无线多媒体网络中动态越区切换方案-软件学报.PDF

1000-9825/2003/14(07)1310 ©2003 Journal of Software 软 件 学 报 Vol.14, No.7 ∗ 无线多媒体网络中动态越区切换方案 + 魏丫丫 , 林 闯, 任丰原, 付 强 (清华大学 计算机科学与技术系,北京 100084) A Dynamic Handoff Scheme in Multimedia Wireless Networks + WEI Ya-Ya , LIN Chuang, REN Feng-Yuan, FU Qiang (Department of Computer Science and Technology, Tsinghua University, Beijing 100084, China) + Corresponding author: E-mail: yywei@ Received 2002-07-08; Accepted 2003-04-09 Wei YY, Lin C, Ren FY, Fu Q. A dynamic handoff scheme in multimedia wireless networks. Journal of Software, 2003,14(7):1310~1317. /1000-9825/14/1310.htm Abstract: In this paper, a Guard Channel (GC) scheme based on dynamic thresholds is proposed. It keeps the ratio of new connection blocking probability to handoff connection blocking probability to a predefined value, which guarantees the priority and fairness among connections. At the same time, it optimizes and improves the performance metrics for handoff: new connection blocking probability and handoff connection blocking probability and system utilization. In addition, the algorithm adopts self-adjusting to be adaptive to varying traffic loads and makes the blocking probability smoother. Lastly the results by analysis and simulation prove the feasibility of this scheme. Key words: guard channel; handoff; wireless network 摘 要: 提出了一种基于动态阈值的保护信道(guard channel, 简称 GC)方案.该方案的目标是使新增连接和切 换连接的阻塞率保持一定的比例关系,从而保证连接之间的优先级和公平性, 同时优化和改善了越区切换的性 能指标:切换连接的阻塞率、新增连接的阻塞率以及系统资源的利用率.此外,算法的自调节特性使系统能够适 应负载的动态变化,保证了阻塞率的平稳性.最后,分析与模拟的结果证明了该方案的可行性. 关键词: 保护信道;越区切换;无线网络 中图法分类号: TP316 文献标识码: A 现在的无线网络设计大都采用小区的结构,每个小区有一个基站(base station),小区的用户通过基站来完成 ∗ Supported by the National Natural Science Foundation of China