Research On Wireless Mesh Network Congestion Control Strategies Based On Cross-Layer Design

With the rapid development of various wireless access technologies, it will be the design goals of the next generation wireless communication network to provide users with Internet access and multimedia service with QoS guarantee conveniently and quickly. As a new wireless access technology, wireless mesh networks can support the wired backbone network with wireless technologies cheaply and implement wireless coverage in region. However, because of the asymmetry of distributed architecture and the multi-hop characteristic in wireless mesh networks, congestion may occur easily in wireless links due to load imbalance. Wireless bandwidth is the rare resources in wireless networks. Therefore, how to alleviate the link congestion effectively and use wireless resources adequately have attracted researchers'extensive attention, and have become one of the current research focuses.In this paper, we combine with cross-layer design and adopt the research approach called"general to specific"to discuss the optimization and application of congestion control algorithms in wireless mesh networks. Firstly, the latest congestion control algorithms in wireless networks are classified and analyzed, and it is emphasized that to research the congestion control in the new network environment is necessary. Then, the relative network background and control technologies which this paper involves are introduced. On the basis of above studies, firstly, the uncooperative game theory is adopted, and then, a cross-layer congestion control algorithm in wireless mesh networks is proposed. This algorithm uses the uncooperative game theory to create game-congestion model in MAC layer, and then obtains the best rate which will be told to the transport layer by cross-layer mechanism. Finally, the transport layer will adjust its sending rate according to the interactive information form the MAC layer. At the next step in this paper, a novel congestion control algorithm is proposed based on the scheduling mechanism of IEEE 802.16 mesh networks. By combining with cross-layer feedback, it implements link congestion control from three respects in MAC layer, and changes the sending window in the transport layer according to the control decisions of MAC layer. Finally, the proposed algorithms are verified by multi-angle experiment simulations and performance analysis in different network scenarios in the NS-2.31 simulation environment. The simulation results show that compared to the traditional congestion control strategy, the proposed algorithms can improve network performance to some extent in throughput, delay, packet loss rate, and so on.