The Research Of QoS Guarantee And Scheduling Algorithm Of Bandwidth Allocation For WiMAX MAC Layer

The technology of WiMAX, which is based on IEEE 802.16 standards has become a 3G standard, for its high transmit rate,services of heterogeneous classes of traffic and effective network mode, it will have a greater future。WiMAX defines 4 different type of application and QoS standard, but how to achieve these target is undefined. Admission controlling, traffic conditioning and packet scheduling are import part parts in implementing QoS guarantees. Research these areas is not only fit for WiMAX network, but also fit for other wireless network. Packet scheduling is the main research spot of the article.This essay will introduce the MAC protocol of IEEE 802.16 especially it's QoS mechanism will be elaborated.And various generic scheduling algorithms which are used in wired and wireless network will be discussed. Based on the analysis and improvement of the scheduling algorithm of different service, the Reservation Based Dynamic Compensated Bandwidth Scheduling architecture for WiMAX MAC layer is proposed, which uses two layers scheduling architecture, the first layer is reservation based and the second layer have four scheduler point to different service. Furthermore, this architecture combined with compensation mechanism,can provide long term fairness for service flow scheduling.At last through simulation the improvement on performance was proved. With NS simulator bandwidth allocation algorithm proposed have some advantages in terms of fairness, time delay, and throughput.