Overview Of State-Of-The-Art WiMAX Technology NetworkWorking

As stated earlier, mobile WiMAX products and certification follow the IEEE 802.16 air interface specifications. The network specifications of mobile WiMAX products, however, are being developed internally by the WiMAX Forum, which include the end-to-end networking specifications and network interoperability specifications. The NetworkWorking Group (NWG) within the WiMAX Forum is responsible for these network specifications, some of which involve Access Service Network (ASN) control and data plane protocols, ASN profiles, Connectivity Services Network (CSN) mobility support, Authentication, Authorization and Accounting (AAA) interworking with other technologies, and various services such as Location-Based Service (LBS), Multicast and Broadcast Service (MCBCS) etc. In this chapter, however, we will focus on the overview of mobile WiMAX technology from the air interface perspective.

The aforementioned composition of the current mobile WiMAX technology, commonly referred to as Release 1.0 profile. Its air interface specifications consist of four related IEEE 802.16 Broadband Wireless Access Standards, that is, IEEE Standard 802.16-2004, IEEE Standard 802.16-2004/Cor.1-2005, IEEE Standard 802.16e 2005 and the IEEE Draft Standard P802.16-2004/Cor.2. Not all of the optional features defined in these IEEE Standards are implemented in WiMAX products and tested for certifications. Through extensive technical investigation analysis to build up the best competitive products, the WiMAX Forum Technical Working Group (TWG) published the first version of mobile WiMAX System Profile Release 1 in early 2006 (WiMAX Forum, 2007). The latest published version to date (Release 10 rev. 1.6.1) incorporated error fixes and minor corrections without touching the main features selected in the first revision.

The mobile WiMAX system profile is presented from the air interface perspective. The system profile is composed of five subprofiles, namely, PHY, MAC, radio, duplexing mode and power classes. Even though there are many different combinations of center frequencies and channel bandwidths accommodating different regional spectrum regulations, all Release 1 mobileWiMAX products share the same PHY and MAC features (profiles) and the same duplexing mode which is Time Division Duplex (TDD). In the following, some detailed descriptions of key PHY and MAC features in the mobile WiMAX system profile are offered.