一种改进的引入预判决及速度阈值的垂直切换算法  

An Improved Vertical Handoff Algorithm Based on Utility Function with Introduction of Pre-judgment and Speed Threshold

作　　者：俞成海[1] 徐立波[1] 马大伟[1] 王丰[1] 汪佳文 YUChenghai XULibo MADawei WANGFeng WANGJiawen(College of Informaties and Electronics, Zhejiang Sei-Tech University, Hangzhou 310018, China)

机构地区：[1]浙江理工大学信息学院,杭州310018

出　　处：《浙江理工大学学报（自然科学版）》2016年第6期872-879,共8页Journal of Zhejiang Sci-Tech University(Natural Sciences)

基　　金：浙江省公益技术研究工业项目(2016C31072);浙江省高校重中之重纺织科学与工程一级学科和浙江省服装工程技术研究中心开放基金课题;国家自然科学基金项目(61502430);浙江省自然科学基金项目(LY12F02041);浙江理工大学研究生课程建设项目(11120132331501)

摘　　要：通常情况下,移动终端的运动速度是一个变量,它将影响异构网络之间的垂直切换性能。假如当前业务为语音业务,并且移动端高速运动时,移动端频繁的切换有可能导致较大的丢包率,严重时导致终端的掉话。考虑到了这种问题,文章将移动端的移动速度和业务类型相结合,引入移动终端的速度阈值作为限制条件。在改进效用函数基础上,提出一种匀加速预判决过程的垂直切换判决算法。采用MATLAB软件对该算法对比RSS(信号强度)、效用函数以及引入预判决的算法进行仿真分析,结果表明,切换次数分别降低了13次、3次和1次;切换呼叫掉线率分别降低了4.2%、2.1%和1.2%,新呼叫阻塞率分别降低了4.2%、2.7%和1.8%。3个性能指标的提升证实了该算法性能的优越性。Usually,the speed of mobile terminal is a variable,which will affect the vertical handover performance of heterogeneous networks.It is assumed that current service is voice service and the mobile terminal moves at a high speed.In such condition,frequent switch of mobile terminal may lead to a large packet loss rate or even stopping communication.In view of this problem,this paper combines the speed of mobile terminal with service type and introduces speed threshold of mobile terminal as the restriction.This paper presents a vertical handover decision algorithm of uniformly accelerated pre-j udgment process,based on the improved utility function.MATLAB software is used to comparatively analyze this algorithm with RSS （signal intensity）,the utility function and the algorithm with introduction of pre-judgment.The results show handover times reduces 13,3 and 2 respectively.Call drop rate decreases by 4.2%,2.1%and 1.2% respectively.New call blocking rate decreases by 4.2%,2.7% and 1.8 % respectively.The improvement of three property indicators verifies the superiority performance of the proposed algorithm.

关 键 词：异构网络 垂直切换 速度阈值 预判决算法 效用函数 呼叫掉话率 新呼叫阻塞率 

分 类 号：TN929.5[电子电信—通信与信息系统]