On The Interference Modeling Issues for Coordinated Distributed Scheduling in IEEE 802.16 Mesh Networks

In IEEE 802.16 mesh networks, a major issue is the performance of coordinated distributed scheduling schemes. To evaluate these schemes, most existing studies in the literature are based on the assumption that the control messages can be transmitted without collision in the extended neighborhood (2-hop or 3-hop). However, in practice, such kind of quasi-interference model might not hold. In this paper, we investigate the performance of coordinated distributed scheduling in IEEE 802.16 mesh networks under realistic, non-quasi-interference model, in which control messages can be interfered. Extensive simulation studies have been conducted to evaluate the performance of the scheduling algorithms in terms of reception collision ratio, etc. We observe that, in realistic scenarios, the collision ratio of control messages can be as high as 20% for 2-hop extended neighborhood, and about 7% for 3-hop extended neighborhood, which is significant. To deal with the collision problems, we then study how to select scheduling parameters. Our studies show that, an appropriate configuration of parameters such as XmtHoldoffExponent may alleviate the collision ratio and hence can potentially improve the overall scheduling performance.