Abstract: To ensure proportional fairness (i.e., the system bandwidth is shared among the user flows according to their weights) in the IEEE 802.11 wireless LANs, a cooperative game theoretic bandwidth sharing scheme, called PF-DCF, is proposed. By setting the throughput based utility function, the bandwidth sharing procedure is modeled as a cooperative game. In the game, the user flows intend to maximize their utilities under the premise that the system utility is maximized. According to the Nash bargaining solution(NBS) of the game, i.e., the user stations’ optimal packet transmission probabilities to acquire proportional fairness, a bandwidth sharing scheme (PF-DCF) is developed. Simulation results indicate that when using PF-DCF in the ad hoc mode, the user flows can fairly share the system bandwidth by broadcasting their weights information and adjust the backoff parameter (CW_min) to the NBS. In addition, by comparison with 802.11e EDCA, PF-DCF can effectively utilize the channel resource.

Key words: wireless LAN, proportional fairness, IEEE 802.11, cooperative game, Nash bargaining solution