存在隐藏终端的IEEE802.11e多跳无线网络模型分析

首次将802.11e的接入机制放入多跳环境中进行仿真分析和定量研究。提出一种新的多跳环境下802.11e网络模型,结合M/G/1/K排队模型,定量分析在隐藏终端影响下802.11e网络的MAC层吞吐率、MAC时延和帧丢失率,研究802.11e在多跳环境下性能表现的内在原因。经过仿真实验结果与数值分析结果的对比,验证了分析模型的准确性;通过有(无)隐藏终端影响下MAC层性能的对比分析,指出了802.11e在多跳无线网络中支持QoS的局限性:受隐藏终端的影响,802.11e对不同接入等级的业务提供QoS区分的性能明显降级。因而有必要研究隐藏终端问题的解决方案,提高802.11e在多跳环境下的性能。

Modeling analysis of multi-hop wireless networks using IEEE 802.11eprotocol with hidden nodes

This paper assessed the effectiveness of the IEEE 802.11e access mechanism in multi-hop wireless networks by quantitative research and simulation results,and built a new modeling analysis methodology for the 802.11e access mechanism in multi-hop environments and analyzed the MAC layer performance of multi-hop wireless networks,such as MAC layer throughput,the mean packet delay and packet discard probability due to packet collisions,with the impact of hidden nodes by using presented M/G/1/K queuing model.The proposed model was calculated numerically and validated against simulation results,then observed a good match between the analytical model and simulation.Simulation and theoretical results show that there is a great restriction in multi-hop wireless networks using 802.11e protocol despite providing prioritized QoS.It is very necessary to investigate the scheme which can resolve hidden nodes problem to improve performance of 802.11e in multi-hop wireless networks.