城市轨道交通CBTC中准无缝切换的研究

在城市轨道交通中,当列车运行跨越由多个AP构成的大型无线网络时,存在切换的问题,切换过程中不可避免引起时延和丢包率问题。安全性是轨道交通永恒的主题,过长的时延和重要数据丢失都会引起行车安全。提出了基于位置的切换算法,减少切换时延的同时实现在相邻AP点间接力数据传输,消除丢包率,实现准无缝切换。

In urban mass transit,when the train runs across a large,multi-AP wireless network,there was the issue of handoff as well as delay and loss of packets occurring inevitably in the process of handoff.Longer delay or loss of important packets might endanger traffic safety.Based on the position,this paper proposes a new handing-over algorithm to reduce handoff delays,which could relay data transmission between adjacent APs and reduce the delays of handoff,eliminating loss of packets and achieving quasi-seamless handoff.