A Hybrid MAC Protocol Based on Incompletely Cooperative Game in Vehicular Ad Hoc Networks

摘要

Vehicular Ad Hoc Networks is a kind of special wireless ad hoc network, which has the characteristics of high node mobility and fast topology changes. In this paper, we proposed a new hybrid MAC protocol based on incompletely cooperative game. This new hybrid mechanism is based on TDMA, while CSMA based on incompletely cooperative game method is added in time slots to improve the MAC performance in both high and low load networks. In the time slots of the proposed hybrid MAC of CSMA mechanism, each vehicular node estimates the current game state (the number of competing nodes) through the quality of the current channel. Then each vehicular node changes its equalization strategy by automatically adjusts its competitive parameters (the minimum competitive window) based on the estimated game state. After that, the result of game is repeated to get the optimal performance until the network matches with the environment. Simulation results show that the proposed hybrid MAC protocol compared with CSMA, TDMA, hybrid MAC (CSMA+TDMA) can effectively increase the system of fairness index (30%), and decrease the packet loss rate (40%).