WiMAX Stands High Performance For Data, Video And Worldwide Orthogonal Frequency Division Multiple Access (OFDMA)

WiMAX stands for Worldwide Interoperability for Microwave Access. WiMAX technology enables ubiquitous delivery of wireless broadband service for fixed and/or mobile users, and became a reality in 2006 when Korea Telecom started the deployment of a 2.3 GHz version of mobile WiMAX service called WiBRO in the Seoul metropolitan area to offer high performance for data and video. In a recent market forecast published in April 2008, WiMAX Forum Subscriber and User Forecast Study, the WiMAX Forum projects a rather aggressive forecast of more than 133 million WiMAX users globally by 2012 (WiMAX Forum, 2008c). The WiMAX Forum also claims that there are more than 250 trials and deployments worldwide.


TheWiMAX Forum is an industry-led non-profit organization which, as of the 1st quarter of 2008, has more than 540 member companies including service providers, equipment vendors, chip vendors and content providers. Its primary mission is to ensure interoperability among IEEE 802.16 based products through its certification process. The air interface of WiMAX technology is based on the IEEE 802.16 standards. In
particular, the current Mobile WiMAX technology is mainly based on the IEEE 802.16e amendment (IEEE, 2006a), approved by the IEEE in December 2005, which specifies the Orthogonal Frequency Division Multiple Access (OFDMA) air interface and provides support for mobility.

The selection of features to be implemented in WiMAX systems and devices is presented in the mobile WiMAX System Profile Release 1.0 (WiMAX Forum, 2007) which was developed in early 2006 and is currently maintained by the WiMAX Forum (WiMAX Forum, 2008a). It is this very technology defined in WiMAX Forum (2007) that was adopted by International Telecommunications Union (ITU) as the 6th air interface of IMT-2000 family (ITU, 2007). The flexible bandwidth allocation and multiple built-in types of Quality-of- Service (QoS) support in the WiMAX network allow the provision of high-speed Internet
access, Voice Over IP (VoIP) and video calls, multimedia chats and mobile entertainment. In addition, the WiMAX connection can be used to deliver content to multimedia gadgets such as the iPod.

Since the completion of the Release 1.0 Mobile System Profile, the WiMAX Forum has been working on a certification program which is a critical step for the proliferation of any modern communication technology throughout the world. As the result, the first WiMAX Forum Certified Seal of Approval for the 2.3 GHz spectrum was awarded to four base stations and four mobile stations in April 2008 (WiMAX Forum, 2008d). In June 2008, another four base stations and six mobile stations were awarded the WiMAX Forum Certified Seal of Approval for the 2.5 GHz spectrum with advanced features such as Multiple Input Multiple
Output (MIMO) in time for commercial deployments around the world (WiMAX Forum, 2008e).

This chapter is intended to provide a high-level overview of the current mobile WiMAX technology with an emphasis on the Physical (PHY) layer and Medium Access Control (MAC) layer features. Some recent discussions and developments of further WiMAX evolution path are also addressed briefly at the end of the chapter.