron pulses with lengths of 20, 50, 100, 200, 400 nS and 3 uS FWHM with corresponding lower peak currents. The accelerator system consists of a gridded electron gun, focusing coil, an electrostatic deflector system, Helmholtz coils, a standing wave side coupled S-band linac, a 2.6 MW peak power magnetron, an RF circulator, a fast toroid, vacuum system and a PLC/PC control system. The system has been operated at repetition rates up to 250pps. The design, simulations and experimental results from the accelerator system are presented in this paper.

L-band brightness temperature disaggregation for use with S-band and C-band radiometer data for WCOM

Science.gov (United States)

Yao, P.; Shi, J.; Zhao, T.; Cosh, M. H.; Bindlish, R.

2017-12-01

There are two passive microwave sensors onboard the Water Cycle Observation Mission (WCOM), which includes a synthetic aperture radiometer operating at L-S-C bands and a scanning microwave radiometer operating from C- to W-bands. It provides a unique opportunity to disaggregate L-band brightness temperature (soil moisture) with S-band C-bands radiometer data. In this study, passive-only downscaling methodologies are developed and evaluated. Based on the radiative transfer modeling, it was found that the TBs (brightness temperature) between the L-band and S-band exhibit a linear relationship, and there is an exponential relationship between L-band and C-band. We carried out the downscaling results by two methods: (1) downscaling with L-S-C band passive measurements with the same incidence angle from payload IMI; (2) downscaling with L-C band passive measurements with different incidence angle from payloads IMI and PMI. The downscaling method with L-S bands with the same incident angle was first evaluated using SMEX02 data. The RMSE are 2.69 K and 1.52 K for H and V polarization respectively. The downscaling method with L-C bands is developed with different incident angles using SMEX03 data. The RMSE are 2.97 K and 2.68 K for H and V polarization respectively. These results showed that high-resolution L-band brightness temperature and soil moisture products could be generated from the future WCOM passive-only observations.

METHODS FOR ASSESSING SECURITY THREATS CONFIDENTIAL INFORMATION FOR THE INFORMATION AND TELECOMMUNICATIONS SYSTEMS

Directory of Open Access Journals (Sweden)

E. V. Belokurova

2015-01-01

Full Text Available The article discusses the different approaches to assessing the safety of confidential information-term for information and telecommunication systems of various pre-appreciable destination in the presence of internal and external threats to its integrity and availability. The difficulty of ensuring the security of confidential information from exposure to information and telecommunication systems of external and internal threats at the present time, is of particular relevance. This problem is confirmed by the analysis of available statistical information on the impact of threats on the security circulating in the information and telecommunications system. Leak confidential information, intellectual property, information, know-how is the result of significant material and moral damage caused to the owner of the restricted information. The paper presents the structure of the indicators and criteria shows that the most promising are analytical criteria. However, their use to assess the level of security of confidential information is difficult due to the lack of appropriate mathematical models. The complexity of the problem is that existing traditional mathematical models are not always appropriate for the stated objectives. Therefore, it is necessary to develop mathematical models designed to assess the security of confidential information and its impact on information and telecommunication system threats.

Case Study: Modelling Telecommunication Systems using Concurrent ML

DEFF Research Database (Denmark)

Hoffmann, Torben

1998-01-01

How can telecommunication hardware be modelled in CML. How are generalities and parallelism captured in CML.......How can telecommunication hardware be modelled in CML. How are generalities and parallelism captured in CML....

48 CFR 870.112 - Telecommunications equipment.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Telecommunications... DEPARTMENT SUPPLEMENTARY REGULATIONS SPECIAL PROCUREMENT CONTROLS Controls 870.112 Telecommunications... specifications for telecommunications equipment, as defined in VA manual MP-6, Part VIII (available at any VA...

Organo-erbium systems for optical amplification at telecommunications wavelengths.

Science.gov (United States)

Ye, H Q; Li, Z; Peng, Y; Wang, C C; Li, T Y; Zheng, Y X; Sapelkin, A; Adamopoulos, G; Hernández, I; Wyatt, P B; Gillin, W P

2014-04-01

Modern telecommunications rely on the transmission and manipulation of optical signals. Optical amplification plays a vital part in this technology, as all components in a real telecommunications system produce some loss. The two main issues with present amplifiers, which rely on erbium ions in a glass matrix, are the difficulty in integration onto a single substrate and the need of high pump power densities to produce gain. Here we show a potential organic optical amplifier material that demonstrates population inversion when pumped from above using low-power visible light. This system is integrated into an organic light-emitting diode demonstrating that electrical pumping can be achieved. This opens the possibility of direct electrically driven optical amplifiers and optical circuits. Our results provide an alternative approach to producing low-cost integrated optics that is compatible with existing silicon photonics and a different route to an effective integrated optics technology.

S-band and X-band integrated PWT photoelectron linacs

International Nuclear Information System (INIS)

Yu, D.; Newsham, D.; Zeng, J.; Rosenzweig, J.

2001-01-01

A compact high-energy injector, which has been developed by DULY Research Inc., will have wide scientific, industrial, and medical applications. The new photoelectron injector integrates the photocathode directly into a multicell linear accelerator. By focusing the beam with solenoids or permanent magnets, and producing high current with low emittance, high brightness and low energy spread are achieved. In addition to providing a small footprint and improved beam quality in an integrated structure, the compact system considerably simplifies external subsystems required to operate the photoelectron linac, including rf power transport, beam focusing, vacuum and cooling. The photoelectron linac employs an innovative Plane-Wave-Transformer (PWT) design, which provides strong cell-to-cell coupling, relaxes manufacturing tolerances and facilitates the attachment of external ports to the compact structure with minimal field interference. DULY Research Inc. under the support of the DOE Small Business Innovation Research (SBIR) program, has developed, constructed and installed a 20-MeV, S-band compact electron source at UCLA. Cold test results for this device are presented. DULY Research is also actively engaged in the development of an X-band photoelectron linear accelerator in a SBIR project. When completed, the higher frequency structure will be approximately three times smaller. Design considerations for this device are discussed following the S-band cold test results

Towards an Equitable Development of Telecommunications ...

African Journals Online (AJOL)

Present and future equitable development of telecommunications services calls for an immediate development of an indigenous telecommunications technology capability in order to effectively and efficiently utilizes the services provided by the country's presently imported telecommunications systems while at the same time ...

Telecommunication Sector of the Russian Economy: Transformation Into a Global Information and Telecommunication Infrastructure

Directory of Open Access Journals (Sweden)

Fokina Elena Anatolyevna

2014-12-01

Full Text Available The author concerns the current state and possible ways of telecommunication sector of the Russian economy development in the conditions of world economy globalization and suggests that the process of globalization reflects the current stage of telecommunication companies’ capital internationalization. The analysis of telecommunication sector shows that it is not only a perspective, highmargin and dynamically developing sector but is still one of the most integrated into the system of world economic relations. The stages of Russian telecommunication companies’ capital internationalization are determined, the internal connections between internationalization process and globalization are revealed. It is revealed that the new information and communication technologies development and expansion results in substantial increase in cooperation between economical entities and provides a sustainable long-term economical growth of telecommunication enterprises. The financial and operational data determining the effectiveness of telecommunication companies’ activity are presented. The analysis of tendencies promoting the extension of the market activity of Russian telecommunication companies at global information and telecommunication infrastructure shows that the main tendencies are the following ones: foreign capital inflow increase, capital integration and expansion of new services based on technologies convergence. The author reasonably concludes in recent times, the telecommunication sector of the Russian economy formation and development is determined by the existing global trends.

The Keenan and Wing bands in S stars

International Nuclear Information System (INIS)

Lambert, D.L.; Clegg, R.E.S.

1980-01-01

New observations of the near infrared spectra of S stars are presented as part of a survey of the unidentified Keenan and Wing bands. Bandhead wavelengths accurate to 0.5 A are presented. A new band is found at 9014 A. The bands are not present in normal M giants and dwarfs. Laboratory spectroscopy of heavy element oxides is reported. Several new identifications are proposed. The 10 300 A Wing band is identified with the Δv = - 1 sequence of the ZrO 9300 A Δv = 0 bands. The ZrO B 1 PI-A 1 Δ (Δv = 0) system may be responsible for either the 9736 A or the 10 515 A Wing bands. Two new bands in the near infrared at 8219 and 8235 A are provided by CeO. A new band with heads at 7503 and 7509 A in a spectrum of R And is tentatively attributed to YS. A band at 8268 A in M stars is the TiO delta(2-1) head. The 8610 A Keenan band is not due to CrH. Potential carriers of the Keenan and Wing bands are reviewed. It is suggested that the heavy element sulphides and, perhaps, chlorides are leading candidates. Identification of YS in R And may provide the first evidence for these sulphides. ZrS is a leading candidate for which laboratory spectroscopy is needed. (author)

Government Procurement Agreements and Telecommunications Business

Directory of Open Access Journals (Sweden)

Shin-Won Kang

2001-12-01

Full Text Available The opening of the telecommunications market is acceleration due to the world trends of deregulation and privatization under the WTO basic telecommunications agreements. Diversification of services and fast and efficient equipment procurement are becoming necessary conditions for the survival of telecommunications operators. However, the issue here is that telecommunications operators are still bound by the GPA (Government Procurement Agreement based on conditions of monopoly even though the procurement market in Korean is open substantially since 1997. Under such conditions, the continued application of the GPA on telecommunications operator who is highly competitive may result in a negative impact on the telecommunications business and quality of telecommunications service by undermining the autonomy of operator and decreasing operator’s procurement competitiveness. Therefore, this study examines the GPA and the issues raised by the agreement, and also attempts to suggest revisions or means of abrogating the unfair GPA with regards to the development and deregulation of the telecommunications business.

High-power test of S-band klystron for long-pulse operation

International Nuclear Information System (INIS)

Morii, Y.; Oshita, E.; Abe, S.; Keishi, T.; Tomimasu, T.; Ohkubo, Y.; Yoshinao, M.; Yonezawa, H.

1994-01-01

FELI(Free Electron Laser Research Institute, Inc.) is constructing a free electron laser facility covering from 20μm (infra red region) to 0.35μm (ultra violet region), using an S-band linac. The linac is commissioning now. An RF system of the linac for FELs is required of long pulse duration and high stability. S-band klystrons (TOSHIBA E3729) of the FELI linac are operated in three pulse operation modes (pulse width and peak RF power; 24μs-24MW, 12.5μs-34MW, 0.5μs-70MW). The S-band klystron and its modulator were combined to test their performance. The high power test results of the S-band klystron are summarized in this paper. (author)

A model for calculating expected performance of the Apollo unified S-band (USB) communication system

Science.gov (United States)

Schroeder, N. W.

1971-01-01

A model for calculating the expected performance of the Apollo unified S-band (USB) communication system is presented. The general organization of the Apollo USB is described. The mathematical model is reviewed and the computer program for implementation of the calculations is included.

Advertising and Consumer Choice of Telecommunication Services in Nigeria

Directory of Open Access Journals (Sweden)

David Oladipo Olalekan

2015-09-01

Full Text Available This study examines the critical influence of advertising on consumer choice of telecommunication services in Nigeria. The advertisement played a key role in providing the consumers with product information. The study investigates the effect of marketing medium of telecommunication as a proxy for advertisement on preference of telecommunication services as a proxy for consumer choice in Nigeria. The Binary Logit Model (BLM and descriptive analytical frameworks are used to evaluate the statistical importance of advertisement, quality of services, income of the consumer, product’s self and related service charges for a consumer choice of telecommunication services through Wald test. The findings show that product’s self service charge and service quality are statistically significant for a consumer choice of telecommunication services in Nigeria at 1 percent significance level. And, related product’s service is statistically significant for a consumer choice of telecommunication services in Nigeria at 5 percent significance level. While advertisement and income of the consumer are statistically significant for a consumer choice of telecommunication services in Nigeria at 10 percent. The study concludes that advertisement is important for the choice of telecommunication services in Nigeria but having less impact. And, product’s self service charge and service quality are hugely significant for the choice of telecommunication services in Nigeria. Therefore, the sector of telecommunications needs more investment in advertisement so as to have telecommunications’ products information spread in order to stimulate the increase in demand for telecommunication services in Nigeria.

47 CFR 15.715 - TV bands database administrator.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administrator. 15.715 Section... Band Devices § 15.715 TV bands database administrator. The Commission will designate one or more entities to administer a TV bands database. Each database administrator shall: (a) Maintain a database that...

S-band multiple-access interference study for advanced tracking and data relay satellite systems

Science.gov (United States)

Peng, Wei-Chung; Yang, Chau-Chin

1990-01-01

The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

Atomic-Monolayer MoS2 Band-to-Band Tunneling Field-Effect Transistor

KAUST Repository

Lan, Yann Wen

2016-09-05

The experimental observation of band-to-band tunneling in novel tunneling field-effect transistors utilizing a monolayer of MoS2 as the conducting channel is demonstrated. Our results indicate that the strong gate-coupling efficiency enabled by two-dimensional materials, such as monolayer MoS2, results in the direct manifestation of a band-to-band tunneling current and an ambipolar transport.

47 CFR 73.7002 - Fair distribution of service on reserved band FM channels.

Science.gov (United States)

2010-10-01

...-Reserved Channels § 73.7002 Fair distribution of service on reserved band FM channels. (a) If timely filed... 47 Telecommunication 4 2010-10-01 2010-10-01 false Fair distribution of service on reserved band FM channels. 73.7002 Section 73.7002 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...

Heat recovery properties from fuel cell system for telecommunications use; Tsushin`yo nenryo denchi system ni okeru hainetsu kaishu tokusei

Energy Technology Data Exchange (ETDEWEB)

Ishizawa, M.; Iida, S.; Abe, I.; Yamamoto, M. [NTT Integrated Information and Energy Systems Laboratories, Tokyo (Japan)

1997-08-20

NTT is developing a phosphoric-acid fuel-cell energy system for telecommunication co-generation systems to reduce energy costs and help preserve the environment. Fuel cells are used to provide electrical power to telecommunication equipment and the heat energy that is generated is used by the absorption refrigerators to cool the telecommunication rooms throughout the year. We field-tested this fuel-cell energy system in a telephone office. Two heat recovery methods were applied in the test: one uses direct steam heat recovery from fuel-cell stack coolant to keep the heat recovery temperature high and to avoid requiring a heat exchanger for the recovery; the other uses heat recovery from the reformer exhaust gas that is directly in contact with the heat recovery water to recover heat more economically. Our field tests confirmed that the average efficiency of heat recovery from fuel-cell stack coolant is 16%, and from the reformer exhaust gas is 9% under 80-kW continuous operation. Maximum total efficiency including electrical power efficiency was confirmed to be about 73% under the condition of 100-kW and an S/C ratio of 2.5 in the winter period: heat recovery from the fuel-cell stack coolant was 23%, from the reformer exhaust gas was 10%, and from electrical conversion was about 40%. 9 refs., 12 figs., 1 tab.

Development of Thermal Design Program for an Electronic Telecommunication System Using Heat Sink

International Nuclear Information System (INIS)

Lee, Jung Hwan; Kim, Jong Man; Chun, Ji Hwan; Bae, Chul Ho; Suh, Myung Won

2007-01-01

The purpose of this study is to investigate the cooling performance of heat sinks for an electronic telecommunication system by adequate natural convection. Heat generation rates of electronic components and the temperature distributions of heat sinks and surrounding air are analyzed experimentally and numerically. In order to perform the heat transfer analysis for the thermal design of telecommunication system, a program is developed. The program used the graphic user interface environment to determine the arrangement of heat sources, interior fan capacity, and heat sink configuration. The simulation results showed that the heat sinks were able to achieve a cooling capacity of up to 230W at the maximum temperature difference of 19 .deg. C. To verify the results from the numerical simulation, an experiment was conducted under the same condition as the numerical simulation, and their results were compared. The design program gave good prediction of the effects of various parameters involved in the design of a heat sinks for an electronic telecommunication system

47 CFR 32.2003 - Telecommunications plant under construction.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Telecommunications plant under construction. 32.2003 Section 32.2003 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet...

CPM Signals for Satellite Navigation in the S and C Bands.

Science.gov (United States)

Xue, Rui; Sun, Yanbo; Zhao, Danfeng

2015-06-05

Frequency allocations in the L band suitable for global navigation satellite system (GNSS) services are getting crowded and system providers face an ever tougher job when they try to bring in new signals and services while maintaining radio frequency compatibility. With the successive opening of the S and C bands to GNSS service, the multi-band combined navigation is predicted to become a key technology for future high-precision positioning navigation systems, and a single modulation scheme satisfying the requirements in each band is a promising solution for reducing user terminal complexity. A universal modulation scheme based on the continuous phase modulation (CPM) family suitable for the above bands' demands is proposed. Moreover, this paper has put forward two specific CPM signals for the S and C bands, respectively. Then the proposed modulation schemes, together with existing candidates, are comprehensively evaluated. Simulation results show that the proposed CPM signals can not only satisfy the constraint condition of compatibility in different bands well and reduce user terminal complexity, but also provide superior performance in terms of tracking accuracy, multi-path mitigation and anti-jamming compared to other candidate modulation schemes.

Satellite Telemetry and Command using Big LEO Mobile Telecommunications Systems

Science.gov (United States)

Huegel, Fred

1998-01-01

Various issues associated with satellite telemetry and command using Big LEO mobile telecommunications systems are presented in viewgraph form. Specific topics include: 1) Commercial Satellite system overviews: Globalstar, ICO, and Iridium; 2) System capabilities and cost reduction; 3) Satellite constellations and contact limitations; 4) Capabilities of Globalstar, ICO and Iridium with emphasis on Globalstar; and 5) Flight transceiver issues and security.

47 CFR 32.2001 - Telecommunications plant in service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Telecommunications plant in service. 32.2001 Section 32.2001 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32...

31 CFR 585.513 - Transactions related to telecommunications authorized.

Science.gov (United States)

2010-07-01

... telecommunications authorized. 585.513 Section 585.513 Money and Finance: Treasury Regulations Relating to Money and... Transactions related to telecommunications authorized. (a) All transactions of U.S. common carriers with respect to the receipt and transmission of telecommunications involving the FRY (S&M) are authorized...

Aspects of transport system management within mining complex using information and telecommunication systems

Science.gov (United States)

Semykina, A. S.; Zagorodniy, N. A.; Konev, A. A.; Duganova, E. V.

2018-05-01

The paper considers aspects of transport system management within the mining complex. It indicates information and telecommunication systems that are used to increase transportation efficiency. It also describes key advantages and disadvantages. It is found that software products of the Modular Company used in pits allow increasing transport performance, minimizing losses and ensuring efficient transportation of minerals.

Short-arc orbit determination using coherent X-band ranging data

Science.gov (United States)

Thurman, S. W.; Mcelrath, T. P.; Pollmeier, V. M.

1992-01-01

The use of X-band frequencies in ground-spacecraft and spacecraft-ground telecommunication links for current and future robotic interplanetary missions makes it possible to perform ranging measurements of greater accuracy than previously obtained. It is shown that ranging data of sufficient accuracy, when acquired from multiple stations, can sense the geocentric angular position of a distant spacecraft. The application of high-accuracy S/X-band and X-band ranging to orbit determination with relatively short data arcs is investigated in planetary approach and encounter scenarios. Actual trajectory solutions for the Ulysses spacecraft constructed from S/X-band ranging and Doppler data are presented; error covariance calculations are used to predict the performance of X-band ranging and Doppler data. The Ulysses trajectory solutions indicate that the aim point for the spacecraft's February 1992 Jupiter encounter was predicted to a geocentric accuracy of 0.20 to 0.23/microrad. Explicit modeling of range bias parameters for each station pass is shown to largely remove systematic ground system calibration errors and transmission media effects from the Ulysses range measurements, which would otherwise corrupt the angle finding capabilities of the data. The Ulysses solutions were found to be reasonably consistent with the theoretical results, which suggest that angular accuracies of 0.08 to 0.1/microrad are achievable with X-band ranging.

Application of a new Terrestrial Telecommunications System in the European Air Traffic

Directory of Open Access Journals (Sweden)

Draško Marin

2012-10-01

Full Text Available Aeronautical Public Correspondence (APC is a telecommtmicationsse!Vice, which enables passengers onboard aircraftto make telecommunication calls to people on the ground.This article describes the terrestrial communications seiVicewhich is based on cellular network for the European CEPTmember countries (CEPT- European Conference of Postaland Telecommunications Administrations named TerrestrialFlight Telecommunications System (TFTS.This system is a Pan-European System, which means theusage of hannonised frequencies in Europe with hannonisedstandards for the TFTS equipment, which have been issued bythe European Telecommunications Standard Institute (ETSI.Frequencies allocated for TFTS have been designated bythe World Administrative Radio Conference, WARC-92 withfrequency bandwidth of 2x5 MHz:1670- 1675 MHz, for ground to air1800- 1805 MHz, for air to ground.TFTS planning is perfonned by the application of frequencyblocks (42 blocks with 164 channels in total. Bandwidthof each radio channel, which contains 4 speech channels,is equal to 30.3 kHz.Due to the very high flight of the aircraft (about 13,000 m,it needs a long distance between the centres of cells (radio stationon the ground to avoid the eo-channel or adjacent channelinteJference.The article presents the planning process with typical cellradius of240km or 350km. In the viewofthatfact, the need ispointed out for finding a compromise solution with regard toemitting power and the influence of interference.Final(v, it is noted that TFTS ground radio stations inCroatia, which are located in Zagreb and Split, may cover theterritory of some neighbouring countries other than Croatia,which is important from the commercial point of view.

Opportunities for electric utilities in telecommunications

International Nuclear Information System (INIS)

Meehan, C.M.

1994-01-01

This article examines the opportunities for utility participation in the telecommunications market on private microwave systems and hybrid microwave and fiber systems. The topics of the article include entering the market, national information infrastructure, business opportunities and considerations, levels of participation in telecommunications market, and regulatory objectives

Application of neural networks to software quality modeling of a very large telecommunications system.

Science.gov (United States)

Khoshgoftaar, T M; Allen, E B; Hudepohl, J P; Aud, S J

1997-01-01

Society relies on telecommunications to such an extent that telecommunications software must have high reliability. Enhanced measurement for early risk assessment of latent defects (EMERALD) is a joint project of Nortel and Bell Canada for improving the reliability of telecommunications software products. This paper reports a case study of neural-network modeling techniques developed for the EMERALD system. The resulting neural network is currently in the prototype testing phase at Nortel. Neural-network models can be used to identify fault-prone modules for extra attention early in development, and thus reduce the risk of operational problems with those modules. We modeled a subset of modules representing over seven million lines of code from a very large telecommunications software system. The set consisted of those modules reused with changes from the previous release. The dependent variable was membership in the class of fault-prone modules. The independent variables were principal components of nine measures of software design attributes. We compared the neural-network model with a nonparametric discriminant model and found the neural-network model had better predictive accuracy.

Dimensioning aspects of 48 V telecommunications power supply systems

Energy Technology Data Exchange (ETDEWEB)

Jakab, L. [Siemens Telefongyar Kft (Hungary)

2000-07-01

Considering the reliable operation of the 48 V telecommunications power supply systems it is essential the appropriate dimensioning. The basic elements of the power supply systems, i.e. batteries, rectifiers, DC/AC cabling, fuses, etc., should be defined by exact calculation. The presentation reviews the main questions and problems of dimensioning. It lays a special emphasis on the optimized planning procedure, further it also deals with the economical impacts of the dimensioning parameters. (orig.)

Optical fiber telecommunications components and subsystems

CERN Document Server

Kaminow, Ivan; Willner, Alan E

2013-01-01

Optical Fiber Telecommunications VI (A&B) is the sixth in a series that has chronicled the progress in the R&D of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition brings a fresh look to many essential topics, including devices, subsystems, systems and networks. A central theme is the enabling of high-bandwidth communications in a cost-effective manner for the development of customer applications. These volumes are an ideal reference for R&D engineers and managers, optical systems implementers, university researchers and s

47 CFR 15.714 - TV bands database administration fees.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administration fees. 15.714... Television Band Devices § 15.714 TV bands database administration fees. (a) A TV bands database administrator may charge a fee for provision of lists of available channels to fixed and personal/portable TVBDs and...

Ka-band Technologies for Small Spacecraft Communications via Relays and Direct Data Downlink

Science.gov (United States)

Budinger, James M.; Niederhaus, Charles; Reinhart, Richard; Downey, Joe; Roberts, Anthony

2016-01-01

As the scientific capabilities and number of small spacecraft missions in the near Earth region increase, standard yet configurable user spacecraft terminals operating in Ka-band are needed to lower mission cost and risk and enable significantly higher data return than current UHF or S-band terminals. These compact Ka-band terminals are intended to operate with both the current and next generation of Ka-band relay satellites and via direct data communications with near Earth tracking terminals. This presentation provides an overview of emerging NASA-sponsored and commercially provided technologies in software defined radios (SDRs), transceivers, and electronically steered antennas that will enable data rates from hundreds of kbps to over 1 Gbps and operate in multiple frequency bands (such as S- and X-bands) and expand the use of NASA's common Ka-bands frequencies: 22.55-23.15 GHz for forward data or uplink; and 25.5-27.0 GHz for return data or downlink. Reductions in mass, power and volume come from integration of multiple radio functions, operations in Ka-band, high efficiency amplifiers and receivers, and compact, flat and vibration free electronically steered narrow beam antennas for up to + 60 degrees field of regard. The software defined near Earth space transceiver (SD-NEST) described in the presentation is intended to be compliant with NASA's space telecommunications radio system (STRS) standard for communications waveforms and hardware interoperability.

48 CFR 239.7405 - Delegated authority for telecommunications resources.

Science.gov (United States)

2010-10-01

... telecommunications resources. 239.7405 Section 239.7405 Federal Acquisition Regulations System DEFENSE ACQUISITION... TECHNOLOGY Telecommunications Services 239.7405 Delegated authority for telecommunications resources. The contracting officer may enter into a telecommunications service contract on a month-to-month basis or for any...

Telecommunications Relay Services

Science.gov (United States)

... Home » Health Info » Hearing, Ear Infections, and Deafness Telecommunications Relay Services On this page: What are telecommunication ... additional information about telecommunication relay services? What are telecommunication relay services? Title IV of the Americans with ...

Specification and validation of telecommunication services in ACPt

NARCIS (Netherlands)

Zhaorui, Y.

1999-01-01

This paper is concerned with the formal specification and validation of telecommunication services. Firstly, we provide a method to model the telecommunication system. Based on this result, we give the formal specification of telecommunication services and the detection of feature interactions,

Remote monitoring of VRLA batteries for telecommunications systems

Energy Technology Data Exchange (ETDEWEB)

Tsujikawa, Tomonobu; Matsushima, Toshio [NTT Facilities Inc., G.H.Y. Building, 2-13-1 Kita-Otsuka, Toshima-ku, Tokyo 170-0004 (Japan)

2007-05-25

This paper describes a remote monitoring system that can be set up in an operating center to monitor the state of valve regulated lead acid batteries (VRLA) used as a backup power supply for telecommunications. This system has a battery voltage monitoring function, a lifetime prediction function based on ambient temperature, and a discharge circuit diagnosis function. In addition, the system can be equipped with an internal resistance measurement function and an electrolyte leakage detection function to further insure power-supply reliability. Various states of batteries observed with the system are transmitted to the remote operating center by a remote monitoring function. This function enables obtaining immediate information about the condition of batteries and helps to avoid unexpected failures. (author)

Guidelines for safety related telecommunications systems on normally attended fixed offshore installations

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-01

Guidance is given on the design of telecommunications systems required for safety purposes on normally attended offshore installations associated with oil and gas production on the United Kingdom continental shelf. Basic requirements for such equipment are presented as a series of objectives which should be capable of being met in the event of any emergency situation arising. The telecommunications facilities necessary to meet these objectives are identified, together with the role of each facility in controlling the emergency, how each would be used and the design considerations to ensure the facilities will remain operational throughout the emergency. (UK)

Optimization of the telecommunication network of a gas utility; Optimisation d'un reseau de telecommunications d'un operateur gazier

Energy Technology Data Exchange (ETDEWEB)

Vinas, Ch.; Abadie, J. [GSO, Gaz Sud-Ouest, 64 - Pau (France)

2001-07-01

The information system of Gaz du Sud-Ouest (GSO) utility, which includes the real time systems for the exploitation of the gas transport and distribution system and its management, is based on heterogenous and separated telecommunication infrastructures. A project has been started which aims at optimizing the architecture of this communication network taking into consideration the technical aspects but also the security and costs constraints. (J.S.)

31 CFR 586.510 - Transactions related to telecommunications authorized.

Science.gov (United States)

2010-07-01

... telecommunications authorized. 586.510 Section 586.510 Money and Finance: Treasury Regulations Relating to Money and... Licensing Policy § 586.510 Transactions related to telecommunications authorized. All transactions with respect to the receipt and transmission of telecommunications involving the FRY (S&M) are authorized. This...

Leo satellite-based telecommunication network concepts

Science.gov (United States)

Aiken, John G.; Swan, Peter A.; Leopold, Ray J.

1991-01-01

Design considerations are discussed for Low Earth Orbit (LEO) satellite based telecommunications networks. The satellites are assumed to be connected to each other via intersatellite links. They are connected to the end user either directly or through gateways to other networks. Frequency reuse, circuit switching, packet switching, call handoff, and routing for these systems are discussed by analogy with terrestrial cellular (mobile radio) telecommunication systems.

47 CFR 32.2002 - Property held for future telecommunications use.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Property held for future telecommunications use. 32.2002 Section 32.2002 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance...

31 CFR 500.571 - Transactions related to telecommunications authorized.

Science.gov (United States)

2010-07-01

... telecommunications authorized. 500.571 Section 500.571 Money and Finance: Treasury Regulations Relating to Money and... telecommunications authorized. All transactions of U.S. common carriers incident to the receipt or transmission of telecommunications involving North Korea are authorized. Note: Exports or reexports to North Korea of goods and...

High Peak Power Test and Evaluation of S-band Waveguide Switches

Science.gov (United States)

Nassiri, A.; Grelick, A.; Kustom, R. L.; White, M.

1997-05-01

The injector and source of particles for the Advanced Photon Source is a 2856-MHz S-band electron-positron linear accelerator (linac) which produces electrons with energies up to 650 MeV or positrons with energies up to 450 MeV. To improve the linac rf system availability, an additional modulator-klystron subsystem is being constructed to provide a switchable hot spare unit for each of the five exsisting S-band transmitters. The switching of the transmitters will require the use of SF6-pressurized S-band waveguide switches at a peak operating power of 35 MW. Such rf switches have been successfully operated at other accelerator facilities but at lower peak powers. A test stand has been set up at the Stanford Linear Accelerator Center (SLAC) Klystron Factory to conduct tests comparing the power handling characteristics of two WR-284 and one WR-340 switches. Test results are presented and their implications for the design of the switching system are discussed.

Application of the ETOM framework for defining processes in the telecommunication systems management network of the Serbian Army

Directory of Open Access Journals (Sweden)

Vladimir B. Suša

2013-10-01

Full Text Available This paper deals with management system requirements in telecommunications. A TMN (Telecommunication Management Network is necessary to be well designed and constantly upgraded. The  ETOM (Enhanced Telecommunication Operation Map framework, defined by the ITU-T Recommendation M.3050, is used to describe various processes that occur in the network for monitoring and control of military telecommunications systems. Their definition is an essential precondition for introducing management applications that would manage all of the processes in their end-to-end structure. Telecommunication networks are categorized in  accordance withg their functions. A set of relevant network processes important for supervision and management is explained for each described subsystem. This defining represents a prerequisite for the management application configuration which aims to automate management functions and services. eTOM frame and its implementation in telecommunication management networks ETOM is defined as a telecommunication conceptual frame which includes all the processes that exist in a telecommunication network. It does not represent a telecommunication model, but gives a basic frame for all the processes to be included within. It ranges throughout three basic areas: operation processes, planning and development processes and production management. ETOM supports two different process grouping perspectives: horizontal and vertical. The aim of this kind of grouping is to provide the complete overview in all the processes a telecommunication management network should include. Horizontal grouping includes functional processes within the same managed system. Vertical grouping includes all the processes within a TMN. Overlapped horizontal and vertical group constellations enable a connected matrix structure of the eTOM frame. Operational processes within a TMN can be divided into a few categories: user-network interaction, services management and

A high peak power S-band switching system for the Advanced Photon Source (APS) Linear Accelerator (Linac)

International Nuclear Information System (INIS)

Grelick, A. E.

1998-01-01

An S-band linear accelerator is the source of particles and front end of the Advanced Photon Source [1] injector. Additionally, it will be used to support a low-energy undulator test line (LEUTL) and to drive a free-electron laser (FEL). To provide maximum linac availability for all uses, an additional modulator-klystron subsystem has been built,and a waveguide-switching and distribution subsystem is now under construction. The combined subsystems provide a hot spare for any of the five S-band transmitters that power the lina cand have been given the additional function of powering an rf gun test stand whenever they are not otherwise needed. Design considerations for the waveguide-switching subsystem, topology selection, timing, control, and system protection provisions are described

75 FR 3913 - President's National Security Telecommunications Advisory Committee

Science.gov (United States)

2010-01-25

...] President's National Security Telecommunications Advisory Committee AGENCY: National Communications System... Telecommunications Advisory Committee (NSTAC) will be meeting by teleconference; the meeting will be open to the... implementing national security and emergency preparedness telecommunications policy. Notice of this meeting is...

China's Expansion Into and U.S. Withdrawal from Argentina's Telecommunications and Space Industries and the Implications for U.S. National Security

National Research Council Canada - National Science Library

Hulse, Janie

2007-01-01

... up. In this monograph, Ms. Janie Hutse, a Latin Amen can specialist based in Buenos Aires, Argentina, argues that increased Chinese investment in regional telecommunications and space industries has implications for U.S. national security...

75 FR 16159 - President's National Security Telecommunications Advisory Committee

Science.gov (United States)

2010-03-31

...] President's National Security Telecommunications Advisory Committee AGENCY: National Communications System... Telecommunications Advisory Committee (NSTAC) will hold its annual meeting on May 6, 2010. The meeting will be open... preparedness telecommunications policy. Notice of this meeting is given under the Federal Advisory Committee...

Planning alternative organizational frameworks for a large scale educational telecommunications system served by fixed/broadcast satellites

Science.gov (United States)

Walkmeyer, J.

1973-01-01

This memorandum explores a host of considerations meriting attention from those who are concerned with designing organizational structures for development and control of a large scale educational telecommunications system using satellites. Part of a broader investigation at Washington University into the potential uses of fixed/broadcast satellites in U.S. education, this study lays ground work for a later effort to spell out a small number of hypothetical organizational blueprints for such a system and for assessment of potential short and long term impacts. The memorandum consists of two main parts. Part A deals with subjects of system-wide concern, while Part B deals with matters related to specific system components.

Protection using telecommunications

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Deregulation in both the telecommunication and electric power industry, together with new telecommunication network technologies and advances in numerical protection, has resulted in the need to reconsider traditional methods of delivering tele-protection schemes and their associated bearer services. Fibre-optic technology is commonly deployed in new telecommunication networks for inter-station communication and utility-owned and public telecommunication networks from third parties are available for protection purposes. (author)

Telecommunications Network Plan

International Nuclear Information System (INIS)

1989-05-01

The Office of Civilian Radioactive Waste Management (OCRWM) must, among other things, be equipped to readily produce, file, store, access, retrieve, and transfer a wide variety of technical and institutional data and information. The data and information regularly produced by members of the OCRWM Program supports, and will continue to support, a wide range of program activities. Some of the more important of these information communication-related activities include: supporting the preparation, submittal, and review of a license application to the Nuclear Regulatory Commission (NRC) to authorize the construction of a geologic repository; responding to requests for information from parties affected by and/or interested in the program; and providing evidence of compliance with all relevant Federal, State, local, and Indian Tribe regulations, statutes, and/or treaties. The OCRWM Telecommunications Network Plan (TNP) is intended to identify, as well as to present the current strategy for satisfying, the telecommunications requirements of the civilian radioactive waste management program. The TNP will set forth the plan for integrating OCRWM's information resources among major program sites. Specifically, this plan will introduce a telecommunications network designed to establish communication linkages across the program's Washington, DC; Chicago, Illinois; and Las Vegas, Nevada, sites. The linkages across these and associated sites will comprise Phase I of the proposed OCRWM telecommunications network. The second phase will focus on the modification and expansion of the Phase I network to fully accommodate access to the OCRWM Licensing Support System (LSS). The primary components of the proposed OCRWM telecommunications network include local area networks; extended local area networks; and remote extended (wide) area networks. 10 refs., 6 figs

47 CFR 61.47 - Adjustments to the SBI; pricing bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Adjustments to the SBI; pricing bands. 61.47... (CONTINUED) TARIFFS General Rules for Dominant Carriers § 61.47 Adjustments to the SBI; pricing bands. (a) In...) Pricing bands shall be established each tariff year for each service category and subcategory within a...

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Science.gov (United States)

2010-10-01

... devices operating in the 608-614 MHz band. For a wireless medical telemetry device operating within the... 47 Telecommunication 5 2010-10-01 2010-10-01 false Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band. 95.1119 Section 95.1119 Telecommunication FEDERAL...

JPL Space Telecommunications Radio System Operating Environment

Science.gov (United States)

Lux, James P.; Lang, Minh; Peters, Kenneth J.; Taylor, Gregory H.; Duncan, Courtney B.; Orozco, David S.; Stern, Ryan A.; Ahten, Earl R.; Girard, Mike

2013-01-01

A flight-qualified implementation of a Software Defined Radio (SDR) Operating Environment for the JPL-SDR built for the CoNNeCT Project has been developed. It is compliant with the NASA Space Telecommunications Radio System (STRS) Architecture Standard, and provides the software infrastructure for STRS compliant waveform applications. This software provides a standards-compliant abstracted view of the JPL-SDR hardware platform. It uses industry standard POSIX interfaces for most functions, as well as exposing the STRS API (Application Programming In terface) required by the standard. This software includes a standardized interface for IP components instantiated within a Xilinx FPGA (Field Programmable Gate Array). The software provides a standardized abstracted interface to platform resources such as data converters, file system, etc., which can be used by STRS standards conformant waveform applications. It provides a generic SDR operating environment with a much smaller resource footprint than similar products such as SCA (Software Communications Architecture) compliant implementations, or the DoD Joint Tactical Radio Systems (JTRS).

Telecommunications: international opportunities for power utilities

Energy Technology Data Exchange (ETDEWEB)

Lewis, A. [Teleglobe Canada, Ottawa, ON (Canada)

1996-08-01

International telecommunications services markets and trends were reviewed in an effort to identify business opportunities for Canadian power utilities. With increasing deregulation in the U.S. and Canada, and other countries around the globe, market opportunities are beginning to open up. In monopoly markets opportunities exist in providing dual infrastructures to upgrade both the power delivery services (frequently poor), and telecommunications. Billing, collection and customer service expertise might be other marketable commodities, perhaps packaged as part of a network provision project as a service to existing power and telecommunications service providers. In countries with directed competition markets local partnerships may be the only vehicle for entering the market. In managed competition markets opportunities were said to exist in cellular radio technology, as well as in switched telephone service, local, long distance, or international. In general, opportunities outside telecommunications-rich North America were considered to have better potential, due to rapid deregulation and higher current growth rates in telecommunications. Careful examination and research of the political and business environment prior to entering any of the potentially fertile areas was advised.

TELECOMMUNICATIONS INFRASTRUCTURE AND GDP /JIPP CURVE/

Directory of Open Access Journals (Sweden)

Mariana Kaneva

2016-07-01

Full Text Available The relationship between telecommunications infrastructure and economic activity is under discussion in many scientific papers. Most of the authors use for research and analysis the Jipp curve. A lot of doubts about the correctness of the Jipp curve appear in terms of applying econometric models. The aim of this study is a review of the Jipp curve, refining the possibility of its application in modern conditions. The methodology used in the study is based on dynamic econometric models, including tests for nonstationarity and tests for causality. The focus of this study is directed to methodological problems in measuring the local density types of telecommunication networks. This study offers a specific methodology for assessing the Jipp law, through VAR-approach and Granger causality tests. It is proved that mechanical substitution of momentary aggregated variables (such as the number of subscribers of a telecommunication network at the end of the year and periodically aggregated variables (such as GDP per capita in the Jipp�s curve is methodologically wrong. Researchers have to reconsider the relationship set in the Jipp�s curve by including additional variables that characterize the Telecommunications sector and the economic activity in a particular country within a specified time period. GDP per capita should not be regarded as a single factor for the local density of telecommunications infrastructure. New econometric models studying the relationship between the investments in telecommunications infrastructure and economic development may be not only linear regression models, but also other econometric models. New econometric models should be proposed after testing and validating with sound economic theory and econometric methodology.

Advances in VRLA battery technology for telecommunications

Energy Technology Data Exchange (ETDEWEB)

Misra, Sudhan S. [SPM Consultants LLC, 112 Gwynmont Circle, North Wales, PA 19454 (United States)

2007-05-25

Wide scale use of the newly emergent VRLA (valve-regulated lead-acid) battery in telecommunication applications and the subsequent problems encountered early in their deployment history spurred intense efforts to improve the design as a continuous endeavor. After implementing improvements to battery placement and containment design to prevent the sudden onset of thermal runaway, the focus of the development work has been on cell internals. These include improved grid and strap alloys, superior AGM (absorbent glass mat) separator that retains compression in the cell, use of beneficial additives to the active materials and the need to avoid contaminants that promote detrimental side reactions. These improvements are now resulting in a vastly superior VRLA experience in the telecommunication applications. To further improve the reliability demanded by today's communication and internet environment VRLA battery installations should include continuous cell/module and system monitoring similar to that incorporated in competing advanced battery systems under development. (author)

A New Agile Radiating System Called Electromagnetic Band Gap Matrix Antenna

Directory of Open Access Journals (Sweden)

Hussein Abou Taam

2014-01-01

Full Text Available Civil and military applications are increasingly in need for agile antenna devices which respond to wireless telecommunications, radars, and electronic warfare requirements. The objective of this paper is to design a new agile antenna system called electromagnetic band gap (EBG matrix. The working principle of this antenna is based on the radiating aperture theory and constitutes the subject of an accepted CNRS patent. In order to highlight the interest and the originality of this antenna, we present a comparison between it and a classical patch array only for the (one-dimensional 1D configuration by using a rigorous full wave simulation (CST Microwave software. In addition, EBG matrix antenna can be controlled by specific synthesis algorithms. These algorithms use inside their; optimization loop an analysis procedure to evaluate the radiation pattern. The analysis procedure is described and validated at the end of this paper.

47 CFR 32.6511 - Property held for future telecommunications use expense.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Property held for future telecommunications use expense. 32.6511 Section 32.6511 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense...

Structural parameter based modification of energy conscious ESPAR antenna system through optimization for WLAN’s dual-band operability

CSIR Research Space (South Africa)

Bembe, MJ

2010-11-01

Full Text Available single device. In this study the focus is on the modification of the antenna designs for dual-band functionality which is limited on the ESPAR antenna’s structural parameter. This modification should result in an antenna system which operates in both 2...

The Telecommunications and Data Acquisition Report

Science.gov (United States)

Yuen, Joseph H. (Editor)

1996-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC). TMOD also performs work funded by other NASA program offices through and with the cooperation of OSC. The first of these is the Orbital Debris Radar Program funded by the Office of Space Systems Development. It exists at Goldstone only and makes use of the planetary radar capability when the antennas are configured as science instruments making direct observations of the planets, their satellites, and asteroids of our solar system. The Office of Space Sciences funds the data reduction and science analyses of data obtained by the Goldstone Solar System Radar. The antennas at all three complexes are also configured for radio astronomy research and, as such, conduct experiments funded by the National Science Foundation in the U.S. and other agencies at the overseas complexes. These experiments are either in microwave spectroscopy or very long baseline interferometry. Finally, tasks funded under the JPL Director's Discretionary Fund and the Caltech President's Fund that involve TMOD are included. This and each succeeding issue of 'The Telecommunications and Data Acquisition Progress Report' will present material in some, but not necessarily all, of the aforementioned programs.

The use of agile systems development methodologies in the telecommunication industry in South Africa / B.M. Mazengera

OpenAIRE

Mazengera, Bruce Mwai Analinafe

2009-01-01

Over the last decade, systems development professionals have recognised the need to use agile systems development methodologies (ASDMs) in the telecommunication industry. This is partly due to the barriers identified by Mansurov (2000) which suggest that the use of agile methodologies in the telecommunication industry would reduce the ratio of time-to-market. In the South African context, the industry has cemented its position as a major driving force of the economy as a whole. The industry's...

47 CFR 25.226 - Blanket licensing provisions for domestic, U.S. Vehicle-Mounted Earth Stations (VMESs) receiving...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Blanket licensing provisions for domestic, U.S... GHz (Earth-to-space) frequency band, operating with Geostationary Satellites in the Fixed-Satellite Service. 25.226 Section 25.226 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON...

Exposure measuring techniques for wide band mobile radio-communications

International Nuclear Information System (INIS)

Trinchero, S.; Benedetto, A.; Anglesio, L.; D'Amore, G.; Trinchero, D.

2004-01-01

The paper illustrates the limits and performances of different experimental monitoring techniques, which are applied to digitally modulated radiofrequency electromagnetic fields used for mobile telecommunications. Different experimental set-ups have been developed, verified and applied for the analysis and characterisation of wide band probes and narrow band measuring procedures. (authors)

A multi-channel S-band FMCW radar front-end

NARCIS (Netherlands)

Maas, A.P.M.; Vliet, F.E. van

2008-01-01

This paper describes the design and performance of a low-cost synthesized FMCW radar module, operating in S band. The bi-layer PCB contains a frequency-agile low phase-noise synthesizer and three identical coherent receive-channels. The transmit channel has an automatic power control system that

Large-scale educational telecommunications systems for the US: An analysis of educational needs and technological opportunities

Science.gov (United States)

Morgan, R. P.; Singh, J. P.; Rothenberg, D.; Robinson, B. E.

1975-01-01

The needs to be served, the subsectors in which the system might be used, the technology employed, and the prospects for future utilization of an educational telecommunications delivery system are described and analyzed. Educational subsectors are analyzed with emphasis on the current status and trends within each subsector. Issues which affect future development, and prospects for future use of media, technology, and large-scale electronic delivery within each subsector are included. Information on technology utilization is presented. Educational telecommunications services are identified and grouped into categories: public television and radio, instructional television, computer aided instruction, computer resource sharing, and information resource sharing. Technology based services, their current utilization, and factors which affect future development are stressed. The role of communications satellites in providing these services is discussed. Efforts to analyze and estimate future utilization of large-scale educational telecommunications are summarized. Factors which affect future utilization are identified. Conclusions are presented.

47 CFR 36.171 - Property held for future telecommunications use-Account 2002; Telecommunications plant under...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Property held for future telecommunications use-Account 2002; Telecommunications plant under construction-Account 2003; and Telecommunications plant adjustment-Account 2005. 36.171 Section 36.171 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...

Towards telecommunication payloads with photonic technologies

Science.gov (United States)

Vono, S.; Di Paolo, G.; Piccinni, M.; Pisano, A.; Sotom, M.; Aveline, M.; Ginestet, P.

2017-11-01

In the last decade, Thales Alenia Space has put a lot of its research effort on Photonic Technologies for Space Application with the aim to offer the market satellite telecommunication systems better performance and lower costs. This research effort has been concentrated on several activities, some of them sponsored by ESA. Most promising applications refer to Payload Systems. In particular, photonic payload applications have been investigated through the following two ESA studies: Artes-1 "Next Generation Telecommunication Payloads based on Photonic Technologies" and Artes-5 "OWR - Optical Wideband Receiver" activities.

Grameenphone: a descriptive study of the factors influencing the youth`s usage of telecommunication services in Singapore and Malaysia

OpenAIRE

Åsheim, Stefanie; Eriksen, Andreas; Groven, Ida Harstad; Köhler, Mats Gunnar Opdal; Pettersen, Marius

2008-01-01

This project is done to provide Grameenphone with a recommendation on whether to have a youth brand in Bangladesh or not. To gather our information, we have used both secondary and primary data. The problem definition for the research project is as follows: “To investigate the factors driving loyalty and the effects of corporate brand attributes on youth in the telecommunications industry.” Grameenphone the largest telecommunications provider in Bangladesh. As of today it has a market s...

Hear recovery properties from fuel cell system for telecommunications use; Tsushin`yo nenryo denchi system no fuirudotesuto ni okeru hainetsu kaishu tokusei

Energy Technology Data Exchange (ETDEWEB)

Ishizawa, M.; Iida, S.; Abe, I.; Amanuma, H. [NTT Integrated Information and Energy Systems Laboratories Tokyo (Japan); Uekusa, T.; Waragai, S. [NTT Power and Building Eacilities Inc., Tokyo (Japan)

1997-12-20

NTT is developing a phosphoric acid fuel cell energy system for telecommunication co-generation systems to reduce energy costs and help preserve the environment. Fuel cells are used to provide electrical power to telecommunication equipment and the heat energy that is generated is used by the absorption refrigerator to cool the telecommunication rooms throughout the year. We fieldtested this fuel cell energy system in a telephone office for three years. Heat recovered water from fuel cell stack coolant was supplied to the absorption refrigerator and further extra-heat was recovered by a heat exchanger. The toral heat recovery amount was about 86000 kca/h (the heat recovery efficiency was 20%) under 200kW operation. The absorption refrigerator was supplied about 49000kcal/h of heat and operated with 0.7 of coefficient of performance throughtout the year. The electrical efficiency was maintained more than 38% after 13000h operation. 12 refs., 10 figs., 3 tabs.

Understanding telecommunications networks

CERN Document Server

Valdar, Andy

2017-01-01

A telecommunications network is an electronic system of links, nodes and the controls that govern their operations to allow voice and data transfer among users and devices. This fully revised, updated and expanded second edition covers all aspects of today's networks, including how they are planned, formed and operated.

160 Gbit/s photonics wireless transmission in the 300-500 GHz band

Directory of Open Access Journals (Sweden)

X. Yu

2016-11-01

Full Text Available To accommodate the ever increasing wireless traffic in the access networks, considerable efforts have been recently invested in developing photonics-assisted wireless communication systems with very high data rates. Superior to photonic millimeter-wave systems, terahertz (THz band (300 GHz-10 THz provides a much larger bandwidth and thus promises an extremely high capacity. However, the capacity potential of THz wireless systems has by no means been achieved yet. Here, we successfully demonstrate 160 Gbit/s wireless transmission by using a single THz emitter and modulating 25 GHz spaced 8 channels (20 Gbps per channel in the 300-500 GHz band, which is the highest bitrate in the frequency band above 300 GHz, to the best of our knowledge.

75 FR 1755 - Public Telecommunications Facilities Program: Notice of Availability of Funds

Science.gov (United States)

2010-01-13

... DEPARTMENT OF COMMERCE National Telecommunications and Information Administration [Docket No. 0911201414-0010-02] Public Telecommunications Facilities Program: Notice of Availability of Funds AGENCY: National Telecommunications and Information Administration, U.S. Department of Commerce. ACTION: Notice of...

The turbulent telecommunications

Czech Academy of Sciences Publication Activity Database

Kuchar, Anton

2006-01-01

Roč. 5, 1/2 (2006), s. 9-14 ISSN 1336-1376. [ELEKTRO 2006 /5./. Žilina, 23.05.2006-24.05.2006] Grant - others:BReATH Consortium EU(XE) EC FP6 1ST Programme Institutional research plan: CEZ:AV0Z20670512 Keywords : optical communication * optical links * telecommunication networks Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Japan nurtures telecommunications on classic formula

Science.gov (United States)

Davis, Neil

1987-03-01

As in other industrial sectors, Japanese telecommunications organizations export significantly more products than they import, even when substantial cost-savings can be realized. One example is optical fibers, which some Japanese service companies do not buy from outside suppliers who have taken advantage of economies of scale. Nippon Telephone and Telegraph, until recently a common carrier, is meeting increasing competition from newly-formed indigenous telecommunications subsidiaries who are taking advantage of fiber optics and microwave communications capabilities. Various cooperative projects with U.S. companies are described, noting the tendency of Japanese manufacturers to cease relationships with U.S. companies when Japanese products become competitive and also the necessity of U.S. firms to gain political cooperation from the Japanese government in order to make sales in Japan.

Laying the Groundwork: Lessons Learned from the Telecommunications Industry for Distributed Generation; Preprint

Energy Technology Data Exchange (ETDEWEB)

Wise, A. L.

2008-05-01

The telecommunications industry went through growing pains in the past that hold some interesting lessons for the growing distributed generation (DG) industry. The technology shifts and stakeholders involved with the historic market transformation of the telecommunications sector mirror similar factors involved in distributed generation today. An examination of these factors may inform best practices when approaching the conduits necessary to accelerate the shifting of our nation's energy system to cleaner forms of generation and use. From a technical perspective, the telecom industry in the 1990s saw a shift from highly centralized systems that had no capacity for adaptation to highly adaptive, distributed network systems. From a management perspective, the industry shifted from small, private-company structures to big, capital-intensive corporations. This presentation will explore potential correlation and outline the lessons that we can take away from this comparison.

Design and development of low level S-Band RF control system for IRFEL injector LINAC

International Nuclear Information System (INIS)

Mohania, Praveen; Mahawar, Ashish; Singh, Adarsh Pratap; Namdeo, Rajkumar; Baxy, Deodatta; Shrivastava, Purushottam

2015-01-01

A low level RF system has been designed and developed for phase and amplitude stabilization of S- Band microwave power being fed to fundamental buncher cavity and the injector LINAC structure of the Infra Red Free Electron Laser being developed at RRCAT Indore. The system uses analog phase shifters and voltage variable attenuators to control the phase and amplitude respectively, the control voltages for phase shifters and attenuators are generated using a 12 Bit ADC and is software controlled. The system has a slow feedback to correct phase and amplitude drifts occurring due to thermal variations and a fast feed forward mechanism to vary amplitude and phase of the output pulse to compensate beam loading and to shape the klystron output power. The present paper describes the design aspects of the LLRF system. (author)

EAS Telecommunications Certification Bodies (TCB)

Data.gov (United States)

Federal Communications Commission — EAS (Equipment Authorization System). A Telecommunication Certification Body (TCB) is an accredited product certification body with the authority to issue Grants of...

Open Source Telecommunication Companies

OpenAIRE

Peter Liu

2007-01-01

Little is known about companies whose core business is selling telecommunications products that lever open source projects. Open source telecommunications (OST) companies operate in markets that are very different from typical software product markets. The telecommunications market is regulated, vertically integrated, and proprietary designs and special chips are widely used. For a telecommunications product to be useful, it must interact with both access network products and core network pro...

Satellite Telecommunications.

Science.gov (United States)

Forum, 1986

1986-01-01

This issue of a quarterly publication of the Council of Europe covers aspects of the history, technology, policies, and impact of telecommunications in Europe, with an emphasis on European television. The following articles are included: (1) "Man and the World of Telecommunications" (Piet Stoffelen); (2) "The European Communications…

Development of new S-band RF window for stable high-power operation in linear accelerator RF system

Science.gov (United States)

Joo, Youngdo; Lee, Byung-Joon; Kim, Seung-Hwan; Kong, Hyung-Sup; Hwang, Woonha; Roh, Sungjoo; Ryu, Jiwan

2017-09-01

For stable high-power operation, a new RF window is developed in the S-band linear accelerator (Linac) RF systems of the Pohang Light Source-II (PLS-II) and the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The new RF window is designed to mitigate the strength of the electric field at the ceramic disk and also at the waveguide-cavity coupling structure of the conventional RF window. By replacing the pill-box type cavity in the conventional RF window with an overmoded cavity, the electric field component perpendicular to the ceramic disk that caused most of the multipacting breakdowns in the ceramic disk was reduced by an order of magnitude. The reduced electric field at the ceramic disk eliminated the Ti-N coating process on the ceramic surface in the fabrication procedure of the new RF window, preventing the incomplete coating from spoiling the RF transmission and lowering the fabrication cost. The overmoded cavity was coupled with input and output waveguides through dual side-wall coupling irises to reduce the electric field strength at the waveguide-cavity coupling structure and the possibility of mode competitions in the overmoded cavity. A prototype of the new RF window was fabricated and fully tested with the Klystron peak input power, pulse duration and pulse repetition rate of 75 MW, 4.5 μs and 10 Hz, respectively, at the high-power test stand. The first mass-produced new RF window installed in the PLS-II Linac is running in normal operation mode. No fault is reported to date. Plans are being made to install the new RF window to all S-band accelerator RF modules of the PLS-II and PAL-XFEL Linacs. This new RF window may be applied to the output windows of S-band power sources like Klystron as wells as the waveguide windows of accelerator facilities which operate in S-band.

Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s-1 directly modulated lasers and 40 Gb s-1 signal-regenerative amplifiers

International Nuclear Information System (INIS)

Sugawara, M; Hatori, N; Ishida, M; Ebe, H; Arakawa, Y; Akiyama, T; Otsubo, K; Yamamoto, T; Nakata, Y

2005-01-01

This paper presents recent progress in the field of semiconductor lasers and optical amplifiers with InAs-based self-assembled quantum dots in the active region for optical telecommunication. Based on our design in terms of the maximum bandwidth for high-speed modulation and p-type doping in quantum dots for high temperature stability, we realized temperature-insensitive 10 Gb s -1 laser diodes on a GaAs substrate at 1.3 μm. The output waveform at 10 Gb s -1 maintained a clear eye opening, average output power and extinction ratio without current adjustments from 20 deg. C to 70 deg. C. We developed ultrawide-band high-power amplifiers in the 1.5 μm wavelength region on an InP substrate. The amplifier showed ultrafast gain response under gain saturation, and enabled signal regeneration at 40 Gb s -1 by suppressing the '1'-level noise due to the beating between the signal and amplified spontaneous emission. We present our amplifier module with polarization diversity to enable a stable polarization-insensitive performance, and also, discuss prospects for polarization-insensitive quantum dots by the close stacking technique

UNITED STATES DEPARTMENT OF TRANSPORTATION GLOBAL POSITIONING SYSTEM (GPS) ADJACENT BAND COMPATIBILITY ASSESSMENT

Science.gov (United States)

2018-04-01

The goal of the U.S. Department of Transportation (DOT) Global Positioning System (GPS) Adjacent Band Compatibility Assessment is to evaluate the maximum transmitted power levels of adjacent band radiofrequency (RF) systems that can be tolerated by G...

The marginal band system in nymphalid butterfly wings.

Science.gov (United States)

Taira, Wataru; Kinjo, Seira; Otaki, Joji M

2015-01-01

Butterfly wing color patterns are highly complex and diverse, but they are believed to be derived from the nymphalid groundplan, which is composed of several color pattern systems. Among these pattern systems, the marginal band system, including marginal and submarginal bands, has rarely been studied. Here, we examined the color pattern diversity of the marginal band system among nymphalid butterflies. Marginal and submarginal bands are usually expressed as a pair of linear bands aligned with the wing margin. However, a submarginal band can be expressed as a broken band, an elongated oval, or a single dot. The marginal focus, usually a white dot at the middle of a wing compartment along the wing edge, corresponds to the pupal edge spot, one of the pupal cuticle spots that signify the locations of color pattern organizing centers. A marginal band can be expressed as a semicircle, an elongated oval, or a pair of eyespot-like structures, which suggest the organizing activity of the marginal focus. Physical damage at the pupal edge spot leads to distal dislocation of the submarginal band in Junonia almana and in Vanessa indica, suggesting that the marginal focus functions as an organizing center for the marginal band system. Taken together, we conclude that the marginal band system is developmentally equivalent to other symmetry systems. Additionally, the marginal band is likely a core element and the submarginal band a paracore element of the marginal band system, and both bands are primarily specified by the marginal focus organizing center.

Model-based energy monitoring and diagnosis of telecommunication cooling systems

International Nuclear Information System (INIS)

Sorrentino, Marco; Acconcia, Matteo; Panagrosso, Davide; Trifirò, Alena

2016-01-01

A methodology is proposed for on-line monitoring of cooling load supplied by Telecommunication (TLC) cooling systems. Sensible cooling load is estimated via a proportional integral controller-based input estimator, whereas a lumped parameters model was developed aiming at estimating air handling units (AHUs) latent heat load removal. The joint deployment of above estimators enables accurate prediction of total cooling load, as well as of related AHUs and free-coolers energy performance. The procedure was then proven effective when extended to cooling systems having a centralized chiller, through model-based estimation of a key performance metric, such as the energy efficiency ratio. The results and experimental validation presented throughout the paper confirm the suitability of the proposed procedure as a reliable and effective energy monitoring and diagnostic tool for TLC applications. Moreover, the proposed modeling approach, beyond its direct contribution towards smart use and conservation of energy, can be fruitfully deployed as a virtual sensor of removed heat load into a variety of residential and industrial applications. - Highlights: • Accurate cooling load prediction in telecommunication rooms. • Development of an input-estimator for sensible cooling load simulation. • Model-based estimation of latent cooling load. • Model-based prediction of centralized chiller energy performance in central offices. • Diagnosis-oriented application of proposed cooling load estimator.

47 CFR 90.691 - Emission mask requirements for EA-based systems.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Emission mask requirements for EA-based systems. 90.691 Section 90.691 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... of Ea-Based Smr Systems in the 809-824/851-869 Mhz Band § 90.691 Emission mask requirements for EA...

The Center for Space Telemetering and Telecommunications Systems

Science.gov (United States)

Horan, S.; DeLeon, P.; Borah, D.; Lyman, R.

2003-01-01

This report comprises the final technical report for the research grant 'Center for Space Telemetering and Telecommunications Systems' sponsored by the National Aeronautics and Space Administration's Goddard Space Flight Center. The grant activities are broken down into the following technology areas: (1) Space Protocol Testing; (2) Autonomous Reconfiguration of Ground Station Receivers; (3) Satellite Cluster Communications; and (4) Bandwidth Efficient Modulation. The grant activity produced a number of technical reports and papers that were communicated to NASA as they were generated. This final report contains the final summary papers or final technical report conclusions for each of the project areas. Additionally, the grant supported students who made progress towards their degrees while working on the research.

System-level design methodologies for telecommunication

CERN Document Server

Sklavos, Nicolas; Goehringer, Diana; Kitsos, Paris

2013-01-01

This book provides a comprehensive overview of modern networks design, from specifications and modeling to implementations and test procedures, including the design and implementation of modern networks on chip, in both wireless and mobile applications.  Topical coverage includes algorithms and methodologies, telecommunications, hardware (including networks on chip), security and privacy, wireless and mobile networks and a variety of modern applications, such as VoLTE and the internet of things.

Worldwide Report. Telecommunications Policy, Research, and Development.

Science.gov (United States)

1985-11-06

important conclusions of the second meeting of the Andean Satellite Telecommunications Commission in Caracas , Venezuela , at which Colombia was represented...including many of the larger exchanges in the government telephone system, died by the wayside. In Metro Manila, there were two giant telephone...telephone services. The telecom- munications de - cade The telecommunications decade for the Philippines has preceded the ESCAP sponsored

Investigation of signal models and methods for evaluating structures of processing telecommunication information exchange systems under acoustic noise conditions

Science.gov (United States)

Kropotov, Y. A.; Belov, A. A.; Proskuryakov, A. Y.; Kolpakov, A. A.

2018-05-01

The paper considers models and methods for estimating signals during the transmission of information messages in telecommunication systems of audio exchange. One-dimensional probability distribution functions that can be used to isolate useful signals, and acoustic noise interference are presented. An approach to the estimation of the correlation and spectral functions of the parameters of acoustic signals is proposed, based on the parametric representation of acoustic signals and the components of the noise components. The paper suggests an approach to improving the efficiency of interference cancellation and highlighting the necessary information when processing signals from telecommunications systems. In this case, the suppression of acoustic noise is based on the methods of adaptive filtering and adaptive compensation. The work also describes the models of echo signals and the structure of subscriber devices in operational command telecommunications systems.

Space Telecommunications Radio System STRS Cognitive Radio

Science.gov (United States)

Briones, Janette C.; Handler, Louis M.

2013-01-01

Radios today are evolving from awareness toward cognition. A software defined radio (SDR) provides the most capability for integrating autonomic decision making ability and allows the incremental evolution toward a cognitive radio. This cognitive radio technology will impact NASA space communications in areas such as spectrum utilization, interoperability, network operations, and radio resource management over a wide range of operating conditions. NASAs cognitive radio will build upon the infrastructure being developed by Space Telecommunication Radio System (STRS) SDR technology. This paper explores the feasibility of inserting cognitive capabilities in the NASA STRS architecture and the interfaces between the cognitive engine and the STRS radio. The STRS architecture defines methods that can inform the cognitive engine about the radio environment so that the cognitive engine can learn autonomously from experience, and take appropriate actions to adapt the radio operating characteristics and optimize performance.

Evolution and convergence in telecommunications

Energy Technology Data Exchange (ETDEWEB)

Radicella, S; Grilli, D [Abdus Salam ICTP, Trieste (Italy)

2002-12-15

These lectures throw a spotlight on different aspects of the evolution of telecommunications networks, namely on the various facets of service and network convergence. The last years progress in data and telecommunications technologies, such as P-based networks, and the enormous potential of mobile communication systems and users' demands for comprehensive and network-independent have led to a convergence of data and telecommunications infrastructures in many aspects. In order to help the reader to an easier understanding of the phenomenon convergence, in the first two parts of this volume the evolution of the basic technologies is described one by one. This is done briefly and is focused on the principle topics, just to build a basis for the third part devoted to problems of convergence in telecommunications. These notes are addressed to those readers, who in a quick overview want to be informed on the future service and network landscape. The notes are equally suited for professionals with the desire to extend their horizon as well as for students looking for an introduction into telecommunications under more general aspects. The authors clearly understand the difficulties in writing a book devoted to the evolution in telecommunications. Today, telecom landscape varies at very high speed. Every few months new network technologies, new products and new services are developed. Attempts to present them in time can be accessible only for magazine publications or contributions to conferences. Therefore, in a number of areas, such as Voice over IP and new switching technologies not much more than the starting point of new paradigms is described. However, the content is up-to-date to a degree, that the phenomenon convergence can be fully understood. Partially, these notes are based on a number of lecture courses that were delivered during recent ICTP winter schools devoted to multimedia and digital communications.

Evolution and convergence in telecommunications

International Nuclear Information System (INIS)

Radicella, S.; Grilli, D.

2002-01-01

These lectures throw a spotlight on different aspects of the evolution of telecommunications networks, namely on the various facets of service and network convergence. The last years progress in data and telecommunications technologies, such as P-based networks, and the enormous potential of mobile communication systems and users' demands for comprehensive and network-independent have led to a convergence of data and telecommunications infrastructures in many aspects. In order to help the reader to an easier understanding of the phenomenon convergence, in the first two parts of this volume the evolution of the basic technologies is described one by one. This is done briefly and is focused on the principle topics, just to build a basis for the third part devoted to problems of convergence in telecommunications. These notes are addressed to those readers, who in a quick overview want to be informed on the future service and network landscape. The notes are equally suited for professionals with the desire to extend their horizon as well as for students looking for an introduction into telecommunications under more general aspects. The authors clearly understand the difficulties in writing a book devoted to the evolution in telecommunications. Today, telecom landscape varies at very high speed. Every few months new network technologies, new products and new services are developed. Attempts to present them in time can be accessible only for magazine publications or contributions to conferences. Therefore, in a number of areas, such as Voice over IP and new switching technologies not much more than the starting point of new paradigms is described. However, the content is up-to-date to a degree, that the phenomenon convergence can be fully understood. Partially, these notes are based on a number of lecture courses that were delivered during recent ICTP winter schools devoted to multimedia and digital communications

Fuel cell/photovoltaic integrated power system for a remote telecommunications repeater

Energy Technology Data Exchange (ETDEWEB)

Lehman, P.; Chamberlin, C.; Zoellick, J.; Engel, R.; Rommel, D. [Humbolt State University, Arcata, CA (United States). Schatz Energy Research Center

2002-07-01

There is a special energy supply challenge associated with remote telecommunication systems, as they require reliable, unattended power system operation in areas and locations where there is no grid power. To supply back-up power to the Schoolhouse Peak remote photovoltaic-powered radio-telephone repeater located in Redwood National Park in northwestern California, the Schatz Energy Research Center built and operated a proton exchange membrane (PEM) fuel cell power system. In those instances where solar insolation is insufficient to maintain state-of-charge of the system's battery, the fuel cell automatically starts. Remote monitoring and control is made possible with the use of a cellular modem. The original fuel cell stack logged 3239 hours of run time in 229 days of operation. Subsequent to improvements and a rebuilt fuel cell stack, it operated for 3836 hours during 269 days. In this paper, system performance, long-term fuel cell voltage decay, and lessons learned and applied in system refurbishment were discussed. During this trial, the flawless performance of the hydrogen storage and delivery subsystem, the battery voltage-sensing relay, the safety shutdowns, and the remote data acquisition and control equipment was noted. To protect the stack from sudden temperature increases while minimizing unneeded parasitic loads, experience showed that a temperature-controlled fan switch, despite its additional complexity, was justified. 4 refs., 10 figs.

Telecommunications, politics, economics, and national sovereignty: A new game

Energy Technology Data Exchange (ETDEWEB)

Bugliarello, G.

1996-12-31

The impact of telecommunications on politics, economics and national sovereignty is creating a new game. Political and economic power may operate over the same territory, as in the now-rare case of isolated economies, but, more often, their domains do not coincide. Increasingly, telecommunications create major challenges for countries preoccupied with issues of national sovereignty because the national state has only a limited ability to control these intrinsic and at times potentially destabilizing powers of telecommunications and the {open_quotes}telecommunities{close_quotes} they make possible. As many traditional aspects of sovereignty are becoming weakened by telecommunications, and as the intense dynamics of networks and the expansion of telecommunities revolutionize business and politics, there is a need to prevent the situation from becoming chaotic and uncontrollable, even while recognizing the possibilities of enhanced opportunities. This requires focusing on a more flexible conception of sovereignty which can enhance the state`s attractiveness for telecommunications infrastructure, while addressing issues of ethics and morality in the new telecommications environment. A new, broad socio-technological research agenda needs to be developed - with the ultimate purpose of providing society with the tools to play the new game and thrive. 10 refs., 3 tabs.

S-band 45 MW peak power test facility at RRCAT

International Nuclear Information System (INIS)

Wanmode, A. Yashwant; Reddy, Sivananda; Mulchandani, J.; Mohania, Praveen; Shrivastava, B. Purushottam

2015-01-01

RRCAT is engaged in the design and development of high energy electron LINAC as future injectors for the Booster Synchrotron for Indus-1 and Indus-2 SRS. The high energy LINAC will need microwave power over 30 MW depending on the number of structures to be energized. In order to have advance preparations for this development a 45 MW S-Band test facility has been designed and developed at RRCAT. The test stand is built around a 45 MW peak power S-band pulsed klystron, A conventional pulse forming network based modulator for klystron has been designed and developed. The WR-284 waveguide transmission system consisting of dual directional couplers, SF 6 gas pressurization unit, high power waveguide load and arc sensor has been developed and interfaced with the klystron. The klystron has been successfully tested up to 30 MW peak power at 2856 MHz on SF 6 pressurized waveguide line. A solid state S Band driver amplifier up to 1 kW output power was designed developed for driving the klystron. This paper describes the results of 30 MW peak power test of this facility. (author)

The Telecommunications Review

Science.gov (United States)

1991-01-01

TELECOMMUNICATION NETWORKS ARE BECOMING INCREASINGLY COMPLEX. THEY MUST MEET THE NEEDS OF SOPHISTICATED USERS WHO DEMAND A HIGH-LEVEL OF FUNCTIONALITY, HIGH PERFORMANCE, AND LOW COST. : TELECOMMUNICATIONS TECHNOLOGY IS CHANGING RAPIDLY TO MEET THA...

Fuel Cell Backup Power System for Grid Service and Micro-Grid in Telecommunication Applications: Preprint

Energy Technology Data Exchange (ETDEWEB)

Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eichman, Joshua D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kurtz, Jennifer M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-22

This paper presents the feasibility and economics of using fuel cell backup power systems in telecommunication cell towers to provide grid services (e.g., ancillary services, demand response). The fuel cells are able to provide power for the cell tower during emergency conditions. This study evaluates the strategic integration of clean, efficient, and reliable fuel cell systems with the grid for improved economic benefits. The backup systems have potential as enhanced capability through information exchanges with the power grid to add value as grid services that depend on location and time. The economic analysis has been focused on the potential revenue for distributed telecommunications fuel cell backup units to provide value-added power supply. This paper shows case studies on current fuel cell backup power locations and regional grid service programs. The grid service benefits and system configurations for different operation modes provide opportunities for expanding backup fuel cell applications responsive to grid needs.

Support for the Core Research Activities and Studies of the Computer Science and Telecommunications Board (CSTB)

Energy Technology Data Exchange (ETDEWEB)

Jon Eisenberg, Director, CSTB

2008-05-13

The Computer Science and Telecommunications Board of the National Research Council considers technical and policy issues pertaining to computer science (CS), telecommunications, and information technology (IT). The functions of the board include: (1) monitoring and promoting the health of the CS, IT, and telecommunications fields, including attention as appropriate to issues of human resources and funding levels and program structures for research; (2) initiating studies involving CS, IT, and telecommunications as critical resources and sources of national economic strength; (3) responding to requests from the government, non-profit organizations, and private industry for expert advice on CS, IT, and telecommunications issues; and to requests from the government for expert advice on computer and telecommunications systems planning, utilization, and modernization; (4) fostering interaction among CS, IT, and telecommunications researchers and practitioners, and with other disciplines; and providing a base of expertise in the National Research Council in the areas of CS, IT, and telecommunications. This award has supported the overall operation of CSTB. Reports resulting from the Board's efforts have been widely disseminated in both electronic and print form, and all CSTB reports are available at its World Wide Web home page at cstb.org. The following reports, resulting from projects that were separately funded by a wide array of sponsors, were completed and released during the award period: 2007: * Summary of a Workshop on Software-Intensive Systems and Uncertainty at Scale * Social Security Administration Electronic Service Provision: A Strategic Assessment * Toward a Safer and More Secure Cyberspace * Software for Dependable Systems: Sufficient Evidence? * Engaging Privacy and Information Technology in a Digital Age * Improving Disaster Management: The Role of IT in Mitigation, Preparedness, Response, and Recovery 2006: * Renewing U.S. Telecommunications

TBT: Telecommunications-Based Training in the 90s (DELTA Programme--Action Line III). Proceedings of the Workshop (Madrid, Spain, January 21-22, 1991).

Science.gov (United States)

Commission of the European Communities, Brussels (Belgium).

This report contains a collection of papers presented at a workshop on telecommunications-based training systems as part of the DELTA (Developing European Learning through Technological Advance) Action Line III, which addressed research in telecommunications for open and distance education. The following presentations are included: (1)…

48 CFR 252.239-7016 - Telecommunications security equipment, devices, techniques, and services.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Telecommunications... SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions And Clauses 252.239-7016 Telecommunications... clause: Telecommunications Security Equipment, Devices, Techniques, and Services (DEC 1991) (a...

Small Aerostationary Telecommunications Orbiter Concept for Mars in the 2020s

Science.gov (United States)

Lock, Robert E.; Edwards, Charles D., Jr.; Nicholas, Austin; Woolley, Ryan; Bell, David J.

2016-01-01

Current Mars science orbiters carry UHF proximity payloads to provide limited access and data services to landers and rovers on Mars surface. In the era of human spaceflight to Mars, very high rate and reliable relay services will be needed to serve a large number of supporting vehicles, habitats, and orbiters, as well as astronaut EVAs. These will likely be provided by a robust network of orbiting assets in very high orbits, such as areostationary orbits. In the decade leading to that era, telecommunications orbits can be operated at areostationary orbit that can support a significant population of robotic precursor missions and build the network capabilities needed for the human spaceflight era. Telecommunications orbiters of modest size and cost, delivered by Solar Electric Propulsion to areostationary orbit, can provide continuous access at very high data rates to users on the surface and in Mars orbit.In the era of human spaceflight to Mars very high rate andreliable relay services will be needed to serve a largenumber of supporting vehicles, habitats, and orbiters, aswell as astronaut EVAs. These could be provided by arobust network of orbiting assets in very high orbits. In thedecade leading to that era, telecommunications orbiterscould be operated at areostationary orbit that could support asignificant population of robotic precursor missions andbuild the network capabilities needed for the humanspaceflight era. These orbiters could demonstrate thecapabilities and services needed for the future but withoutthe high bandwidth and high reliability requirements neededfor human spaceflight.Telecommunications orbiters of modest size and cost,delivered by Solar Electric Propulsion to areostationaryorbit, could provide continuous access at very high datarates to users on the surface and in Mars orbit. Twoexamples highlighting the wide variety of orbiter deliveryand configuration options were shown that could providehigh-performance service to users.

47 CFR 25.256 - Special Requirements for operations in the 3.65-3.7 GHz band.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Special Requirements for operations in the 3.65-3.7 GHz band. 25.256 Section 25.256 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.256 Special Requirements for...

Resonant enhancement of band-to-band tunneling in in-plane MoS2/WS2 heterojunctions

Science.gov (United States)

Kuroda, Tatsuya; Mori, Nobuya

2018-04-01

The band-to-band (BTB) tunneling current J through in-plane MoS2/WS2 heterojunctions is calculated by the nonequilibrium Green function method combined with tight-binding approximation. Types A and B of band configurations are considered. For type-A (type-B) heterojunctions, a potential notch exists (or is absent) at the heterointerface. Both type-A and type-B MoS2/WS2 heterojunctions can support a higher BTB current than MoS2 and WS2 homojunctions. For type-A heterojunctions, the resonant enhancement of J occurs resulting in a significantly higher BTB tunneling current.

47 CFR 25.260 - Time sharing between DoD meteorological satellite systems and non-voice, non-geostationary...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Time sharing between DoD meteorological satellite systems and non-voice, non-geostationary satellite systems in the 400.15-401 MHz band. 25.260 Section 25.260 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

Regulatory governance of telecommunications liberalisation in Taiwan

International Nuclear Information System (INIS)

Cheng, Kuo-Tai; Hebenton, Bill

2008-01-01

This paper examines the changing role of government and market in regulating the telecommunications sector from since 1996 in Taiwan. It contextualises the theoretical aspects of regulatory governance for institutional design and practices, and reviews the concepts and mechanisms for appraising privatisation and regulatory systems. Using a conceptual framework for researching privatisation and regulation, it describes the process and issues pertinent to telecommunications liberalisation and privatisation in Taiwan, supported by a brief presentation of theoretical points of view as well as practitioners' views. The paper presents results concerning criteria for appraising privatisation and regulatory governance and considers policy lessons that can be learned from the experiences of the Taiwanese telecommunications sector's liberalisation. (author)

A Multiple-Channel Sub-Band Transient Detection System

Energy Technology Data Exchange (ETDEWEB)

David A. Smith

1998-11-01

We have developed a unique multiple-channel sub-band transient detection system to record transient electromagnetic signals in carrier-dominated radio environments; the system has been used to make unique observations of weak, transient HF signals. The detection system has made these observations possible through improved sensitivity compared to conventional broadband transient detection systems; the sensitivity improvement is estimated to be at least 20 dB. The increase in sensitivity has been achieved through subdivision of the band of interest (an 18 MHz tunable bandwidth) into eight sub-band independent detection channels, each with a 400 kHz bandwidth and its own criteria. The system generates a system trigger signal when a predetermined number of channels (typically five) trigger within a predetermined window of time (typically 100 ~s). Events are recorded with a broadband data acquisition system sampling at 50 or 100 Msample/s, so despite the fact that the detection system operates on portions of the signal confined to narrow bands, data acquisition is broadband. Between May and September of 1994, the system was used to detect and record over six thousand transient events in the frequency band from 3 to 30 MHz. Approximately 500 of the events have been characterized as paired bursts of radio noise with individual durations of 2 to 10 ps and separations between the bursts of 5 to 160 ps. The paired transients are typically 5 to 40 dB brighter than the background electromagnetic spectrum between carrier signals. We have termed these events SubIonospheric Pulse Pairs (SIPPS) and presently have no explanation as to their source. Our observations of SIPPS resemble observations of TransIonospheric Pulse Pairs (TIPPs) recorded by the Blackboard instrument on the ALEXIS satellite; the source of TIPP events is also unknown. Most of the recorded SIPP events do not exhibit frequency dispersion, implying propagation along a line-of-sight (groundwave) path; but seven of

Method and system for conserving power in a telecommunications network during emergency situations

Energy Technology Data Exchange (ETDEWEB)

Conrad, Stephen H [Algodones, NM; O' Reilly, Gerard P [Manalapan, NJ

2011-10-11

Disclosed is a method and apparatus for conserving power in a telecommunications network during emergency situations. A permissible number list of emergency and/or priority numbers is stored in the telecommunications network. In the event of an emergency or power failure, input digits of a call to the telecommunications network are compared to the permissible number list. The call is processed in the telecommunications network and routed to its destination if the input digits match an entry in the permissible number list. The call is dropped without any further processing if the input digits do not match an entry in the permissible number list. Thus, power can be conserved in emergency situations by only allowing emergency and/or priority calls.

Summary and Analysis of the U.S. Government Bat Banding Program

Science.gov (United States)

Ellison, Laura E.

2008-01-01

This report summarizes the U.S. Government Bat Banding Program (BBP) from 1932 to 1972. More than 2 million bands were issued during the program, of which approximately 1.5 million bands were applied to 36 bat species by scientists in many locations in North America including the U.S., Canada, Mexico, and Central America. Throughout the BBP, banders noticed numerous and deleterious effects on bats, leading to a moratorium on bat banding by the U.S. Fish and Wildlife Service, and a resolution to cease banding by the American Society of Mammalogists in 1973. One of the main points of the memorandum written to justify the moratorium was to conduct a 'detailed evaluation of the files of the bat-banding program.' However, a critical and detailed evaluation of the BBP was never completed. In an effort to satisfy this need, I compiled a detailed history of the BBP by examining the files and conducting a literature review on bat banding activities during the program. I also provided a case study in managing data and applying current mark-recapture theory to estimate survival using the information from a series of bat bands issued to Clyde M. Senger during the BBP. The majority of bands applied by Senger were to Townsend's big-eared bat (Corynorhinus townsendii), a species of special concern for many states within its geographic range. I developed a database management system for the bat banding records and then analyzed and modeled survival of hibernating Townsend's big-eared bats at three main locations in Washington State using Cormack-Jolly-Seber (CJS) open models and the modeling capabilities of Program MARK. This analysis of a select dataset in the BBP files provided relatively precise estimates of survival for wintering Townsend's big-eared bats. However, this dataset is unique due to its well-maintained and complete state and because there were high recapture rates over the course of banding; it is doubtful that other unpublished datasets of the same quality exist

Ultra-High Gradient S-band Linac for Laboratory and Industrial Applications

Science.gov (United States)

Faillace, L.; Agustsson, R.; Dolgashev, V.; Frigola, P.; Murokh, A.; Rosenzweig, J.; Yakimenko, V.

2010-11-01

A strong demand for high gradient structures arises from the limited real estate available for linear accelerators. RadiaBeam Technologies is developing a Doubled Energy Compact Accelerator (DECA) structure: an S-band standing wave electron linac designed to operate at accelerating gradients of up to 50 MV/m. In this paper, we present the radio-frequency design of the DECA S-band accelerating structure, operating at 2.856 GHz in the π-mode. The structure design is heavily influenced by NLC collaboration experience with ultra high gradient X-band structures; S-band, however, is chosen to take advantage of commonly available high power S-band klystrons.

47 CFR 25.147 - Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing provision for NGSO MSS feeder downlinks in the band 6700-6875 MHz. 25.147 Section 25.147 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space...

Handbook of optimization in telecommunications

CERN Document Server

Pardalos, Panos M

2008-01-01

Covers the field of optimization in telecommunications, and the optimization developments that are frequently applied to telecommunications. This book aims to provide a reference tool for scientists and engineers in telecommunications who depend upon optimization.

The Quality of Management Information Systems and Its Effect on the Employees Performance at the Yemeni Public Telecommunication Corporation

Directory of Open Access Journals (Sweden)

عبد اللطيف مصلح محمد عايض

2017-10-01

Full Text Available In spite of the interest of many organizations in the development of information systems, some organizations did not give enough attention to this issue, including the Yemeni organizations. This is what the researchers noted in their dealings with some of these organizations. The Yemeni Public Telecommunications Corporation is one of them. It was noted that some of the administrative units concerned with the application of management information systems in the organization have certain weaknesses in some dimensions of the employees performance in the organization, and this may be due to the quality of their management information systems. This study aimed at demonstrating the effect of the quality of management information systems on the employees performance that was applied on the Public Telecommunication Corporation (PTC. The population of the study included all users of management information systems in PTC totaling (117 employees. Their number was, to some extent, small, so they were selected to be the study sample. To achieve the objectives of the study, the descriptive and analytical method was used. To collect the data of the study, a questionnaire was developed and validated to measure the study objectives and to test its hypotheses.  To analyze the data, (SPSS program was used. The study found a set of conclusions the most important of which was that the level of both the quality of management information systems and the performance of employees in the Yemeni Public Telecommunications Corporation was high. Moreover, there was a positive effect for the quality of management information systems on the employees’ performance in PTC. Keywords: Quality of management information systems, Employees performance, Yemeni Public Telecommunications Corporation.

Impact of Distributed Energy Resources on the Reliability of a Critical Telecommunications Facility

Energy Technology Data Exchange (ETDEWEB)

Robinson, D.; Atcitty, C.; Zuffranieri, J.; Arent, D.

2006-03-01

Telecommunications has been identified by the Department of Homeland Security as a critical infrastructure to the United States. Failures in the power systems supporting major telecommunications service nodes are a main contributor to major telecommunications outages, as documented by analyses of Federal Communications Commission (FCC) outage reports by the National Reliability Steering Committee (under auspices of the Alliance for Telecommunications Industry Solutions). There are two major issues that are having increasing impact on the sensitivity of the power distribution to telecommunication facilities: deregulation of the power industry, and changing weather patterns. A logical approach to improve the robustness of telecommunication facilities would be to increase the depth and breadth of technologies available to restore power in the face of power outages. Distributed energy resources such as fuel cells and gas turbines could provide one more onsite electric power source to provide backup power, if batteries and diesel generators fail. But does the diversity in power sources actually increase the reliability of offered power to the office equipment, or does the complexity of installing and managing the extended power system induce more potential faults and higher failure rates? This report analyzes a system involving a telecommunications facility consisting of two switch-bays and a satellite reception system.

Polarization Optics in Telecommunications

CERN Document Server

Damask, Jay N

2005-01-01

The strong investments into optical telecommunications in the late 1990s resulted in a wealth of new research, techniques, component designs, and understanding of polarization effects in fiber. Polarization Optics in Telecommunications brings together recent advances in the field to create a standard, practical reference for component designers and optical fiber communication engineers. Beginning with a sound foundation in electromagnetism, the author offers a dissertation of the spin-vector formalism of polarization and the interaction of light with media. Applications discussed include optical isolators, optical circulators, fiber collimators, and a variety of applied waveplate and prism combinations. Also included in an extended discussion of polarization-mode dispersion (PMD) and polarization-dependent loss (PDL), their representation, behavior, statistical properties, and measurement. This book draws extensively from the technical and patent literature and is an up-to-date reference for researchers and c...

NCDC feed of Global Telecommunication System (GTS) marine observations in International Maritime Meteorological Archive (IMMA) Format

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The data contained here are surface marine observations from many different sources via the NCDC Global Telecommunication System (GTS) Marine in International...

47 CFR 25.134 - Licensing provisions of Very Small Aperture Terminal (VSAT) and C-band Small Aperture Terminal...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing provisions of Very Small Aperture Terminal (VSAT) and C-band Small Aperture Terminal (CSAT) networks. 25.134 Section 25.134 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS...

Telecommunication networks

CERN Document Server

Iannone, Eugenio

2011-01-01

Many argue that telecommunications network infrastructure is the most impressive and important technology ever developed. Analyzing the telecom market's constantly evolving trends, research directions, infrastructure, and vital needs, Telecommunication Networks responds with revolutionized engineering strategies to optimize network construction. Omnipresent in society, telecom networks integrate a wide range of technologies. These include quantum field theory for the study of optical amplifiers, software architectures for network control, abstract algebra required to design error correction co

Deep space propagation experiments at Ka-band

Science.gov (United States)

Butman, Stanley A.

1990-01-01

Propagation experiments as essential components of the general plan to develop an operational deep space telecommunications and navigation capability at Ka-band (32 to 35 GHz) by the end of the 20th century are discussed. Significant benefits of Ka-band over the current deep space standard X-band (8.4 GHz) are an improvement of 4 to 10 dB in telemetry capacity and a similar increase in radio navigation accuracy. Propagation experiments are planned on the Mars Observer Mission in 1992 in preparation for the Cassini Mission to Saturn in 1996, which will use Ka-band in the search for gravity waves as well as to enhance telemetry and navigation at Saturn in 2002. Subsequent uses of Ka-band are planned for the Solar Probe Mission and the Mars Program.

47 CFR 25.145 - Licensing conditions for the Fixed-Satellite Service in the 20/30 GHz bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing conditions for the Fixed-Satellite Service in the 20/30 GHz bands. 25.145 Section 25.145 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25...

DEVELOPMENT OF PROTOTYPE SYSTEM FOR REGULATING THERMAL CONDITIONS OF TELECOMMUNICATIONS EQUIPMENT CABINETS

Directory of Open Access Journals (Sweden)

A. T. Rashidkhanov

2017-01-01

Full Text Available Objectives. The main objective of the study was to regulate the thermal regime and ensure the reliability of electronic equipmentMethods. In order to conduct experimental studies of the thermoelectric cooling system using heat pipes, a stand was assembled on which the developed and manufactured prototype was studied. The object of the experimental studies was a prototype cooling system, consisting of a thermoelectric battery made of conventional unified thermoelectric materials of ICE-71 type. The solution of the research problems carried out by the method of reduction to ordinary differential equations (Kantorovich method provides acceptable accuracy for such a class of problems.Results. A design of a telecommunication equipment cabinet with a thermal management system based on the use of heat pipes and thermoelectric cooling units is proposed. A mathematical model for the determination of the thermal field in the cabinet volume is considered; an experimental stand for the prototype study is described; the results of experimental studies for various power sources of heat release are presented.Conclusion. Experimental studies confirm the operability of the developed cooling system for cabinets with telecommunication equipment; this cooling method has advantages over conventional forced or natural cooling; the temperature in the block volume and the peak values of the heat sources are significantly reduced; at dissipation powers on one board within 50 W there is no need to use special means to remove heat from hot junctions of the thermoelectric battery.

Software Development Process Changes in the Telecommunications Industry

Directory of Open Access Journals (Sweden)

John Kevin Doyle

2006-06-01

Full Text Available The tremendous changes in the telecommunications business in the last several years drove changes in the software development processes of telecommunications equipment providers. We compare changes in these very large projects, in two companies, with those proposed in the Theory of Constraints / Critical Chains, Extreme Programming, and Agile development models. The 2000s have been a time of significant challenge in the telecommunications equipment business. Telecommunications service providers have excess equipment capacity. Many are waiting for next generation telephone switches that will simultaneously lower operating costs and enable additional revenue generation. The large service providers have drastically reduced their capital and expense purchases. Many small service providers, particularly the dot-coms, went bankrupt; much of their equipment is on the secondary market, at a fraction of the original cost. Thus the equipment market has significantly shrunk, and the equipment providers have been reducing expenses, while continuing to deliver software and hardware equipment at the high quality level required by the service providers. This drove many changes in the software development process. While the process changes are reported in two telecommunication equipment development organizations, the changes are applicable in any product development organization.

Telecommunication Reform and WTO

DEFF Research Database (Denmark)

Henten, Anders

1996-01-01

An analysis of the negotiations on telecommunication liberalisation in the World Trade Organization.......An analysis of the negotiations on telecommunication liberalisation in the World Trade Organization....

Open Source Telecommunication Companies

Directory of Open Access Journals (Sweden)

Peter Liu

2007-08-01

Full Text Available Little is known about companies whose core business is selling telecommunications products that lever open source projects. Open source telecommunications (OST companies operate in markets that are very different from typical software product markets. The telecommunications market is regulated, vertically integrated, and proprietary designs and special chips are widely used. For a telecommunications product to be useful, it must interact with both access network products and core network products. Due to specifications in Service Agreements Levels, penalties for failures of telecommunications products are very high. This article shares information that is not widely known, including a list of OST companies and the open source projects on which they depend, the size and diversity of venture capital investment in OST companies, the nature of the commercial product-open source software and company-project relationships, ways in which OST companies make money, benefits and risks of OST companies, and competition between OST companies. Analysis of this information provides insights into the ways in which companies can build business models around open source software. These findings will be of interest to entrepreneurs, top management teams of incumbent companies that sell telecommunications products, and those who care about Ontario's ability to compete globally.

C-band RF-system development for e{sup +}e{sup -} linear collider

Energy Technology Data Exchange (ETDEWEB)

Shintake, T.; Akasaka, N.; Matsumoto, H. [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Oh, J.S.; Yoshida, M.; Watanabe, K.; Ohkubo, Y.; Yonezawa, H.; Baba, H.

1998-11-01

Hardware R and D on the C-band (5712 MHz) RF-system for an electron/positron linear collider started in 1996 at KEK. During two years R and D, we have developed a 50-MW C-band klystron (TOSHIBA E3746), a 'Smart Modulator', a traveling-wave resonator (TWR) and a cold model of the rf-pulse compressor. A C-band accelerating structure, which uses the choke-mode cavity, is under development. Its HOM damping performance will be tested using short-bunch beams of ASSET beam-line at SLAC in this year. The C-band system is able to accelerate a high-current beam at an accelerating gradient higher than that in a conventional S-band system, therefore, there will be various applications in the future beside the linear collider. For example, we can build an injector for a SR-ring and for various physics experiments within a short site-length. Additionally, since the C-band components are compact, it has a big potentiality to be widely used in various medical and industrial applications, such as an electron-beam radiotherapy machine, or a compact non-destructive X-ray imaging system. (author)

47 CFR 54.502 - Supported telecommunications services.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Supported telecommunications services. 54.502 Section 54.502 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES... telecommunications services. For purposes of this subpart, supported telecommunications services provided by...

Testing and Implementation Progress on the Advanced Photon Source (APS) Linear Accelerator (Linac) High-Power S-band Switching System

OpenAIRE

Grelick, A. E.; Arnold, N.; Berg, S.; Dohan, D.; Goeppner, G.; Kang, Y. W.; Nassiri, A.; Pasky, S.; Pile, G.; Smith, T.; Stein, S. J.

2000-01-01

An S-band linear accelerator is the source of particles and the front end of the Advanced Photon Source injector. In addition, it supports a low-energy undulator test line (LEUTL) and drives a free-electron laser (FEL). A waveguide-switching and distribution system is now under construction. The system configuration was revised to be consistent with the recent change to electron-only operation. There are now six modulator-klystron subsystems, two of which are being configured to act as hot sp...

Seven-core active fibre for application in telecommunication satellites

Science.gov (United States)

Filipowicz, Marta; Napierała, Marek; Murawski, Michał; Ostrowski, Łukasz; Szostkiewicz, Łukasz; Szymański, Michał; Tenderenda, Tadeusz; Anders, Krzysztof; Piramidowicz, Ryszard; Wójcik, Grzegorz; Makara, Mariusz; Poturaj, Krzysztof; Mergo, Paweł; Nasiłowski, Tomasz

2015-12-01

The use of optical elements and other photonic components makes it possible to overcome telecommunication satellite's bottleneck problems such as size and weight reduction. Despite the unquestionable potential of such elements, nowadays they are not widely used in systems operating in space. This is due to many factors, including the fact that space radiation has disruptive influence on optical fibre. Namely it introduces additional radiation induced attenuation (RIA) that significantly lowers efficiency of optical fibre based systems. However, there is a possibility to produce radiation-hardened (rad-hard) components. One of them is seven core erbium-doped active fibre (MC-EDF) for fibre amplifiers in satellites that we have been developing. In this paper we present a detailed description of seven core structure design as well as experimental results. We report that average gain of 20 dB in C-band with noise figure of 5.8 dB was obtained. We also confirmed that low crosstalk value for a multicore fibre amplifier based on our fibre can be achieved.

An overview of research on technological and telecommunication development

Directory of Open Access Journals (Sweden)

Marina Budimir

2014-10-01

Full Text Available The scientific and professional research on technological and telecommunication development started in the second half of the 20th century as the use of new media and technologies began to cause structural business and social changes. A review of research published in the early 1980s revealed that the focus was mainly on the acceptance, usefulness and impact of new media and information technology on the information society, whereas research conducted at the turn of the century was mostly interdisciplinary and related to the effect of technological and telecommunication development on various scientific and professional fields. The focus of this paper is an overview of published research on information technology since the 1980s to date, as well as technological and telecommunication development in recent years based on the latest official published data. On the basis of previous research, it can be concluded that more attention needs to be directed to monitoring trends of ICT products and services in order to increase benefits and reduce the costs for active users, as well as improving infrastructure and providing information to attract passive users in order to reduce technological and telecommunication gap between developed, developing and underdeveloped countries.

CRC handbook of modern telecommunications

CERN Document Server

Morreale, Patricia A

2001-01-01

This authoritative handbook, contributed to by a team of international experts, covers the most dynamic areas in the changing telecommunications landscape. Written for telecommunications specialists who implement the new technologies, The CRC Handbook of Modern Telecommunications is an excellent companion volume to the authors' The Telecommunications Handbook, but stands well on its own, as it extends the range of topics to include voice over Internet, traffic management, quality of service, and other dominant future trends. It is an indispensable reference for all professionals working in the

Predicting Customer Churn and Retention Rates in Nigeria’s Mobile Telecommunication Industry Using Markov Chain Modelling

Directory of Open Access Journals (Sweden)

Adebiyi Sulaimon Olanrewaju

2015-12-01

Full Text Available The telecommunication industry is one of the service industries that is most affected by the problem of subscribers’ churn. Although several techniques have been used to predict customer churn in developed countries, many of those studies used secondary data which are not readily available in Nigeria for researchers. This study investigates how Markov chains help in modelling and predicting the customer churn and retention rate in the Nigerian mobile telecommunication industry. The data generated through the survey were input in the Windows-based Quantitative System for Business (WinQSB for analysis. The results reveal that in the study area MTN has the highest retention rate (86.11%, followed by GLO (70.51%, Airtel (67%, and Etisalat (67.5%. This result has implications for telecom firms’ strategies for competitive advantage in particular and survival in general.

Dictionary of Telecommunications.

Science.gov (United States)

Bones, R. A.

A wide range of terms used in the telecommunications industry are defined in this dictionary. Many of the terms and definitions are either reproduced from, or based on, the "Glossary of Terms Used in Telecommunications (including Radio) and Electronics" prepared by the British Standards Institute. The principal entry for each term is found under…

Case Study: Using The OMG SWRADIO Profile and SDR Forum Input for NASA's Space Telecommunications Radio System

Science.gov (United States)

Briones, Janette C.; Handler, Louis M.; Hall, Steve C.; Reinhart, Richard C.; Kacpura, Thomas J.

2009-01-01

The Space Telecommunication Radio System (STRS) standard is a Software Defined Radio (SDR) architecture standard developed by NASA. The goal of STRS is to reduce NASA s dependence on custom, proprietary architectures with unique and varying interfaces and hardware and support reuse of waveforms across platforms. The STRS project worked with members of the Object Management Group (OMG), Software Defined Radio Forum, and industry partners to leverage existing standards and knowledge. This collaboration included investigating the use of the OMG s Platform-Independent Model (PIM) SWRadio as the basis for an STRS PIM. This paper details the influence of the OMG technologies on the STRS update effort, findings in the STRS/SWRadio mapping, and provides a summary of the SDR Forum recommendations.

New Radiofrequency Exposure System with Real Telecommunication Signals

Directory of Open Access Journals (Sweden)

Jakub Misek

2018-01-01

Full Text Available In recent years, there has been an increase in the number of studies on biological effects of Electromagnetic (EM fields emitted from Base Transceiver Stations (BTSs. The biological effects of generated and real telecommunication signals produced by different types of exposure systems are discussed. However, the proper exposure methods for such experiments are very limited. We successfully developed a simple and cost-effective exposure unit with real GSM/DCS/UMTS signal from BTS containing proper modulations or intermittence (continuous, interrupted. Signal processing and conditioning unit is based on a Radiofrequency (RF repeater. The downlink signal is filtered by integrated high selectivity passband filters and amplified to a required level. The main part of exposure unit is a Faraday cage with the specimen (exposure area measuring 150 x 250 mm with E-field percent deviation less than 18%. This exposure system can be helpful in experiments with living organisms in in vivo studies and in vitro studies with normal or pathological cells and other micro scale structures being exposed to RF EM fields from BTS.

Portable, x-band, linear accelerator systems

International Nuclear Information System (INIS)

Schonberg, R.G.; Deruyter, H.; Fowkes, W.R.; Johnson, W.A.; Miller, R.H.; Potter, J.M.; Weaver, J.N.

1985-01-01

Three light-weight, x-band, electron accelerators have been developed to provide a series of highly portable sources of x-rays and neutrons for nondestructive testing. The 1.5 MeV x-ray unit has a 200 kW magnetron for an RF source and an air-cooled, traveling wave accelerating structure to minimize its weight. The 4 and 6 MeV units share the same drive system which contains a 1.2 MW magnetron. The 4 MeV unit uses a traveling-wave guide to produce x-rays and the 6MeV unit uses a standing-wave guide to produce x-rays or neutrons. The choice of 9.3 GHz was dictated by the availability of a high power coaxial magnetron and by the obvious dimensional and weight advantages of a higher frequency over the more common S-band frequencies around 3 GHz

Portable, x-band, linear accelerator systems

International Nuclear Information System (INIS)

Schonberg, R.G.; Deruyter, H.; Fowkes, W.R.; Johnson, W.A.; Miller, R.H.; Potter, J.M.; Weaver, J.N.

1985-01-01

Three light-weight, x-band, electron accelerators have been developed to provide a series of highly portable sources of x-rays and neutrons for non-destructive testing. The 1.5 MeV x-ray unit has a 200 kW magnetron for an RF source and an air-cooled, traveling wave accelerating structure to minimize its weight. The 4 and 6 MeV units share the same drive system which contains a 1.2 MW magnetron. The 4 MeV unit uses a traveling-wave guide to produce x-rays and the 6MeV unit uses a standing-wave guide to produce x-rays or neutrons. The choice of 9.3 GHz was dictated by the availability of a high power coaxial magnetron and by the obvious dimensional and weight advantages of a higher frequency over the more common S-band frequencies around 3 GHz

Spectrum Band Selection in Delay-QoS Constrained Cognitive Radio Networks

KAUST Repository

Yang, Yuli

2014-01-01

In this paper, a cognitive radio (CR) network with multiple spectrum bands available for secondary users (SUs) is considered. For the SU\\'s active spectrum-band selection, two criteria are developed. One is to select the band with the highest secondary channel power gain, and the other is to select the band with the lowest interference channel power gain to primary users (PUs). With the quality-of-service (QoS) requirement concerning delay, the effective capacity (EC) behaviors over secondary links are investigated for both criteria under two spectrum-sharing constraints. To begin by presenting full benefits in these criteria, the constraint imposed on the secondary transmitter (ST) is the average interference limitation to PUs only. Furthermore, taking into account the ST\\'s battery/energy budget, the ST is imposed by joint constraints on its average interference to PUs, as well as on its own average transmit power. For either constraint, we formulate the ST\\'s optimal transmit power allocation to maximize the SU\\'s EC with both band-selection criteria and, correspondingly, obtain the secondary\\'s power allocation and maximum EC in closed forms. Numerical results demonstrated subsequently substantiate the validity of our derivations and provide a powerful tool for the spectrum-band selection in CR networks with multiple bands available. © 1967-2012 IEEE.

Band structural properties of MoS2 (molybdenite)

International Nuclear Information System (INIS)

Gupta, V.P.

1980-01-01

Semiconductivity and superconductivity in MoS 2 (molybdenite) can be understood in terms of the band structure of MoS 2 . The band structural properties of MoS 2 are presented here. The energy dependence of nsub(eff) and epsilon(infinity)sub(eff) is investigated. Using calculated values of nsub(eff) and epsilon(infinity)sub(eff), the Penn gap has been determined. The value thus obtained is shown to be in good agreement with the reflectivity data and also with the value obtained from the band structure. The Ravindra and Srivastava formula has been shown to give values for the isobaric temperature gradient of Esub(G)[(deltaEsub(G)/deltaT)sub(P)], which are in agreement with the experimental data, and the contribution to (deltaEsub(G)/deltaT)sub(P) due to the electron lattice interaction has been evaluated. In addition, the electronic polarizability has been calculated using a modified Lorentz-Lorenz relation. (author)

Nanoscale resonant-cavity-enhanced germanium photodetectors with lithographically defined spectral response for improved performance at telecommunications wavelengths.

Science.gov (United States)

Balram, Krishna C; Audet, Ross M; Miller, David A B

2013-04-22

We demonstrate the use of a subwavelength planar metal-dielectric resonant cavity to enhance the absorption of germanium photodetectors at wavelengths beyond the material's direct absorption edge, enabling high responsivity across the entire telecommunications C and L bands. The resonant wavelength of the detectors can be tuned linearly by varying the width of the Ge fin, allowing multiple detectors, each resonant at a different wavelength, to be fabricated in a single-step process. This approach is promising for the development of CMOS-compatible devices suitable for integrated, high-speed, and energy-efficient photodetection at telecommunications wavelengths.

Photovoltaics for telecommunications networks in Libya, uses and experiences

International Nuclear Information System (INIS)

Ibrahim, Ibrahim M. Saleh; Adam, M. S.; Ben-Hamed, Khalifa

2006-01-01

The use of photovoltaic systems as a stand-alone power supply in Libyan telecommunication networks has been in use since 1980. It was proved that PV generators are reliable and cost effective in this type of applications in comparison with diesel generators. In Libya about 100 photovoltaic systems were put into work to supply electricity for repeater stations instead of diesel generators, these PV systems proved to be reliable, very low or no communication stops, and and more economical in comparison with stations running by diesel generators, a wide knowledge of experience has been built of using photovoltaic systems in this applications. This paper is focusing on the role of stand-alone PV systems in communication networks of Libya, as a stand alone power source for telecommunication repeater stations. We will evaluate some of these systems after ten years of work, discuss the past experience, their reliability, and running cost, Stand-alone systems can be used in telecommunication networks, and in general the experienced advantages of using PV solar generators can be summarized as low running cost, high reliability, fewer services visits,, low maintenance cost, less number of thefts, no communication stops.(Author)

The Pacific Islands. Policy options for telecommunications investment.

Science.gov (United States)

Jussawalla, M; Ogden, M R

1989-03-01

The Independent Commission for World-Wide Telecommunications Development (Maitland Commission) reported that telecommunication networks, including public telephone systems, are an infrastructure which aids economic development throughout the world. The Commissions objective is to bring the majority of the world's population within easy access of a telephone and, in time, other communications services. Development in the Pacific Islands region is slowed by a lack of efficient communications. The islands are spread over 29 million square kilometers of ocean and extremely vulnerable to natural disasters. Pacific Island Nations (PINs) have problems of foreign exchange, skill shortages, and poor credit terms. Telecommunications infrastructure audits showed the overall regional teledensity of 3 telephones per 100 population. The individual countries vary form 8.3 in Fiji to 1.5 in Papua New Guinea and 25.2 in New Zealand. The population of the developing island countries is in mostly rural areas where there is a chronic shortage of telephones. The constraints on radio systems can be overcome with satellite technology. The new technologies are coming on the market faster than these countries can afford to handle them. By using satellite technology and sharing facilities PINs can greatly reduce the cost of telecommunications systems. Fiber optic cables will be used to carry large volumes of traffic over major routes while satellites can be used for a array of services for the smallest PIN nation to the largest route rim country. Work is being done to standardize the equipment specifications and to develop policies for the coordination of regional telecommunications training. To further facilitate communications development in this area, changes need to be made in international funding priorities for development, and recommendations by the Maitland Commission must be taken seriously.

Benchmarking Further Single Board Computers for Building a Mini Supercomputer for Simulation of Telecommunication Systems

Directory of Open Access Journals (Sweden)

Gábor Lencse

2016-01-01

Full Text Available Parallel Discrete Event Simulation (PDES with the conservative synchronization method can be efficiently used for the performance analysis of telecommunication systems because of their good lookahead properties. For PDES, a cost effective execution platform may be built by using single board computers (SBCs, which offer relatively high computation capacity compared to their price or power consumption and especially to the space they take up. A benchmarking method is proposed and its operation is demonstrated by benchmarking ten different SBCs, namely Banana Pi, Beaglebone Black, Cubieboard2, Odroid-C1+, Odroid-U3+, Odroid-XU3 Lite, Orange Pi Plus, Radxa Rock Lite, Raspberry Pi Model B+, and Raspberry Pi 2 Model B+. Their benchmarking results are compared to find out which one should be used for building a mini supercomputer for parallel discrete-event simulation of telecommunication systems. The SBCs are also used to build a heterogeneous cluster and the performance of the cluster is tested, too.

Microwave systems applications in deep space telecommunications and navigation - Space Exploration Initiative architectures

Science.gov (United States)

Hall, Justin R.; Hastrup, Rolf C.; Bell, David J.

1992-06-01

The general support requirements of a typical SEI mission set, along with the mission operations objectives and related telecommunications, navigation, and information management (TNIM) support infrastructure options are described. Responsive system architectures and designs are proposed, including a Mars orbiting communications relay satellite system and a Mars-centered navigation capability for servicing all Mars missions. With the TNIM architecture as a basis, key elements of the microwave link design are proposed. The needed new technologies which enable these designs are identified, and current maturity is assessed.

Status of the C-band RF System for the SPARC-LAB high brightness photo-injector

CERN Document Server

Boni, R.; Bellaveglia, M.; Di Pirro, G.; Ferrario, M.; Gallo, A.; Spataro, B.; Mostacci, A.; Palumbo, L.

2013-01-01

The high brightness photo-injector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy so improving the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

Use of satellite telecommunications for telemedicine

Science.gov (United States)

Tamkovich, Gennady

1991-01-01

The use of space telecommunications facilities in the interests of medicine should establish a reliable and timely connection between the specialists involved and access for each of them to information sources the need. Since a certain global-scale program should be implemented for this goal to be achieved, one of the top-priority tasks is to determine appropriate orbital facilities for telecommunications as well as appropriate areas and countries for them, outlining the territories where portable data receive/transport records can be placed and stations that are cheap and simple enough to operate can be stored. Eventually the satellite telecommunications system should encourage health workers to unite in a world community on the basis of a regular and efficient information exchange with the goal of protecting the health of man and the peace of Earth. This goal could only be achieved by gradually removing differences in the domain of medical education and information in different regions over the globe, by providing a possibility of rapid and coordinated access to the information on medical problems of interest on the global scale, as well as by coordinating the discussion and solution of all problems associated with the development and progress of the satellite communications system.

Medical image telecommunication

International Nuclear Information System (INIS)

Handmaker, H.; Bennington, J.L.; Lloyd, R.W.; Caspe, R.A.

1986-01-01

After years of waiting for Picture Archiving and Communication Systems (PACS) to become technologically mature and readily available at competitive costs, it appears that the ingredients are now available for producing at least the telecommunication component of the PACS. They are as follows: 1. A variety of pathways now exist for long-distance high-speed digital data transmission at acceptable costs. 2. Developments in computer technology and keen competition in the microcomputer and video display markets have markedly reduced to costs for components of digital data terminals. 3. The volume of native digitally acquired images is expanding yearly, whereas at the same time the pressure for converting images acquired in analog format to digital format is increasing. 4. The advantages of and potential for processing and storing imaging data in digital format are becoming more widely recognized. These factors, individually and collectively, favor the successful applications of image telecommunication to the field of diagnostic imaging. The authors have attempted to provide an overview of the subject and the basics of this emerging technology

47 CFR 90.615 - Individual channels available in the General Category in 806-824/851-869 MHz band.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Individual channels available in the General Category in 806-824/851-869 MHz band. 90.615 Section 90.615 Telecommunication FEDERAL COMMUNICATIONS... Critical Infrastructure Industry Categories from three to five years after the release of a public notice...

A study of current world telecommunications and a projection of the future

Science.gov (United States)

Karageorgis, Costas

1992-09-01

Telecommunications today are important factors in economic and social progress. The last decades of the 20th century and the early years of the 21st have been characterized as the Information Age. Telecommunications, the movement of information through distances, is absolutely critical to the economic and military survival of nations. This thesis is an attempt to predict the future of telecommunications, by studying and analyzing the past and present. First it examines the meaning of telecommunications today and some basics of information transmission. The current status of telecommunications is then presented, by examining the regional profiles as they are divided by the International Telecommunications Union. A number of statistical studies are given, which present a thorough picture of current world telecommunications. In an effort to predict future industry trends, the competition among the three largest telecommunications markets, U.S.A., Japan and the European Community, is also considered by looking at their present telecommunications industry, the efforts they make to improve their technology, and their plans for future investment. Finally, some major technological trends including BISDN, the use of fiber technology in the communications loop, and the use of solitons are examined. The new Metropolitan Area Network Protocol, FDDI-2 is also reviewed.

Network Performance and Coordination in the Health, Education, Telecommunications System. Satellite Technology Demonstration, Technical Report No. 0422.

Science.gov (United States)

Braunstein, Jean; Janky, James M.

This paper describes the network coordination for the Health, Education, Telecommunications (HET) system. Specifically, it discusses HET network performance as a function of a specially-developed coordination system which was designed to link terrestrial equipment to satellite operations centers. Because all procedures and equipment developed for…

Public Service Telecommunications: PEACESAT.

Science.gov (United States)

Okamura, Norman H.; Mukaida, Lori Van Dusen

1996-01-01

Describes the Pan-Pacific Education and Communication Experiments by Satellite (PEACESAT), a public service telecommunication program developed to facilitate the use of telecommunications and information technologies. Highlights include the historical development; digital capabilities; cooperation and collaboration with users, government, and…

Medical device integration using mobile telecommunications infrastructure.

Science.gov (United States)

Moorman, Bridget A; Cockle, Richard A

2013-01-01

Financial pressures, an aging population, and a rising number of patients with chronic diseases, have encouraged the use of remote monitoring technologies. This usually entails at least one physiological parameter measurement for a clinician. Mobile telecommunication technologies lend themselves to this functionality, and in some cases, avoid some of the issues encountered with device integration. Moreover, the inherent characteristics of the mobile telecommunications infrastructure allow a coupling of business and clinical functions that were not possible before. Table I compares and contrasts some key aspect of device integration in and out of a healthcare facility. An HTM professional may be part of the team that acquires and/or manages a system using a mobile telecommunications technology. It is important for HTM professionals to ensure the data is in a standard format so that the interfaces across this system don't become brittle and break easily if one part changes. Moreover, the security and safety considerations of the system and the data should be a primary consideration in and y purchase, with attention given to the proper environmental and encryption mechanisms. Clinical engineers and other HTM professionals are unique in that they understand the patient/clinician/device interface and the need to ensure its safety and effectiveness regardless of geographical environment.

History and structures of telecommunication in pathology, focusing on open access platforms.

Science.gov (United States)

Kayser, Klaus; Borkenfeld, Stephan; Djenouni, Amina; Kayser, Gian

2011-11-07

Telecommunication has matured to a broadly applied tool in diagnostic pathology. Contemporary with the development of fast electronic communication lines (Integrated digital network services (ISDN), broad band connections, and fibre optics, as well as the digital imaging technology (digital camera), telecommunication in tissue--based diagnosis (telepathology) has matured. Open access (internet) and server--based communication have induced the development of specific medical information platforms, such as iPATH, UICC-TPCC (telepathology consultation centre of the Union International against Cancer), or the Armed Forces Institute of Pathology (AFIP) teleconsultation system. They have been closed, and are subject to be replaced by specific open access forums (Medical Electronic Expert Communication System (MECES) with embedded virtual slide (VS) technology). MECES uses php language, data base driven mySqL architecture, X/L-AMPP infrastructure, and browser friendly W3C conform standards. The server--based medical communication systems (AFIP, iPATH, UICC-TPCC) have been reported to be a useful and easy to handle tool for expert consultation. Correct sampling and evaluation of transmitted still images by experts reported revealed no or only minor differences to the original images and good practice of the involved experts. β tests with the new generation medical expert consultation systems (MECES) revealed superior results in terms of performance, still image viewing, and system handling, especially as this is closely related to the use of so--called social forums (facebook, youtube, etc.). In addition to the acknowledged advantages of the former established systems (assistance of pathologists working in developing countries, diagnosis confirmation, international information exchange, etc.), the new generation offers additional benefits such as acoustic information transfer, assistance in image screening, VS technology, and teaching in diagnostic sampling, judgement

Demonstration of 352 Gbit/s Photonically-enabled D-Band Wireless Delivery in one 2x2 MIMO System

DEFF Research Database (Denmark)

Puerta Ramírez, Rafael; Yu, Jianjun; Li, Xinying

2017-01-01

First demonstration of photonically-enabled independent side-bands D-Band wireless transmission up to 352 Gbit/s with a BER below 3.8×10-3. These results were achieved by means of advanced DSP and antenna polarization multiplexing (2x2 MIMO)....

Cloud Computing Boosts Business Intelligence of Telecommunication Industry

Science.gov (United States)

Xu, Meng; Gao, Dan; Deng, Chao; Luo, Zhiguo; Sun, Shaoling

Business Intelligence becomes an attracting topic in today's data intensive applications, especially in telecommunication industry. Meanwhile, Cloud Computing providing IT supporting Infrastructure with excellent scalability, large scale storage, and high performance becomes an effective way to implement parallel data processing and data mining algorithms. BC-PDM (Big Cloud based Parallel Data Miner) is a new MapReduce based parallel data mining platform developed by CMRI (China Mobile Research Institute) to fit the urgent requirements of business intelligence in telecommunication industry. In this paper, the architecture, functionality and performance of BC-PDM are presented, together with the experimental evaluation and case studies of its applications. The evaluation result demonstrates both the usability and the cost-effectiveness of Cloud Computing based Business Intelligence system in applications of telecommunication industry.

47 CFR 27.16 - Network access requirements for Block C in the 746-757 and 776-787 MHz bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Network access requirements for Block C in the 746-757 and 776-787 MHz bands. 27.16 Section 27.16 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... network restrictions on industry-wide consensus standards, such restrictions would be presumed reasonable...

An adaptive software defined radio design based on a standard space telecommunication radio system API

Science.gov (United States)

Xiong, Wenhao; Tian, Xin; Chen, Genshe; Pham, Khanh; Blasch, Erik

2017-05-01

Software defined radio (SDR) has become a popular tool for the implementation and testing for communications performance. The advantage of the SDR approach includes: a re-configurable design, adaptive response to changing conditions, efficient development, and highly versatile implementation. In order to understand the benefits of SDR, the space telecommunication radio system (STRS) was proposed by NASA Glenn research center (GRC) along with the standard application program interface (API) structure. Each component of the system uses a well-defined API to communicate with other components. The benefit of standard API is to relax the platform limitation of each component for addition options. For example, the waveform generating process can support a field programmable gate array (FPGA), personal computer (PC), or an embedded system. As long as the API defines the requirements, the generated waveform selection will work with the complete system. In this paper, we demonstrate the design and development of adaptive SDR following the STRS and standard API protocol. We introduce step by step the SDR testbed system including the controlling graphic user interface (GUI), database, GNU radio hardware control, and universal software radio peripheral (USRP) tranceiving front end. In addition, a performance evaluation in shown on the effectiveness of the SDR approach for space telecommunication.

Market structures in international telecommunications

DEFF Research Database (Denmark)

Henten, Anders

1998-01-01

Paper dealing with the internationalisation of telecommunications and the developing market structures.......Paper dealing with the internationalisation of telecommunications and the developing market structures....

Design of an S band narrow-band bandpass BAW filter

Science.gov (United States)

Gao, Yang; Zhao, Kun-li; Han, Chao

2017-11-01

An S band narrowband bandpass filter BAW with center frequency 2.460 GHz, bandwidth 41MHz, band insertion loss - 1.154 dB, the passband ripple 0.9 dB, the out of band rejection about -42.5dB@2.385 GHz; -45.5dB@2.506 GHz was designed for potential UAV measurement and control applications. According to the design specifications, the design is as follows: each FBAR's stack was designed in BAW filter by using Mason model. Each FBAR's shape was designed with the method of apodization electrode. The layout of BAW filter was designed. The acoustic-electromagnetic cosimulation model was built to validate the performance of the designed BAW filter. The presented design procedure is a common one, and there are two characteristics: 1) an A and EM co-simulation method is used for the final BAW filter performance validation in the design stage, thus ensures over-optimistic designs by the bare 1D Mason model are found and rejected in time; 2) An in-house developed auto-layout method is used to get compact BAW filter layout, which simplifies iterative error-and-try work here and output necessary in-plane geometry information to the A and EM cosimulation model.

Mapping Forest Cover and Forest Cover Change with Airborne S-Band Radar

Directory of Open Access Journals (Sweden)

Ramesh K. Ningthoujam

2016-07-01

Full Text Available Assessments of forest cover, forest carbon stocks and carbon emissions from deforestation and degradation are increasingly important components of sustainable resource management, for combating biodiversity loss and in climate mitigation policies. Satellite remote sensing provides the only means for mapping global forest cover regularly. However, forest classification with optical data is limited by its insensitivity to three-dimensional canopy structure and cloud cover obscuring many forest regions. Synthetic Aperture Radar (SAR sensors are increasingly being used to mitigate these problems, mainly in the L-, C- and X-band domains of the electromagnetic spectrum. S-band has not been systematically studied for this purpose. In anticipation of the British built NovaSAR-S satellite mission, this study evaluates the benefits of polarimetric S-band SAR for forest characterisation. The Michigan Microwave Canopy Scattering (MIMICS-I radiative transfer model is utilised to understand the scattering mechanisms in forest canopies at S-band. The MIMICS-I model reveals strong S-band backscatter sensitivity to the forest canopy in comparison to soil characteristics across all polarisations and incidence angles. Airborne S-band SAR imagery over the temperate mixed forest of Savernake Forest in southern England is analysed for its information content. Based on the modelling results, S-band HH- and VV-polarisation radar backscatter and the Radar Forest Degradation Index (RFDI are used in a forest/non-forest Maximum Likelihood classification at a spatial resolution of 6 m (70% overall accuracy, κ = 0.41 and 20 m (63% overall accuracy, κ = 0.27. The conclusion is that S-band SAR such as from NovaSAR-S is likely to be suitable for monitoring forest cover and its changes.

Telecommunication Networks

DEFF Research Database (Denmark)

Olsen, Rasmus Løvenstein; Balachandran, Kartheepan; Hald, Sara Ligaard

2014-01-01

In this chapter, we look into the role of telecommunication networks and their capability of supporting critical infrastructure systems and applications. The focus is on smart grids as the key driving example, bearing in mind that other such systems do exist, e.g., water management, traffic control......, etc. First, the role of basic communication is examined with a focus on critical infrastructures. We look at heterogenic networks and standards for smart grids, to give some insight into what has been done to ensure inter-operability in this direction. We then go to the physical network, and look...... threats to the critical infrastructure. Finally, before our conclusions and outlook, we give a brief overview of some key activities in the field and what research directions are currently investigated....

Aeronautical telecommunications network advances, challenges, and modeling

CERN Document Server

Musa, Sarhan M

2015-01-01

Addresses the Challenges of Modern-Day Air Traffic Air traffic control (ATC) directs aircraft in the sky and on the ground to safety, while the Aeronautical Telecommunications Network (ATN) comprises all systems and phases that assist in aircraft departure and landing. The Aeronautical Telecommunications Network: Advances, Challenges, and Modeling focuses on the development of ATN and examines the role of the various systems that link aircraft with the ground. The book places special emphasis on ATC-introducing the modern ATC system from the perspective of the user and the developer-and provides a thorough understanding of the operating mechanism of the ATC system. It discusses the evolution of ATC, explaining its structure and how it works; includes design examples; and describes all subsystems of the ATC system. In addition, the book covers relevant tools, techniques, protocols, and architectures in ATN, including MIPv6, air traffic control (ATC), security of air traffic management (ATM), very-high-frequenc...

InGaAsP/InP-air-aperture microcavities for single-photon sources at 1.55-μm telecommunication band

Science.gov (United States)

Guo, Sijie; Zheng, Yanzhen; Weng, Zhuo; Yao, Haicheng; Ju, Yuhao; Zhang, Lei; Ren, Zhilei; Gao, Ruoyao; Wang, Zhiming M.; Song, Hai-Zhi

2016-11-01

InGaAsP/InP-air-aperture micropillar cavities are proposed to serve as 1.55-μm single photon sources, which are indispensable in silica-fiber based quantum information processing. Owing to air-apertures introduced to InP layers, and adiabatically tapered distributed Bragg-reflector structures used in the central cavity layers, the pillar diameters can be less than 1 μm, achieving mode volume as small as (λ/n)3, and the quality factors are more than 104 - 105, sufficient to increase the quantum dot emission rate for 100 times and create strong coupling between the optical mode and the 1.55- μm InAs/InP quantum dot emitter. The mode wavelengths and quality factors are found weakly changing with the cavity size and the deviation from the ideal shape, indicating the robustness against the imperfection of the fabrication technique. The fabrication, simply epitaxial growth, dry and chemical etching, is a damage-free and monolithic process, which is advantageous over previous hybrid cavities. The above properties satisfy the requirements of efficient, photonindistinguishable and coherent 1.55-μm quantum dot single photon sources, so the proposed InGaAsP/InP-air-aperture micropillar cavities are prospective candidates for quantum information devices at telecommunication band.

Telecommunication service markets through the year 2000 in relation to millimeter wave satellite systems

Science.gov (United States)

Stevenson, S. M.

1979-01-01

NASA is currently conducting a series of millimeter wave satellite system market studies to develop 30/20 GHz satellite system concepts that have commercial potential. Four contractual efforts were undertaken: two parallel and independent system studies and two parallel and independent market studies. The marketing efforts are focused on forecasting the total domestic demand for long haul telecommunications services for the 1980-2000 period. Work completed to date and reported in this paper include projections of: geographical distribution of traffic; traffic volume as a function of urban area size; and user identification and forecasted demand.

Comparison and classification of all-optical CDMA systems for future telecommunication networks

Science.gov (United States)

Iversen, Kay; Hampicke, Dirk

1995-12-01

This paper shows the state of the art in fiber optical code-division multiple-access (CDMA). Recent work in this area for both, systems and sequences is reviewed and analyzed. For that purpose a classification of systems, corresponding to the manner of signal processing and a classification of known (0,1)-sequences are presented. It is shown that due to the limits by currently available device technology especially two techniques are promising for implementation in broadband telecommunication networks: spectral encoding with integrated optical filters and CDMA in combination with wavelength multiple access schemes. Further an overview about some important experiments in this field is given.

7 CFR 1700.55 - Telecommunications Program.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Telecommunications Program. 1700.55 Section 1700.55... AGRICULTURE GENERAL INFORMATION Loan and Grant Approval Authorities § 1700.55 Telecommunications Program. (a..., Telecommunications Program, has the authority to approve the following loans, loan guarantees, and lien...

7 CFR 1700.29 - Telecommunications Program.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Telecommunications Program. 1700.29 Section 1700.29... AGRICULTURE GENERAL INFORMATION Agency Organization and Functions § 1700.29 Telecommunications Program. RUS and RTB, through the Telecommunications Program, make loans and loan guarantees to furnish and improve...

Droplet epitaxial growth of highly symmetric quantum dots emitting at telecommunication wavelengths on InP(111)A

International Nuclear Information System (INIS)

Ha, Neul; Kuroda, Takashi; Liu, Xiangming; Mano, Takaaki; Mitsuishi, Kazutaka; Noda, Takeshi; Sakuma, Yoshiki; Sakoda, Kazuaki; Castellano, Andrea; Sanguinetti, Stefano

2014-01-01

We demonstrate the formation of InAs quantum dots (QDs) on InAlAs/InP(111)A by means of droplet epitaxy. The C 3v symmetry of the (111)A substrate enabled us to realize highly symmetric QDs that are free from lateral elongations. The QDs exhibit a disk-like truncated shape with an atomically flat top surface. Photoluminescence signals show broad-band spectra at telecommunication wavelengths of 1.3 and 1.5 μm. Strong luminescence signals are retained up to room temperature. Thus, our QDs are potentially useful for realizing an entangled photon-pair source that is compatible with current telecommunication fiber networks

Tanzania Telecommunication Company Limited as a Mobile Service Provider

OpenAIRE

Ndyamukama, Edna

2014-01-01

This bachelor’s thesis was researched and written under the consent and authority of Tanzania Telecommunication Company Limited (TTCL), with the purpose to find out ways of improving sales and profits of its mobile service department. The mobile service department of TTCL is performing poorly as compared to its competitors despite being managed by a strategically positioned and experienced company in tele-communication services. It was also meant to find out the positive contribution of compe...

High Efficiency S-Band 20 Watt Amplifier

Data.gov (United States)

National Aeronautics and Space Administration — This project includes the design and build of a prototype 20 W, high efficiency, S-Band amplifier.   The design will incorporate the latest semiconductor technology,...

Doped Sc2C(OH)2 MXene: new type s-pd band inversion topological insulator.

Science.gov (United States)

Balcı, Erdem; Akkuş, Ünal Özden; Berber, Savas

2018-04-18

The electronic structures of Si and Ge substitutionally doped Sc 2 C(OH) 2 MXene monolayers are investigated in density functional theory. The doped systems exhibit band inversion, and are found to be topological invariants in Z 2 theory. The inclusion of spin orbit coupling results in band gap openings. Our results point out that the Si and Ge doped Sc 2 C(OH) 2 MXene monolayers are topological insulators. The band inversion is observed to have a new mechanism that involves s and pd states.

Doped Sc2C(OH)2 MXene: new type s-pd band inversion topological insulator

Science.gov (United States)

Balcı, Erdem; Özden Akkuş, Ünal; Berber, Savas

2018-04-01

The electronic structures of Si and Ge substitutionally doped Sc2C(OH)2 MXene monolayers are investigated in density functional theory. The doped systems exhibit band inversion, and are found to be topological invariants in Z 2 theory. The inclusion of spin orbit coupling results in band gap openings. Our results point out that the Si and Ge doped Sc2C(OH)2 MXene monolayers are topological insulators. The band inversion is observed to have a new mechanism that involves s and pd states.

47 CFR 90.267 - Assignment and use of frequencies in the 450-470 MHz band for low power use.

Science.gov (United States)

2010-10-01

...-470 MHz band for low power use. 90.267 Section 90.267 Telecommunication FEDERAL COMMUNICATIONS... Special Frequencies or Frequency Bands § 90.267 Assignment and use of frequencies in the 450-470 MHz band... medical radio telemetry device with an output power not to exceed 20 milliwatts without specific...

Radiation-hardened optical amplifier based on multicore fiber for telecommunication satellites

Science.gov (United States)

Filipowicz, M.; Napierała, M.; Murawski, M.; Ostrowski, L.; Szostkiewicz, L.; Mergo, P.; Kechagias, M.; Farzana, J.; Stampoulidis, L.; Kehayas, E.; Crabb, J.; Nasilowski, T.

2017-10-01

Our research results concerning a space-dedicated C-band optical amplifier for application in telecommunication satellites are presented in this article. The device is based on a 7-core microstructured fiber where independent access to each core is granted by an all fiber fan-in/ fan-out coupler. The amplifier properties are described as well as its performance after irradiation to a maximal dose of 100 kRad. Also the difference between two kinds of fiber material compositions is discussed with regard to radiation resistance.

Band structure and orbital character of monolayer MoS2 with eleven-band tight-binding model

Science.gov (United States)

Shahriari, Majid; Ghalambor Dezfuli, Abdolmohammad; Sabaeian, Mohammad

2018-02-01

In this paper, based on a tight-binding (TB) model, first we present the calculations of eigenvalues as band structure and then present the eigenvectors as probability amplitude for finding electron in atomic orbitals for monolayer MoS2 in the first Brillouin zone. In these calculations we are considering hopping processes between the nearest-neighbor Mo-S, the next nearest-neighbor in-plan Mo-Mo, and the next nearest-neighbor in-plan and out-of-plan S-S atoms in a three-atom based unit cell of two-dimensional rhombic MoS2. The hopping integrals have been solved in terms of Slater-Koster and crystal field parameters. These parameters are calculated by comparing TB model with the density function theory (DFT) in the high-symmetry k-points (i.e. the K- and Γ-points). In our TB model all the 4d Mo orbitals and the 3p S orbitals are considered and detailed analysis of the orbital character of each energy level at the main high-symmetry points of the Brillouin zone is described. In comparison with DFT calculations, our results of TB model show a very good agreement for bands near the Fermi level. However for other bands which are far from the Fermi level, some discrepancies between our TB model and DFT calculations are observed. Upon the accuracy of Slater-Koster and crystal field parameters, on the contrary of DFT, our model provide enough accuracy to calculate all allowed transitions between energy bands that are very crucial for investigating the linear and nonlinear optical properties of monolayer MoS2.

German telecommunications satellite (Deutscher fernmelde satellit) (DFS-1 and -2)

Science.gov (United States)

Hiendlmeier, G.; Schmeller, H.

1991-01-01

The German Telecommunications Satellite (DFS) Program is to provide telecommunications service for high data rate transmission of text and video data to the Federal Republic of Germany within the 11-14 GHz and 20-30 GHz bands. The space segment of this program is composed of three satellites, DFS-1, DFS-2, and DFS-3, which will be located at 23.5 degrees E longitude of the geostationary orbit. The DFS will be launched from the Center Spatial Guyanis in French Giana on an Ariane launch vehicle. The mission follows the typical injection sequence: parking orbit, transfer orbit, and earth orbit. Attitude maneuvers will be performed to orient the spacecraft prior to Apogee Kick Motor (AKM) firing. After AKM firing, drift phase orbital and attitude maneuvers will be performed to place the spacecraft in its final geostationary position. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. Information is presented in tabular form for the following areas: DSN support, compatibility testing, frequency assignments, telemetry, command, and tracking support responsibilities.

Performance of a 150-MW S-band klystron

International Nuclear Information System (INIS)

Sprehn, D.; Phillips, R.M.; Caryotakis, G.

1994-09-01

As part of an international collaboration, the Stanford Linear Accelerator Center (SLAC) klystron group has designed, fabricated, and tested a 60-Hz, 3-μs, 150-MW S-band klystron built for Deutsches Elektronen Synchrotron (DESY). A test diode with a 535-kV, 700-A electron beam was constructed to verify the gun operation. The first klystron was built and successfully met design specifications. The 375-MW electron beam represents a new record for SLAC accelerator klystrons in terms of voltage, current, energy, and ruggedness of design. The rf output power is a 150% increase over the S-band tubes currently used in the two-mile-long linear accelerator at SLAC. This paper discusses design issues and experimental results of the diode and klystron

SPECTRUM AGGREGATION WITH OPTIMAL MULTI-BAND SCHEDULING

DEFF Research Database (Denmark)

Mihovska, Albena D.

2010-01-01

This paper seeks to explore the integration of spectrum and network resource management functionalities to the benefit of achieving higher performance and capacity gains in an International Mobile Telecommunications-Advanced (IMT-A) scenario. In particular, we investigate the allocation of users...... over two frequency bands (i.e., 2 GHz and 5 GHz) for a single operator scenario. The same type of Radio Access Technology (RAT) is considered for both frequency bands. It is assumed that the operator has gained access to a non-shared 2 GHz band and to part (or all) of the frequency pool band at 5 GHz....... The performance gain is analyzed in terms of higher data throughput. The performance is heavily dependent on the channel quality for each user in the considered bands which, in turn, is a function of the path loss and the distance from the Base Station (BS). The operator will have relevant improvements when...

The effect of introducing increased-reliability-risk electronic components into 3rd generation telecommunications systems

International Nuclear Information System (INIS)

Salmela, Olli

2005-01-01

In this paper, the dependability of 3rd generation telecommunications network systems is studied. Special attention is paid to a case where increased-reliability-risk electronic components are introduced to the system. The paper consists of three parts: First, the reliability data of four electronic components is considered. This includes statistical analysis of the reliability test data, thermo-mechanical finite element analysis of the printed wiring board structures, and based on those, a field reliability estimate of the components is constructed. Second, the component level reliability data is introduced into the network element reliability analysis. This is accomplished by using a reliability block diagram technique and Monte Carlo simulation of the network element. The end result of the second part is a reliability estimate of the network element with and without the high-risk component. Third, the whole 3rd generation network having multiple network elements is analyzed. In this part, the criticality of introducing high-risk electronic components into a 3rd generation telecommunications network is considered

The effect of introducing increased-reliability-risk electronic components into 3rd generation telecommunications systems

Energy Technology Data Exchange (ETDEWEB)

Salmela, Olli [Nokia Networks, P.O. Box 301, 00045 Nokia Group (Finland)]. E-mail: olli.salmela@nokia.com

2005-08-01

In this paper, the dependability of 3rd generation telecommunications network systems is studied. Special attention is paid to a case where increased-reliability-risk electronic components are introduced to the system. The paper consists of three parts: First, the reliability data of four electronic components is considered. This includes statistical analysis of the reliability test data, thermo-mechanical finite element analysis of the printed wiring board structures, and based on those, a field reliability estimate of the components is constructed. Second, the component level reliability data is introduced into the network element reliability analysis. This is accomplished by using a reliability block diagram technique and Monte Carlo simulation of the network element. The end result of the second part is a reliability estimate of the network element with and without the high-risk component. Third, the whole 3rd generation network having multiple network elements is analyzed. In this part, the criticality of introducing high-risk electronic components into a 3rd generation telecommunications network is considered.

Development of an S-band cavity Beam Position Monitor for ATF2

Science.gov (United States)

Heo, A.; Kim, E.-S.; Kim, H.; Son, D.; Honda, Y.; Tauchi, T.

2013-04-01

We have developed an S-band cavity Beam Position Monitor (BPM) in order to measure the position of an electron beam in the final focus area at ATF2, which is the test facility for the final focus design for the International Linear Collider (ILC). The lattice of the ILC Beam Delivery System (BDS) has been modified, requiring a larger physical aperture of 40 mm in the final focus area. The beam orbit measurement in this area is now covered with high resolution S-Band cavity BPMs. In this paper we summarize the design of the cavity BPM and the first experimental results. The calibration slopes were measured as 0.87 counts/μm in the x-coordinate direction and 1.16 counts/μm in the y-coordinate direction.

Bio-inspired computation in telecommunications

CERN Document Server

Yang, Xin-She; Ting, TO

2015-01-01

Bio-inspired computation, especially those based on swarm intelligence, has become increasingly popular in the last decade. Bio-Inspired Computation in Telecommunications reviews the latest developments in bio-inspired computation from both theory and application as they relate to telecommunications and image processing, providing a complete resource that analyzes and discusses the latest and future trends in research directions. Written by recognized experts, this is a must-have guide for researchers, telecommunication engineers, computer scientists and PhD students.

A PDA-based flexible telecommunication system for telemedicine applications.

Science.gov (United States)

Nazeran, Homer; Setty, Sunil; Haltiwanger, Emily; Gonzalez, Virgilio

2004-01-01

Technology has been used to deliver health care at a distance for many years. Telemedicine is a rapidly growing area and recently there are studies devoted to prehospital care of patients in emergency cases. In this work we have developed a compact, reliable, and low cost PDA-based telecommunication device for telemedicine applications to transmit audio, still images, and vital signs from a remote site to a fixed station such as a clinic or a hospital in real time. This was achieved based on a client-server architecture. A Pocket PC, a miniature camera, and a hands-free microphone were used at the client site and a desktop computer running the Windows XP operating system was used as a server. The server was located at a fixed station. The system was implemented on TCP/IP and HTTP protocol. Field tests have shown that the system can reliably transmit still images, audio, and sample vital signs from a simulated remote site to a fixed station either via a wired or wireless network in real time. The Pocket PC was used at the client site because of its compact size, low cost and processing capabilities.

Performance analysis for a chaos-based code-division multiple access system in wide-band channel

Directory of Open Access Journals (Sweden)

Ciprian Doru Giurcăneanu

2015-08-01

Full Text Available Code-division multiple access technology is widely used in telecommunications and its performance has been extensively investigated in the past. Theoretical results for the case of wide-band transmission channel were not available until recently. The novel formulae which have been published in 2014 can have an important impact on the future of wireless multiuser communications, but limitations come from the Gaussian approximations used in their derivation. In this Letter, the authors obtain more accurate expressions of the bit error rate (BER for the case when the model of the wide-band channel is two-ray, with Rayleigh fading. In the authors’ approach, the spreading sequences are assumed to be generated by logistic map given by Chebyshev polynomial function of order two. Their theoretical and experimental results show clearly that the previous results on BER, which rely on the crude Gaussian approximation, are over-pessimistic.

Modulators for the S-band test linac at DESY

Science.gov (United States)

Bieler, M.; Choroba, S.; Hameister, J.; Lewin, H.-Ch.

1995-07-01

The development of adequate modulators for high peak power klystrons is one of the focus points for linear collider R&D programs. For the DESY/THD S-band linear collider study 150 MW rf-pulse power at 50 Hz repetition rate and 3 μs pulse duration is required [1]. Two different modulator schemes are under investigation. One is the conventional line type pulser, using a pulse forming network and a step up transformer, the other one is a hard tube pulser, using a dc power source at the full klystron voltage and a switch tube. This paper is focused on the modulator development for the S-band Test Linac at DESY. After a short overview over the test linac and a brief description of the 150 MW S-band klystron the circuitry of the line type pulse (LTP) is given. A hard tube pulser (HTP), which switches the high voltage directly from a storage capacitor to the klystron, has been built up at DESY. Circuitry and the results of the commissioning of the switch tube are reported.

Space Telecommunications Radio System (STRS) Application Repository Design and Analysis

Science.gov (United States)

Handler, Louis M.

2013-01-01

The Space Telecommunications Radio System (STRS) Application Repository Design and Analysis document describes the STRS application repository for software-defined radio (SDR) applications intended to be compliant to the STRS Architecture Standard. The document provides information about the submission of artifacts to the STRS application repository, to provide information to the potential users of that information, and for the systems engineer to understand the requirements, concepts, and approach to the STRS application repository. The STRS application repository is intended to capture knowledge, documents, and other artifacts for each waveform application or other application outside of its project so that when the project ends, the knowledge is retained. The document describes the transmission of technology from mission to mission capturing lessons learned that are used for continuous improvement across projects and supporting NASA Procedural Requirements (NPRs) for performing software engineering projects and NASAs release process.

AN INSTITUTIONAL AND NETWORK PERSPECTIVE OF ORGANISATIONAL LEGITIMACY: EMPIRICAL EVIDENCE FROM CHINA′S TELECOMMUNICATIONS MARKET

Directory of Open Access Journals (Sweden)

Brian Low

2010-07-01

Full Text Available This perspective paper combines institutional and industrial network theory to develop a framework for analysing organisational legitimacy. The main subject, Nokia China, is found to be sensitive to network-legitimating initiatives, with consequences that accommodate multiple, conflicting stakeholders′ interests in China′s politically sensitive and protective telecommunications market. This paper offers new insights into institutional isomorphism that is manifested empirically as incremental conformity to regulative processes, institutional norms and cognitive knowledge and meanings within the environment, thereby extending commonly held views of institutional theory to include organisational legitimacy in industrial networks.

Guidelines for safety related telecommunications systems on normally unattended fixed offshore installations

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-01

Guidance is given on the design of telecommunications systems required for safety purposes on normally unattended offshore installations associated with oil and gas production on the United Kingdom continental shelf. The guidelines are mainly concerned with ensuring that: while the installation is unattended, its operation can be remotely monitored and controlled effectively to prevent the escalation of any abnormal situation; the installation can be safely approached when it is necessary to transfer personnel on board; persons on board, for example for inspection or maintenance activities, are safe. (UK)

47 CFR 25.257 - Special requirements for operations in the band 29.1-29.25 GHz between NGSO MSS and LMDS.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Special requirements for operations in the band 29.1-29.25 GHz between NGSO MSS and LMDS. 25.257 Section 25.257 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25...

Developing a Telecommunications Curriculum for Students with Physical Disabilities.

Science.gov (United States)

Gandell, Terry S.; Laufer, Dorothy

1993-01-01

A telecommunications curriculum was developed for students (ages 15-21) with physical disabilities. Curriculum content included an internal mailbox program (Mailbox), interactive communication system (Blisscom), bulletin board system (Arctel), and a mainframe system (Compuserv). (JDD)

Regulation of Telecommunications: The Choice Between Market and Regulatory Failures

Directory of Open Access Journals (Sweden)

Dmitrii Trubnikov

2017-04-01

Full Text Available Purpose – The paper examines the main regulatory frameworks of the telecommunications industry through the concept of market failure and analyses how and why the policy often leads to undesirable outcomes that might be considered as regulatory failure. Methodology/approach/design – The research uses the EU regulatory framework for electronic communications as a base for the analysis of the main policy objectives through the prism of the market failure theory with an eye to the interests of the main market players in the telecommunications markets. Findings – About any aspect of regulation allows to find ways to create opportunities for some groups of the industry and stifle activity of others. Despite the theory of market failure provides reasonable justifications for regulation of telecommunications markets, it is possible to argue that many of these problems are mainly the consequence of the policy and could be better solved by market mechanisms. Originality/value – The results of the research allow to look at the problems of telecommunications development and issues of the high level of concentration of the telecommunications markets as regulatory formed problems rather than consequences of the inherited industry’s characteristics.

47 CFR 90.259 - Assignment and use of frequencies in the bands 216-220 MHz and 1427-1432 MHz.

Science.gov (United States)

2010-10-01

... MHz band are secondary to the Wireless Medical Telemetry Service except in the locations specified in... operations are secondary to the Wireless Medical Telemetry Service in the 1429-1431.5 MHz band. (3) All... 47 Telecommunication 5 2010-10-01 2010-10-01 false Assignment and use of frequencies in the bands...

Broadband S-band class E HPA

NARCIS (Netherlands)

Wanum, M.; van Dijk, R.; de Hek, A.P.; van Vliet, Frank Edward

2009-01-01

A broadband class E High Power Amplifier (HPA) is presented. This HPA is designed to operate at S-band (2.75 to 3.75 GHz). A power added efficiency of 50% is obtained for the two stage amplifier with an output power of 35.5 dBm on a chip area of 5.25 times 2.8 mm2.

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation in the bands 174-216 MHz and 470-668... bands 174-216 MHz and 470-668 MHz. (a) The marketing and operation of intentional radiators under the... services, facilities, and beds for use beyond 24 hours in rendering medical treatment and institutions and...

Cd-free buffer layer materials on Cu2ZnSn(SxSe1-x)4: Band alignments with ZnO, ZnS, and In2S3

Science.gov (United States)

Barkhouse, D. Aaron R.; Haight, Richard; Sakai, Noriyuki; Hiroi, Homare; Sugimoto, Hiroki; Mitzi, David B.

2012-05-01

The heterojunctions formed between Cu2ZnSn(SxSe1-x)4 (CZTSSe) and three Cd-free n-type buffers, ZnS, ZnO, and In2S3, were studied using femtosecond ultraviolet photoemission and photovoltage spectroscopy. The electronic properties including the Fermi level location at the interface, band bending in the CZTSSe substrate, and valence and conduction band offsets were determined and correlated with device properties. We also describe a method for determining the band bending in the buffer layer and demonstrate this for the In2S3/CZTSSe system. The chemical bath deposited In2S3 buffer is found to have near optimal conduction band offset (0.15 eV), enabling the demonstration of Cd-free In2S3/CZTSSe solar cells with 7.6% power conversion efficiency.

Potential health risks due to telecommunications radiofrequency ...

African Journals Online (AJOL)

Background: The global system mobile telecommunications system (GSM) which was recently introduced in Nigeria is now being used by over 40 million people in Nigeria. The use of GSM is accompanied with exposure of the users to radiofrequency radiation (RFR), which if significant, may produce health hazards. This is ...

Electron correlations in narrow band systems

International Nuclear Information System (INIS)

Kishore, R.

1983-01-01

The effect of the electron correlations in narrow bands, such as d(f) bands in the transition (rare earth) metals and their compounds and the impurity bands in doped semiconductors is studied. The narrow band systems is described, by the Hubbard Hamiltonian. By proposing a local self-energy for the interacting electron, it is found that the results are exact in both atomic and band limits and reduce to the Hartree Fock results for U/Δ → 0, where U is the intra-atomic Coulomb interaction and Δ is the bandwidth of the noninteracting electrons. For the Lorentzian form of the density of states of the noninteracting electrons, this approximation turns out to be equivalent to the third Hubbard approximation. A simple argument, based on the mean free path obtained from the imaginary part of the self energy, shows how the electron correlations can give rise to a discontinous metal-nonmetal transition as proposed by Mott. The band narrowing and the existence of the satellite below the Fermi energy in Ni, found in photoemission experiments, can also be understood. (Author) [pt

Equivalent unit in telecommunications services

Directory of Open Access Journals (Sweden)

Luiza Santangelo Reis

2016-03-01

Full Text Available The aim of this study is to analyze the relationship between the “cost” and “production” variables in a telecommunications company, measuring the latter in the unit of measure termed Network Units (NU.  The study shows a Pearson correlation coefficient of 0.55 -evaluated as moderate - over the course of a 24-month period and resulting from 177 trials.  Subsequently, only the work teams composed of the company´s standard structure were taken into consideration, which yielded 32 observations of interest and a derived correlation coefficient of 0.8.  Finally, the data pertaining to each individual work team over a determined length of time was analyzed, showing strong correlation coefficients in seven of the eleven, and in the remainder, a moderate linear relationship between the variables analyzed.  These results suggest the viability of applying the NU production measurement model in the telecommunications company in question

Testing Time and Frequency Fiber-Optic Link Transfer by Hardware Emulation of Acoustic-Band Optical Noise

Directory of Open Access Journals (Sweden)

Lipiński Marcin

2016-06-01

Full Text Available The low-frequency optical-signal phase noise induced by mechanical vibration of the base occurs in field-deployed fibers. Typical telecommunication data transfer is insensitive to this type of noise but the phenomenon may influence links dedicated to precise Time and Frequency (T&F fiber-optic transfer that exploit the idea of stabilization of phase or propagation delay of the link. To measure effectiveness of suppression of acoustic noise in such a link, a dedicated measurement setup is necessary. The setup should enable to introduce a low-frequency phase corruption to the optical signal in a controllable way. In the paper, a concept of a setup in which the mechanically induced acoustic-band optical signal phase corruption is described and its own features and measured parameters are presented. Next, the experimental measurement results of the T&F transfer TFTS-2 system’s immunity as a function of the fibre-optic length vs. the acoustic-band noise are presented. Then, the dependency of the system immunity on the location of a noise source along the link is also pointed out.

A microwave window for K band electromagnetic systems

DEFF Research Database (Denmark)

Rybalko, Oleksandr

2017-01-01

This article proposes a solution for microwave window at K band. Properties of the window such as performance (transparency) at microwave frequencies, dimensions, and mounting place are discussed. The dimensions of the window were optimized in a full-wave simulator. To verify the design...... and simulation results the prototype of the window is realized by implementing into transition section and tested experimentally. The microwave window provides low return loss |S11| below −30 dB, low insertion loss |S21| below −0.5 dB and can be used for electromagnetic systems where vacuum sealing is required...

Studies of an application of a mobile communication system to the private telecommunication network. Part 1. Present condition of mobile communication system and proposal of the customer information network by PHS; Idotai tsushin system no denryoku tsushinmo eno tekiyo. 1. Idotai tsushin system no genjo to PHS ni yoru juyo kakei network no teian

Energy Technology Data Exchange (ETDEWEB)

Iwasaki, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

1996-03-01

An application of various mobile communication systems to the electric power telecommunication network has been investigated. Among these, the customer information network by PHS (personal handy-phone system) has been proposed. Although great numbers of base stations are required for PHS, it can be applied as the customer information network by connecting to the power controller developed by the Central Research Institute of Electric Power Industry. The geostationary satellite telecommunication has been positively utilized by the electric power industry since the Hanshin-Awaji Great Earthquake. It can be used as the customer information network in the future. Since the radio access is a one-way communication, it cannot be applied to the electric power telecommunication network at present. It can be applied to the simple message communication or relatively low-speed data communication through the two-way communication. Public ground mobile telecommunication in the future includes various mobile telecommunication systems. To start the operation in 2000, the ITU (International Telecommunication Union) is making specifications common in the world. It is required to investigate the utilization as multipurpose systems. The network for PHS can be applied to the telecommunication network without optical cable. 20 refs., 5 figs., 3 tabs.

Telecommunications Is Here and Now.

Science.gov (United States)

Clark, Chris

1988-01-01

Presents an overview of telecommunications and its use in the field of education. Topics discussed include conferencing, electronic messaging, distance learning, networking, database searching, and projects relating to educational telecommunications sponsored by the International Council for Computers in Education (ICCE). (LRW)

Impact of distributed energy resources on the reliability of a critical telecommunications facility.

Energy Technology Data Exchange (ETDEWEB)

Robinson, David; Zuffranieri, Jason V.; Atcitty, Christopher B.; Arent, Douglas (National Renewable Energy Laboratory, Golden, CO)

2006-03-01

This report documents a probabilistic risk assessment of an existing power supply system at a large telecommunications office. The focus is on characterizing the increase in the reliability of power supply through the use of two alternative power configurations. Telecommunications has been identified by the Department of Homeland Security as a critical infrastructure to the United States. Failures in the power systems supporting major telecommunications service nodes are a main contributor to major telecommunications outages. A logical approach to improve the robustness of telecommunication facilities would be to increase the depth and breadth of technologies available to restore power in the face of power outages. Distributed energy resources such as fuel cells and gas turbines could provide one more onsite electric power source to provide backup power, if batteries and diesel generators fail. The analysis is based on a hierarchical Bayesian approach and focuses on the failure probability associated with each of three possible facility configurations, along with assessment of the uncertainty or confidence level in the probability of failure. A risk-based characterization of final best configuration is presented.

Reliability of telecommunications systems following a major disaster: survey of secondary and tertiary emergency institutions in Miyagi Prefecture during the acute phase of the 2011 Great East Japan Earthquake.

Science.gov (United States)

Kudo, Daisuke; Furukawa, Hajime; Nakagawa, Atsuhiro; Abe, Yoshiko; Washio, Toshikatsu; Arafune, Tatsuhiko; Sato, Dai; Yamanouchi, Satoshi; Ochi, Sae; Tominaga, Teiji; Kushimoto, Shigeki

2014-04-01

Telecommunication systems are important for sharing information among health institutions to successfully provide medical response following disasters. The aim of this study was to clarify the problems associated with telecommunication systems in the acute phase of the Great East Japan Earthquake (March 11, 2011). All 72 of the secondary and tertiary emergency hospitals in Miyagi Prefecture were surveyed to evaluate the telecommunication systems in use during the 2011 Great Japan Earthquake, including satellite mobile phones, multi-channel access (MCA) wireless systems, mobile phones, Personal Handy-phone Systems (PHS), fixed-line phones, and the Internet. Hospitals were asked whether the telecommunication systems functioned correctly during the first four days after the earthquake, and, if not, to identify the cause of the malfunction. Each telecommunication system was considered to function correctly if the hospital staff could communicate at least once in every three calls. Valid responses were received from 53 hospitals (73.6%). Satellite mobile phones functioned correctly at the highest proportion of the equipped hospitals, 71.4%, even on Day 0. The MCA wireless system functioned correctly at the second highest proportion of the equipped hospitals. The systems functioned correctly at 72.0% on Day 0 and at 64.0% during Day 1 through Day 3. The main cause of malfunction of the MCA wireless systems was damage to the base station or communication lines (66.7%). Ordinary (personal or general communication systems) mobile phones did not function correctly at any hospital until Day 2, and PHS, fixed-line phones, and the Internet did not function correctly at any area hospitals that were severely damaged by the tsunami. Even in mildly damaged areas, these systems functioned correctly at telecommunications systems do not function.

International Telecommunications Satellite Organization (INTELSAT) Agreement Between the United States of American and Other Governments and Operating Agreement.

Science.gov (United States)

Department of State, Washington, DC.

The INTELSAT (International Telecommunications Satellite) agreement was reached because of the desirability of continuing the development of a telecommunications satellite system. INTELSAT's aim was to achieve a single global commercial system as part of an improved global telecommunications network which will provide expanded services to all…

Telecommunications Reform in Nigeria: The Marketing Challenges ...

African Journals Online (AJOL)

Telecommunications Reform in Nigeria: The Marketing Challenges. ... Journal of Research in National Development ... This paper discusses the telecommunications reforms process, the role of the regulatory body (Nigeria Commission, the current state of the telecommunication sector and the marketing challenges in ...

Forecast for the Future: Telecommunications.

Science.gov (United States)

Sekaquaptewa, Sam; Yawakie, Madonna; Scheer, Roger; Yawakie, Mel

1999-01-01

Four telecommunications experts comment on changes in the industry and how these changes may result in career opportunities for American Indians. American Indian reservations have limited access to telecommunications and information technology and would benefit from the advocacy of Native professionals. (CDS)

A comparison of L-band and C-band rf guns as sources for inline-injection systems

International Nuclear Information System (INIS)

Gallardo, J.C.; Kirk, H.G.; Meyerer, T.

1994-12-01

We consider the beam dynamics associated with installing a BNL type 1 1/2 cell L-band or C-band rf gun before two TESLA L-band cryomodules. This system will deliver a 25 MeV electron beam with peak currents on the order of 100 A suitable for further magnetic compression. evaluate the injection systems utilizing the electron beam dynamic code PARMELA from the point of view of minimizing the transverse invariant emittance

The Danish Regulatory Reform of Telecommunications

DEFF Research Database (Denmark)

Skouby, Knud Erik

1998-01-01

An overview of the liberalisation process and regulatory reform of telecommunications in Denmark......An overview of the liberalisation process and regulatory reform of telecommunications in Denmark...

Kids Interactive Telecommunications Project by Satellite (KITES): A Telecommunications Partnership To Empower Middle School Students.

Science.gov (United States)

LeBaron, John

Kids Interactive Telecommunications Project by Satellite (KITES) is a cooperative international telecommunications partnership involving the University of Lowell, Digital's corporate video network, Videostar Connections Inc. (a satellite networking broker), PanAmSat (a satellite operator), and several other public education institutions in…

47 CFR 74.690 - Transition of the 1990-2025 MHz band from the Broadcast Auxiliary Service to emerging technologies.

Science.gov (United States)

2010-10-01

... Broadcast Auxiliary Service to emerging technologies. 74.690 Section 74.690 Telecommunication FEDERAL... of the 1990-2025 MHz band from the Broadcast Auxiliary Service to emerging technologies. (a) New... licensed emerging technology services will maintain primary status in the band until the Existing Licensee...

Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

Energy Technology Data Exchange (ETDEWEB)

Kim, Won Tae [Kongju National Univ., Kongju (Korea, Republic of); Song, Kyu Sub [Electronics and Telecommunications Research Institute, Taejon (Korea, Republic of); Lee, Young [Univ. of Ottawa, Ontario (Canada)

1998-10-01

A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm{sup 2}. The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm{sup 2} with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion.

Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

International Nuclear Information System (INIS)

Kim, Won Tae; Song, Kyu Sub; Lee, Young

1998-01-01

A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm 2 . The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm 2 with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion

The evolution of investments decision mode in China's telecommunication

Institute of Scientific and Technical Information of China (English)

ZHANG Ai-hua; ZHAO Lian-qiang; SHU Hua-ying

2007-01-01

This essay analyzes the data of Chinese telecommunication market, telecommunication investments and investment benefits over the past 20 years. On the basis of these data, the essay reviews Chinese changing telecommunication policies and discusses the major events in the course of China's telecommunication development. It is argued that telecommunication policies, regime backgrounds and market demand characteristics have a significant impact on investment decision mode in telecommunication industry. The evolution of network investments decision mode in China's telecommunication has corresponded to the transformation of these key factors. Considering the special events in the development of Chinese telecommunication as divisions, the essay discusses three stages of the evolution of investments decision mode in China's telecommunication. With the firm environment and problems that Chinese telecommunication operators have been facing since 2000 analyzed. it is demonstrated that Chinese telecommunication operators should change their mode of investment decision into the "profit-oriented investment decision mode" in order to achieve a high growth performance in the capital market,. This investment decision mode will result in increase of the investment profit with limited investment capital. The main procedure of profit-oriented investment decision mode is set out, which is abstracted to a mathematical model eventually.

A regulations’ survey for the wireless telecommunications deployment in Colombia

Directory of Open Access Journals (Sweden)

José Gustavo Morales-Guarín

2016-01-01

Full Text Available This paper describes the current wireless telecommunications infrastructure deployment regulations in Colombia. It also refers to the possible effects that this infrastructure could cause to the country`s health and environment. similarly, the results obtained show a comparison between the Argentina’s current regulations, one of the most relevant researches carried out and the Colombian case. finally, some recommendations are proposed that can be considered in the project of regulations applicable in Colombia for the ensuring purpose that the non-ionizing radiation generated by wireless communications systems do not have effects on health and the environment.

7 CFR 1703.112 - Expedited telecommunications loans

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Expedited telecommunications loans 1703.112 Section... § 1703.112 Expedited telecommunications loans RUS will expedite consideration and determination of an application submitted by an RUS telecommunications borrower for a loan under the Act or an advance of such...

How streamlining telecommunications can cut IT expense.

Science.gov (United States)

McIntyre, Greg

2016-02-01

Hospitals and health systems can save IT expenses by implementing more efficient processes in accordance with the principles of effective telecommunications expense management. This approach involves three primary steps: Inventory of existing infrastructure. Charge verification. Optimization of rates and design for continual improvement.

Determination of band offsets at GaN/single-layer MoS2 heterojunction

KAUST Repository

Tangi, Malleswararao

2016-07-25

We report the band alignment parameters of the GaN/single-layer (SL) MoS2 heterostructure where the GaN thin layer is grown by molecular beam epitaxy on CVD deposited SL-MoS2/c-sapphire. We confirm that the MoS2 is an SL by measuring the separation and position of room temperature micro-Raman E1 2g and A1 g modes, absorbance, and micro-photoluminescence bandgap studies. This is in good agreement with HRTEM cross-sectional analysis. The determination of band offset parameters at the GaN/SL-MoS2 heterojunction is carried out by high-resolution X-ray photoelectron spectroscopy accompanying with electronic bandgap values of SL-MoS2 and GaN. The valence band and conduction band offset values are, respectively, measured to be 1.86 ± 0.08 and 0.56 ± 0.1 eV with type II band alignment. The determination of these unprecedented band offset parameters opens up a way to integrate 3D group III nitride materials with 2D transition metal dichalcogenide layers for designing and modeling of their heterojunction based electronic and photonic devices.

Determination of band offsets at GaN/single-layer MoS2 heterojunction

KAUST Repository

Tangi, Malleswararao; Mishra, Pawan; Ng, Tien Khee; Hedhili, Mohamed N.; Janjua, Bilal; Alias, Mohd Sharizal; Anjum, Dalaver H.; Tseng, Chien-Chih; Shi, Yumeng; Joyce, Hannah J.; Li, Lain-Jong; Ooi, Boon S.

2016-01-01

We report the band alignment parameters of the GaN/single-layer (SL) MoS2 heterostructure where the GaN thin layer is grown by molecular beam epitaxy on CVD deposited SL-MoS2/c-sapphire. We confirm that the MoS2 is an SL by measuring the separation and position of room temperature micro-Raman E1 2g and A1 g modes, absorbance, and micro-photoluminescence bandgap studies. This is in good agreement with HRTEM cross-sectional analysis. The determination of band offset parameters at the GaN/SL-MoS2 heterojunction is carried out by high-resolution X-ray photoelectron spectroscopy accompanying with electronic bandgap values of SL-MoS2 and GaN. The valence band and conduction band offset values are, respectively, measured to be 1.86 ± 0.08 and 0.56 ± 0.1 eV with type II band alignment. The determination of these unprecedented band offset parameters opens up a way to integrate 3D group III nitride materials with 2D transition metal dichalcogenide layers for designing and modeling of their heterojunction based electronic and photonic devices.

Space Telecommunications Radio System (STRS) Compliance Testing

Science.gov (United States)

Handler, Louis M.

2011-01-01

The Space Telecommunications Radio System (STRS) defines an open architecture for software defined radios. This document describes the testing methodology to aid in determining the degree of compliance to the STRS architecture. Non-compliances are reported to the software and hardware developers as well as the NASA project manager so that any non-compliances may be fixed or waivers issued. Since the software developers may be divided into those that provide the operating environment including the operating system and STRS infrastructure (OE) and those that supply the waveform applications, the tests are divided accordingly. The static tests are also divided by the availability of an automated tool that determines whether the source code and configuration files contain the appropriate items. Thus, there are six separate step-by-step test procedures described as well as the corresponding requirements that they test. The six types of STRS compliance tests are: STRS application automated testing, STRS infrastructure automated testing, STRS infrastructure testing by compiling WFCCN with the infrastructure, STRS configuration file testing, STRS application manual code testing, and STRS infrastructure manual code testing. Examples of the input and output of the scripts are shown in the appendices as well as more specific information about what to configure and test in WFCCN for non-compliance. In addition, each STRS requirement is listed and the type of testing briefly described. Attached is also a set of guidelines on what to look for in addition to the requirements to aid in the document review process.

Telecommunication for the Physically Handicapped.

Science.gov (United States)

Cunningham, Pat; Gose, Joan

The paper examines the uses of telecommunication for physically handicapped students. Basic equipment, including a modem and keyboard interface, are described. The types and uses of computer bulletin boards are also described. Among benefits of telecommunications for physically handicapped students noted in the paper are social prestige,…

47 CFR 25.258 - Sharing between NGSO MSS Feeder links Stations and GSO FSS services in the 29.25-29.5 GHz Bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Sharing between NGSO MSS Feeder links Stations and GSO FSS services in the 29.25-29.5 GHz Bands. 25.258 Section 25.258 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25...

A comparative cepstral based analysis of simulated and measured S-band and X-band radar Doppler spectra of human motion

CSIR Research Space (South Africa)

Van Eeden, WD

2015-10-01

Full Text Available targets. It is also shown that, whereas the motion of most body parts of a human target can be observed in the X-band data, only the main torso sway can be observed at S-band. This implies that X-band data is well suited to cepstrum based human motion...

Telecommunications and Technology Infrastructure Program, 2013

Science.gov (United States)

California Community Colleges, Chancellor's Office, 2014

2014-01-01

This 16th annual report highlights up-to-date information on the programs supported through the Chancellor's Office Telecommunications and Technology Infrastructure Program (TTIP). To summarize 2012-13, one would describe it as a year of planning and preparation. The system-wide budget cuts of the past few years, reports of impacted classes, staff…

Fiber optic sensing for telecommunication satellites

Science.gov (United States)

Reutlinger, Arnd; Glier, Markus; Zuknik, Karl-Heinz; Hoffmann, Lars; Müller, Mathias; Rapp, Stephan; Kurvin, Charles; Ernst, Thomas; McKenzie, Iain; Karafolas, Nikos

2017-11-01

Modern telecommunication satellites can benefit from the features of fiber optic sensing wrt to mass savings, improved performance and lower costs. Within the course of a technology study, launched by the European Space Agency, a fiber optic sensing system has been designed and is to be tested on representative mockups of satellite sectors and environment.

Planning Alternative Organizational Frameworks For a Large Scale Educational Telecommunications System Served by Fixed/Broadcast Satellites. Memorandum Number 73/3.

Science.gov (United States)

Walkmeyer, John

Considerations relating to the design of organizational structures for development and control of large scale educational telecommunications systems using satellites are explored. The first part of the document deals with four issues of system-wide concern. The first is user accessibility to the system, including proximity to entry points, ability…

Effect of wind speed and solar irradiation on the optimization of a PV-Wind-Battery system to supply a telecommunications station

Energy Technology Data Exchange (ETDEWEB)

Dufo-Lopez, Rodolfo; Bernal-Agustin, Jose L.; Lujano, Juan; Zubi, Ghassan [Zaragoza Univ. (Spain). Electrical Engineerign Dept.

2010-07-01

This paper shows the optimization of a PV-Wind hybrid system with batteries storage to supply the electrical power to a small telecommunications station. The load demanded by the station is 100 W continuously. We have considered 6 different wind speed profiles, from 2 m/s average speed (low wind speed in many places in Spain) to 8 m/s average (very high wind speed, in few places in Spain) and 3 different irradiation profiles, from the lowest average daily irradiation in Spain, about 2.5 kWh/m{sup 2}/day, to the highest one in Spain, about 5 kWh/m{sup 2}/day. Therefore we have considered 6 x 3 = 18 combinations of wind speed and irradiation profiles. For each combination of wind speed and irradiation profiles, we have optimized the PV-Wind-Battery system to supply the power demand, considering some different PV panels, wind turbines and batteries. We have also considered in the optimization non-hybrid systems (PV-Battery systems and Wind-Battery systems). The simulation of the system performance has been done hourly. The optimal system for each combination of wind speed and irradiation is the one which can supply the whole demand of the telecommunications station with the lowest Net Present Cost of the system. Simulation and optimization has been done using HOGA (Hybrid Optimization by Genetic Algorithms) software, developed by some of the authors. The results show that, with actual prices of PV panels and wind turbines, in 13 of the 18 combinations of wind speed and irradiation profiles the optimal system is a hybrid system (it includes PV panels, wind turbine and batteries). In the other 5 combinations (the ones with lowest wind speed and/or highest irradiation), the optimal system is PV-Battery, i.e., without wind turbine. We conclude that, in most of the places in Spain, the optimal system to supply the demand of a communications station (with continous demand profile) is a hybrid system (PV-Wind-Batteries) instead of a PV-Batteries system or a Wind

80 Gbit/s 16-QAM Multicarrier THz Wireless Communication Link in the 400 GHz Band

DEFF Research Database (Denmark)

Jia, Shi; Yu, Xianbin; Hu, Hao

2016-01-01

We experimentally demonstrate a high-speed multicarrier THz wireless communication system operating in the 400 GHz band. The use of spectrally efficient 16-QAM modulation and broadband THz transceivers enable link data rates up to 80 Gbit/s....

A 30 Gb/s full-duplex bi-directional transmission optical wireless-over fiber integration system at W-band.

Science.gov (United States)

Tang, Chanjuan; Yu, Jianjun; Li, Xinying; Chi, Nan; Xiao, Jiangnan; Tian, Yumin; Zhang, Junwen

2014-01-13

We propose and experimentally demonstrate a full-duplex bi-directional transmission optical wireless-over fiber integration system at W-band (75-100 GHz) with the speed up to 15 Gb/s for both 95.4 GHz link and 88.6 GHz link for the first time. The generation of millimeter-wave (mm-wave) wireless signal is based on the photonic technique by heterodyne mixing of an optical quadrature-phase-shift-keying (QPSK) signal with a free-running light at different wavelength. After 20 km fiber transmission, up to 30 Gb/s mm-wave signal is delivered over 2 m wireless link, and then converted to the optical signal for another 20 km fiber transmission. At the wireless receiver, coherent detection and advanced digital signal processing (DSP) are introduced to improve receiver sensitivity and system performance. With the OSNR of 15 dB, the bit error ratios (BERs) for 10 Gb/s signal transmission at 95.4 GHz and 88.6 GHz are below the forward-error-correction (FEC) threshold of 3.8 × 10(-3) whether post filter is used or not, while the BER for 15 Gb/s QPSK signal employing post filter in the link of 95.4 GHz is 2.9 × 10(-3).

Bunch monitor for an S-band electron linear accelerator

International Nuclear Information System (INIS)

Otake, Yuji; Nakahara, Kazuo

1991-01-01

The measurement of bunch characteristics in an S-band electron linear accelerator is required in order to evaluate the quality of accelerated electron beams. A new-type bunch monitor has been developed which combines micro-stripline technology with an air insulator and wall-current monitoring technology. The obtained time resolution of the monitor was more than 150 ps. This result shows that the monitor can handle the bunch number of an S-band linac. The structure of the monitor is suitable for being installed in the vacuum area, since it is constructed of only metal and ceramic parts. It can therefore easily be employed in an actual machine

31 CFR 538.512 - Transactions related to telecommunications authorized.

Science.gov (United States)

2010-07-01

... telecommunications authorized. 538.512 Section 538.512 Money and Finance: Treasury Regulations Relating to Money and... telecommunications authorized. All transactions with respect to the receipt and transmission of telecommunications... a person in Sudan of telecommunications equipment or technology. ...

47 CFR 43.61 - Reports of international telecommunications traffic.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Reports of international telecommunications traffic. 43.61 Section 43.61 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... Reports of international telecommunications traffic. (a) Each common carrier engaged in providing...

Frequency Arrangement For 700 MHz Band

Directory of Open Access Journals (Sweden)

Ancans G.

2015-02-01

Full Text Available The 694-790 MHz (700 MHz band was allocated by the 2012 World Radiocommunication Conference (WRC-12 in ITU Region 1 (Europe included, to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT. At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15. In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.

Impact of Distributed Energy Resources on the Reliability of Critical Telecommunications Facilities: Preprint

Energy Technology Data Exchange (ETDEWEB)

Robinson, D. G.; Arent, D. J.; Johnson, L.

2006-06-01

This paper documents a probabilistic risk assessment of existing and alternative power supply systems at a large telecommunications office. The analysis characterizes the increase in the reliability of power supply through the use of two alternative power configurations. Failures in the power systems supporting major telecommunications service nodes are a main contributor to significant telecommunications outages. A logical approach to improving the robustness of telecommunication facilities is to increase the depth and breadth of technologies available to restore power during power outages. Distributed energy resources such as fuel cells and gas turbines could provide additional on-site electric power sources to provide backup power, if batteries and diesel generators fail. The analysis is based on a hierarchical Bayesian approach and focuses on the failure probability associated with each of three possible facility configurations, along with assessment of the uncertainty or confidence level in the probability of failure. A risk-based characterization of final best configuration is presented.

Band alignment at the Cu{sub 2}ZnSn(S{sub x}Se{sub 1-x}){sub 4}/CdS interface

Energy Technology Data Exchange (ETDEWEB)

Haight, Richard; Barkhouse, Aaron; Gunawan, Oki; Shin, Byungha; Copel, Matt; Hopstaken, Marinus; Mitzi, David B [IBM TJ Watson Research Center, P.O. Box 218, Yorktown Hts., New York 10598 (United States)

2011-06-20

Energy band alignments between CdS and Cu{sub 2}ZnSn(S{sub x}Se{sub 1-x}){sub 4} (CZTSSe) grown via solution-based and vacuum-based deposition routes were studied as a function of the [S]/[S+Se] ratio with femtosecond laser ultraviolet photoelectron spectroscopy, photoluminescence, medium energy ion scattering, and secondary ion mass spectrometry. Band bending in the underlying CZTSSe layer was measured via pump/probe photovoltage shifts of the photoelectron spectra and offsets were determined with photoemission under flat band conditions. Increasing the S content of the CZTSSe films produces a valence edge shift to higher binding energy and increases the CZTSSe band gap. In all cases, the CdS conduction band offsets were spikes.

Design and Security Analysis of a Fragment of Internet of Things Telecommunication System

Directory of Open Access Journals (Sweden)

V. A. Alexandrov

2016-01-01

Full Text Available This paper comprises the development and implementation of systems using the concept of Internet of Things. In terms of active development of industries, use the concept of the Internet of Things, the information security problem is urgent. To create a protected module of information-telecommunication system which implements the Internet of Things concept, it is important to take into account all its aspects. To determine relevant threats, it is necessary to use the detailed risk analysis according to existing GOST standards when choosing protection measures, one must rely on identified relevant threats. Actual threats and necessary protective actions are determined in this paper for implementation of Smart House computer appliance module, in order to develop a protected part of Smart House, which is necessary for realization of room access control. We solved the following tasks in the work, namely, a description of the system Smart Home, a description of steps and evaluation system security Smart Home; implementation of hardware assembly and writing a code for the selected fragment of the system; safety evaluation of the selected fragment Smart House and identification of actual threats; make recommendations to counter current threats; software implementation of one of the most urgent threats and software implementation of protective measures for a selected threat. A feature of the work is an integrated approach to the design with the use of the intruder models, analysis of the system’s assets and evaluation of their security.

The Nordic Mobile Telecommunication Cluster

DEFF Research Database (Denmark)

Jørgensen, Ulrik

2000-01-01

A study of the historic role of the Nordic mobile telephone and telecommunications cluster and its background in both coordinated innovation policies and societal developments in Scandinavia.......A study of the historic role of the Nordic mobile telephone and telecommunications cluster and its background in both coordinated innovation policies and societal developments in Scandinavia....

Fundamental limits of measurement in telecommunications: Experimental and modeling studies in a test optical network on proposal for the reform of telecommunication quantitations

International Nuclear Information System (INIS)

Egan, James; McMillan, Normal; Denieffe, David

2011-01-01

Proposals for a review of the limits of measurement for telecommunications are made. The measures are based on adapting work from the area of chemical metrology for the field of telecommunications. Currie has introduced recommendations for defining the limits of measurement in chemical metrology and has identified three key fundamental limits of measurement. These are the critical level, the detection limit and the determination limit. Measurements on an optical system are used to illustrate the utility of these measures and discussion is given into the advantages of using these fundamental quantitations over existing methods.

Fundamental limits of measurement in telecommunications: Experimental and modeling studies in a test optical network on proposal for the reform of telecommunication quantitations

Energy Technology Data Exchange (ETDEWEB)

Egan, James; McMillan, Normal; Denieffe, David, E-mail: eganj@itcarlow.ie [IT Carlow (Ireland)

2011-08-17

Proposals for a review of the limits of measurement for telecommunications are made. The measures are based on adapting work from the area of chemical metrology for the field of telecommunications. Currie has introduced recommendations for defining the limits of measurement in chemical metrology and has identified three key fundamental limits of measurement. These are the critical level, the detection limit and the determination limit. Measurements on an optical system are used to illustrate the utility of these measures and discussion is given into the advantages of using these fundamental quantitations over existing methods.

Methods and Algorythms of Alternatives Ranging in Managing the Telecommunication Services Guality.

Directory of Open Access Journals (Sweden)

Pham Quang Hiep

2015-07-01

Full Text Available The article deals with methods of solving the problem of ranging of alternatives in information-analytical system of managing the quality of telecommunication services rendering process. Tasks of choice are determined, in which the alternatives are as follows: states of quality of different objects in the structure of telecommunication company management. An algorithm of ranging of objects is elaborated for the case of using unstructured set of indices. The algorithm enables to determine the objects priorities and to select the best ones among them. The suggested methods may be used while elaborating the programs of improvement of telecommunication companies competitiveness.

47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

Science.gov (United States)

2010-10-01

... board aircraft. Air-ground systems operating in these frequency bands are referred to in this part as... systems. 22.857 Section 22.857 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground...

Acquisition Information Management system telecommunication site survey results

Energy Technology Data Exchange (ETDEWEB)

Hake, K.A. [Oak Ridge National Lab., TN (United States); Key, B.G. [COR, Inc., Oak Ridge, TN (United States)

1993-09-01

The Army acquisition community currently uses a dedicated, point-to-point secure computer network for the Army Material Plan Modernization (AMPMOD). It must transition to the DOD supplied Defense Secure Network 1 (DSNET1). This is one of the first networks of this size to begin the transition. The type and amount of computing resources available at individual sites may or may not meet the new network requirements. This task surveys these existing telecommunications resources available in the Army acquisition community. It documents existing communication equipment, computer hardware, associated software, and recommends appropriate changes.

A low-power RF system with accurate synchronization for a S-band RF-gun using a laser-triggered photocathode

International Nuclear Information System (INIS)

Otake, Y.; Naito, T.; Shintake, T.; Takata, K.; Takeuchi, Y.; Urakawa, J.; Yoshioka, M.; Akiyama, H.

1992-01-01

An S-band RF-gun using a laser-triggered photocathode and its low-power RF system have been constructed. The main elements of the low-power RF system comprise a 600-W amplifier, an amplitude modulator, a phase detector, a phase shifter and a frequency-divider module. Synchronization between the RF fields for acceleration and the mode-locked laser pulses for beam triggering are among the important points concerning the RF-gun. The frequency divider module which down-converts from 2856 MHz(RF) to 89.25 MHz(laser), and the electrical phase-shifter were specially developed for stable phase control. The phase jitter of the frequency divider should be less than 10 ps to satisfy our present requirements. The first experiments to trigger and accelerate beams with the above-mentioned system were carried out in January, 1992. (Author) 6 figs., 5 refs

ARTES: the future of satellite telecommunication

Science.gov (United States)

González-Blázquez, Angel; Detain, Dominique

2005-08-01

Throughout its 30-year existence, ESA has played a key role by providing telecommunications infrastructures that have allowed the in-orbit validation, qualification and demonstration of equipment, technology and services. In the past, this has been achieved through the provision of dedicated satellites like OTS, Marecs, Olympus and Artemis, as well as by the implementation of piggy-back payloads on other ESA or commercial satellites. Today, due to the importance of satellite telecommunications, ESA continues to support this sector mainly through its ARTES - Advanced Research in Telecommunications - Programme.

A 20fs synchronization system for lasers and cavities in accelerators and FELs

Science.gov (United States)

Wilcox, R. B.; Byrd, J. M.; Doolittle, L. R.; Huang, G.; Staples, J. W.

2010-02-01

A fiber-optic RF distribution system has been developed for synchronizing lasers and RF plants in short pulse FELs. Typical requirements are 50-100fs rms over time periods from 1ms to several hours. Our system amplitude modulates a CW laser signal, senses fiber length using an interferometer, and feed-forward corrects the RF phase digitally at the receiver. We demonstrate less than 15fs rms error over 12 hours, between two independent channels with a fiber path length difference of 200m and transmitting S-band RF. The system is constructed using standard telecommunications components, and uses regular telecom fiber.

Dilip Subramanian, Telecommunications Industry in India: State, Business and Labour in a Global Economy

Directory of Open Access Journals (Sweden)

David Picherit

2011-10-01

Full Text Available In 1948, Indian Telephone Industries (ITI, a telecommunications equipment manufacturer, became India’s first State-run enterprise. In 2009, the company was privatized. Dilip Subramanian’s book provides a remarkable in-depth history of the journey of this Indian State-owned factory in post-colonial India, from the birth of the Nehruvian model of industrialization to the contemporary deregulation of the telecommunications industry. In a context of global neoliberal policies and discourses agai...

The Telecommunications Industry; Integration Vs. Competition.

Science.gov (United States)

Irwin, Manley R.

Vertical integration stands as the salient structural configuration of the telecommunications equipment market. Computer hardware manufacturers are obviously potential competitors with the captive telecommunications equipment suppliers. Direct government policies, such as patents and a permissive attitude toward mergers, and indirect policies,…

Generation of nanosecond S band microwave pulses based on superradiance

International Nuclear Information System (INIS)

Ginzburg, N.S.; Zotova, I.V.; Rozental, R.M.

2002-01-01

Modeling carried out demonstrates possibility of generation of gigawatt power level S band microwave pulse with duration of several nanoseconds using superradiation of short electron beam moving along slow-wave periodical structure. A 10 ns / 500 keV / 5 kA accelerator of Kanazawa University can be used in such experiments. It is shown that significant increasing peak power can be obtained by optimization of voltage and current pulses waveforms. Required increasing of electron energy and current by the end of electron pulse can be achieved by using self-acceleration of a short beam passing through a system of passive cavities. (author)

Generation of nanosecond S band microwave pulses based on superradiance

Energy Technology Data Exchange (ETDEWEB)

Ginzburg, N.S.; Zotova, I.V.; Rozental, R.M. [Russian Academy of Science, Institute of Applied Physics, Nizhny Novgorod (RU)] [and others

2002-06-01

Modeling carried out demonstrates possibility of generation of gigawatt power level S band microwave pulse with duration of several nanoseconds using superradiation of short electron beam moving along slow-wave periodical structure. A 10 ns / 500 keV / 5 kA accelerator of Kanazawa University can be used in such experiments. It is shown that significant increasing peak power can be obtained by optimization of voltage and current pulses waveforms. Required increasing of electron energy and current by the end of electron pulse can be achieved by using self-acceleration of a short beam passing through a system of passive cavities. (author)

Telecommunication Networks: Economy, Ecology, Rule

OpenAIRE

Cubitt, Sean

2014-01-01

This essay deals with technologies, techniques, business models and legal structures governing telecommunications infrastructures. Megacities are especially vulnerable to shifting agencies in telecoms provision. This paper addresses the relation of the economics of growth, built-in obsolescence and product life cycles with the complex determinations of telecommunications governance in relation to the physical environment of megacities. It argues that an ‘environmentalism of the poor’ must be ...

Communications Satellite Systems Conference, 9th, San Diego, CA, March 7-11, 1982, Collection of Technical Papers

Science.gov (United States)

The Shuttle-to-Geostationary Orbital Transfer by mid-level thrust is considered along with multibeam antenna concepts for global communications, the antenna pointing systems for large communication satellites, the connection phase of multidestination protocols for broadcast satellites, and an experiment in high-speed international packet switching. Attention is given to a dynamic switch matrix for the TDMA satellite switching system, the characterization of 16 bit microprocessors for space use, in-orbit operation and test of Intelsat V satellites, the first operational communications system via satellite in Europe, the Arab satellite communications systems, second generation business satellite systems for Europe, and a high performance Ku-band satellite for the 1980's. Other topics investigated are related to Ku-band terminal design tradeoffs, progress in the definition of the Italian satellite for domestic telecommunications, future global satellite systems for Intelsat, and satellite refuelling in orbit.

Highly miniaturised semi-loop meandered dual-band MIMO antenna system

KAUST Repository

Jehangir, Syed S.

2017-12-05

A novel dual-band two-element directional multiple-input-multiple-output (MIMO) antenna system is presented with 68% miniaturisation, which is achieved using a semi-loop meandered driven element and a small ground plane. The centre frequency of operation is 2 GHz. The antenna system covers two bands: the telemetry L-band 1.27-1.43 GHz and the global system for mobile communications/long-term evolution band 1.8-2.133 GHz. The simulation and measurement results are in good agreement. The proposed antenna system mimics the quasi-Yagi antenna configuration with a measured front-to-back ratio of around 15 dB at 1.35 GHz and 17 dB at 2 GHz, which is achieved without using a large ground plane, extra metallic structures, multiple reflector elements, or any complex technique. A gain of more than 5 dBi is measured for the single element with a total radiation efficiency of around 85% in both bands. The measured isolation of the proposed MIMO antenna is more than 15 dB with < 0.0785 measured envelope correlation coefficient values in both bands.

Highly miniaturised semi-loop meandered dual-band MIMO antenna system

KAUST Repository

Jehangir, Syed S.; Sharawi, Mohammad S.; Shamim, Atif

2017-01-01

A novel dual-band two-element directional multiple-input-multiple-output (MIMO) antenna system is presented with 68% miniaturisation, which is achieved using a semi-loop meandered driven element and a small ground plane. The centre frequency of operation is 2 GHz. The antenna system covers two bands: the telemetry L-band 1.27-1.43 GHz and the global system for mobile communications/long-term evolution band 1.8-2.133 GHz. The simulation and measurement results are in good agreement. The proposed antenna system mimics the quasi-Yagi antenna configuration with a measured front-to-back ratio of around 15 dB at 1.35 GHz and 17 dB at 2 GHz, which is achieved without using a large ground plane, extra metallic structures, multiple reflector elements, or any complex technique. A gain of more than 5 dBi is measured for the single element with a total radiation efficiency of around 85% in both bands. The measured isolation of the proposed MIMO antenna is more than 15 dB with < 0.0785 measured envelope correlation coefficient values in both bands.

Evaluating managed care's special telecommunications needs.

Science.gov (United States)

Harrison, P; Schenk, D

1993-11-01

Right now, managed care is a vast cosmic soup. But whether its ultimate form is the result of a bureaucratic big bang or a series of small industry explosions, one thing seems clear: telecommunications is the framework upon which managed care will be built. Managed care's primary players--purchasers, providers and payors--have already discovered the unifying power of telecommunications within their respective worlds. However, as the three worlds collide, an entirely new set of special telecommunications needs arises. And most of these needs can be distilled into three basic requirements: bigger networks, faster networks and smarter networks.

Telecommunications and Higher Education. Occasional Paper No. 3.

Science.gov (United States)

Froke, Marlowe, Ed.; And Others

The first of the three papers which set the theme for this monograph on telecommunications is an examination of the implications of telecommunications developments for the learning society by Michael B. Spring. Marlowe Froke then looks at telecommunications development in institutions of higher education and discusses institutional change that…

Demand Modelling in Telecommunications

Directory of Open Access Journals (Sweden)

M. Chvalina

2009-01-01

Full Text Available This article analyses the existing possibilities for using Standard Statistical Methods and Artificial Intelligence Methods for a short-term forecast and simulation of demand in the field of telecommunications. The most widespread methods are based on Time Series Analysis. Nowadays, approaches based on Artificial Intelligence Methods, including Neural Networks, are booming. Separate approaches will be used in the study of Demand Modelling in Telecommunications, and the results of these models will be compared with actual guaranteed values. Then we will examine the quality of Neural Network models. 

Functional separation in telecommunications

DEFF Research Database (Denmark)

Jess Olsen, Ole; Henten, Anders; Falch, Morten

2008-01-01

During the past 20 to 30 years, public utilities have been subject to market reforms in most parts of the world. Liberalisation has been introduced to improve efficiency in terms of lower costs and more and better services. The subject of this paper is the Danish reforms of its public utilities....... The focus is on the utilities where the reforms were first introduced, i.e. telecommunications and electricity. The paper examines the following questions: Which are the main reasons for the different regulatory approaches to the liberalisation of telecommunications and electricity supply? In which...

75 FR 42376 - Proposed Information Collection; Comment Request; NTIA/FCC Web-based Frequency Coordination System

Science.gov (United States)

2010-07-21

... Information Collection; Comment Request; NTIA/FCC Web- based Frequency Coordination System AGENCY: National.... Abstract The National Telecommunications and Information Administration (NTIA) hosts a Web-based system...) bands that are shared on a co-primary basis by federal and non-federal users. The Web-based system...

An integrated service digital network (ISDN)-based international telecommunication between Samsung Medical Center and Hokkaido University using telecommunication helped radiotherapy planning and information system (THERAPIS)

International Nuclear Information System (INIS)

Huh, S.J.; Kim, D.Y.; Ahn, Y.C.; Choi, D.; Shirato, H.; Hashimoto, S.; Shimizu, S.; Miyasaka, K.; Mizuno, J.

2000-01-01

This study introduces the integrated service digital network (ISDN)-based international teleradiotherapy system (THERAPIS) in radiation oncology between hospitals in Seoul, South Korea and in Sapporo, Japan. THERAPIS has the following functions: (1) exchange of patient's image data, (2) real-time teleconference, and (3) communication of the treatment planning, dose calculation and distribution, and of portal verification images between the remote hospitals. Our preliminary results of applications on eight patients demonstrated that the international telecommunication using THERAPIS was clinically useful and satisfactory with sufficient bandwidth for the transfer of patient data for clinical use in radiation oncology. (author)

An integrated service digital network (ISDN)-based international telecommunication between Samsung Medical Center and Hokkaido University using telecommunication helped radiotherapy planning and information system (THERAPIS).

Science.gov (United States)

Huh, S J; Shirato, H; Hashimoto, S; Shimizu, S; Kim, D Y; Ahn, Y C; Choi, D; Miyasaka, K; Mizuno, J

2000-07-01

This study introduces the integrated service digital network (ISDN)-based international teleradiotherapy system (THERAPIS) in radiation oncology between hospitals in Seoul, South Korea and in Sapporo, Japan. THERAPIS has the following functions: (1) exchange of patient's image data, (2) real-time teleconference, and (3) communication of the treatment planning, dose calculation and distribution, and of portal verification images between the remote hospitals. Our preliminary results of applications on eight patients demonstrated that the international telecommunication using THERAPIS was clinically useful and satisfactory with sufficient bandwidth for the transfer of patient data for clinical use in radiation oncology.

Business analysis methodology in telecommunication industry – the research based on the grounded theory

Directory of Open Access Journals (Sweden)

Hana Nenickova

2013-10-01

Full Text Available The objective of this article is to present the grounded theory using in the qualitative research as a basis to build a business analysis methodology for the implementation of information systems in telecommunication enterprises in Czech Republic. In the preparation of the methodology I have used the current needs of telecommunications companies, which are characterized mainly by high dependence on information systems. Besides that, this industry is characterized by high flexibility and competition and compressing of the corporate strategy timeline. The grounded theory of business analysis defines the specifics of the telecommunications industry, focusing on the very specific description of the procedure for collecting the business requirements and following the business strategy.

AN ANALYSIS OF THE APPLICATION END TO END QUALITY OF SERVICE ON 3G TELECOMMUNICATION NETWORK

Directory of Open Access Journals (Sweden)

Cahya Lukito

2012-05-01

Full Text Available End to End Quality of Service is a way to provide data package service in a telecommunication network that based on Right Price, Right Service Level, and Right Quality. The goal of this research is to analyze the impact of End to End QoS use on 3G telecommunication network for voice service and data. This research uses an analysis method by doing the application on the lab. The result that is achieved in this research shows that End to End QoS is very influental to the Service Level Agreement to the users of the telecommunication service.Keywords: End to End Qos, SLA, Diffserv

The telecommunications industry and economic growth: how the market structure matters

Czech Academy of Sciences Publication Activity Database

Jerbashian, Vahagn

2015-01-01

Roč. 51, December (2015), s. 515-523 ISSN 0264-9993 Grant - others:UK(CZ) GAUK 79310 Institutional support: PRVOUK-P23 Keywords : telecommunications industry * market structure * economic growth Subject RIV: AH - Economic s Impact factor: 0.997, year: 2015

The political economy of competition in telecommunication

DEFF Research Database (Denmark)

Henten, Anders; Skouby, Knud Erik

1998-01-01

Article dealing with the regulation of telecommunications and the establishment of a competitive regime.......Article dealing with the regulation of telecommunications and the establishment of a competitive regime....

Basic functions of telecommunication channel elements for successful information transmission

Directory of Open Access Journals (Sweden)

Milorad S. Markagić

2011-04-01

the observed messages. Coder of messages generated by a message source should be transmitted to the recipient. For that purpose, an appropriate communication channel is used, with appropriate electrical signals as material bearers of the message. Definition of the code and the code system The set of combinations of digits that mirrors the elements of the set A is called a code. The established rule considers situations when each symbol from the set A is associated with the combination of elements of the set B. The function f defining this translation must be defined. This replacement is called a code replacement. Signal coder A coder performs signal transformation of coded messages to an electrical signal adapted for transmission via the transmission system. The most common signals are voltage transmission via cable connection or an electromagnetic field in the radio transmission. Modern systems for transferring discrete messages contain codecs and modems. Portable system A portable system is the medium for signal transmission from the source to the point of receipt. It can be wired and wireless. A wired transmission system is used in the stationary elements of communication systems. Wireless signal transmission is used in all conditions and it is more rational, efficient and economical. On their way through the transmission system, signals are subject to a variety of interferences. For a better insight into the interference impact, the source of interference is added to the whole system. Conclusion The model of the telecommunication channel is a complex system of a series of mutually dependent elements. Effectiveness of these elements is evaluated by the performances of the probability that the transfer of information through the channel will be successful. In a thus modeled telecommunication channel, regardless of the technical means used which is either a system or a circuit, the place and role of each element can be considered, which is the basis for consideration

Danish Telecommunications: Keeping the Policy Options Open

DEFF Research Database (Denmark)

Henten, Anders; Wulff, Thomas

1996-01-01

In recent years Danish telecommunications policy has gone through a marked change in emphasis, Tele Danmark, formed only 6 years ago as the national operator in order to strengthen the Danish telecom industry, has come under pressure in the present liberalization. This article discusses Tele...... Danmark's situation and future possibilities and presents background information on the new Danish telecommunications legislation, the present Danish telecommunications market, and Tele Danmark's strategies. Copyright (C) 1996 Elsevier Science Ltd...

Advanced Spatial-Division Multiplexed Measurement Systems Propositions—From Telecommunication to Sensing Applications: A Review

Directory of Open Access Journals (Sweden)

Yi Weng

2016-08-01

Full Text Available The concepts of spatial-division multiplexing (SDM technology were first proposed in the telecommunications industry as an indispensable solution to reduce the cost-per-bit of optical fiber transmission. Recently, such spatial channels and modes have been applied in optical sensing applications where the returned echo is analyzed for the collection of essential environmental information. The key advantages of implementing SDM techniques in optical measurement systems include the multi-parameter discriminative capability and accuracy improvement. In this paper, to help readers without a telecommunication background better understand how the SDM-based sensing systems can be incorporated, the crucial components of SDM techniques, such as laser beam shaping, mode generation and conversion, multimode or multicore elements using special fibers and multiplexers are introduced, along with the recent developments in SDM amplifiers, opto-electronic sources and detection units of sensing systems. The examples of SDM-based sensing systems not only include Brillouin optical time-domain reflectometry or Brillouin optical time-domain analysis (BOTDR/BOTDA using few-mode fibers (FMF and the multicore fiber (MCF based integrated fiber Bragg grating (FBG sensors, but also involve the widely used components with their whole information used in the full multimode constructions, such as the whispering gallery modes for fiber profiling and chemical species measurements, the screw/twisted modes for examining water quality, as well as the optical beam shaping to improve cantilever deflection measurements. Besides, the various applications of SDM sensors, the cost efficiency issue, as well as how these complex mode multiplexing techniques might improve the standard fiber-optic sensor approaches using single-mode fibers (SMF and photonic crystal fibers (PCF have also been summarized. Finally, we conclude with a prospective outlook for the opportunities and challenges of

Advanced Spatial-Division Multiplexed Measurement Systems Propositions—From Telecommunication to Sensing Applications: A Review

Science.gov (United States)

Weng, Yi; Ip, Ezra; Pan, Zhongqi; Wang, Ting

2016-01-01

The concepts of spatial-division multiplexing (SDM) technology were first proposed in the telecommunications industry as an indispensable solution to reduce the cost-per-bit of optical fiber transmission. Recently, such spatial channels and modes have been applied in optical sensing applications where the returned echo is analyzed for the collection of essential environmental information. The key advantages of implementing SDM techniques in optical measurement systems include the multi-parameter discriminative capability and accuracy improvement. In this paper, to help readers without a telecommunication background better understand how the SDM-based sensing systems can be incorporated, the crucial components of SDM techniques, such as laser beam shaping, mode generation and conversion, multimode or multicore elements using special fibers and multiplexers are introduced, along with the recent developments in SDM amplifiers, opto-electronic sources and detection units of sensing systems. The examples of SDM-based sensing systems not only include Brillouin optical time-domain reflectometry or Brillouin optical time-domain analysis (BOTDR/BOTDA) using few-mode fibers (FMF) and the multicore fiber (MCF) based integrated fiber Bragg grating (FBG) sensors, but also involve the widely used components with their whole information used in the full multimode constructions, such as the whispering gallery modes for fiber profiling and chemical species measurements, the screw/twisted modes for examining water quality, as well as the optical beam shaping to improve cantilever deflection measurements. Besides, the various applications of SDM sensors, the cost efficiency issue, as well as how these complex mode multiplexing techniques might improve the standard fiber-optic sensor approaches using single-mode fibers (SMF) and photonic crystal fibers (PCF) have also been summarized. Finally, we conclude with a prospective outlook for the opportunities and challenges of SDM

Telecommunication Policy Structure in Japan. Summary.

Science.gov (United States)

Komatsuzaki, Seisuke

This paper outlines the structure of Japanese telecommunication industries and how the various parts of the mechanism work together. Explanations of the Japanese: 1) structure of telecommunication industries; 2) control of regulatory lags; 3) text information service and regulation; and 4) text information service and the telecommunication…

VT Telecommunication Facilities

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The UtilityTelecom_TELEFAC data layer contains points which are intended to represent the location of telecommunications facilities (towers and/or...

47 CFR 54.201 - Definition of eligible telecommunications carriers, generally.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Definition of eligible telecommunications carriers, generally. 54.201 Section 54.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... § 54.201 Definition of eligible telecommunications carriers, generally. (a) Carriers eligible to...

47 CFR 25.250 - Sharing between NGSO MSS Feeder links Earth Stations in the 19.3-19.7 GHz and 29.1-29.5 GHz Bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Sharing between NGSO MSS Feeder links Earth Stations in the 19.3-19.7 GHz and 29.1-29.5 GHz Bands. 25.250 Section 25.250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25...

47 CFR 68.106 - Notification to provider of wireline telecommunications.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Notification to provider of wireline telecommunications. 68.106 Section 68.106 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... of Terminal Equipment § 68.106 Notification to provider of wireline telecommunications. (a) General...

High school science teachers' perceptions of telecommunications utilizing a Concerns-Based Adoption Model (CBAM)

Science.gov (United States)

Slough, Scott Wayne

The purpose of this study was to describe high school science teachers' perceptions of telecommunications. The data were collected through open-ended ethnographic interviews with 24 high school science teachers from five different high schools in a single suburban school district who had been in an emerging telecommunications-rich environment for two and one-half years. The interview protocol was adapted from Honey and Henriquez (1993), with the Concerns-Based Adoption Model (CBAM) (Bailey & Palsha, 1992) providing a conceptual framework for data analysis. For this study, the emerging telecommunications-rich environment included a district-wide infrastructure that had been in place for two and one-half years that included a secure district-wide Intranet, 24 network connections in each classroom, full Internet access from the network, four computers per classroom, and a variety of formal and informal professional development opportunities for teachers. Categories of results discussed include: (a) teacher's profession use of telecommuunications; (b) teachers' perceptions of student's use of telecommunications; (c) teachers' perceptions of barriers to the implementation of telecommunications; (d) teachers' perceptions of supporting conditions for the implementation of telecommunications; (e) teachers' perceptions of the effect of telecommunications on high school science instruction; (f) teachers' perceptions of the effect of telecommunications on student's learning in high school science; and (g) the demographic variables of the sex of the teacher, years of teaching experience, school assignment within the district, course assignment(s), and academic preparation. Implications discussed include: (a) telecommunications can be implemented successfully in a variety of high school science classrooms with adequate infrastructure support and sufficient professional development opportunities, including in classes taught by females and teachers who were not previously

Determination of band offsets at GaN/single-layer MoS{sub 2} heterojunction

Energy Technology Data Exchange (ETDEWEB)

Tangi, Malleswararao; Mishra, Pawan; Ng, Tien Khee; Janjua, Bilal; Alias, Mohd Sharizal; Ooi, Boon S., E-mail: boon.ooi@kaust.edu.sa [Photonics Laboratory, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Hedhili, Mohamed Nejib; Anjum, Dalaver H. [Adavanced Nanofabrication Imaging and Characterization, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Tseng, Chien-Chih; Shi, Yumeng; Li, Lain-Jong [Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Joyce, Hannah J. [Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, Cambridgeshire CB3 0FA (United Kingdom)

2016-07-18

We report the band alignment parameters of the GaN/single-layer (SL) MoS{sub 2} heterostructure where the GaN thin layer is grown by molecular beam epitaxy on CVD deposited SL-MoS{sub 2}/c-sapphire. We confirm that the MoS{sub 2} is an SL by measuring the separation and position of room temperature micro-Raman E{sup 1}{sub 2g} and A{sup 1}{sub g} modes, absorbance, and micro-photoluminescence bandgap studies. This is in good agreement with HRTEM cross-sectional analysis. The determination of band offset parameters at the GaN/SL-MoS{sub 2} heterojunction is carried out by high-resolution X-ray photoelectron spectroscopy accompanying with electronic bandgap values of SL-MoS{sub 2} and GaN. The valence band and conduction band offset values are, respectively, measured to be 1.86 ± 0.08 and 0.56 ± 0.1 eV with type II band alignment. The determination of these unprecedented band offset parameters opens up a way to integrate 3D group III nitride materials with 2D transition metal dichalcogenide layers for designing and modeling of their heterojunction based electronic and photonic devices.

The telecommunications industry and economic growth: how the market structure matters

Czech Academy of Sciences Publication Activity Database

Jerbashian, Vahagn

2011-01-01

Roč. 3, č. 42 (2011), s. 1-68 ISSN N R&D Projects: GA MŠk LC542 Grant - others:UK(CZ) GAUK 79310 Institutional research plan: CEZ:MSM0021620846 Keywords : telecommunication industry * market structure * economic growth Subject RIV: AH - Economic s

40-Gb/s PDM-QPSK signal transmission over 160-m wireless distance at W-band.

Science.gov (United States)

Xiao, Jiangnan; Yu, Jianjun; Li, Xinying; Xu, Yuming; Zhang, Ziran; Chen, Long

2015-03-15

We experimentally demonstrate a W-band optical-wireless transmission system over 160-m wireless distance with a bit rate up to 40 Gb/s. The optical-wireless transmission system adopts optical polarization-division-multiplexing (PDM), multiple-input multiple-output (MIMO) reception and antenna polarization diversity. Using this system, we experimentally demonstrate the 2×2 MIMO wireless delivery of 20- and 40-Gb/s PDM quadrature-phase-shift-keying (PDM-QPSK) signals over 640- and 160-m wireless links, respectively. The bit-error ratios (BERs) of these transmission systems are both less than the forward-error-correction (FEC) threshold of 3.8×10-3.

Band-gap and sub-band-gap photoelectrochemical processes at nanocrystalline CdS grown on ZnO by successive ionic layer adsorption and reaction method

International Nuclear Information System (INIS)

Malashchonak, M.V.; Streltsov, E.A.; Mazanik, A.V.; Kulak, A.I.; Poznyak, S.K.; Stroyuk, O.L.; Kuchmiy, S.Ya.; Gaiduk, P.I.

2015-01-01

Cadmium sulfide nanoparticle (NP) deposition by the successive ionic layer adsorption and reaction (SILAR) method on the surface of mesoporous ZnO micro-platelets with a large specific surface area (110 ± 10 m 2 g −1 ) results in the formation of ZnO/CdS heterostructures exhibiting a high incident photon-to-current conversion efficiency (Y) not only within the region of CdS fundamental absorption (Y max = 90%; 0.1 M Na 2 S + 0.1 M Na 2 SO 3 ), but also in the sub-band-gap (SBG) range (Y max = 25%). The onset potentials of SBG photoelectrochemical processes are more positive than the band-gap (BG) onset potential by up to 100 mV. A maximum incident photon-to-current conversion efficiency value for SBG processes is observed at larger amount of deposited CdS in comparison with the case of BG ones. The Urbach energy (E U ) of CdS NPs determined from the photocurrent spectra reaches a maximal value on an early deposition stage (E U = 93 mV at SILAR cycle number N = 5), then lowers somewhat (E U = 73 mV at N = 10) and remains steady in the range of N from 20 to 300 (E U = 67 ± 1 mV). High efficiency of the photoelectrochemical SBG processes are interpreted in terms of light scattering in the ZnO/CdS heterostructures. - Highlights: • ZnO/CdS films demonstrate high quantum efficiency (25%) for sub-band-gap transitions. • Onset photocurrent potentials for sub-band-gap processes differ than those for band-gap ones. • Sub-band-gap transitions are caused by band-tail states in CdS nanoparticles

Band-gap and sub-band-gap photoelectrochemical processes at nanocrystalline CdS grown on ZnO by successive ionic layer adsorption and reaction method

Energy Technology Data Exchange (ETDEWEB)

Malashchonak, M.V., E-mail: che.malasche@gmail.com [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Streltsov, E.A., E-mail: streltea@bsu.by [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Mazanik, A.V. [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Kulak, A.I., E-mail: kulak@igic.bas-net.by [Institute of General and Inorganic Chemistry, National Academy of Sciences of Belarus, Surganova str., 9/1, Minsk 220072 (Belarus); Poznyak, S.K. [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Stroyuk, O.L., E-mail: stroyuk@inphyschem-nas.kiev.ua [L.V. Pysarzhevsky Institute of Physical Chemistry of National Academy of Sciences of Ukraine, 31 prosp. Nauky, 03028 Kyiv (Ukraine); Kuchmiy, S.Ya. [L.V. Pysarzhevsky Institute of Physical Chemistry of National Academy of Sciences of Ukraine, 31 prosp. Nauky, 03028 Kyiv (Ukraine); Gaiduk, P.I. [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus)

2015-08-31

Cadmium sulfide nanoparticle (NP) deposition by the successive ionic layer adsorption and reaction (SILAR) method on the surface of mesoporous ZnO micro-platelets with a large specific surface area (110 ± 10 m{sup 2}g{sup −1}) results in the formation of ZnO/CdS heterostructures exhibiting a high incident photon-to-current conversion efficiency (Y) not only within the region of CdS fundamental absorption (Y{sub max} = 90%; 0.1 M Na{sub 2}S + 0.1 M Na{sub 2}SO{sub 3}), but also in the sub-band-gap (SBG) range (Y{sub max} = 25%). The onset potentials of SBG photoelectrochemical processes are more positive than the band-gap (BG) onset potential by up to 100 mV. A maximum incident photon-to-current conversion efficiency value for SBG processes is observed at larger amount of deposited CdS in comparison with the case of BG ones. The Urbach energy (E{sub U}) of CdS NPs determined from the photocurrent spectra reaches a maximal value on an early deposition stage (E{sub U} = 93 mV at SILAR cycle number N = 5), then lowers somewhat (E{sub U} = 73 mV at N = 10) and remains steady in the range of N from 20 to 300 (E{sub U} = 67 ± 1 mV). High efficiency of the photoelectrochemical SBG processes are interpreted in terms of light scattering in the ZnO/CdS heterostructures. - Highlights: • ZnO/CdS films demonstrate high quantum efficiency (25%) for sub-band-gap transitions. • Onset photocurrent potentials for sub-band-gap processes differ than those for band-gap ones. • Sub-band-gap transitions are caused by band-tail states in CdS nanoparticles.

Mobile telecommunication networks choice among Ghanaians

Directory of Open Access Journals (Sweden)

Boateng Henry

2013-07-01

Full Text Available The paper investigates the factors influencing customers choice of telecommunication network in Ghana. The survey design was employed to enable the researchers perform statistical analysis. Questionnaire consisting of Likert scale question was used to collect the primary data. Multiple regression analysis was performed to ascertain the factors influencing customers’ choice of telecommunication networks. The study found six factors that influence customers to choose a particular network. These factors include; brand awareness, brand image, perceived quality, price, convenience and brand loyalty. The study concludes that all the six factors contribute to the factors that drive consumer choice of telecommunications service in Ghana.

Worldwide Intelligent Systems: Approaches to Telecommunications and Network Management. Frontiers in Artificial Intelligence and Applications, Volume 24.

Science.gov (United States)

Liebowitz, Jay, Ed.; Prerau, David S., Ed.

This is an international collection of 12 papers addressing artificial intelligence (AI) and knowledge technology applications in telecommunications and network management. It covers the latest and emerging AI technologies as applied to the telecommunications field. The papers are: "The Potential for Knowledge Technology in…

Estimating network effects in China's mobile telecommunications

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

A model is proposed along with empirical investigation to prove the existence of network effects in China's mobile telecommunications market. Futhernore, network effects on China's mobile telecommunications are estimated with a dynamic model. The structural parameters are identified from regression coefficients and the results are analyzed and compared with another literature. Data and estimation issues are also discussed. Conclusions are drawn that network effects are significant in China's mobile telecommunications market, and that ignoring network effects leads to bad policy making.

77 FR 75182 - President's National Security Telecommunications Advisory Committee

Science.gov (United States)

2012-12-19

... Telecommunications Advisory Committee AGENCY: National Protection and Programs Directorate, DHS. ACTION: Committee... Security Telecommunications Advisory Committee (NSTAC) will meet on Friday, January 11, 2013, via... related to national security and emergency preparedness telecommunications policy. Agenda: The NSTAC...

Telecommunication Value Network in Malaysia

OpenAIRE

Ong, Li Chien

2009-01-01

Business network is believed to offer a superior way of managing the challenges related to the uncertainty and complexity of the contemporary business environment in Malaysia telecommunication industry. This study strives to analyze the value business network in Malaysia telecommunication industry with emphasize on the market leader, Maxis Communication Bhd in its mobile content services. The business network represents the form of organization where the focal company focuses on certain key a...

Telecommunications Technology and Service Changes Since the Telecommunications Act of 1996

National Research Council Canada - National Science Library

Simmons, Matthew

2002-01-01

The Telecom Act of 1996 was intended to address the lack of competition and reduce regulation in local telephone services and in other areas of the telecommunications sector, The competitive situation...

47 CFR 101.77 - Public safety licensees in the 1850-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands.

Science.gov (United States)

2010-10-01

..., 2110-2150 MHz, and 2160-2200 MHz bands. 101.77 Section 101.77 Telecommunication FEDERAL COMMUNICATIONS...-1990 MHz, 2110-2150 MHz, and 2160-2200 MHz bands. (a) In order for public safety licensees to qualify... a Police licensee, a Fire Licensee, or an Emergency Medical Licensee as defined in § 90.7 of this...

78 FR 45255 - President's National Security Telecommunications Advisory Committee

Science.gov (United States)

2013-07-26

... Telecommunications Advisory Committee AGENCY: National Protection and Programs Directorate, DHS. [[Page 45256... President's National Security Telecommunications Advisory Committee (NSTAC) will meet on Tuesday, August 20... related to national security and emergency preparedness (NS/EP) telecommunications policy. Agenda: The...

Electronic structure of the misfit layer compound (SnS)(1.20)TiS2 : Band structure calculations and photoelectron spectra

NARCIS (Netherlands)

Fang, CM; deGroot, RA; Wiegers, GA; Haas, C

1996-01-01

In order to understand the electronic structure of the incommensurate misfit layer compound (SnS)(1.20)TiS2 we carried out an ab initio band structure calculation in the supercell approximation. The band structure is compared with that of the components 1T-TiS2 and hypothetical SnS with a similar

Electronic structure of the misfit layer compound (SnS)1.20TiS2 : band structure calculations and photoelectron spectra

NARCIS (Netherlands)

Fang, C.M.; Groot, R.A. de; Wiegers, G.A.; Haas, C.

1996-01-01

In order to understand the electronic structure of the incommensurate misfit layer compound (SnS)1.20TiS2 we carried out an ab initio band structure calculation in the supercell approximation. The band structure is compared with that of the components 1T-TiS2 and hypothetical SnS with a similar

Airborne S-Band SAR for Forest Biophysical Retrieval in Temperate Mixed Forests of the UK

Directory of Open Access Journals (Sweden)

Ramesh K. Ningthoujam

2016-07-01

Full Text Available Radar backscatter from forest canopies is related to forest cover, canopy structure and aboveground biomass (AGB. The S-band frequency (3.1–3.3 GHz lies between the longer L-band (1–2 GHz and the shorter C-band (5–6 GHz and has been insufficiently studied for forest applications due to limited data availability. In anticipation of the British built NovaSAR-S satellite mission, this study evaluates the benefits of polarimetric S-band SAR for forest biophysical properties. To understand the scattering mechanisms in forest canopies at S-band the Michigan Microwave Canopy Scattering (MIMICS-I radiative transfer model was used. S-band backscatter was found to have high sensitivity to the forest canopy characteristics across all polarisations and incidence angles. This sensitivity originates from ground/trunk interaction as the dominant scattering mechanism related to broadleaved species for co-polarised mode and specific incidence angles. The study was carried out in the temperate mixed forest at Savernake Forest and Wytham Woods in southern England, where airborne S-band SAR imagery and field data are available from the recent AirSAR campaign. Field data from the test sites revealed wide ranges of forest parameters, including average canopy height (6–23 m, diameter at breast-height (7–42 cm, basal area (0.2–56 m2/ha, stem density (20–350 trees/ha and woody biomass density (31–520 t/ha. S-band backscatter-biomass relationships suggest increasing backscatter sensitivity to forest AGB with least error between 90.63 and 99.39 t/ha and coefficient of determination (r2 between 0.42 and 0.47 for the co-polarised channel at 0.25 ha resolution. The conclusion is that S-band SAR data such as from NovaSAR-S is suitable for monitoring forest aboveground biomass less than 100 t/ha at 25 m resolution in low to medium incidence angle range.

A Flexible System for Simulating Aeronautical Telecommunication Network

Science.gov (United States)

Maly, Kurt; Overstreet, C. M.; Andey, R.

1998-01-01

At Old Dominion University, we have built Aeronautical Telecommunication Network (ATN) Simulator with NASA being the fund provider. It provides a means to evaluate the impact of modified router scheduling algorithms on the network efficiency, to perform capacity studies on various network topologies and to monitor and study various aspects of ATN through graphical user interface (GUI). In this paper we describe briefly about the proposed ATN model and our abstraction of this model. Later we describe our simulator architecture highlighting some of the design specifications, scheduling algorithms and user interface. At the end, we have provided the results of performance studies on this simulator.

Collapse and revival in inter-band oscillations of a two-band Bose-Hubbard model

Energy Technology Data Exchange (ETDEWEB)

Ploetz, Patrick; Wimberger, Sandro [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, 69120 Heidelberg (Germany); Madronero, Javier, E-mail: ploetz@thphys.uni-heidelberg.d [Physik Department, Technische Universitaet Muenchen, James-Franck-Str. 1, 85748 Garching (Germany)

2010-04-28

We study the effect of a many-body interaction on inter-band oscillations in a two-band Bose-Hubbard model with an external Stark force. Weak and strong inter-band oscillations are observed, where the latter arise from a resonant coupling of the bands. These oscillations collapse and revive due to a weak two-body interaction between the atoms. Effective models for oscillations in and out of resonance are introduced that provide predictions for the system's behaviour, particularly for the time scales for the collapse and revival of the resonant inter-band oscillations. (fast track communication)

47 CFR 32.2000 - Instructions for telecommunications plant accounts.

Science.gov (United States)

2010-10-01

... known, of telecommunications plant, governmental franchises and other similar rights acquired shall be..., and Property Held For Future Telecommunications Use, as appropriate, and credited to Account 1439... depreciation, or Account 3200, Accumulated depreciation—held for future telecommunications use, or Account 3410...

31 CFR 594.508 - Transactions related to telecommunications authorized.

Science.gov (United States)

2010-07-01

... telecommunications authorized. 594.508 Section 594.508 Money and Finance: Treasury Regulations Relating to Money and... related to telecommunications authorized. All transactions ordinarily incident to the receipt or transmission of telecommunications involving persons whose property or interests in property are blocked...

75 FR 29781 - President's National Security Telecommunications Advisory Committee

Science.gov (United States)

2010-05-27

...] President's National Security Telecommunications Advisory Committee AGENCY: National Protection and Programs... Security Telecommunications Advisory Committee (NSTAC) will be meeting by teleconference; the meeting will... telecommunications policy. Notice of this meeting is given under the Federal Advisory Committee Act (FACA), Public...

31 CFR 545.508 - Transactions related to telecommunications authorized.

Science.gov (United States)

2010-07-01

... telecommunications authorized. 545.508 Section 545.508 Money and Finance: Treasury Regulations Relating to Money and... related to telecommunications authorized. All transactions ordinarily incident to the receipt or transmission of telecommunications involving the territory of Afghanistan controlled by the Taliban are...

Regionalizing Telecommunications Reform in West Africa

OpenAIRE

World Bank

2007-01-01

This report assesses the potential gains from regionalized telecommunications policy in West Africa. The report seeks to assist officials in the Economic Community of West African States (ECOWAS), the West African Telecommunications Regulators Assembly (WATRA) and member states in designing an effective regional regulatory process. To this end, the report: (i) discusses how regional coop...

Transition metal atoms absorbed on MoS2/h-BN heterostructure: stable geometries, band structures and magnetic properties.

Science.gov (United States)

Wu, Yanbing; Huang, Zongyu; Liu, Huating; He, Chaoyu; Xue, Lin; Qi, Xiang; Zhong, Jianxin

2018-06-15

We have studied the stable geometries, band structures and magnetic properties of transition-metal (V, Cr, Mn, Fe, Co and Ni) atoms absorbed on MoS2/h-BN heterostructure systems by first-principles calculations. By comparing the adsorption energies, we find that the adsorbed transition metal (TM) atoms prefer to stay on the top of Mo atoms. The results of the band structure without spin-orbit coupling (SOC) interaction indicate that the Cr-absorbed systems behave in a similar manner to metals, and the Co-absorbed system exhibits a half-metallic state. We also deduce that the V-, Mn-, Fe-absorbed systems are semiconductors with 100% spin polarization at the HOMO level. The Ni-absorbed system is a nonmagnetic semiconductor. In contrast, the Co-absorbed system exhibits metallic state, and the bandgap of V-absorbed system decreases slightly according to the SOC calculations. In addition, the magnetic moments of all the six TM atoms absorbed on the MoS2/h-BN heterostructure systems decrease when compared with those of their free-standing states.

C-Band Airport Surface Communications System Standards Development, Phase I

Science.gov (United States)

Hall, Edward; Isaacs, James; Zelkin, Natalie; Henriksen. Steve

2010-01-01

This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." The proposed future C-band (5091- to 5150-MHz) airport surface communication system, referred to as the Aeronautical Mobile Airport Communications System (AeroMACS), is anticipated to increase overall air-to-ground data communications systems capacity by using a new spectrum (i.e., not very high frequency (VHF)). Although some critical services could be supported, AeroMACS will also target noncritical services, such as weather advisory and aeronautical information services as part of an airborne System Wide Information Management (SWIM) program. AeroMACS is to be designed and implemented in a manner that will not disrupt other services operating in the C-band. This report defines the AeroMACS concepts of use, high-level system requirements, and architecture; the performance of supporting system analyses; the development of AeroMACS test and demonstration plans; and the establishment of an operational AeroMACS capability in support of C-band aeronautical data communications standards to be advanced in both international (International Civil Aviation Organization, ICAO) and national (RTCA) forums. This includes the development of system parameter profile recommendations for AeroMACS based on existing Institute of Electrical and Electronics Engineering (IEEE) 802.16e- 2009 standards

Telecommunications

OpenAIRE

Fransman, Martin; Krafft, Jackie

2002-01-01

What is the telecommunications industry? How does it relate to other activities in areas such as computing, software, semiconductors, the internet and electronic commerce, and the media? Where are its boundaries? What products and services should be included within it? What are its major markets? Which companies should be included in the industry? In this paper, we tackle these important questions by developing a layer model in order to map the industry. Layer models generally have a long and...

77 FR 73462 - Sunshine Act Meeting FCC To Hold Open Commission Meeting Wednesday, December 12, 2012

Science.gov (United States)

2012-12-10

... Telecommunication Commission's Rules with Regard s, International to Commercial Operations in the and Office of 3550... Advanced Telecommunication Wireless Services in the 2000- s. 2020 MHz and 2180-2200 MHz Bands (WT Docket No. 12-70); Fixed and Mobile Services in the Mobile Satellite Service Bands at 1525- 1559 MHz and 1626.5...

Design of a two-phase loop thermosyphon for telecommunications system(II): analysis and simulation

International Nuclear Information System (INIS)

Kim, Won Tae; Song, Kyu Sub; Lee, Young

1998-01-01

A computer simulation is performed for a two-phase loop thermosyphon for the B-ISDN telecommunications. The aim of this code development is to provide capabilities to predict the affects of many variables on the performance of the proposed TLT system using different empirical correlations obtained from the literature for the evaporation and condensation, and the shape factors available. In this present study, the simulation code is based on the sectorial thermal resistance network built on the flow regimes of the two-phase flows involved. The nodal resistances are solved by the typical Gauss-Seidal iteration method. The code can predict whether the proposed design is possible based on the flooding limit calculation of the system and its results are compared with the experimental results

Design of a two-phase loop thermosyphon for telecommunications system(II): analysis and simulation

Energy Technology Data Exchange (ETDEWEB)

Kim, Won Tae [Kongju National Univ., Kongju (Korea, Republic of); Song, Kyu Sub [Electronics and Telecommunications Research Institute, Taejon (Korea, Republic of); Lee, Young [Univ. of Ottawa, Ontario (Canada)

1998-10-01

A computer simulation is performed for a two-phase loop thermosyphon for the B-ISDN telecommunications. The aim of this code development is to provide capabilities to predict the affects of many variables on the performance of the proposed TLT system using different empirical correlations obtained from the literature for the evaporation and condensation, and the shape factors available. In this present study, the simulation code is based on the sectorial thermal resistance network built on the flow regimes of the two-phase flows involved. The nodal resistances are solved by the typical Gauss-Seidal iteration method. The code can predict whether the proposed design is possible based on the flooding limit calculation of the system and its results are compared with the experimental results.

Development of Korea telecommunication technology

International Nuclear Information System (INIS)

1992-06-01

It concentrates on development of Korea telecommunication technology, which is made up seven chapters. It gives description of manual central telephone exchange or private automatic telephone exchange, transmission technology on wire line and cable line technology and optical transmission, radio communication technology on mobile and natural satellite communication, network technology with intelligent network, broadband ISDN and packet switched Data Network, terminal technology with telephone and data communication terminal and development of Information Technology in Korea. It has an appendix about development of military communication system.

Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control

Science.gov (United States)

Kim, Gi-Woo; Wang, K. W.

2007-04-01

The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.

The influence of band Jahn-Teller effect and magnetic order on the magneto-resistance in manganite systems

Energy Technology Data Exchange (ETDEWEB)

Rout, G.C., E-mail: gcr@iopb.res.i [Condensed Matter Physics Group, Department of Applied Physics and Ballistics, F.M. University, Balasore, Orissa 756019 (India); Parhi, Nilima [Department of Physics, M.P.C. (Autonomous) College, Baripada, Orissa 757001 (India); Behera, S.N. [Institute of Material Science, Bhubaneswar 751004 (India)

2009-08-01

A model calculation is presented in order to study the magneto-resistivity through the interplay between magnetic and structural transitions for the manganite systems. The model consists of an orbitally doubly degenerate conduction band and a periodic array of local moments of the t{sub 2g} electrons. The band electrons interact with the local t{sub 2g} electrons via the s-f hybridization. The phonons interact with the band electrons through static and dynamic band Jahn-Teller (J-T) interaction. The model Hamiltonian including the above terms is solved for the single particle Green's functions and the imaginary part of the self-energy gives the electron relaxation time. Thus the magneto-resistivity (MR) is calculated from the Drude formula. The MR effect is explained near the magnetic and structural transition temperatures.

Band gap engineering of MoS{sub 2} upon compression

Energy Technology Data Exchange (ETDEWEB)

López-Suárez, Miquel, E-mail: miquel.lopez@nipslab.org [NiPS Laboratory, Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia (Italy); Neri, Igor [NiPS Laboratory, Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia (Italy); INFN Sezione di Perugia, via Pascoli, 06123 Perugia (Italy); Rurali, Riccardo [Institut de Ciència de Materials de Barcelona (ICMAB–CSIC) Campus de Bellaterra, 08193 Bellaterra, Barcelona (Spain)

2016-04-28

Molybdenum disulfide (MoS{sub 2}) is a promising candidate for 2D nanoelectronic devices, which shows a direct band-gap for monolayer structure. In this work we study the electronic structure of MoS{sub 2} upon both compressive and tensile strains with first-principles density-functional calculations for different number of layers. The results show that the band-gap can be engineered for experimentally attainable strains (i.e., ±0.15). However, compressive strain can result in bucking that can prevent the use of large compressive strain. We then studied the stability of the compression, calculating the critical strain that results in the on-set of buckling for free-standing nanoribbons of different lengths. The results demonstrate that short structures, or few-layer MoS{sub 2}, show semi-conductor to metal transition upon compressive strain without bucking.

76 FR 72124 - Internet-Based Telecommunications Relay Service Numbering

Science.gov (United States)

2011-11-22

... Docket No. 10-191; FCC 11-123] Internet-Based Telecommunications Relay Service Numbering AGENCY: Federal..., the information collection associated with the Commission's Internet- Based Telecommunications Relay... Telecommunications Relay Service Numbering, CG Docket No. 03-123; WC Docket No. 05-196; WC Docket No. 10-191; FCC 11...

31 CFR 515.542 - Mail and telecommunications-related transactions.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Mail and telecommunications-related... Licenses, Authorizations, and Statements of Licensing Policy § 515.542 Mail and telecommunications-related..., incident to the provision of telecommunications services between the United States and Cuba, the provision...

High resolution emission Fourier transform infrared spectra of the 4p-5s and 5p-6s bands of ArH.

Science.gov (United States)

Baskakov, O I; Civis, S; Kawaguchi, K

2005-03-15

In the 2500-8500 cm(-1) region several strong emission bands of (40)ArH were observed by Fourier transform spectroscopy through a dc glow discharge in a mixture of argon and hydrogen. Rotational-electronic transitions of the two previously unstudied 4p-5s and 5p-6s,v = 0-0, bands of (40)ArH were measured and assigned in the 6060 and 3770 cm(-1) regions, respectively. A simultaneous fit of the emission transitions of the 4p-5s and 5p-6s bands and an extended set of transitions of the 6s-4p band observed by Dabrowski, Tokaryk, and Watson [J. Mol. Spectrosc. 189, 95 (1998)] and remeasured in the present work yielded consistent values of the spectroscopic parameters of the electronic states under investigation. In the branch of the 4p-5s band with transitions of type (Q)Q(f(3)e) we observed a narrowing in the linewidths with increasing rotational quantum number N. The rotational dependence of the linewidth is caused by predissociation of the 5s state by the repulsive ground 4s state through homogeneous coupling and changes in overlap integrals of the vibrational wave functions with the rotational level. Analysis was based on the Fermi's golden rule approximation model. In the 4p-5s band region a vibrational sequence ofv(')-v(")=1-1, 2-2, and 3-3 were recorded and a number of transitions belonging to the strongest (Q)Q(f(3)e) form branch of the 1-1 band were analyzed.

Hazard banding in compliance with the new Globally Harmonised System (GHS) for use in control banding tools.

Science.gov (United States)

Arnone, Mario; Koppisch, Dorothea; Smola, Thomas; Gabriel, Stefan; Verbist, Koen; Visser, Remco

2015-10-01

Many control banding tools use hazard banding in risk assessments for the occupational handling of hazardous substances. The outcome of these assessments can be combined with advice for the required risk management measures (RMMs). The Globally Harmonised System of Classification and Labelling of Chemicals (GHS) has resulted in a change in the hazard communication elements, i.e. Hazard (H) statements instead of Risk-phrases. Hazard banding schemes that depend on the old form of safety information have to be adapted to the new rules. The purpose of this publication is to outline the rationales for the assignment of hazard bands to H statements under the GHS. Based on this, this publication proposes a hazard banding scheme that uses the information from the safety data sheets as the basis for assignment. The assignment of hazard bands tiered according to the severity of the underlying hazards supports the important principle of substitution. Additionally, the set of assignment rules permits an exposure-route-specific assignment of hazard bands, which is necessary for the proposed route-specific RMMs. Ideally, all control banding tools should apply the same assignment rules. This GHS-compliant hazard banding scheme can hopefully help to establish a unified hazard banding strategy in the various control banding tools. Copyright © 2015 Elsevier Inc. All rights reserved.

Croatian Telecommunication Market: Concentration Trends in the Period from 2003 to 2008

Directory of Open Access Journals (Sweden)

Mirjana Pejić Bach

2013-01-01

Full Text Available Telecommunication markets are a valuable factor that contributes to the economic growth and development. The development of the telecommunication markets and services was slower in the countries in transition than in developed European countries, altough after the fall of communism countries in transition implemented a big progress in spreading and modernizing of their telecommunication network.The paper analysis the level of concentration of telecommunication industry in Croatia from 2003 to 2008. The data used in the analysis consider 50 Croatian largest IT firms that are operating on telecommunication market and specific telecommunication sectors: producers of telecommunication equipment, distributers of telecommunication services and implementers of telecommunication solutions. The main two conclusions of this article are: (1 degree of concentration on the telecommunication market in Croatia changed differently in different market shares, (2 degree of concentration on the telecommunication market in Croatia is influenced by different barriers to enter the market.The analysis finds that Croatian telecommunication industry is in a good position even a few steps ahead of some other transition countries.

Tracking and Data Relay Satellite System user impact and network compatibility study. [antenna design and telecommunication links

Science.gov (United States)

1973-01-01

The report contains data on antenna configurations for the low data rate users of the Tracking and Data Relay Satellite System (TDRSS). It treats the coverage and mutual visibility considerations between the user satellites and the relay satellites and relates these considerations to requirements of antenna beamwidth and fractional user orbital coverage. A final section includes user/TDRS telecommunication link budgets and forward and return link data rate tradeoffs.

Electronics and telecommunications in Poland - issues and perspectives

CERN Document Server

Modelski, J; 10.1117/12.871182; 10.1117/12.871183; 10.1117/12.871196

2010-01-01

Electronics is under development in this country in an organized and institutional way since the beginning of 30-ties of the previous century. It grew up from electrical engineering of weak currents and its first name used popularly was communications. It was time when television was born and the radio was maturing. Electronics is a branch of research and technology which deals with generation and processing of electrical and electromagnetic signals. A subject of telecommunications is signal transmission for a distance. Electronics and telecommunications (ET) includes or is combined with other branches like: microelectronics, radioelectronics, optoelectronics, photonics, acoustoelectronics, magnetronics, bioelectronics, energoelectronics, material engineering, semiconductor physics, automation and robotics, mechatronics and microsystems, informatics, teleinformatics, software engineering and other. Devices and functional systems of ET such as computers, data warehouses, cell phones, TV sets, Internet, GPS are...

31 CFR 560.508 - Telecommunications and mail transactions authorized.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Telecommunications and mail... REGULATIONS Licenses, Authorizations and Statements of Licensing Policy § 560.508 Telecommunications and mail... telecommunications and mail between the United States and Iran are authorized. For purposes of this section, the term...

Body area networks using IEEE 802156 implementing the ultra wide band physical layer

CERN Document Server

Hernandez, Marco; Mucchi, Lorenzo

2014-01-01

The market of wearable wireless medical sensors is experiencing a rapid growth and the associated telecommunications services for the healthcare sector are forecast to further increase in the next years. Medical body area networks (MBANs) allow the mobility of patients and medical personnel by facilitating the remote monitoring of patients suffering from chronic or risky diseases. Currently, MBANs are being introduced in unlicensed frequency bands, where the risk of mutual interference with other electronic devices radiating in the same band can be high. Thus, coexistence is an issue on which

The DSS-14 C-band exciter

Science.gov (United States)

Rowan, D. R.

1989-01-01

The development and implementation of a C-band exciter for use with the Block IV Receiver-Exciter Subsystem at Deep Space Station 14 (DSS-14) has been completed. The exciter supplements the standard capabilities of the Block IV system by providing a drive signal for the C-band transmitter while generating coherent translation frequencies for C-band (5-GHz) to S-band (2.2- to 2.3-GHz) Doppler extraction, C-band to L-band (1.6-GHz) zero delay measurements, and a level calibrated L-band test signal. Exciter functions are described, and a general explanation and description of the C-band uplink controller is presented.

Direct imaging of band profile in single layer MoS2 on graphite: quasiparticle energy gap, metallic edge states, and edge band bending.

Science.gov (United States)

Zhang, Chendong; Johnson, Amber; Hsu, Chang-Lung; Li, Lain-Jong; Shih, Chih-Kang

2014-05-14

Using scanning tunneling microscopy and spectroscopy, we probe the electronic structures of single layer MoS2 on graphite. The apparent quasiparticle energy gap of single layer MoS2 is measured to be 2.15 ± 0.06 eV at 77 K, albeit a higher second conduction band threshold at 0.2 eV above the apparent conduction band minimum is also observed. Combining it with photoluminescence studies, we deduce an exciton binding energy of 0.22 ± 0.1 eV (or 0.42 eV if the second threshold is use), a value that is lower than current theoretical predictions. Consistent with theoretical predictions, we directly observe metallic edge states of single layer MoS2. In the bulk region of MoS2, the Fermi level is located at 1.8 eV above the valence band maximum, possibly due to the formation of a graphite/MoS2 heterojunction. At the edge, however, we observe an upward band bending of 0.6 eV within a short depletion length of about 5 nm, analogous to the phenomena of Fermi level pinning of a 3D semiconductor by metallic surface states.

TV White spaces for wireless broadband in rural areas: the regulator, broadcaster and telecommunication(s) operator viewpoint

CSIR Research Space (South Africa)

Mfupe, LP

2012-05-01

Full Text Available Communications Authority of South Africa (ICASA) has recently conducted occupancy measurement audit of two Ultra High Frequency (UHF) radio spectrum bands: the 450 - 470 MHz and the 790- 862 MHz in major South African cities. The results from these audits..., such as 3GPP Long Term Evolution (LTE), to a possible operation in UHF TVWS bands is considered. In many cases, it is assumed that TVWS would be largely available in rural areas where broadband connectivity is rarely available. The LTE - Time Division...

76 FR 48939 - Announcement of Meeting of the International Telecommunication Advisory Committee

Science.gov (United States)

2011-08-09

... Street, NW., Washington, DC 20520, to seek advice from the telecommunications industry on: (a) The consultation of International Telecommunication Union, Telecommunication Standardization Sector Study Group 15... Telecommunication Advisory Committee SUMMARY: This notice announces a meeting of the International Telecommunication...

The Low Band Observatory (LOBO): Expanding the VLA Low Frequency Commensal System for Continuous, Broad-band, sub-GHz Observations

Science.gov (United States)

Kassim, Namir E.; Clarke, Tracy E.; Helmboldt, Joseph F.; Peters, Wendy M.; Brisken, Walter; Hyman, Scott D.; Polisensky, Emil; Hicks, Brian

2015-01-01

The Naval Research Laboratory (NRL) and the National Radio Astronomy Observatory (NRAO) are currently commissioning the VLA Low Frequency Ionosphere and Transient Experiment (VLITE) on a subset of JVLA antennas at modest bandwidth. Its bounded scientific goals are to leverage thousands of JVLA on-sky hours per year for ionospheric and transient studies, and to demonstrate the practicality of a prime-focus commensal system on the JVLA. Here we explore the natural expansion of VLITE to a full-antenna, full-bandwidth Low Band Observatory (LOBO) that would follow naturally from a successful VLITE experience. The new Low Band JVLA receivers, coupled with the existing primary focus feeds, can access two frequency bands: 4 band (54 - 86 MHz) and P band (236-492 MHz). The 4 band feeds are newly designed and now undergoing testing. If they prove successful then they can be permanently mounted at the primary focus, unlike their narrow band predecessors. The combination of Low Band receivers and fixed, primary-focus feeds could provide continuous, broad-band data over two complimentary low-frequency bands. The system would also leverage the relatively large fields-of-view of ~10 degrees at 4 band, and ~2.5 degrees at P band, coupling an excellent survey capability with a natural advantage for serendipitous discoveries. We discuss the compelling science case that flows from LOBO's robust imaging and time domain capabilities coupled with thousands of hours of wide-field, JVLA observing time each year. We also touch on the possibility to incorporate Long Wavelength Array (LWA) stations as additional 'dishes' through the LOBO backend, to improve calibration and sensitivity in LOBO's 4 band.

Fire protection for telecommunications central offices

International Nuclear Information System (INIS)

McKenna, L.A. Jr.

1990-01-01

The provision of continuous, uninterrupted telecommunications service is vital to modern life. In order to provide uninterrupted service to customers, a service continuity program has been in place with AT and T for many years. This program integrates many different protection strategies and plans, each designed to mitigate one of the many threats to service continuity. The fire protection program implemented within AT and T is a part of this service continuity program. In the design of this program, a number of unusual problems had to be addressed due to the service continuity requirements. Typical solutions to fire protection problems (ignition prevention, detection, and suppression) which are embodied in building and fire prevention codes are inadequate to provide service continuity. This presentation outlines the basic arrangement of a telecommunications central office, the specific fire protection problems encountered, the fire protection philosophy developed through the use of a systems approach, and the implementation of the fire protection program. Special emphasis is placed on the strategies employed in lieu of more traditional fire protection schemes and the stimuli for selecting them

47 CFR 54.307 - Support to a competitive eligible telecommunications carrier.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Support to a competitive eligible telecommunications carrier. 54.307 Section 54.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED....307 Support to a competitive eligible telecommunications carrier. (a) Calculation of support. A...

CULTURAL INFLUENCES ON PRE-PAY MOBILE TELECOMMUNICATIONS SERVICES USERS

Directory of Open Access Journals (Sweden)

Georgeta-Madalina MEGHISAN

2015-06-01

Full Text Available Purpose: The purpose of this research paper is to identify the preferences of the pre-pay mobile telecommunications services young users from Romania. Approach/ methodology: The analysis of the pre-pay mobile telecommunications services was made using statistical functions: descriptive statistics, t test, correlation and factor analysis. Results: According to the analysis made, we could underline the habits of usage from the part of pre-pay mobile telecommunications services consumers. Originality: The paper drew an objective analysis on the pre-pay mobile telecommunications services from the perspective of young consumers.

A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

Science.gov (United States)

Kelly, Kenneth C.; Huang, John

2000-01-01

A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

47 CFR 54.621 - Access to advanced telecommunications and information services.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Access to advanced telecommunications and information services. 54.621 Section 54.621 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... § 54.621 Access to advanced telecommunications and information services. (a) Twenty-five percent of the...

Robotics and telecommunication systems to provide better access to ultrasound expertise in the OR.

Science.gov (United States)

Angelini, L; Papaspyropoulos, V

2000-01-01

Surgery has begun to evolve as a result of the intense use of technological innovations. The result of this is better services for patients and enormous opportunities for the producers of biomedical instruments. The surgeon and the technologist are fast becoming allies in applying the latest developments of robotics, image treatment, simulation, sensors and telecommunications to surgery, in particular to the emerging field of minimally-invasive surgery. Ultrasonography is at present utilised both for diagnostic and therapeutic purposes in various fields. Intraoperative US examination can be of primary importance, especially when dealing with space-occupying lesions. The widening use of minimally-invasive surgery has furthered the development of US for use during this type of surgery. The success of a US examination requires not only a correct execution of the procedure, but also a correct interpretation of the images. We describe two projects that combine robotics and telecommunication systems to provide better access to US expertise in the operating room. The Midstep project has as its object the realisation of two robotic arms, one for the distant control of the US probe during laparoscopic surgery and the second to perform tele-interventional US. The second project, part of the Strategic CNR Project-'Robotics in Surgery', involves the realisation of a common platform for tracking and targeting surgical instruments in video-assisted surgery.

Telecommunications Primer

OpenAIRE

Joseph Becker

2013-01-01

A description of modern telecommunications devices which can be useful in inter-library communications, including their capacities, types of signals and carriers. Described are telephone lines, radio broadcasting, coaxial cable, microwave and communications satellites. This article, and the one following, were presented as tutorials by the author's to participants at the American Library Association's Atlantic City Convention on June 25, 1969.

Report: Wells Band Council Needs to Improve Its Accounting System to Comply With Federal Regulations

Science.gov (United States)

Report #14-2-0316, July 14, 2014. The Wells Band Council’s accounting system did not comply with federal regulations, which resulted in $390,000 of questioned costs and proposed high-risk designation for the grantee.

A microscopic study of the S band in the generator co-ordinate approach

International Nuclear Information System (INIS)

Wuest, E.; Ansari, A.

1985-04-01

Using particle number and spin projected cranked Hartree-Fock-Bogolubov (CHFB) wave functions in the generator co-ordinate method (GCM) with the cranking frequency as a GC the shortcomings of the usual CHFB theory are removed and the ground as well as the s band are studied simultaneously. In particular, low-spin properties of the s band are discussed for a backbending nucleus 158 Dy. (author)

Dual Band Magnonic Crystals: Model System and Basic Spin Wave Dynamics

Directory of Open Access Journals (Sweden)

Federico Montoncello

2016-01-01

Full Text Available We investigate a special design of two-dimensional magnonic crystal, consisting of two superimposed lattices with different lattice constants, such that spin waves (SWs can propagate either in one or the other sublattice, depending on which of the two frequency bands they belong to. The SW bands are separated by a very large bandgap (in our model system, 6 GHz, easily tunable by changing the direction of an applied magnetic field, and the overlap of their spatial distribution, for any frequency of their bands, is always negligible. These properties make the designed system an ideal test system for a magnonic dual band waveguide, where the simultaneous excitation and subsequent propagation of two independent SW signals are allowed, with no mutual interference.

Electronic structure of the misfit-layer compound (SnS)1.17NbS2 deduced from band-structure calculations and photoelectron spectra

NARCIS (Netherlands)

Fang, C.M.; Ettema, A.R.H.F.; Haas, C.; Wiegers, G.A.; Leuken, H. van; Groot, R.A. de

1995-01-01

In order to understand the electronic structure of the misfit-layer compound (SnS)1.17NbS2 we carried out an ab initio band-structure calculation of the closely related commensurate compound (SnS)1.20NbS2. The band structure is compared with calculations for NbS2 and for hypothetical SnS with

Design and control strategy for a hybrid green energy system for mobile telecommunication sites

Science.gov (United States)

Okundamiya, Michael S.; Emagbetere, Joy O.; Ogujor, Emmanuel A.

2014-07-01

The rising energy costs and carbon footprint of operating mobile telecommunication sites in the emerging world have increased research interests in green technology. The intermittent nature of most green energy sources creates the problem of designing the optimum configuration for a given location. This study presents the design analysis and control strategy for a cost effective and reliable operation of the hybrid green energy system (HGES) for GSM base transceiver station (BTS) sites in isolated regions. The design constrains the generation and distribution of power to reliably satisfy the energy demand while ensuring safe operation of the system. The overall process control applies the genetic algorithm-based technique for optimal techno-economic sizing of system's components. The process simulation utilized meteorological data for 3 locations (Abuja, Benin City and Sokoto) with varying climatic conditions in Nigeria. Simulation results presented for green GSM BTS sites are discussed and compared with existing approaches.

Telecommunications technology and rural education in the United States

Science.gov (United States)

Perrine, J. R.

1975-01-01

The rural sector of the US is examined from the point of view of whether telecommunications technology can augment the development of rural education. Migratory farm workers and American Indians were the target groups which were examined as examples of groups with special needs in rural areas. The general rural population and the target groups were examined to identify problems and to ascertain specific educational needs. Educational projects utilizing telecommunications technology in target group settings were discussed. Large scale regional ATS-6 satellite-based experimental educational telecommunications projects were described. Costs and organizational factors were also examined for large scale rural telecommunications projects.

In-Fiber Subpicosecond Pulse Shaping for Nonlinear Optical Telecommunication Data Processing at 640 Gbit/s

Directory of Open Access Journals (Sweden)

J. Azaña

2012-01-01

Full Text Available We review recent work on all-fiber (long-period fiber grating devices for optical pulse shaping, particularly flat-top pulse generation, down to the subpicosecond range and their application for nonlinear switching (demultiplexing of optical time-division multiplexed (OTDM data signals in fiber-optic telecommunication links operating up to 640 Gbit/s. Experiments are presented demonstrating error-free 640-to-10 Gbit/s demultiplexing of the 64 tributary channels using the generated flat-top pulses for temporal gating in a Kerr-effect-based nonlinear optical loop mirror. The use of flat-top pulses has critical benefits in the demultiplexing process, including a significantly increased timing-jitter tolerance (up to ~500 fs, i.e., 30% of the bit period and the associated improvement in the bit-error-rate performance (e.g., with a sensitivity increase of up to ~13 dB as compared with the use of Gaussian-like gating pulses. Long-period fiber grating pulse shapers with reduced polarization dependence are fabricated and successfully used for polarization-independent 640-to-10 Gbit/s demultiplexing experiments.

(abstract) Telecommunications for Mars Rovers and Robotic Missions

Science.gov (United States)

Cesarone, Robert J.; Hastrup, Rolf C.; Horne, William; McOmber, Robert

1997-01-01

Telecommunications plays a key role in all rover and robotic missions to Mars both as a conduit for command information to the mission and for scientific data from the mission. Telecommunications to the Earth may be accomplished using direct-to-Earth links via the Deep Space Network (DSN) or by relay links supported by other missions at Mars. This paper reviews current plans for missions to Mars through the 2005 launch opportunity and their capabilities in support of rover and robotic telecommunications.

7 CFR 1755.30 - List of telecommunications standard contract forms.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false List of telecommunications standard contract forms... UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.30 List of telecommunications standard contract forms. (a...

Telecommunications Primer

Directory of Open Access Journals (Sweden)

Joseph Becker

2013-05-01

Full Text Available A description of modern telecommunications devices which can be useful in inter-library communications, including their capacities, types of signals and carriers. Described are telephone lines, radio broadcasting, coaxial cable, microwave and communications satellites. This article, and the one following, were presented as tutorials by the author's to participants at the American Library Association's Atlantic City Convention on June 25, 1969.

76 FR 65965 - Contributions to the Telecommunications Relay Services Fund

Science.gov (United States)

2011-10-25

...] Contributions to the Telecommunications Relay Services Fund AGENCY: Federal Communications Commission. ACTION... Telecommunications Relay Services (TRS) Fund in a manner prescribed by regulation that is consistent with and... . SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Contributions to the Telecommunications Relay...

Telecommunications Policy Research Conference. International Comparisons I (Europe) Section. Papers.

Science.gov (United States)

Telecommunications Policy Research Conference, Inc., Washington, DC.

Three papers consider telecommunications policy in Great Britain and Germany specifically, and the nations of the European Economic Community generally. The first paper, "German Telecommunications Law and Policies" (Ernst-Joachim Mestamacker) outlines the present structure of telecommunications in West Germany, and discusses deregulation…

47 CFR 32.6561 - Depreciation expense-telecommunications plant in service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Depreciation expense-telecommunications plant... Expense Accounts § 32.6561 Depreciation expense—telecommunications plant in service. This account shall include the depreciation expense of capitalized costs in Accounts 2112 through 2441, inclusive. [69 FR...

Study and design of a hybrid wind-diesel-compressed air system for providing electricity to a remote telecommunication station; Etudes et conception d'un systeme hybride eolien-diesel-air comprime pour l'electrification d'une station de telecommunications isolee

Energy Technology Data Exchange (ETDEWEB)

Ibrahim, H.; Dimitrova, M. [TechnoCentre eolien Gaspesie-les Iles, Gaspe, PQ (Canada); Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada); Perron, J. [Quebec Univ., Chicoutimi, PQ (Canada)

2010-07-01

This poster reported on a study that examined the feasibility of using a hybrid wind-diesel-compressed air system to produce electricity at remote telecommunication stations. Low and high penetration wind-diesel hybrid systems were studied in order to reduce the diesel consumption. The use of a high penetration wind-diesel system together with compressed air energy storage (CAES) was shown to be a viable alternative to improve the overall percentage of renewable energy and reduce the cost of electricity in remote areas where a good wind resource is available. Different technical solutions for the CAES system were compared. refs., figs.

Telecommunications in South Africa: Governance of who is actually regulating?

Directory of Open Access Journals (Sweden)

L-F Pau

2013-09-01

Full Text Available Although the Republic of South Africa telecommunications market is a maturing one with a large customer base to serve, it has been repeatedly been observed over the past few years that many good intentions were formulated in the regulatory sphere with sometimes poor outcomes and unclear governance. A number of surprising observations have been made on the outcomes, the delays or other process related events linked to regulatory measures. The paper thus researches first, from a governance point of view, who is actually regulating the telecommunications industry; it identifies next opportunities and bottlenecks whereby a change might happen to reach the expected outcomes. A political economy methodology is taken, backed up by extensive field work over 2010 and 2011, leading to a web of conjectures providing answers to the first question, based on an extensive analysis of key stakeholders goals, positions and interactions. Finally, a number of measures are proposed to improve the governance, regulatory impact and efficiency, and evolve the South African telecommunications eco-system.

The electronic band parameters calculated by the Kronig-Penney method for Cd1-xZnxS quantum dot superlattices

International Nuclear Information System (INIS)

Sakly, A.; Safta, N.; Mejri, H.; Lamine, A. Ben

2009-01-01

This work reports on a theoretical study of superlattices based on Cd 1-x Zn x S quantum dots embedded in an insulating material. We show, in particular, how this system can be assumed to a series of flattened cylindrical quantum dots with a finite barrier height at the boundary. In this paper, are also reviewed the approximations needed to calculate the band edges of the Cd 1-x Zn x S superlattices with use of the Kronig-Penney model. The electronic states and the electron effective masses of both Γ 1 - and Γ 2 -minibands have been computed as a function of zinc composition for different inter-quantum dot separations. As is found, the CdS system is appropriate to give rise a superlattice behavior for conduction electrons in a relatively large range of inter-sheet separations. An attempt to explain the electron band parameters calculated will be presented.

Silicon photonics for telecommunications and biomedicine

CERN Document Server

Fathpour, Sasan

2011-01-01

Given silicon's versatile material properties, use of low-cost silicon photonics continues to move beyond light-speed data transmission through fiber-optic cables and computer chips. Its application has also evolved from the device to the integrated-system level. A timely overview of this impressive growth, Silicon Photonics for Telecommunications and Biomedicine summarizes state-of-the-art developments in a wide range of areas, including optical communications, wireless technologies, and biomedical applications of silicon photonics. With contributions from world experts, this reference guides

Realization of an X-Band RF System for LCLS

CERN Document Server

McIntosh, Peter; Brooks, William; Emma, Paul; Rago, Carl

2005-01-01

A single X-band (11.424 GHz) accelerating structure is to be incorporated in the LCLS Linac design to linearize the energy-time correlation (or gradient) across each bunch, features which originate in the preceding accelerating structures (L0 and L1). This harmonic RF system will operate near the negative RF crest to decelerate the beam, reducing these non-linear components of the correlation, providing a more efficient compression in the downstream bunch compressor chicanes (BC1 and BC2). These non-linear correlation components, if allowed to grow, would lead to Coherent Synchrotron Radiation (CSR) instabilities in the chicanes, effectively destroying the coherence of the photon radiation in the main LCLS undulator. The many years devoted at SLAC in the development of X-band RF components for the NLC/JLC linear collider project, has enabled the technical and financial realization of such an RF system for LCLS. This paper details the requirements for the X-band system and the proposed scheme planned for achie...

34 CFR 668.38 - Enrollment in telecommunications and correspondence courses.

Science.gov (United States)

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Enrollment in telecommunications and correspondence... Student Eligibility § 668.38 Enrollment in telecommunications and correspondence courses. (a) If a student..., or graduate degree. (b)(1) For purposes of this section, a student enrolled in a telecommunications...

Benchmarking in Identifying Priority Directions of Development of Telecommunication Operators

Directory of Open Access Journals (Sweden)

Zaharchenko Lolita A.

2013-12-01

Full Text Available The article analyses evolution of development and possibilities of application of benchmarking in the telecommunication sphere. It studies essence of benchmarking on the basis of generalisation of approaches of different scientists to definition of this notion. In order to improve activity of telecommunication operators, the article identifies the benchmarking technology and main factors, that determine success of the operator in the modern market economy, and the mechanism of benchmarking and component stages of carrying out benchmarking by a telecommunication operator. It analyses the telecommunication market and identifies dynamics of its development and tendencies of change of the composition of telecommunication operators and providers. Having generalised the existing experience of benchmarking application, the article identifies main types of benchmarking of telecommunication operators by the following features: by the level of conduct of (branch, inter-branch and international benchmarking; by relation to participation in the conduct (competitive and joint; and with respect to the enterprise environment (internal and external.

Telecommunications Deregulation

OpenAIRE

Jerry A. Hausman; William E. Taylor

2012-01-01

From Fred Kahn's writings and experiences as a telecommunications regulator and commenter, we draw the following conclusions: prices must be informed by costs; costs are actual incremental costs; costs and prices are an outcome of a Schumpeterian competitive process, not the starting point; excluding incumbents from markets is fundamentally anticompetitive; and a regulatory transition to deregulation entails propensities to micromanage the process to generate preferred outcomes, visible compe...

A telecommunications journey rural health network.

Science.gov (United States)

Moore, Joe

2012-01-01

Utilizing a multi-gigabit statewide fiber healthcare network, Radiology Consultants of Iowa (RCI) set out to provide instantaneous service to their rural, critical access, hospital partners. RCIs idea was to assemble a collection of technologies and services that would even out workflow, reduce time on the road, and provide superior service. These technologies included PACS, voice recognition enabled dictation, HL7 interface technology, an imaging system for digitizing paper and prior films, and modern communication networks. The Iowa Rural Health Telecommunication Project was undertaken to form a system that all critical access hospitals would participate in, allowing RCI radiologists the efficiency of "any image, anywhere, anytime".

International Conference on Microelectronics, Electromagnetics and Telecommunications

CERN Document Server

Rao, N; Kumar, S; Raj, C; Rao, V; Sarma, G

2016-01-01

This volume contains 73 papers presented at ICMEET 2015: International Conference on Microelectronics, Electromagnetics and Telecommunications. The conference was held during 18 – 19 December, 2015 at Department of Electronics and Communication Engineering, GITAM Institute of Technology, GITAM University, Visakhapatnam, INDIA. This volume contains papers mainly focused on Antennas, Electromagnetics, Telecommunication Engineering and Low Power VLSI Design.

Geothermal and Trigeneration Systems as Innovative and EnvironmentallyFriendly Solutions for Telecommunication Plant Cooling

Directory of Open Access Journals (Sweden)

Paolo Trotta

2016-12-01

Full Text Available The paper deals with a model-based analysis of innovative cooling systems, to be deployed in telecommunication (TLC plants in consideration of their size, geographical location and typology (e.g. central Offices or data-centers. Environmentally friendly systems, such as geothermal heat pumps and trigeneration plants, were considered. The trade-off between the investment and operating costs was first analyzed, followed by a comparative evaluation of economic savings achievable via each candidate solution with respect to reference benchmarks, here represented by traditional air-water heat pump and conventional interaction with electrical grid. In this way, a preliminary macroscopic assessment of the best solutions was accomplished, according to the different scenarios (i.e. small or big TLC plant under investigation. A more detailed analysis, concerning the comparison between traditional and geothermal systems, was specifically carried out to evaluate savings as a function of the external temperature and, consequently, of geographical location.

47 CFR 54.209 - Annual reporting requirements for designated eligible telecommunications carriers.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Annual reporting requirements for designated eligible telecommunications carriers. 54.209 Section 54.209 Telecommunication FEDERAL COMMUNICATIONS... Service Support § 54.209 Annual reporting requirements for designated eligible telecommunications carriers...

The Construction of Infrastructure for Library's Digital Document Telecommunications.

Science.gov (United States)

Changxing, Ying; Zuzao, Lin

This paper discusses the construction of the infrastructure for libraries' digital document telecommunications. The first section describes the topologies of the library LAN (Local Area Network) cabling system, including the main characteristics of the LAN and three classical topologies typically used with LANs, i.e., the bus, star, and ring…

47 CFR 0.304 - Authority for determinations of exempt telecommunications company status.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Authority for determinations of exempt telecommunications company status. 0.304 Section 0.304 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... determinations of exempt telecommunications company status. Authority is delegated to the Chief, Wireline...

ICTEI-2015: International Conference on Telecommunications, Electronics and Informatics. Proceedings

International Nuclear Information System (INIS)

Kantser, V.; Andronic, S.

2015-01-01

This book includes articles which cover a vast range of subjects, such as: telecommunications networks and technologies; electronic, optoelectronic, photonic and information systems and devices; materials, components and equipment in electronics and communications; informatics and computer science; software development and testing etc.

Twenty-Five Years of Applications of the Modified Allan Variance in Telecommunications.

Science.gov (United States)

Bregni, Stefano

2016-04-01

The Modified Allan Variance (MAVAR) was originally defined in 1981 for measuring frequency stability in precision oscillators. Due to its outstanding accuracy in discriminating power-law noise, it attracted significant interest among telecommunications engineers since the early 1990s, when it was approved as a standard measure in international standards, redressed as Time Variance (TVAR), for specifying the time stability of network synchronization signals and of equipment clocks. A dozen years later, the usage of MAVAR was also introduced for Internet traffic analysis to estimate self-similarity and long-range dependence. Further, in this field, it demonstrated superior accuracy and sensitivity, better than most popular tools already in use. This paper surveys the last 25 years of progress in extending the field of application of the MAVAR in telecommunications. First, the rationale and principles of the MAVAR are briefly summarized. Its adaptation as TVAR for specification of timing stability is presented. The usage of MAVAR/TVAR in telecommunications standards is reviewed. Examples of measurements on real telecommunications equipment clocks are presented, providing an overview on their actual performance in terms of MAVAR. Moreover, applications of MAVAR to network traffic analysis are surveyed. The superior accuracy of MAVAR in estimating long-range dependence is emphasized by highlighting some remarkable practical examples of real network traffic analysis.

Mini-RF S- and X-band Bistatic Observations of the Floor of Cabeus Crater

Science.gov (United States)

Patterson, Gerald Wesley; Stickle, Angela; Turner, Franklin; Jensen, James; Cahill, Joshua; Mini-RF Team

2017-10-01

The Mini-RF instrument aboard NASA’s Lunar Reconnaissance Orbiter (LRO) is a hybrid dual-polarized synthetic aperture radar (SAR) and operates in concert with the Arecibo Observatory (AO) and the Goldstone deep space communications complex 34 meter antenna DSS-13 to collect S- and X-band bistatic radar data of the Moon. Bistatic radar data provide a means to probe the near subsurface for the presence of water ice, which exhibits a strong response in the form of a Coherent Backscatter Opposition Effect (CBOE). This effect has been observed in radar data for the icy surfaces of the Galilean satellites, the polar caps of Mars, polar craters on Mercury, and terrestrial ice sheets in Greenland. Previous work using Mini-RF S-band (12.6 cm) bistatic data suggests the presence of a CBOE associated with the floor of the lunar south polar crater Cabeus. The LRO spacecraft has begun its third extended mission. For this phase of operations Mini-RF is leveraging the existing AO architecture to make S-band radar observations of additional polar craters (e.g., Haworth, Shoemaker, Faustini). The purpose of acquiring these data is to determine whether other polar craters exhibit the response observed for Cabeus. Mini-RF has also initiated a new mode of operation that utilizes the X-band (4.2cm) capability of the instrument receiver and a recently commissioned X/C-band transmitter within the Deep Space Network’s (DSN) Goldstone complex to collect bistatic X-band data of the Moon. The purpose of acquiring these data is to constrain the depth/thickness of materials that exhibit a CBOE response - with an emphasis on observing the floor of Cabeus. Recent Mini-RF X-band observations of the floors of the craters Cabeus do not show evidence for a CBOE. This would suggest that the upper ~0.5 meters of the regolith for the floor of Cabeus do not harber water ice in a form detectable at 4.2 cm wavelengths.

Pair Formation of Hard Core Bosons in Flat Band Systems

Science.gov (United States)

Mielke, Andreas

2018-05-01

Hard core bosons in a large class of one or two dimensional flat band systems have an upper critical density, below which the ground states can be described completely. At the critical density, the ground states are Wigner crystals. If one adds a particle to the system at the critical density, the ground state and the low lying multi particle states of the system can be described as a Wigner crystal with an additional pair of particles. The energy band for the pair is separated from the rest of the multi-particle spectrum. The proofs use a Gerschgorin type of argument for block diagonally dominant matrices. In certain one-dimensional or tree-like structures one can show that the pair is localised, for example in the chequerboard chain. For this one-dimensional system with periodic boundary condition the energy band for the pair is flat, the pair is localised.

Band alignment of two-dimensional metal monochalcogenides MXs (M=Ga,In; X=S,Se,Te

Directory of Open Access Journals (Sweden)

Huazheng Sun

2017-09-01

Full Text Available Monolayer metal monochalcogenides MXs (M=Ga,In; X=S,Se,Te form a new class of two-dimensional semiconductors with indirect band gaps, and their band alignment information is investigated via first principles calculations. The dependence of band gap, valence-band maximum, conduction band minimum, and charge transfer on the M or X element has been obtained and can be understood from the orbital analysis of the band edges. Potential applications of metal monochalcogenides to design van der Waals heterostructures and catalyse the photo-splitting reaction of water have been discussed.

X-band RF power sources for accelerator applications

International Nuclear Information System (INIS)

Kirshner, Mark F.; Kowalczyk, Richard D.; Wilsen, Craig B.; True, Richard B.; Simpson, Ian T.; Wray, John T.

2011-01-01

The majority of medical and industrial linear accelerators (LINACs) in use today operate at S-band. To reduce size and weight, these systems are gradually migrating toward X-band. The new LINACs will require suitable RF components to power them. In anticipation of this market, L-3 Communications Electron Devices Division (EDD) has recently developed a suite of RF sources operating at 9.3 GHz to complement our existing S-band product line. (author)

47 CFR 25.159 - Limits on pending applications and unbuilt satellite systems.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Limits on pending applications and unbuilt... § 25.159 Limits on pending applications and unbuilt satellite systems. (a) Applicants with a total of... band, or a combination of pending GSO-like applications and licensed-but-unbuilt GSO-like space...

The effects on employment of the liberalisation process in the telecommunications sector

DEFF Research Database (Denmark)

Wulff, Thomas

An analysis of how the liberalisation process in the telecommunications sector in Finland has affected the employment development in the telecommunications sector......An analysis of how the liberalisation process in the telecommunications sector in Finland has affected the employment development in the telecommunications sector...

Satellites for U.S. education - Needs, opportunities and systems.

Science.gov (United States)

Morgan, R. P.; Singh, J. P.; Anderson, B. D.; Greenberg, E.

1972-01-01

This paper presents results of a continuing interdisciplinary study of the potential applications of Fixed- and Broadcast-Satellites for educational information transfer in the United States for the period 1975-1985. The status of U.S. education is examined and needs, trends and issues are discussed. The existing educational telecommunications infrastructure is examined and opportunities for satellite services are defined. Potential uses include networking of educational institutions and service centers for delivery of public and instructional television, computer-aided instruction, computing and information resources to regions and groups not now adequately served. Systems alternatives and some of the organizational and economic issues inherent in the deployment of an educational satellite system are discussed.-

Interactive Distributed Multimedia Systems and Telecommunication Services : 7th International Workshop, IDMS 2000 Enschede, The Netherlands, October 17–20, 2000 Proceedings

NARCIS (Netherlands)

Scholten, Hans; van Sinderen, Marten J.

2000-01-01

The first International Workshop on Interactive Distributed Multimedia Systems and Telecommunication Services (IDMS) was organized by Prof. K. Rothermel and Prof. W. Effelsberg, and took place in Stuttgart in 1992. It had the form of a national forum for discussion on multimedia issues related to

Bandwidth Extension of an S-band, Fundamental-Mode Eight-Beam Klystron

Science.gov (United States)

2006-04-01

Extension of an S - band , Fundamental-Mode Eight-Beam Klystron Khanh T. Nguyen Beam-Wave Research, Inc. Bethesda, MD 20814 Dean E. Pershing ATK Mission...of a five-cavity, approximately 18 cm downstream from the center of the broadband, high - power multiple-beam klystron (MBK) first gap - the logical...the circuit generates >550 kW across the band with a peak power of more than 600 kW at -3.27 Keywords: Multiple-beam klystron ; MBK; bandwidth GHz. The 1

Deep Space Telecommunications

Science.gov (United States)

Kuiper, T. B. H.; Resch, G. M.

2000-01-01

The increasing load on NASA's deep Space Network, the new capabilities for deep space missions inherent in a next-generation radio telescope, and the potential of new telescope technology for reducing construction and operation costs suggest a natural marriage between radio astronomy and deep space telecommunications in developing advanced radio telescope concepts.

Block 3 X-band receiver-exciter

Science.gov (United States)

Johns, C. E.

1987-01-01

The development of an X-band exciter, for use in the X-Band Uplink Subsystem, was completed. The exciter generates the drive signal for the X-band transmitter and also generates coherent test signals for the S- and X-band Block 3 translator and a Doppler reference signal for the Doppler extractor system. In addition to the above, the exciter generates other reference signals that are described. Also presented is an overview of the exciter design and some test data taken on the prototype. A brief discussion of the Block 3 Doppler extractor is presented.

Windfarms and telecommunications towers (Scotland)

Energy Technology Data Exchange (ETDEWEB)

Munro, Hector; Kellett-Bowman, Elaine; Harris, David [and others

1996-10-30

A debate in the United Kingdom House of Commons on the environmental impact of windfarms and telecommunications towers in Scotland is reported. Concern was expressed over the adverse visual impact of such structures in rural areas which are often of considerable natural beauty. Counter arguments were based on the positive effects of new technology. The need to reconcile environmental protection with technological innovation was expressed. A Government spokesman described the comprehensive planning policy framework which has been put in place to secure sound planning decisions on renewable energy developments and the conditions on amenity protection in the regulations governing the erection of telecommunications towers. (UK)

Windfarms and telecommunications towers (Scotland)

International Nuclear Information System (INIS)

Munro, Hector; Kellett-Bowman, Elaine; Harris, David

1996-01-01

A debate in the United Kingdom House of Commons on the environmental impact of windfarms and telecommunications towers in Scotland is reported. Concern was expressed over the adverse visual impact of such structures in rural areas which are often of considerable natural beauty. Counter arguments were based on the positive effects of new technology. The need to reconcile environmental protection with technological innovation was expressed. A Government spokesman described the comprehensive planning policy framework which has been put in place to secure sound planning decisions on renewable energy developments and the conditions on amenity protection in the regulations governing the erection of telecommunications towers. (UK)

Real-space description of semiconducting band gaps in substitutional systems

International Nuclear Information System (INIS)

Magri, R.; Zunger, A.

1991-01-01

The goal of ''band-gap engineering'' in substitutional lattices is to identify atomic configurations that would give rise to a desired value of the band gap. Yet, current theoretical approaches to the problems, based largely on compilations of band structures for various latice configurations, have not yielded simple rules relating structural motifs to band gaps. We show that the band gap of substitutional AlAs/GaAs lattices can be usefully expanded in terms of a hierarchy of contributions from real-space ''atomic figures'' (pairs, triplets, quadruplets) detemined from first-principles band-structure calculations. Pair figures (up to fourth neighbors) and three-body figures are dominant. In analogy with similar cluster expansions of the total energy, this permits a systematic search among all lattice configurations for those having ''special'' band gaps. This approach enables the design of substitutional systems with certain band-gap properties by assembling atomic figures. As an illustration, we predict that the [0 bar 12]-oriented (AlAs) 1 /(GaAs) 4 /(AlAs) 1 /(GaAs) 2 superlattice has the largest band gap among all Al 0.25 Ga 0.75 As lattices with a maximum of ten cations per unit cell

Life test on indigenous s-band pulsed magnetron

International Nuclear Information System (INIS)

Wanmode, Y.D.; Shrivastava, P.; Hannurkar, P.R.

1999-01-01

A 2 MW S-band pulsed magnetron has been developed under joint collaboration between CAT and CEERI. In this development effort several lab prototypes were evaluated on 2 MW microwave test facility developed at CAT. One magnetron is subjected to life test. The present paper describes the setup and procedures used for life test. Various observations and corrections made during the life tests are also described. Results of the tests are discussed. (author)

The Effects on Employment of the Liberalisation Process in the Telecommunications Sector

DEFF Research Database (Denmark)

Henten, Anders; Wulff, Thomas

An analysis of the effects of the policies of liberalisation and privatisation in the telecommunications field on the employment development in the telecommunications sector.......An analysis of the effects of the policies of liberalisation and privatisation in the telecommunications field on the employment development in the telecommunications sector....

Pacific Telecommunications Council Annual Conference Proceedings (15th, Honolulu, Hawaii, January 17-20, 1993). Volumes I and II.

Science.gov (United States)

Savage, James G., Ed.; Wedemeyer, Dan J., Ed.

This two-volume set contains 165 papers presented at a conference that brought together over 1,100 telecommunications leaders and leading commentators from over 40 countries across the Pacific region. The papers indicate that the optimism of the telecommunications industry is possibly greater than during the 1980s, although tempered by a more…

Simulation study of the high intensity S-Band photoinjector

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xiongwei; Nakajima, Kazuhisa [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2001-10-01

In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 {pi} mm mrad can be outputted at the exit of photoinjector. (author)

Simulation study of the high intensity S-Band photoinjector

International Nuclear Information System (INIS)

Zhu, Xiongwei; Nakajima, Kazuhisa

2001-01-01

In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 π mm mrad can be outputted at the exit of photoinjector. (author)

Analysis and Synthesis of Double Negative Dielectric Media Rectenna Systems for Ambient Microwave Energy Harvesting

Directory of Open Access Journals (Sweden)

Apostolia Karampatea

2018-01-01

Full Text Available The concept of harvesting the ambient electromagnetic radiation energy, coming from public telecommunication wireless networks, has been recently subject of extensive research. Techniques proposed for this target use mainly antennas, as the grade gathering the radiation power. In this work, a method introducing the usage of specific dielectric structures with artificially negative electric permittivity and magnetic permeability (double negative media or DNG in combination with wire dipole antenna sensors is proposed as an RF harvesting system. Theoretical study of the synthesized DNG medium’s performance and the distribution of the electromagnetic field in its interior is made, with the intention of finding the areas of maximum electric field intensity at which the antenna sensors would be positioned for maximum power scavenging. The received numerical results show that the synthesized schemes are capable of enhancing the energy gathering ability. Compared to the same antenna sensors positioned in free space, they ensure higher input voltage to the rectifier and also an increase of the available power about 10 dB. Moreover, they exhibit this performance for every direction of arrival of the incoming waves. The hybrid schemes DNG dipole antenna were designed for the Universal Mobile Telecommunication System (UMTS frequency band, but the method is general and would be applied to any other frequency band and also with other antenna types.

NARROW-K-BAND OBSERVATIONS OF THE GJ 1214 SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Colón, Knicole D.; Gaidos, Eric, E-mail: colonk@hawaii.edu [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

2013-10-10

GJ 1214 is a nearby M dwarf star that hosts a transiting super-Earth-size planet, making this system an excellent target for atmospheric studies. Most studies find that the transmission spectrum of GJ 1214b is flat, which favors either a high mean molecular weight or cloudy/hazy hydrogen (H) rich atmosphere model. Photometry at short wavelengths (<0.7 μm) and in the K band can discriminate the most between these different atmosphere models for GJ 1214b, but current observations do not have sufficiently high precision. We present photometry of seven transits of GJ 1214b through a narrow K-band (2.141 μm) filter with the Wide Field Camera on the 3.8 m United Kingdom Infrared Telescope. Our photometric precision is typically 1.7 × 10{sup –3} (for a single transit), comparable with other ground-based observations of GJ 1214b. We measure a planet-star radius ratio of 0.1158 ± 0.0013, which, along with other studies, also supports a flat transmission spectrum for GJ 1214b. Since this does not exclude a scenario where GJ 1214b has an H-rich envelope with heavy elements that are sequestered below a cloud/haze layer, we compare K-band observations with models of H{sub 2} collision-induced absorption in an atmosphere for a range of temperatures. While we find no evidence for deviation from a flat spectrum (slope s = 0.0016 ± 0.0038), an H{sub 2}-dominated upper atmosphere (<60 mbar) cannot be excluded. More precise observations at <0.7 μm and in the K band, as well as a uniform analysis of all published data, would be useful for establishing more robust limits on atmosphere models for GJ 1214b.

8-band and 14-band kp modeling of electronic band structure and material gain in Ga(In)AsBi quantum wells grown on GaAs and InP substrates

Energy Technology Data Exchange (ETDEWEB)

Gladysiewicz, M.; Wartak, M. S. [Faculty of Fundamental Problems of Technology, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Kudrawiec, R. [Faculty of Fundamental Problems of Technology, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

2015-08-07

The electronic band structure and material gain have been calculated for GaAsBi/GaAs quantum wells (QWs) with various bismuth concentrations (Bi ≤ 15%) within the 8-band and 14-band kp models. The 14-band kp model was obtained by extending the standard 8-band kp Hamiltonian by the valence band anticrossing (VBAC) Hamiltonian, which is widely used to describe Bi-related changes in the electronic band structure of dilute bismides. It has been shown that in the range of low carrier concentrations n < 5 × 10{sup 18 }cm{sup −3}, material gain spectra calculated within 8- and 14-band kp Hamiltonians are similar. It means that the 8-band kp model can be used to calculate material gain in dilute bismides QWs. Therefore, it can be applied to analyze QWs containing new dilute bismides for which the VBAC parameters are unknown. Thus, the energy gap and electron effective mass for Bi-containing materials are used instead of VBAC parameters. The electronic band structure and material gain have been calculated for 8 nm wide GaInAsBi QWs on GaAs and InP substrates with various compositions. In these QWs, Bi concentration was varied from 0% to 5% and indium concentration was tuned in order to keep the same compressive strain (ε = 2%) in QW region. For GaInAsBi/GaAs QW with 5% Bi, gain peak was determined to be at about 1.5 μm. It means that it can be possible to achieve emission at telecommunication windows (i.e., 1.3 μm and 1.55 μm) for GaAs-based lasers containing GaInAsBi/GaAs QWs. For GaInAsBi/Ga{sub 0.47}In{sub 0.53}As/InP QWs with 5% Bi, gain peak is predicted to be at about 4.0 μm, i.e., at the wavelengths that are not available in current InP-based lasers.

Legal and Political Aspects of Satellite Telecommunication: An Annotated Bibliography.

Science.gov (United States)

Shervis, Katherine, Comp.

The potential of satellites for telecommunication is enormous; however, it is possible that political and legal barriers rather than technological considerations will ultimately shape the utilization of satellite systems. This annotated bibliography is designed for use by lawyers, political scientists, technicians, engineers, and scholars who need…

47 CFR 101.82 - Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Reimbursement and relocation expenses in the... License Transfers, Modifications, Conditions and Forfeitures § 101.82 Reimbursement and relocation expenses in the 2110-2150 MHz and 2160-2200 MHz bands. (a) Reimbursement and relocation expenses for the...