Abstract:

Due to the inherent broadcast and overhearing capabilities of wireless network, the network coding technique is very suitable for the wireless mesh network. Through the theoretical analysis and simulation results, it is observed that the MAC mechanism of the IEEE802.11 standard may make the node more competitive after accessing the channel successfully, which unbalances the amount of packets of different coding flows in the buffer of the coding node in a short period, and finally, some coding opportunities are lost. A cross-layer optimization mechanism is proposed. In the mechanism, the priorities of coding flows are calculated by using the buffer occupancy information and are sent to the upstream node, and then the corresponding upstream node adjusts its MAC parameters, which yields more coding opportunities. Simulation results show that the proposed mechanism can adjust the rate of flows whose packets can be encoded together adaptively, and improve the total throughput of network.