Wimax (802.16) Standards - Wimax Specifications
Wimax standards & Specifications
Many standards are often referred to as Wimax (802.16)or broadband access standards just like Wi-Fi. Technically, Wimax supports IEEE 802.16 wimax specifications and will continue to developments as the specifications evolve, but other standards have also been produced based on the 802.16 specification. Some of them are extensive enough to get attention by the Wimax Forum, including HiperMAN and WiBro. Wimax (802.16) effectively holds all of Wimax (802.16) standards.
This standard is the formal one being used for current fixed and nomadic Line Of Sight(LOS) and Non Line Of Sight(NLOS) Wimax (IEEE 802.16) implementations and is based on and backwardly compatible with 802.16 and 802.16a . The WiMAX Forum profiles supporting IEEE 802.16 2004 are in the 3.5 GHz and 5.8 GHz frequency bands. Vendors are currently creating indoor and outdoor customer subscriber stations equipment and laptop PCMCIA cards to support this specification. This standard will be used for cell creation in non-mobile scenarios and LOS distance links.
The theory of duplexing refers to the management of upstream and downstream traffic flows. Frequency division duplexing (FDD) uses two channels. One channel is used for upstream traffic and the other is used for downstream traffic. Time division duplexing (TDD) uses a single channel, and the devices at each end must exchanges between sending and receiving. (Jeff Goldman, July 2, 2004)
802.16e standard is an extension to the 802.16-2004 specification and supports mobile communications. This mobility is provided through handoffs and roaming support built in to the standard. While intended to provide mobility, this technology is used by service providers to provide fixed access as well. 802.16e specification operates in the 2.3 and 2.5 GHz frequency bands. (Vikki Lipset, September 2, 2003)
The European Telecommunications Standards Institute produced the HiperMAN standard for broadband wireless MAN implementations. The HiperMAN standard operates in the frequency ranges between 2 GHz and 11 GHz. It was purposely made in close association with the IEEE Standards; it is based on 802.16 and is compatible with the 802.16a-2003 specification. Like WiMAX, HyperMAN supports both point-to-multipoint and mesh network implementations. (Wimax.com)
WiBro Stands for Wireless Broadband, it is a wireless Metropolitan Area Network (MAN) standard initially built by the Telecommunication Technology Association (TTA) of South Korea. Phase 1 of WiBro was approved in November 2004. The standard was developed to fill the space between 3G and Wireless Local Area Network (WLAN) standards; providing more data rate, mobility and coverage required delivering internet access to mobile clients via handheld devices.
The standard uses 100 MHz of licensed Radio Frequency (RF) spectrum, from 2.30 to 2.40 GHz, allocated by the South Korean Ministry of Information and Communication for mobile wireless internet usage, and adjacent to the international unlicensed 2.4 GHz ISM band. The IEEE 802.16-2004 and Draft 3 of the 802.16e standard were the basis for the development of WiBro, and the key PHY parameters are compatible between the two standards. (Steve Rackley, 2007)
The WiBro Medium Access Control (MAC) supports three discreet service levels including guaranteed Quality of Service (QoS) for delay sensitive applications, based on real time polling of station requirements, and an intermediate QoS level for delay tolerant application that require a minimum guaranteed data rate.
Phase 2 of the standard is designed to focus on network capacity enhancement technology, including Multiple Input Multiple Output (MIMO) radio, adaptive antenna systems and space time coding, as well as additional standardization with 802.16e (WiMAX). (Steve Rackley, 2007)
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WiMAX Coverage : WIMAX 2 Technology : Wimax Deployments : Wimax Equipments & Products : Wimax Applications : Wimax Architecture : How Wimax Works : Wimax Features : Wimax Limitations : Wimax Services : Wimax Vs WiFi : WiMAX