Network coding,which exploits the broadcast nature of wireless medium,is an effective way to improve network performance in wireless multi-hop networks,but the first practical wireless network coding system COPE cannot actively detect a route with more coding opportunities and limit the coding structure within two-hop regions.An on-demand coding-aware routing scheme (OCAR) for wireless Mesh networks is proposed to overcome the limitations specified above by actively detecting a route with more coding opportunities along the entire route rather than within two-hop regions.Utilizing more coding opportunities tends to route multiple flows ‘close to each other’ while avoiding interference requires routing multiple flows ‘away from each other’.OCAR achieves a tradeoff by adopting RC AIA as routing metric in route discovery,which is not only coding-aware but also considers both inter and intra flow interference.Simulation results show that,compared with Ad-hoc on-demand distance vecfor routing (AODV) and AODV+COPE,OCAR can find more coding opportunities,thus effectively increase network throughput,reduce end to end delay and alleviate network congestion.
SUN Jian-zhen,LIU Yuan-an,HU He-fei,YUAN Dong-ming Wireless Communications and EMC Laboratory,Beijing University of Posts and Telecommunications,Beijing 100876,China
