IEEE 802.11p无线车载网信标广播技术的性能优化方法研究

Performance enhancement of broadcasting of IEEE 802.11p beacon messages

IEEE 802.11p车载网络中利用定期广播信标的方法,提供道路安全服务。由于车载网络中的节点具有高移动性,因此,车载网网络拓扑变化较快。然而IEEE 802.11p信道接入技术采用恒定的竞争窗口,该方法在网络拓扑动态变化的环境下性能较低下。此外,无线信道的状态不稳定,对车联网的信标通信也具有较大的影响。针对上述问题,研究了IEEE 802.11p无线车载网信标广播技术的性能优化方法,提出了根据信标广播失败概率以及信道状态动态调节竞争窗口和传输速率的方法。利用NS3网络仿真工具验证了本研究提出的方法能够有效地提升802.11p信标广播技术的性能。

The IEEE 802.11 p vehicular networks provide road safety services by broadcasting of beacons periodically.Since nodes move in high velocities,the topology of VANETs changes fast.However,the IEEE 802.11 p channel access technology employs a constant contention window,the performance of which degrades in the network with high mobility.In addition,the wireless channel is not stable,and a channel with high bit-error rate introduces in high packet loss.Considering the above issues,a method is proposed to dynamically adjust the contention window size and the transmission rate based on beacon broadcast failure probability and channel state,in order to enhance the performance of the IEEE 802.11 p VANETs beaconing.The NS3 network simulation tool is used to verify that the proposed method can effectively improve the performance of the 802.11 p beaconing.