Điện thoại di động băng thông rộng không dây P1

Summary and IntroductionBroadband wireless communications have gained an increased interest during the last few years. This has been fuelled by a large demand on high frequency utilisation as well as a large number of users requiring simultaneous high data rate access for the applications of wireless mobile Internet and e-commerce. The convergence of wireless mobile and access will be the next storm in the wireless communications, which will use a new network architecture to deliver broadband services in a more generic configuration to wireless customers and supports value-added services and emerging interactive multimedia communications....
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Điện thoại di động băng thông rộng không dây P1 Broadband Wireless Mobile: 3G and Beyond. Edited by Willie W. Lu Copyright  2002 John Wiley & Sons, Ltd. ISBN: 0-471-48661-21Summary and IntroductionBroadband wireless communications have gained an increased interest during the last fewyears. This has been fuelled by a large demand on high frequency utilisation as well as a largenumber of users requiring simultaneous high data rate access for the applications of wirelessmobile Internet and e-commerce. The convergence of wireless mobile and access will be thenext storm in the wireless communications, which will use a new network architecture todeliver broadband services in a more generic configuration to wireless customers andsupports value-added services and emerging interactive multimedia communications.Large bandwidth, guaranteed quality of service and ease of deployment coupled with recentgreat advancements in semiconductor technologies make this converged wireless system avery attractive solution for broadband service delivery.1.1 Introduction‘The future of wireless is not just wireless, it is a part of life’. When we trace back to the1980s, everyone dreamed to have a nice mobile phone. But if we dream of the wirelesspicture in 2010, the story will be totally different. Why? Because by that time, the wirelessinfrastructure (not just for communications) will be totally multi-dimensional, whether intechnologies (diversified and harmonised), applications (free mobile, local or global), orservices (service/bandwidth on demand). Our wireless personal communicator or assistant(the size of a wallet or up to a book with enough bandwidth and memory) can help us enjoyour lives. Wireless becomes easy and affordable in the mass market, even when you are awayfrom your office; your business will never be off-line. The global roaming and high-speedwireless link (thanks to the tremendous silicon advancements) will make our travels wonder-ful and feel at home. The key applications evolved from the advancement of broadband wireless, and the under-lining technologies, including broadband wireless mobile (3Gwireless and 4Gmobile), broad-band wireless access, broadband wireless networking, as well as broadband satellite solutionswill surely dominate the whole communications market and therefore improve the businessmodel in many aspects. Convergence of broadband wireless mobile and access will be the next storm in wirelesscommunications. Fuelled by many emerging technologies including digital signal processing,software definable radio, intelligent antennas, superconductor devices as well as digitaltransceiver, the future wireless system will be much more compact with limited hardwareentity and more flexible and intelligent software elements. Re-configurable and adaptive2 Broadband Wireless Mobile: 3G and Beyondterminals and base stations helps the system easily applied in the wireless mobile as well aswireless access applications. The compact hardware and very small portion of software(called Common Air Interface Basic Input-Output System or CAI-BIOS) will go the wayas the computer industries did in the past. A compact multi-dimensional broadband wirelessmodel will be adopted for the system design and implementation. Wireless Mobile Internet will be the key application of this converged broadband wirelesssystem. The terminal will be very smart instead of dumb, compatible to mobile and accessservices including wireless multicasting as well as wireless trunking. This new wirelessterminal will contain the following features:† 90% of traffic will be data;† security function will be enhanced, e.g. finger print chip embedded;† voice recognition function will be enhanced, the keypad or keyboard attachment will be an option, and wireless;† the terminal will support single and multiple users with various service options;† the terminal will be a fully adaptive software reconfigurable terminal. As the wireless communications evolve to this convergence, the 4Gmobile (FourthGeneration Mobile Wireless Communications) will be an ideal mode to support high data-rate connections from 2Mbps to 20Mbps based on the new spectrum requirement for IMT-2000 as well as the co-existence of the current spectrum for broadband wireless access. This4Gmobile system’s vision aims at:† providing a technological response to an accelerated growth in the demand for broadband wireless connectivity;† ensuring seamless services provisioning across a multitude of wireless systems and networks, from private to public, from indoor to wide area;† providing the optimum delivery of the user’s wanted service via the most appropriate network available;† coping with the expected growth in the Internet-based communications;† opening new spectrum frontiers. Figure 1.1 shows the convergence of wireless mobile and access in one track and generatesthe 4Gmobile. In the following sections, we will discuss some detailed implementation issuesincluding system architecture, reference model, protocol stack as well as system design. Figure 1.1 Convergence of wireless mobile and access in one track.Summary and Introduction 3 Figure 1.2 Network reference model.1.2 Network ArchitectureThe future wireless network should be an open platform supporting multi-carrier, multi-band-width and multi-standard air interfaces, and content-oriented bandwidth-on-demand (BoD)services will dominate throughout the whole network. In this way, the packetised transmissionwill go all the way from one wireless end terminal to ano ...