Medium Access Control Based on Two Dimentional Random Backoff of Power Level and Sensing Time for Ad Hoc Networks

This paper analyzes the limitation of IEEE 802.11 protocol using a single power for node communication. On the basis of IEEE 802.11protocol and the basic power backoff protocol which introduces the idea of power backoff, a CSMATPB protocol with time and space backoff is proposed. The protocol increases the time competition window, while making the power backoff reduce the interference between nodes. Then, the three dimensional Markov chain model is established for this protocol. Through the results of numerical calculation and simulation analysis, it is proved that the protocol mechanism can effectively solve the problem that the lower space reuse rate of IEEE 802.11 protocol and the problem that the basic power backoff protocol discards the packet prematurely. So CSMA-TPB protocol can effectively improve the saturation throughput and energy utilization of the network.