Definition of WiMax

The terms "WiMAX", "mobile WiMAX", "802.16d" and "802.16e" are frequently used incorrectly. Correct definitions are the following:

• 802.16-2004 is often called 802.16d, since that was the working party that developed the standard. It is also frequently referred to as "fixed WiMAX" since it has no support for mobility.

• 802.16e-2005 is an amendment to 802.16-2004 and is often referred to in shortened form as 802.16e. It introduced support for mobility, among other things and is therefore also known as "mobile WiMAX".
  

Fixed WiMAX is similar in some respects to WLAN with an OFDM-based physical layer. Mobile WiMAX is based on an OFDMA physical layer. It uses both frequency division multiplex and time division multiplex. Groups of sub-carriers represent individual data streams. Uplink and Downlink communications can also utilize Time Division techniques. Because of increased signal complexity, high-speed measurements are required. This is absolutely necessary for complicated OFDM and MIMO (multiple-input multiple-output) signal structures.

The technology provides up to 3 Mbit/s broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access). The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL".