The+Technology+Of+WiMAX


 * 9.0 THE TECHNOLOGIES **

The emergence of WiMAX (Wireless Interoperability for Microwave Access) as a broadband wireless access (BWA) technology adds another alternative for users to access broadband services, specifically high speed Internet (HSI). WiMAX has the capability to deliver triple play services, i.e. voice, video and data over microwave RF (Radio Frequency) spectrum to stationary or moving users making broadband available anywhere. That is what leads WiMAX being touted as a Personal Broadband technology.


 * 9.1 WiMAX Mobile **

WiMAX combines the familiarity of Wi-Fi with the mobility of cellular that will deliver personal mobile broadband that moves with you. It will let you get connected to the Internet, miles from the nearest Wi-Fi hotspot. Soon, Mobile WiMAX will blanket large areas- metropolitan, suburban, or rural- delivering mobile broadband Internet access at speeds similar to existing broadband.

WiMAX is built for the future with advanced, efficient wireless technology that provides higher speeds than today’s wide area wireless technologies. It will be able to completely transform your mobile Internet lifestyle, enabling you to connect in ways you’ve only dreamed about.

Mobile Broadband Wireless Access (MBWA) is a technology being developed by IEEE 802.20 and is aimed at wireless mobile broadband for operations from 120 to 350 km/h. The 802.20 standard committee was first to define many of the methods which were later funneled into Mobile WiMAX, including high speed dynamic modulation and similar scalable OFDMA capabilities. It apparently retains fast hand-off, Forward Error Correction (FEC) and cell edge enhancements.

The Working Group was temporarily suspended in mid 2006 by the IEEE-SA Standards Board since it had been the subject of a number of appeals, and a preliminary investigation of one of these "revealed a lack of transparency, possible 'dominance,' and other irregularities in the Working Group".[IEEE-SA Standards Board directed that all activities of the 802.20 Working Group be temporarily suspended]

In September 2006 the IEEE-SA Standards Board approved a plan to enable the working group to continue under new conditions, and the standard is now expected to be finalized by Q2 2008.

** 9.2 **** 3G and 4G Cellular Phone Systems ** Both major 3G systems, CDMA2000 and UMTS, compete with WiMAX. Both aim to offer DSL-class Internet access in addition to phone service. UMTS has also been enhanced to compete directly with WiMAX in the form of UMTS-TDD, which can use WiMAX oriented spectrum and provides a more consistent, if lower bandwidth at peak, user experience than WiMAX. 3G cellular phone systems usually benefit from already having entrenched infrastructure, being upgraded from earlier systems. Users can usually fall back to older systems when they move out of range of upgraded equipment, often relatively seamlessly. The major cellular standards are being evolved to so-called 4G, high bandwidth, low latency, all-IP networks with voice services built on top. With GSM/UMTS, the move to 4G is the 3GPP Long Term Evolution effort. For AMPS/TIA derived standards such as CDMA2000, a replacement called Ultra Mobile Broadband is under development. In both cases, existing air interfaces are being discarded, in favour of OFDMA for the downlink and a variety of OFDM based solutions for the uplink, much akin to WiMAX. In some areas of the world the wide availability of UMTS and a general desire for standardization has meant spectrum has not been allocated for WiMAX: in July 2005, the EU-wide frequency allocation for WiMAX was blocked.

** 9.3 **** Internet-Oriented Systems ** Early Wireless MAN standards, the European standard HIPERMAN and Korean standard WiBro have been harmonized as part of WiMAX and are no longer seen as competition but as complementary. All networks now being deployed in South Korea, the home of the WiBro standard, are now WiMAX.

As a short-range mobile Internet solution, such as in cafes and at transportation hubs like airports, the popular Wi-Fi 802.11b/g system is widely deployed, and provides enough coverage for some users to feel subscription to a WiMAX service is unnecessary.


 * 9.4** **Analysis of WiMAX, WLAN and 3G**



**The Future Of WiMAX** **__Future Enhancement__**