Research And Simulation On MAC Protocol Based On Auction Algorithm In Cognitive Ad Hoc Network

Facing a severe scarcity of spectrum resource, effective allocation and reasonable utilization of spectrum become crucially important. As a result, secondary allocation of underutilized spectrum resource to authorized users in cognitive Ad Hoc network MAC protocol is the crux to improve spectrum efficiency, solve resource shortage and improve network performance.Combined with game-based idea of spectrum resource allocation, this thesis proposes a MAC protocol of cognitive Ad Hoc networks based on auction mechanism, constructing secondary spectrum market model to maximize the spectrum utilization efficiency as the goal, considering bandwidth demand of cognitive users as well. Spectrum auction is defined as polling procedure, including two subphase of asking price and bidding price. Based on supply-demand relationship of idle channel, buyers and sellers adjust their strategy automatically. Driven by short-term benefits, sellers will be able to swindle. As a result, repeated auction mechanism is proposed to prevent fraud in order to build up the trust between buyers and sellers, ensuring to maximize the spectrum utilization efficiency. The effectiveness of auction mechanism is proved by mathematical methods as well.The proposed MAC protocol is simulated by NS-2 to prove the effectiveness. The results shows that the proposed protocol is able to improve the spectrum utilization efficiency, optimize the networks performance and has a good expandability.