根据IEEE802.11DCF基本访问模式,建立了无线链路传输模型和信道竞争模型,定义了链路和节点对共享信道的竞争度,提出了信道竞争感知的多速率多跳无线网络端到端时延路由测量CCAD。基于无线链路传输模型和信道竞争度计算链路及传输路径的时延,实现了对多速率多跳无线网络中链路的质量、传输速率以及信道竞争的测量。NS2仿真实验结果表明,CCAD的性能明显优ETX、ETT和MIC等现有的路由测量。
Link quality, transmission rate of wireless links and channel competition among them determine the transmission capacity of multi-rate and multi-hop wireless networks together. This paper first builds a transmission mode and channel competition mode of wireless links, according to IEEE 802.11 DCF basic mode, and then gives the channel competition degree definitions both of wireless link and node, and finally proposes a channel competition aware end-to-end delay routing metric (CCAD) for multi-rate and multi-hop wireless networks CCAD calculates the delays of wireless link and route, based on the transmission mode of wireless links and the channel competition degree of wireless nodes. As a result, link quality, transmission rate and channel competition are captured and measured together. NS2 simulation results show CCAD outperforms other metrics that have appeared in the literature, such as ETX, ETT and MIC.