p-RWBO: a novel low-collision and QoS-supported MAC for wireless ad hoc networks

QoS supported MAC mechanism is a key issue for supporting QoS in wireless ad hoc networks. A new backoff algorithm, named RWBO+BEB, was proposed previously to decrease the packet collision probability significantly. In this paper, it is explored how to make RWBO+BEB support service differentiation in wireless ad hoc networks, and a novel proportional service differentiation algorithm, named p-RWBO, is proposed to allocate the wireless bandwidth according to the bandwidth ratio of each station. In p-RWBO, station n’s walking probability (p _w,n ) is selected according to its allocated bandwidth ratio. An analytical model is proposed to analyze how to choose p _w,n according to the bandwidth ratios of station n. The simulation results indicate that p-RWBO can differentiate services in terms of both bandwidth and delay. Supported by the National Key Basic Research Program (Grant No. 2007CB310706), the National Science Fund for Distinguished Young Scholars (Grant No. 60725102), the National Natural Science Foundation of China (Grant No. 60702055, 60672045), the National High Technology Research and Development Program of China (Grant No. 2007AA01Z246, 2007AA01Z227), Research Fund for the Doctoral Program of Higher Education (Grant No. 20060614018), and Program for New Century Excellent Talents in University