A selfishness-aware coexistence scheme for 802.22 and 802.11af networks

We investigate the coexistence issue between 802.22 and 802.11af networks over the TV White Space (TVWS). The coexistence scheme is vulnerable to selfish attacks. In this paper, the scenario of selfish attack wherein 802.22 subscribers intend to occupy the allocated spectrum selfishly is studied. Consequently, 802.11af users have less opportunity to access the spectrum, which leads to low overall spectral efficiency. We propose a centralized coexistence framework wherein the spectrum coordinator is in charge of allocating spectrum resources. The objective of our coexistence mechanism is to maximize the overall spectral efficiency. Our coexistence problem is modeled as 0-1 Multiple Knapsack Problem. This problem is solved by combining bandwidth allocation and channel allocation. In addition, the fairness of each subnetwork is considered in the design of bandwidth allocation. As a result, the selfish attack in the coexistence scheme is defeated. Simulation results demonstrate that the overall system spectral efficiency is significantly improved compared to existing coexistence schemes.