Note: Many topics at this site are reduced versions of the text in "The Encyclopedia of Networking and Telecommunications." Search results will not be as extensive as a search of the book's CD-ROM.

Wireless broadband access technologies refers to high-speed wireless access services that businesses can use to build metropolitan area networks or gain Internet access. These wireless services take the place of traditional TDM circuits.

Wireless access systems are usually owned by a service provider that operates within a metropolitan areas. Services include Internet access for businesses, MTUs (multitenant units), and homes, as well as private LAN bridging in metro areas. The topic "Wireless LANs" covers enterprise wireless networking in which an enterprise owns and manages wireless systems used to interconnect its users and systems. Even shorter in range than wireless LANs are wireless PANs (personal area networks) that let nearby users create spontaneous networks. See "Bluetooth" and "Wireless PANs (Personal Area Networks)."

This topic is also about "fixed" wireless systems, as opposed to mobile wireless systems. The cellular telephone system, as covered under "Wireless Mobile Communications," allows users to move about, not only within the range of the local base station but to other cells within the same system and even to other service provider systems. The fixed wireless systems discussed here allow some mobility, but do not typically support the extended roaming features of mobile cellular systems.

Wireless broadband access systems have relatively high data rates and the target subscriber is often an entire enterprise rather than an individual subscriber. Broadband wireless systems can provide bandwidth that exceeds DSL and cable network technologies. Also, the traffic is data, although some of the fixed wireless systems use spectrum that was originally designated for one-way delivery of cable TV.

The IEEE 802.16 specifications are called IEEE 802.16 Wireless MAN, but the working group is called IEEE 802.16 Wireless BWA (Broadband Wireless Access). IEEE 802.16 is covered later. In addition, wireless broadband is called FWBA (fixed wireless broadband access) if the system does not support mobile users, but some systems do allow mobility within a small range of the base station.

The advantage of wireless systems is obvious: there is no need to install cable or rely on existing copper infrastructure that may be inadequate for various reasons. International Data Corporation has estimated that under 10 percent of the office buildings in the United States are reachable by fiber cable. Therefore, wireless access technologies should offer a large market opportunity.

This topic continues in "The Encyclopedia of Networking and Telecommunications" with a discussion of the following:

• Wireless broadband topologies
• Point-to-point
• Point-to-multipoint
• Multipoint-to-multipoint mesh topology
• Broadband wireless frequency allocations
• U-NII (Unlicensed-National Information Infrastructure)
• WLL (wireless local loop)
• Wireless access technologies
• Point-to-point wireless bridges
• Satellite communication systems
• DBS (Direct Broadcast Satellite)
• HALOs (High Altitude Long Operation)
• MMDS (Multichannel Multipoint Distribution Services)
• LMDS (Local Multipoint Distribution Services)
• Wireless mesh systems
• HDR (High Data Rate)
• UWB (Ultra Wideband)
• Example: Nokia's RoofTop wireless mesh system
• Free-space optical networking
• Characteristics of broadband wireless
• Air interface
• DVB Downstream/DOCSIS Upstream
• TDD (Time Division Duplexing)
• Wireless standards and initiatives
• IEEE 802.16 Wireless MAN (metropolitan area network)
• ETSI (European Telecommunications Standards Institute) and its HiperLAN (Higher-Performance Radio LAN) and HiperAccess standards
• Wireless DSL Consortium
• N-WEST (National Wireless Electronic Systems Testbed) http://nwest.nist.gov/.

Copyright (c) 2001 Tom Sheldon and Big Sur Multimedia.
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