Research On GPSS-based Uplink Scheduling Algorithm In IEEE 802.16

As a series of 802.11 products being used, people realized the advantages and convenience of accessing internet by broadband wireless network. But at the same time, there were some shortage in aspects of bandwidth, access rate, coverage, security and quality of service of 802.11. In order to meet the requirement of broadband wireless access in the future, the IEEE standard organization proposed 802.16 series standard. The standard supported reliable telecom level QoS by supporting strict delay requirement applications, such as voice and video etc.In fixed Broadband Width Access system, providing QoS guarantees for various kinds of traffic with different QoS requirement is a very important and challenging task. Although IEEE 802.16 MAC protocol claimed to support QoS guarantees for different applications, it did not give the concrete method to schedule traffic. In order to provide different levels of QoS and keep system throughput higher relatively, it is required to integrate a QoS architecture into the MAC layer. In this paper, we will have a talk about the QoS architecture and investigate in the relative problems.At first, this article proposes a new 802.16 scheduling architecture based on GPSS,integrating some kinds of existing scheduling algorithms. Then it gives an model implementation simulating 802.16 MAC protocol using OPNET. At Last, the combined scheduling algorithms are added into the model. The scheduling architecture accords with the description of MAC protocol in 802.16 standard and the four kinds of services'models. The scheduling algorithms based on strict priority guarantee the delay requirement of real time applications, and best effort service will not be starved through control of high priority services'data rate. So it meets the different QoS requirement of services. The max-min fair scheduling algorithm ensures fairness between SS. Finally, this paper gives a new scheduling algorithm to be used in BS considering the wireless physical condition of IEEE 802.16 .The simulation results prove the new QoS architecture is effective, which can not only meet the delay requirement of real time applications, but also guarantee fairness among subscriber stations.