基于模糊控制的垂直切换决定算法

A Fuzzy Control Based Decision Algorithm for Vertical Handoff

蜂窝网络(cellular network)与无线局域网(WLAN)的融合是下一代移动通信的发展趋势,在通信过程中,节点将在两种网络间进行垂直切换。文中提出了一种垂直切换决定算法,该算法采用学习机制建立模糊集合的隶属度函数,并从用户对WLAN选择度、WLAN的信号强度以及带宽3个方面进行考虑,通过模糊推理,最终作出切换决定。分析及仿真表明本算法能够在综合多种影响切换的因素基础上作出准确的切换决定,与传统算法相比较,本算法的切换次数降低到传统算法的50%以下。

The integration of cellular networks and WLAN is the development trend of the next generation mobile communications,nodes will handoff between the two kinds of networks.This paper proposes a decision algorithm for vertical handoff which sets up membership functions by using a study mechanism.The algorithm makes a handoff decision on the basis of fuzzy inference method by taking into consideration of the user＇s preference,the signal strength of WLAN and the bandwidth of WLAN.Simulation shows that the algorithm can make precise judge and can reduce the number of handoff to less than 50% compared with traditional algorithm.