Research Of IEEE 802.16e MAC Layer

Broadband wireless access technology is developed very fast in last few years. IEEE 802.16 standard is a wireless access standard which has a bright future that it can provide high speed connectivity for the Internet. It is mainly applied to Metropolitan Area Network (MAN), and it can be transmitted voices, images, videos, data and so on. It is also a proper solution for "the last one mile" access of many families and enterprise.IEEE 802.16e is based on IEEE 802.16d, and it is also added support for mobility. The physical layer of two standards is designed as the same. Because of mobile characteristic, some technologies are used for IEEE 802.16e MAC layer. For example, handover, power management, and QoS support to five kinds of scheduling. Through researching these key technologies, it is beneficial to make application.This paper's major contribution is laid on researching IEEE 802.16e MAC layer. The MAC layer is composed of service specific convergence sublayer, common part sublayer and security sublayer, the main functions and features of these sublayers are introduced firstly. Then three key technologies (QoS, handover and power management) are analysed. In this paper, the algorithm for sleep mode in power management is a key research point. The performance of algorithm for sleep mode is analysed by model and simulation. The result shows that more energy consumption and bigger delay are existed in lower traffic rate. To get a better performance, an improved algorithm is proposed for sleep mode. The simulation results show that this improved algorithm could effectively reduce energy consumption and delay.