无线局域网能耗性能分析

为得到IEEE802．11分布式协调功能（DCF）在无线局域网环境中饱和状态下的能耗性能，根据节点在每一虚拟时隙内发送的报文概率和条件碰撞概率，通过计算节点在每个虚拟时隙内的平均能耗和每个虚拟时隙的平均系统时间，得到了节点的平均功耗和网络的载荷能耗率．分析结果表明：报文越长、信道速率越高，网络的载荷能耗率越低，能耗性能越好；网络的载荷能耗率与网络规模呈近似线性关系；随着信道速率的提高，基本接入机制将逐渐显示出较RTS／CTS接入机制更大的优势；当网络超过一定规模时，节点的平均功耗主要取决于接收功耗，而发送功耗、空闲功耗仅对其有微弱影响．

Analysis of Energy-Consumption Performance for Wireless LANs

In order to reveal the energy-consumption performance of IEEE 802.11DCF(Distributed Coordination Function) in a saturated wireless LAN environment,both the average energy consumption and the average system time of the node in each virtual slot are calculated according to the corresponding transmission probability and conditional collision probability of the node.The power consumption of the node and the goodput energy-consumption rate of the network are thus obtained.Analytical results show that,(1) the longer the packet and the higher the channel rate,the lower the goodput energy-consumption rate which means a better energy-consumption(perfor-)mance;(2) there exists a near-linear relationship between the goodput energy-consumption rate and the network size;(3) the basic access mechanism becomes better than the RTS/CTS access mechanism at an increasing channel rate;and(4) the average power consumption of the node is mainly determined by the received power consumption when the network size is large enough,but rarely affected by the transmitted and idle power consumptions.