Research Of Buffer Management In Multihop Wireless Networks Based On802.11MAC

Due to its self-configuration, low installation and maintenance costs, robustness, high system capacity, ease of deployment and expansibility, Wireless Mesh Network (WMN) technology is an attractive network architecture and gaining increasing attention, which is widely used in public safety and security systems, broadband wireless Internet access and heterogeneous backhaul networks and so on.In multihop wireless networks, flows spanning multiple hops suffer from dismal throughput performance compared to flows traversing fewer hops. In this paper, we analyse the reasons for the unfairness and starvation of long hop length flows, including802.11MAC protocol and its "Drop Tail" mechanism.Then, we propose a fair buffer management algorithm (FBMA) and its enhanced version. This algorithm can improve and protect the throughput performance of multihop flows by fair assignment of buffer space, dynamic use of buffer space, the periodic adjustment of buffer share and the probabilistic acceptance mechanism.In the paper, we also show the correctness and validity of the algorithm. Further more, we study the end-to-end theoretical maximum throughput in multihop wireless networks based on collision domain. The theoretical results are validated by simulations. A classic fairness index is adopted to exactly describe and quantitatively evaluate the fairness degree that different algorithms can support. At last, the proposed algorithm and its performance are validated by simulations results based on OPNET simulation platform.