改进的异构无线网垂直切换算法

Improvement of vertical handoff algorithm on heterogeneous wireless networks

对异构无线网络融合中垂直切换判定算法进行研究。以典型的全球通信系统与无线局域网融合为例,引入乒乓带概念,利用移动终端当前位置、运动速度与径向运动角度等参数扩展驻留定时器算法。模拟仿真结果显示,移动终端采用该算法后即可实现预决策提前进行切换操作,避免不必要的切换,从而可保最大限度与无线局域网相连接。

The study of vertical handoff decision of wireless network heterogeneous is based on the typical roaming client between GSM and WLAN.At First,the concept of Ping-Pang Strip is presented.Secondly,the Dwell-Timer algorithm is extended with the parameters of mobile node which are the current location,velocity,the angle of radial direction.In simulation,the mobile node can take vertical handoff in advance by the pre-decision algorithm.Meanwhile,some unnecessary handoffs are trimmed down.Improved algorithm can keep the mobile node connect to the WLAN as long as possible.