TETRA专业移动无线通信系统随机接入时延分析

研究TETRA专业移动无线通信系统随机接入时延性能. 基于马尔科夫链和排队论模型,结合TETRA系统空中接口协议,分析了随机接入帧长和等待时间对随机接入时延的影响. 数值结果表明,大业务量下,接入帧长小或等待时间短而导致的信令重发冲突概率高是产生时延的最主要原因;小业务量下,接入帧长大或等待时间长而导致的信令重发等待时间长是产生时延的最主要原因. 通过优化参数得到了TETRA系统单个基站所能支持的最大用户数,为系统容量规划提供了依据. 

Random Access Delay Performance of TETRA Professional Mobile Radio System

Random access delay performance of TETRA professional mobile radio system is studied in this research. Based on Markov chain and queue theory models, the impact of random access frame length and waiting time on signaling delay in TETRA air interface protocol is analyzed. Numerical results show that, under heavy traffic load condition, the short access frame length or waiting time, which results in the high probability of collision when signaling is retransmitted, is the main reason of generating delay; while under light traffic load condition, the long access frame length or waiting time, which results in the long waiting time before signaling is retransmitted, is the main reason of generating delay. The maximum number of users which can be served by TETRA system under one base station (BS) is achieved through parameter optimization, which provides a basis for system capacity planning.