Date Added: Aug 2009
IEEE 802.16 group of standards defines a high speed wireless access system with support for various multimedia services. The standard contains specifications of Media Access Control layer (MAC) and of PHYsical layer (PHY). There are several possible realizations of the PHY layer. However the most popular one is Orthogonal Frequency Division Multiple Access (OFDMA). Originally IEEE 802.16 has been designed for fixed Subscriber Stations (SS), but the most recent IEEE 802.16e standard has support for Mobile Subscribers (MS). Therefore power saving is one of the constitutive issues and increasing MS energy efficiency is an important objective. To solve the issues the IEEE 802.16e standard defines the handover process and the sleep mode operation.