关键词: 802.11s, 混合无线网格协议, 期望传输次数, 期望传输时间, 加权累积期望传输时间

Abstract: Path metric of Hybrid Wireless Mesh Protocol pays too much attention to the compatibility of path selection in different mesh network，but the influence is not considered to path selection by different link types in 802.11s.Considering the demand of supporting multi-rate communication in 802.11s，a new solution of path metric based on traditional WCETT for the problem is proposed in this paper.At last simulation results show that the new metric is helpful to increase network throughput and reduce packet-loss rate.So it is effective on optimizing the path selection of wireless mesh network based on 802.11 and improving the performance of network.

Key words: 802.11s, Hybrid Wireless Mesh Protocol（HWMP）, Expected Transmission Count（ETX）, Expected Transmission Time（ETT）, Weighted Cumulative ETT（WCETT）