Nash Bargaining Solution for Cooperative Shared-Spectrum WLAN Networks

Interference in unlicensed band is a severe problem due to sharing of the limited spectrum resource and uncoordinated power transmission of wireless access points. To solve this problem, we aim for minimizing interference among Access Points'coverage while preserving throughput fairness. We investigate this problem by modelling the spectrum sharing WLAN networks as a cooperative game. A bargaining game model is desirable in this frequently changing WLAN networking environment. Our solution is developed based on Nash Bargaining Solution, which can derive desirable properties such as Pareto Efficiency and proportional fairness. In this paper, we first derive the Nash Bargaining Solution for a 2-AP case and a 3-AP case. Then we provide a general solution for scenario with arbitrary number of APs. Simulation results show that the total networking throughput in maximum in the proposed scheme, compared with all other possible transmission power strategies. The interference between WLAN APs is minimal. Our work can lead to a cooperative spectrum sharing WLAN networking design with allocation fairness and optimal throughput performance.