An Enhanced Mechanism to Reduce the Waste of Allocated Minislots in WiMAX Mesh Networks

In WiMAX Mesh Networks, the waste problem of allocated minislots in the three-way handshaking procedure of Coordinated Distributed Scheduling (CDS) will degrade the end-to-end performance of traffic flows. In this paper, an enhanced mechanism which combines adaptive holdoff algorithm with regrant solution is proposed to deal with the above-mentioned problem. Moreover, a new grant horizon based on the grant algorithm in Fair End-to-end Bandwidth Allocation (FEBA) algorithm is presented. Simulations using the network simulator NS-2 show that our enhanced mechanism can increase the end-to-end throughput by 91% and decrease the average end-to-end delay by 25% when compared to the situation without considering minislot waste. In addition, this mechanism can extend the application area of original regrant solution by reducing the beginning point of grant horizon under a given network topology. Meanwhile, our proposed grant horizon outperforms two kinds of existing grant horizon when adaptive holdoff algorithm is used.