Improving Channel Access in WLANs by Dynamic Tuning of Contention Window and Transmission Opportunity

Transmission opportunity limit and contention window are two influenced parameters in accessing the media in the networks based IEEE 802.11e standard. In these networks¡ every wireless station by setting of its contention window value¡ determines the chance of access to wireless media. Furthermore¡ a transmission opportunity limit provides a period of transmission without contact for a station. In order to increase the productivity of the wireless media¡ these two parameters can be determined by considering the network variable conditions in the dynamic form. In this regard¡ since Games Theory is a robust tool for modeling¡ analysis and optimization of competitive environment with shared resources¡ in this research¡ the problem of simultaneous setting of transmission opportunity and contention window in the framework of Game theory have been surveyed and this problem has been modeled in the format of a game. In this Game¡ by defining the consequence function¡ every wireless station plays a role of a player and selects its strategy in setting these two parameters by maximizing its consequence function and in accordance with the quality of services requirements and increasing the productivity of wireless media. Simulation results show that the proposed method has caused to improve access to the channel and relative fairness retention.