一种基于星上ATM交换系统接纳控制算法的改进方法研究  

Research of improve method based on CAC algorithms for satellite ATM switching system

作　　者：熊辉波[1] 李勇[1] 

机构地区：[1]西北工业大学电子信息学院,西安710072

出　　处：《电子测量技术》2007年第10期21-25,共5页Electronic Measurement Technology

摘　　要：接纳控制算法(call admission control)在星上ATM交换系统中是重要的组成部分。针对I-CAC算法可能存在超额概率和拥塞等问题,提出了以二元开关型马尔可夫流模型为基础、将B-CAC算法、Bahadur-Rao理论以及Weiss理论进行结合的方法,对原有方法进行了改进,并进行了相应的仿真分析。仿真结果显示,在信元峰值/链路速率比较小、突发度较高的背景下(符合星上通信特点以及实时业务特性的需求),链路利用率及统计复用增益均得到明显提高;复用后引入了小缓冲区,有效地降低了信元丢失率,提高了可连接信源数,连接信元数的增多,在确保前二者的前提下仍然保证了星上处理对小缓存的要求。Call admission control （CAC） algorithms is a vital part in the satellite ATM switching system. Aiming at the problem of the excess demand probability and congestion that existing in I-CAC algorithms, we present a improved method based on On-Off two state Markov flow model and combined with B-CAC algorithm, Bahadur-Rao theory and Weiss theory. Simulation results show that when the PDR/CR is small and burst degree is high （meet the requirement of characteristic of Satellite communication and the demand of VBR）, the chain utilization and statistic multiplex gain get obvious improvement The introduce of small buffer effectively reduced the cell loss rate, improved the connectable signal resources and the cell number as well. Under this precondition of above two, small buffer that the OBP demand are also guarantee.

关 键 词：星上交换 ATM 接纳控制 快速缓存预留 Bahadur-Rao理论 Weiss理论 

分 类 号：TP393.15[自动化与计算机技术—计算机应用技术]