NATIONAL SECURITY/EMERGENCY PREPAREDNESS AND DISASTER RECOVERY COMMUNICATIONS VIA ACTS

During the period from early 1993 to 1994, the U.S. National Communication System (NCS), a government agency, sponsored the development and execution of several fixed and mobile experiments using the advanced communications technology satellite (ACTS). The purpose of these experiments was to evaluate the feasibility of integrating an ACTS-like communications system into national security/emergency preparedness (NS/EP) operational scenarios. These experiments focused on clear and secure voice communications in both the fixed and mobile environment. For the mobile experiments, the focus was on the performance of both clear and secure voice in the land-mobile satellite communications channel. For the fixed experiments, the focus was on the use of a T1 terminal for restoration of communication services in the event of a disaster and for remote user communications. The results of these experiments are described in this paper.     

European third-generation mobile systems

Vast importance is being placed in Europe on the development of third-generation mobile telecommunications systems, since it is expected that mobile and personal communications will become a key driver for growth and innovation in the next millenium as well as being a necessary building block of the wireless information society. Significant progress has been made since 1988 by a number of European Union funded R&D projects working toward the development of future generations of mobile communication concepts, systems, and networks. The ACTS (Advanced Communications Technologies and Services) program will offer, in the period 1995-1998, service providers, communications operators, and equipment manufacturers greater opportunities to master and trial mobile and personal communications services and technologies. From the user's perspective the ACTS program will strive to ensure that current mobile services are extended to include multimedia and broadband services, that access to services are made without regard to the underlying networks, and that convenient, lightweight, compact, and power-efficient terminals adapt automatically to whatever air-interface parameters are appropriate to the user's location and desired services     

NCIH services, architecture, and implementation

The telecommunications planners for the North Carolina State Government recognising the potential of asynchronous transfer mode and synchronous optical network, asked BellSouth, Carolina Telephone, and GTE to develop a proposal for a network based on ATM and SONET to enable a multitude of high-speed data and video applications throughout the state. This B-ISDN, now known as the North Carolina Information Highway (NCIH), has become widely recognized as a model for the National Information Infrastructure (NII). The services provided by the NCIH are designed to be able to support numerous emerging applications that are expected to provide significant benefits in the areas of education, health care, crime control, economic development, and government     

Emergency Medical Communications in Texas

The Texas State Department of Health has been instrumental in developing an emergency medical communications network throughout the state. This type of network has proved to be a daily convenience and a priceless necessity in times of widespread disaster. It provides a basic voice communications system between hospitals, ambulances, and emergency medical personnel in the state, yet remains simple to operate and annoyance free. This network should result in significantly better emergency medical care in the state.     

中国数字集群与应急通信发展策略

文章在论述目前广为关注的社会应急联动通信系统的基出上,探讨了中国数字集群及应急通信的相关发展策略,如有关国家/省/城市级应急联动通信的重要性,如何基于NGN及3G演进概念规划与建设新一代应急联动通信系统,如何正确处理与有机协调公众网络与专网应急联动通信之间的关系,如何加速技术创新,如何开放相关标准与接口、促进有效互联互通、维持多厂商环境下运营商及用户利益最大化等.     

An Improved GGSN Failure Restoration Mechanism for UMTS

Universal mobile telecommunications system (UMTS) provides packet-switched data services for mobile users. To efficiently deliver packets in the UMTS core network, the PDP contexts (i.e., the routing information) are maintained in the volatile storage (e.g., memory) of SGSN, GGSN, and UE. The GGSN routes packets between the UMTS core network and external data networks, and thus has heavy traffic and computation loading, which may result in PDP contexts lost or corrupted, and the QoS of the UMTS network may degrade significantly. To resolve this issue, 3GPP 23.007 proposes a mechanism for GGSN failure restoration. In this mechanism, the corrupted PDP contexts can be restored through the PDP Context Activation procedure. However, this incurs extra signaling cost to the network. To reduce the network signaling cost and delay for restoration of the corrupted PDP contexts, this paper proposes an improved mechanism “GGSN Failure Restoration” (GFR) with different backup algorithms. The analytic models and simulation experiments are conducted to evaluate GFR.Our study indicates that the GFR mechanism can significantly reduce the cost for the PDP context restoration. Phone Lin (M'02) received his BSCSIE degree and Ph.D. degree from National Chiao Tung University, Taiwan, R.O.C. in 1996 and 2001, respectively. From August 2001 to July 2004, he was an Assistant Professor in Department of Computer Science and Information Engineering (CSIE), National Taiwan University, R.O.C. Since August 2004, he has been an Associate Professor in Department of Computer Science and Information Engineering (CSIE), National Taiwan University, R.O.C. His current research interests include personal communications services, wireless Internet, and performance modeling. Dr. Lin is a Guest Editor for IEEE Wireless Communications special issue on Mobility and Resource Management. He is also an Associate Editorial Member for the WCMC Journal. Guan-Hua Tu received his B.S.C.S.I.E degree from National Central University, Taiwan, R.O.C., in 2001 and his Master degree in Computer Science from National Taiwan University, Taiwan, R.O.C., in 2003. He is currently a software engineer in MediaTek Inc. His resarch interests include personal communication services, mobile computing, and performance modeling.     

Personal Access Communications System: fixed wireless local loopand mobile configurations and services

The Personal Access Communications System (PACS) supports wireline quality voice, voiceband data, digital data, and messaging services and is based on a low-power, low-complexity design. Operating environments for PACS include indoor and outdoor; fixed, low mobility, and vehicular mobility; and private and public access. PACS is a microcellular system providing high frequency reuse efficiency and thus is capable of supporting high traffic density. These attributes make PACS ideal for providing fixed wireless local loop and mobile services in moderate to densely populated areas, including developing countries. PACS mobile and fixed wireless local loop service can be offered by interfacing PACS with advanced intelligent network/ISDN switches, any traditional wireline switches, or with cellular/personal communications system mobile switching centers. The PACS air interface has been standardized by the American National Standards Institute     

香港回归话电信

１９９７年７月１日，中国政府半恢复对香港行使主权，香港的电信发展前景引人注目。本文回顾香港通信的发展简史，剖析了香港今天的电信管制和业务市场，并勾绘出香港通信的未来前景。     

Contingency/disaster recovery planning for transmission systems ofthe Defense Information System Network

The paper provides recommendations for the enhancement and protection of the Defense Information System Network (DISN) for disaster recovery and contingencies. The DISN is a worldwide Defense Department network designed to serve consolidated and integrated communication requirements of the defense services and agencies. The ability to recover from disasters and allow for contingencies must be inherent in the design of this network. Basic design aspects of the DISN are described, along with several complementary programs for disaster recovery planning being implemented by the Office of the Manager, National Communications System (OMNCS). Both hostile and nonhostile threats are examined to set the stage for recommendations that follow. Techniques for disaster and contingency preparedness are described that will improve DISN survivability and disaster recovery. Specific technologies are considered for provision of independent orderwires and backup transmission systems. An interface device designed for transmission recovery is recommended for both satellite and terrestrial media. Other specific recommendations are made for network management within the various hierarchical levels of DISN management     

Next generation satellite systems for aeronautical communications

U.S. airspace is reaching its capacity with the current air traffic control (ATC) system. The number of flights is constantly rising and it is estimated to be over 58 million per year by 2005. The FAA has undertaken several projects to modernize the National Airspace System (NAS) to ensure the safety of the increasing number of flights. Of special importance is the modernization of the air–ground communications infrastructure, which is the heart of the ATC. The current plan in the modernization of the air–ground communications is to migrate from analog voice only system to integrated digital voice and data system. The next generation satellite systems can be an alternative to the terrestrial air–ground systems by their low propagation and transmission delays, global coverage, high capacity and free flight suitable characteristics. In this paper, we give an overview of the current and the future ATC architectures, describe the systems and the communications issues in these systems and develop a framework in which next generation satellite systems can be integrated to the future ATC systems. Copyright © 2004 John Wiley & Sons, Ltd.     

Telecommunications quality-a TQM viewpoint

The present issue of the IEEE Journal on Selected Areas in Communications addresses the quality of telecommunications services, networks, and products. It is necessary to introduce quality both in a contextual sense, denote the present progress of quality implementation, and to indicate the challenges that lie in the future. Two of the engineering quality futurists, Tony Coppola (1991) and David Jones (1991), have scoped quality from an engineering base and telecommunications have always been driven by engineering innovation. In the present paper, an insight to quality definitions is presented along with benchmark information on telecommunications     

Mobile communications

The principal problem faced by networks with mobile users is how to ensure that the service provider functions keep pace with the continually changing network state resulting from user mobility, without consuming large amounts of network resources in the process. Regardless of whether the users are mobile or stationary, all telecommunications networks must perform basic service provider functions such as controlling access to services, locating users, routing traffic, and accounting and billing for service use. However, in the presence of mobile users, all of these functions must be performed much more often and much more rapidly. Developing low-overhead high-performance service provider solutions has been and will continue to be a key area of research in mobile communications. This special issue on mobile communications comprises five articles, each of which covers a different aspect of mobile communications     

The organizational impact of docket 19880

The field of emergency medical services (EMS)provides an organizational and operational environment which lacks the geopolitical structure and discipline of other public safety services. The opportunity to rearrange the various service provider elements of EMS into a unified regional agency is not likely in current political and economic circumstances. The new EMS radio communications structure which has evolved from Federal Communications Commission Docket 19880 provides the opportunity for operational order and discipline within the various provider elements of EMS. Despite the opportunity for creating the common system approach to EMS communications, many human elements must be dealt with in breaking down traditional barriers to change.     

System Throughput Analysis of Rate Adaptive TDMA System Supporting Two Class Services

In this paper, an adaptive transmission scheme is proposed to improve the spectral efficiency of TDMA systems. Services accommodated in such systems are classified as QoS services and BE services. Unlike conventional adaptive TDMA systems where the time slot duration is fixed for each user, our proposed system employs transmission slots with adaptive duration. For QoS services, rate adaptive modulation is adopted to make use of the instantaneous channel conditions of individual user. For BE services, a media access control strategy (MAC) that takes the instantaneous transmission conditions of all physical links of all BE services into consideration is employed. A framework to study the proposed system in terms of the average packet loss and the average system throughput is presented. The maximum number of QoS services that can be supported in the system while a predefined requirement on the average packet loss is still satisfied is investigated. A comparison study shows that our proposed scheme has higher system throughput over both conventional fixed and adaptive TDMA systems. Ronghong Mo received her B.Sc. and M. Sc. Degree from Zhongshan University, Guangzhou, China, both in Physics. From July 1999 to July 2003, she was a research scholar in the department of Electrical and Computer Engineering in National University of Singapore (NUS), toward her PhD degree. She is currently working as a research engineer in NUS. Her research interests include adaptive modulation, synchronization and channel estimation in wireless communications. Yong Huat Chew received the B.Eng, M.Eng and Ph.D. degrees in Electrical Engineering from National University of Singapore, Singapore. Since 1996, he has been with the Institute for Infocomm Research (formerly also known as Center for Wireless Communications and Institute for Communications Research), an institute under Agency for Science, Technology and Research, where he is presently a lead Scientist. His research interests are in wireless communications, transmission over HFC, DSL and all-optical networks.     

Subscriber Stations in Service Integrated Optical Broad Band Communications Systems

Subscriber stations in service integrated communications systems can be implemented in many different ways. Within the HHI Broad-Band Communications System two extremely different solutions have been realized: on the one hand, subscriber stations in a conventional star type network with central exchange and analog transmission, and on the other hand, subscriber stations in a digital, loop-structured network employing distributed control. In both cases, the same services (telephone, data, videophone, TV, and stereo broadcasting) are carried to the subscriber via one single optical fiber. This paper describes these different realizations of service integrated subscriber stations in detail. The size of terminal equipment, power consumption, extendability to further subscribers, and services and reliability are the main parameters of an appropriate comparison. An analysis of both realizations, giving emphasis to the switching and multiplexing, and the feasibility of analog optical transmission will be made. Alternative realizations and an estimation concerning subscriber stations for future service integrated broad band communications systems will be presented.     

中国国家金融网络的规划设计和应用

正在试点的中国国家金融网络，是一个基于开放系统结构的，支持国家级金融应用系统的数据通信网络，它有用模块化结构设计，物理网络分主干网和区域子网２层，并将向准网格状网络拓扑演进。网络层以Ｘ．２５协议为基础并引入了帧中继技术。该网的网管系统和灾难恢复措施使网络具有较高的安全性。ＣＮＦＮ将全方位地为我国金融界广大用户提供各类数据通信服务。     

Ku-band satellite digital transmission systems

A nation-wide data communications service is being placed in service by a major telecommunications carrier. This service will rely on a satellite network being provided and installed by Harris Satellite Communications Corporation. The network supports information data rates from 56 kb/s to 2·048 Mb/s. This data communications network has been architectured to include a number of innovative monitor and control functions, up-link power control, modular equipment shelter design and a modular antenna/feed subsystem. This paper will detail this application.     

The NC-REN meets the North Carolina Information Highway

The North Carolina Research and Education Network (NC-REN), formerly known as CONCERT, is an existing video and data network, owned and operated by MCNC. NC-REN's purpose has been to provide network-based support for collaboration in the research community within the state since 1985. The first major application planned for the North Carolina Information Highway (NCIH) is an interactive video distance learning system. A secondary application proposed is the use of Switched Multimegabit Data Service (SMDS) as a means of providing data communications services over NCIH. The user community currently supported by NC-REN has come to expect high levels of service, reliability, interoperability and performance for data and video communications. MCNC is committed to see that NC-REN users receive service that is equal to or better than what is currently provided by the existing network. The prospect of migrating NC-REN-provided services to NCIH-provided transport has raised challenging technical and unique service issues     

The Application of Telecommunications to City Services

In June 1971, the Committee on Telecommunications, National Academy of Engineering produced a report "Communications Technology for Urban Improvement" containing some twenty specific ideas on the use of telecommunications-information technologies to improve living conditions in U. S. cities. The suggestions covered such urban applications as citizen-local government interaction, education, health care, environmental monitoring, transportation, citizen safety, and emergency services. In the several years that have elapsed since the Committee's report was published, an encouraging number of the suggestions are being implemented or planned experimentally. A relative lack of market aggregation, and other problems attendant on experiments involving cities has resulted in the Federal Government being the principal fundor of experiments. The Committee on Telecommunications is now carrying out studies in the following areas: 1) the planning of the viable metropolitan communications system of the future; 2) reviewing for the Department of Housing and Urban Development its ongoing experiment on the development of information systems to serve city needs, and 3) studying for the U. S. Postal Service the latter's long term, i.e., 10 to 15 year, needs for electronic message distribution systems.     

天津通信电信管理网网络管理系统的设计与实现

本重点论述如何为基于TCP／IP的计算机网络“量身定做”网络管理系统。首先介绍了网络管理的定义、网络管理体系结构。天津通信电信管理网是天津通信公司为了实现对本地电话网程控交换机的远程监控和集中操作维护而构建的计算机广域网络系统。本深入讨论了天津通信电信管理网网络管理系统的设计与实现。