Broadband wireless access

This article reviews the technologies and potential markets, applications, and architectures for broadband wireless access. The emergence of wireless communications for cellular systems is presented, together with its projected future evolution to mobile wideband systems. The field of broadband access systems, services, and network architectures is also covered, and then systems for broadband wireless communications for indoor local area networks and outdoor public fixed access networks are discussed. Broadband wireless access systems are emerging as a new and growing area of telecommunications, since the ability to provide access without extensive installation of copper or fiber infrastructures make wireless technology well suited for broadband services. Finally, some of the key enabling technologies, such as adaptive antennas and video compression, and the future architectural directions of broadband wireless networks are presented     

WiMAX应用潜力分析

文章分析了WiMAX在固定宽带无线接入场合和便携、移动通信场合的应用前景.文章认为:在固定宽带无线通信中,WiMAX会广泛应用于家庭用户、IP语音用户、传输承载用户和集团客户,为他们提供宽带无线接入;在便携、移动通信中,IEEE802.16即将集成到笔记本电脑和个人数字助理(PDA)等便携式电子设备中,实现在城域网范围内的可移动的宽带无线数据服务;用户需求加上WiMAX设备的批量上市及终端成本的下降,WiMAX的应用潜力巨大,市场将呈几何级增长.     

New concepts and technologies for achieving highly reliable andhigh-capacity multimedia wireless communications systems

The rapid growth of multimedia wireless communications services forces the development of advanced digital wireless systems with high reliability and high speed as well as flexibility for varying traffic conditions. To achieve such advanced wireless systems. New system design concepts different from the conventional ones aiming at increasing system capacity for voice transmission would be required. Since multimedia wireless communications require high quality, high speed, and high flexibility as well as temporary and spatial control of traffic under severe fading environments, the so-called conventional system design concept will be insufficient. New system design concepts and techniques for achieving highly reliable and high-capacity multimedia wireless communications are discussed using both time division multiple access (TDMA) and code division multiple access (CDMA) systems. The demands for high-speed and high-reliability mobile, personal, and multimedia wireless communications services strongly require matching with the trunk network constructed by a broadband optical fiber system or wired system     

Antenna systems for broadband wireless access

Broadband wireless access along with evolving mobile Internet and multimedia services are driving the surge of research and development activities for future wireless communication systems. We provide an overview of antenna systems for broadband wireless communications and introduce some of the important issues surrounding them. The approach we use is to first provide a general framework of how antenna systems may be utilized in wireless communication systems and then describe the antenna systems themselves. In particular, we consider antenna systems for the base station, mobile station, and then finally multiple-input multiple-output antenna systems where antenna systems are utilized at both the base and mobile stations     

Broadband fixed wireless access as a key component of the futureintegrated communications environment

It is an exciting time for broadband fixed wireless with key developments in frequency bands from 1 to 60 GHz and a range of new technologies being developed. While working on these new technologies, it is easy to forget that fixed wireless access will form part of an integrated communications environment of the future where users will have one communications device working in the home, at the office, and outdoors. This article predicts the communications environment of the next 20 years and looks at the role of fixed access within that environment. This involves assessing how fixed access systems will interface and integrate with in-home wireless networks, how their architecture will enable multiservice operators to utilize the same core network across a range of different access technologies, and how they will act as a channel to carry mobile traffic originating within the building. Based on the requirements this vision and architecture implies, this article critically assesses the different fixed wireless technologies available to date and compares their capabilities to provide future-proof broadband fixed wireless platforms     

The future generations of mobile communications based on broadband access technologies

The forthcoming mobile communication systems are expected to provide a wide variety of services, from high-quality voice to high-definition videos, through high data rate wireless channels anywhere in the world. The high data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band, and millimeter-wave. Broadband wireless channels have to be connected to broadband fixed networks such as the Internet and local area networks. The future-generation systems will include not only cellular phones, but also many new types of communication systems such as broadband wireless access systems, millimeter-wave LANs, intelligent transport systems, and high altitude stratospheric platform station systems. Key to the future generations of mobile communications are multimedia communications, wireless access to broadband fixed networks, and seamless roaming among different systems. This article discusses future-generation mobile communication systems.     

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     

Flexible optical wireless links and networks

The worldwide demand for broadband communications is being met in many places by installed single-mode fiber networks. However, there is still a significant "first-mile" problem, which seriously limits the availability of broadband Internet access. Free-space optical wireless communications has emerged as a viable technology for bridging gaps in existing high-data-rate communications networks, and as a temporary backbone for rapidly deployable mobile wireless communication infrastructure. In this article we describe research designed to improve the performance of such networks along terrestrial paths, including the effects of atmospheric turbulence, obscuration, transmitter and receiver design, and topology control.     

On architectures for broadband wireless systems

The growing popularity of portable and mobile computing and communication devices, along with the introduction of wireline broadband networks, is fueling demand for wireless broadband networks. Since ATM has been accepted as the standard for broadband integrated service networks, the authors consider the problem of providing “ATM-like services” to mobile devices. The fundamental issues that have to be tackled in order to provide broadband services which are currently available (or will be very shortly) to wireline hosts are discussed. The authors compare and contrast the architectures that have been proposed for extending the broadband wireline network infrastructure to the wireless environment. It is argued that transporting small ATM cells over the air leads to inefficient utilization of the already scarce transmission capacity. Subsequently, the authors propose an architecture for integrated wireless and wireline broadband networks which allows the wireline and wireless parts of the network to be designed independently, therefore allowing each to be optimized for the environment in which it operates. At the same time, the proposed architecture also permits simple and efficient interconnection between the wireline and wireless infrastructures     

光纤无线融合网络(FiWi)能效改善综述

光纤无线宽带接入网架构(Fiber Wireless Broadband Access Network,FiWi)能随时随地为终端用户提供高质量的宽带接入服务.然而,由于大量智能设备的互联和指数级数据业务的增长,Fi-Wi接入网也面临着高能耗的潜在挑战.针对融合FiWi接入网中无线反复重传、业务共存转发以及跨域资源整合所引发的高能耗问题,从高效频带分配、协作计算卸载以及网络虚拟化等方面介绍了国内外研究现状并进行了展望,以期在满足服务质量约束时进一步降低FiWi接入网中的能耗.     

未来中国4G开放移动通信终端和网络接入架构

This paper relates to an advanced open mobile communication system and method of integrating the mobile communications, wireless access systems and wired communications into one common platform architecture for China＇s 4th generation mobile communications, supporting costeffective broadband voice, data and video services in wireless, mobile and wired environment with one single integrated mobile terminal device. The paper includes new architecture in the integrated mobile device and converged network access, and minimum modification in the existing mobile telecommunication infrastructures. This paper introduces the long-term evolution strategy for China＇s TDD system platform towards China＇s future 4G mobile communications.     

Broadband Wireless Access Solutions - Progressive Challenges and Potential Valueof Next Generation Mobile Networks

The growth in mobile communication will accelerate over the next years. Today most of the mobile subscribers use cellular services only. But this will change in the near future towards broadband wireless access services like WiFi and WiMAX. This paper describes a fundamental overview of the broadband wireless access technologies and outlines the market view, major trends and introduces OFDM technologies. New developments for integration of broadband wireless access into the operators' infrastructure are also discussed.     

Mobility management in wireless ATM networks

Mobile ATM offers a common wired network infrastructure to support mobility of wireless terminals, independent of the wireless access protocol. In addition, it allows seamless migration to future wireless broadband services, such as wireless ATM, by enabling mobility of end-to-end ATM connections. In spite of the diversity in mobile networking technologies (e.g., cellular telephony, mobile-IP, packet data services, PCS), all of them require two fundamental mechanisms: location management and handoff. This article describes different schemes for augmenting a wired ATM network to support location management of mobile terminals and handoff protocols for rerouting a connection data path when the endpoint moves. A prototype implementation of mobile ATM integrating mobility support with ATM signaling and connection setup, is presented. It shows how mobile ATM may be used to provide mobility support to an IP terminal using non-ATM wireless access     

Editorial - Advanced signal processing for wireless and mobile communications

Wireless and mobile communications have developed rapidly in recent years due to the endless demand for broadband multimedia Internet access and wireless connection anywhere and any time. Several 4G standards have been proposed such as WiMax, LTE and IEEE 802.11n. Signal processing plays a key role in the evolution of wireless and mobile communications. With the emergence of various 4G enabling technologies, advanced signal processing has become ever increasingly important for low complexity, low power and efficient physical implementations of future multimedia communication systems. Multi-antenna, multi-frequency, multi-user and cooperative technologies have emerged as powerful enablers for high date rate and highly reliable broadband communications. To harvest the benefits of these technologies maximally, both excellent opportunities and significant challenges are present in the research of signal processing. The aim of this special issue was to publish some most recent advances in the signal processing aspects of these wireless and mobile communication technologies. Five papers have been selected for the special issue. These papers cover various multi-antenna topics including MIMO detection, spacetime equalization, MIMO channel prediction and estimation, and space-time coding. Some papers also consider cooperative relay communications, OFDM, and multiuser systems.     

WiMAX关键技术及网络结构探讨

WiMAX支持非视距传播条件下的无线宽带接入,它致力于为无线网络提供低时延、高质量的语音和数据服务,正迅速发展并将在无线城域网中扮演重要角色。WiMAX技术因其定位于城域级的无线宽带接入,具有覆盖范围广、传输距离远、传输速率快等优势,在未来的无线宽带移动通信领域将会占有相当重要的主导地位。文中从WiMAX的基本特征、关键技术和网络结构及应用3个维度对WiMAX进行了分析与探讨。     

BRAIN—an architecture for a broadband radio access network of the next generation

The tremendous growth rates of the Internet as well as the area of mobile communications give rise to the chance that the mobile Internet is most promising by combining both the Internet and mobile communications. These prospects are the motivation for the European research project BRAIN (Broadband Radio Access for IP‐based Networks), which is developing an open architecture for a broadband wireless mobile access network offering an integrated communication platform across heterogeneous networks and, thus, goes beyond current third generation systems and towards the mobile Internet. The project covers three major technical areas: support of seamless service provision in a mobile environment; the design of an IP‐based access network that will support non‐cellular technologies such as wireless LANs; and requirements of a broadband air interface suitable for hot spots. BRAIN is going to integrate HIPERLAN/2 with UMTS by means of an IP access network. The work is guided by a user‐centric top‐down approach ensuring that user functionality is the key driver of the project. This article will focus on that part of the BRAIN work which specifies the main interfaces of the BRAIN architecture and deals with aspects related to the support of Quality of Service and mobility. Copyright © 2001 John Wiley & Sons, Ltd.     

Dynamic multiuser resource allocation and adaptation for wireless systems

Driven by the increasing popularity of wireless broadband services, future wireless systems will witness a rapid growth of high-data-rate applications with very diverse quality of service requirements. To support such applications under limited radio resources and harsh wireless channel conditions, dynamic resource allocation, which achieves both higher system spectral efficiency and better QoS, has been identified as one of the most promising techniques. In particular, jointly optimizing resource allocation across adjacent and even nonadjacent layers of the protocol stack leads to dramatic improvement in overall system performance. In this article we provide an overview of recent research on dynamic resource allocation, especially for MIMO and OFDM systems. Recent work and open issues on cross-layer resource allocation and adaptation are also discussed. Through this article, we wish to show that dynamic resource allocation will become a key feature in future wireless communications systems as the subscriber population and service demands continue to expand.     

一种适合高速铁路的宽带无线接入网络架构

快速发展的高速铁路是需要覆盖移动语音和数据业务的新热点场景,这使得高速铁路宽带无线接入系统成为研究重点。根据高速铁路的特定环境,本文提出了一种基于光载无线通信技术的新型高速铁路宽带无线接入网络架构,阐述了相对应的媒体接入控制方案,并对其移动性管理进行了说明。     

Technological developments and socio-economic issues of wireless mobile communications

During the last 10 years, wireless communications can be considered as the fastest growing segment of telecommunications. In fact, mobile telephones have become an everyday accessory for hundreds of million people, and they are increasingly being used in the most developed and many developing countries in the world. Current forecasts indicate that demands for wireless access will exceed the number of fixed access lines by year 2010. This paper examines the technological developments, as well as the worldwide social-economic impacts of wireless mobile communications. More specifically, it gives an overview on the technological developments of wireless mobile communications, describes the evolution towards the next-generation systems, analyzes the reasons for the growth rate of subscribers, and the related social development. As a conclusion, it suggests several solutions in response to dangerous behaviour generated by wireless terminals.     

ROF在无线宽带移动通信中的应用

文章从光载无线通信(ROF)的基本原理出发,提出了ROF在未来无线宽带移动通信中的多种应用方式,包括ROF技术在多体制无线接入重载中的应用以及ROF在无线移动网络中实现基站与光网络节点设备的互联等.总结了ROF的技术优势,提出了有待解决的关键技术问题.