WiMAX (Worldwide interoperability for Microwave Access) is a wireless system based on the IEEE 802.16e standard which supports Wireless Metropolitan Area Network (WMAN). In order to meet the requirements of different types of access, two versions of WiMAX have been defined. The first is based on 802.16-2004 and is not implemented support of handovers between cells. This version of WiMAX allows only fixed and nomadic access. The second version is an improvement over the first version and is designed to support portability and mobility based on the IEEE 802.16e amendment to the standard.