Research On Cross-layer Link-layer And Routing Protocols For Multi-channel Multi-interface Wireless Mesh Networks

Abstract:For multi-channel&multi-interface wireless mesh networks, the low interference and concurrent transmissions make it effective while the decreased connectivity and increased transmission delay limit its performance. Under such conditions, our paper has proposed a load balance link-layer protocol, LBLP, and an expected path bandwidth routing protocol, EPBWR, which cooperate with each other aiming to improve the network throughput and balance the traffic load.Dividing all interfaces into three categories with two working modes, the link-layer protocol, LBLP, mainly makes three contributions. For the receiving interfaces, a channel assignment estimating the interference accurately and a load allocation algorithm based on Huffman are developed to reduce the interference and balance the received traffic; the sending interfaces adopt a dynamic link schedule mechanism which raises the interface utilization and reduces the delay; to balance the load between the receiving and sending interfaces, according to the statistical traffic, the adaptive interfaces change the working modes automatically.The routing protocol, EPBWR, works with the metric, EPBW, which has considered the channel quality, the intra-and inter-flow interference and the path length to calculate the path bandwidth. EPBWR works in a distributed way and makes all the nodes along the path split the computation overhead, and for the routing update, the combination of proactive and passive methods, which decreases the protocol overhead and balances the load, ensures the routing paths are always effective.At last, we implement and simulate the proposed protocols, LBLP and EPBWR, in NS3. They cooperate to compare with other protocols such as AODV-MR, PCU-CA and WCETT. The results show that our protocols can reduce the interference and balance the traffic load to offer a higher network throughput.