Self-adaptive truncated binary exponential backoff scheme for WiMAX P2MP network with heavy traffic

As a new wireless network access technology, IEEE 802.16 can provide broadband Internet connection to user. However, it was found that the mandatory contention resolution scheme in IEEE 802.16 can not run perfectly in most cases, especially when the traffic is heavy. In this paper, a novel self-adaptive truncated binary exponential backoff scheme has been proposed to improve the performance of the whole network, especially when the number of subscriber stations sending bandwidth request is far more than the number of transmission opportunities in current time frame. The number of available transmission opportunities and subscriber stations which send bandwidth request in next round contention will be self-adaptively updated according to the average collision probability and transmission opportunity utilization present during last frame. The results of analysis and simulation show our scheme can achieve better performance than contention resolution scheme in the standards.