个人通信网和个人通信服务

作为第三代移动通信的创新概念“个人通信”被提出以来，个人通信网和个人通信服务从定义、理论、技术、设备等各方面得到不断发展和明显进步，得到全世界通信学界的极大重视，本文依据个人通信网的定义和现实发展，对个人通信网的研究发展方向，技术重点，实现个人通信服务所需求的功能和应用前景等进行讨论。     

A radio system proposal for widespread low-power tetherlesscommunications

It is suggested that low-power digital radio as an access technology could be integrated into a local exchange network to provide a ubiquitous personal communications network (PCN). High-quality tetherless communications services that could be provided by such an exchange-network-based PCN are described. A possible low-power exchange access digital radio system for providing these exchange-network based PCS services is discussed. The radio system uses a spectrum-efficient time-division multiple-access (TDMA) architecture made possible by advanced digital signal processing techniques. Control of the frequency reuse system is described, and frequency spectrum needs are indicated     

Personal communications-a viewpoint

A personal view of an extended concept of personal communications is discussed. The relationship between low-power digital cordless technology and some alternatives (analog cordless, digital mobile radio, and cellular mobile radio) is examined. Personal communication network (PCN) power requirements, circuit quality, level of network integration, and access to network intelligence (e.g. call forwarding, call transfer, and personal number calling) are emphasized     

Broadband CDMA for personal communications systems

Multipath propagation in a broadband CDMA environment is described. A propagation model for broadband spread-spectrum signals is presented. Experimental results relating to the sharing of the band by fixed service microwave users and mobile personal communications network (PCN) users are discussed. Field tests indicate that PCN systems can provide high-quality communications when sharing the spectrum with fixed-service microwave systems in suburban and urban areas     

Personal communications services

The history of the US Federal Communications Commission (FCC) examination of proposals to allocate radio frequency spectrum to a new and innovative range of services it calls personal communications services (PCS) is outlined. Personal communication networks (PCN), which will supply mobile two-way, mass-market communications services, the most advanced offering of the PCS area, and spectrum allocation for PCS are discussed. The results of a consumer market study of the potential for PCN services are also discussed     

Advances in satellite CDMA transmission for mobile and personalcommunications

An ubiquitous network for multimedia personal communications (Personal Communications Network (PCN)) with small, individual low-cost terminals is one of the most ambitious worldwide projects for the 21st century that are being pursued nowadays. In the development of such PCN, Geostationary, Medium, and Low Earth Orbiting (GEO, MEO, LEO) satellite constellations will play a fundamental role to provide worldwide coverage for most services required by the end-user. The characteristics of efficiency and flexibility inherently required by that scenario suggest, amidst other possibilities, to take into special consideration a radio interface based on code division multiple access (CDMA) to ensure, in addition to the features mentioned above, a sufficient grade of power and spectral efficiency of the relevant satellite radio link. The aim of this paper is a review of the current status of those issues in the field of satellite CDMA transmission systems design that, in our opinion, appear fundamental to the successful operation of an efficient PCN. In particular, we survey the techniques for multiplexing, coding and transmission of direct-sequence spread spectrum (DS/SS) signals, and we touch upon the techniques for the minimization of the self-noise effect, and the related topics of power-control and multiuser detection. We also shortly address in this respect some technological aspects related to an efficient modem design via digital signal processing techniques. The final part of the paper deals more specifically with some typical issues of satellite transmission, namely the minimization of the detrimental effects of the nonlinear satellite transponder and of multipath propagation; the applicability of diversity reception to a multisatellite network is also addressed as possible means of performance boost     

802.6 MAN based personal communications network over CATV plants

An infrastructure shared 802.6 MAN based personal communication network(PCN) is to be discussed. Considering the network configurations of CATV and 802.6 MAN based PCNs, a possible architecture is proposed. It is shown that the unidirectional dual buses can be implemented over star topological CATV distribution cable networks with only two cores. The design considerations related to the network capacity and the signaling loads for wireless personal communications are investigated with numerical example. The MAN partitioning is considered to extend the capacity of the network. An analytical method to evaluate the signaling loads of 802.6 MAN based PCNs is presented with a new mobility model. It is shown that the signaling traffic increased by partitioning is not the critical constraint for the feasibility of 802.6 MAN based PCN     

Wireless digital communication: a view based on three lessonslearned

The implications of Shannon's information theory for personal communication network (PCN) design are outlined. Examples of improvements in satellite communication, magnetic recording, and modem technologies that have increasingly approached information-theoretic limits are given. The emphasis is on the application of Shannon's work to control of four types of interference: multi-user, multiple cell, multipath, and multiple media. Code-division multiple access (CDMA), time-division multiple access (TDMA), and frequency-division multiple access (FDMA) techniques in personal communications are compared     

Third generation PCN and the intelligent multimode mobile portable

The radio interfaces required for a third generation personal communications network (PCN), and the attributes of an intelligent multimode portable to operate within the PCN are speculated upon. After discussing key factors in determining spectral efficiency in PCNs, multiple access methods are considered for radio interfaces associated with high-capacity network nodes, microcellular networks, macrocellular networks, megacells, satellite mobile and private mobile radio. Modulation issues are then addressed, followed by source and channel coding. Some elements of a third generation PCN are considered next. Finally the authors present their views on an intelligent multimode mobile portable that will function in many different geographical environments and, in any one, be adaptive in changing its subsystems to variations in the channel conditions and local teletraffic loading     

Technologies on the horizon-deploying personal communicationnetworks

Present plans for personal communication networks (PCNs) in Great Britain are described. These are networks that allow mass communications between users who are generally mobile. They represent a significant extension of the capabilities of today's cellular mobile telephone networks with much smaller cells and far lower station power requirements. The relationship between PCNs and current cellular networks is examined. Technical approaches that will promote widespread PCN availability are explored     

PCS in the US and Europe

It is argued that Europe is well ahead of the US in spectrum identification, standards development, and equipment deployment for personal communication networks (PCNs). However, the very speed with which wireless activities vaulted the Europeans into prominence has caused the process to outrun the marketplace, the realities of which have slowed the process. In the US, the pace of PCN deployment will speed up now that the Federal Communications Commission (FCC) has selected the spectrum location and has promised a fast track for the rulemaking. The progress made over the last three years in the US and Europe in wireless communications and, specifically PCNs are discussed     

Engineering the information age

Electronics, computing and communications are becoming mature technologies, although there is still a tremendous amount of innovation and new technology ahead. However, the information technologies being created on this established technological base are in their infancy, and their impact on society is only just beginning. As the information age dawns, the author describes the implications for our personal and professional lives     

You'll never talk alone [cellular radio networks]

The transition in the 1990s from analogue to digital technology in cellular radio networks marked a turning point in mobile telephony, heralding a future of ubiquitous, low-cost, personal communications. The global growth of personal communications has continued at an incredibly rapid pace. The commercial pressures in today's markets are such that the development of future standards and systems are driven not simply by technology, but by commercial opportunity and market pull. In this respect personal communications has gone up a gear since the development of the early GSM digital cellular standards. The opportunities to apply PCS technology into adjacent markets and applications are huge, with new products and services limited only by imagination     

Location management strategies for cellular mobile networks

Location management in mobile communication systems is concerned with those network functions necessary to allow the users to be reached wherever they are in the network coverage area. The basic operations for that purpose-paging and location updating-are resource-consuming since both involve signalling over the radio link between the mobile stations and base stations. Future cellular mobile communication networks (wireless personal communication networks (PCN)) will have to support a large number of users, so a significant amount of radio signalling can be expected. This paper describes the conventional location management strategy (the one used in modern cellular systems like the Global System for Mobile communications (GSM)) and reviews, describes and comments on some alternative location management proposals for future high-density PCN environments that aim to reduce this expected high (radio) signalling load     

Packet CDMA versus dynamic TDMA for multiple access in anintegrated voice/data PCN

A comparative evaluation of dynamic time-division multiple access (TDMA) and spread-spectrum packet code-division multiple access (CDMA) approaches to multiple access in an integrated voice/data personal communications network (PCN) environment are presented. After briefly outlining a cellular packet-switching architecture for voice/data PCN systems, dynamic TDMA and packet CDMA protocols appropriate for such traffic scenarios are described. Simulation-based network models which have been developed for performance evaluation of these competing access techniques are then outlined. These models are exercised with example integrated voice/data traffic models to obtain comparative system performance measures such as channel utilization, voice blocking probability, and data delay. Operating points based on typical performance constraints such as voice blocking probability 0.01 (for TDMA), voice packet loss rate 10^-3 (for CDMA), and data delay 250 ms are obtained, and results are presented     

Personal communications networks: Competition,convergence, and cooperation

The increasing mobility of the workforce, combined with the rapid convergence of computer, communications, and consumer electronics technologies, has spurred the development of numerous new wireless communications products and services. Accelerating competition has vastly increased the number of technological options available to consumers to meet their needs for personal communications. Unfortunately, this increase in options has been accompanied by increased and undesirable complexities. Even for simple wireless voice communications, the average customer has to deal with multiple telephone numbers, roaming codes, and confusing pricing arrangement. Exacerbating the inherent difficulties in using individual wireless technologies is the lack of interoperability among these services. Existing wireline networks, with their ubiquity, seamless operations, and ease of use, have provided clear benchmarks for satisfying customers' basic personal communications needs. There are considerable potential benefits to be realized, in terms of increased investment efficiencies, reduced time to market and the ability to meet the individual needs of consumers more closely, through the increase in the level of cooperation among competing services and technologies.     

Equalization and space diversity techniques in mobile environments

The development of high-quality digital mobile radio systems has become a major goal in the field of digital communications. The possibility of providing speech and data services free of wire constrictions in different environments is a very attractive proposition, supported by means of the personal communications network (PCN) concept. The aim of the present article is to analyze the behavior of different receiver structures for such systems in order to obtain some clues to be used in designing the next generation of mobile systems. These systems have to provide both low- and high-data-rate services (up to 1 Mb/s) and be efficient in environments where a high density of traffic is generated. Moreover, as the carrier frequencies will range between 1 and 4 GHz, and the vehicle speed can be as high as 400 km/hr (e.g., high-speed trains), large Doppler frequency values must be coped with. Under certain conditions, diversity techniques perform better than equalization techniques in typical mobile radio environments     

移动通信新技术——LTE快速发展

我国移动通信的跨越式发展,技术进步的推动是关键因素.数据业务爆发式增长,物联网技术加速对移动带宽的需求,视频业务对流量的巨大需求,加速了LTE技术的发展;而LTE技术也必将推动移动通信进入一个新阶段.     

European mobile communications on the move

A brief summary of the main activities performed under the RACE program in the field of mobile communications is presented, In particular, the technological studies and development have been outlined, showing that work has significantly progressed with major systems performance results already available from the various testbeds developed and coordinated by the projects. In parallel, possible evolution paths from second to third generation systems have been presented, together with regulatory trends, Beyond the technological work performed under the RACE program, it is hoped that the new ACTS program will further the progress in developing wireless technologies while paying progressively growing attention to the development of a strategic vision of mobile and personal communications beyond the year 2000. Finally, a brief presentation of the ACTS program has shown that the coming years should be devoted to services validation through active user involvement in field trials. The results are expected to he of great use to potential operators, providing them the possibility of testing user acceptance of broadband mobile services. Future mobile communications systems will need to provide users with broadband capabilities and advanced services, allowing for seamless provision across fixed and mobile networks