中文摘要：

提出了一种适用于蜂窝移动通信系统的多媒体业务随机接入协议动态坚持度等级自适应转换机制.基于数据包传输时延,使用各坚持度等级的吞吐量曲线的相交点作为坚持度等级变化的转换点;当节点发送数据包的平均时延超过当前级别转换点时延时,坚持度等级发生变化.给出了该协议的工作原理,进行了转换点位置理论分析.理论和仿真结果表明,采用该机制可以使高优先级多媒体业务服务质量在系统重载时得到保障,能达到采用UMTS系统基站调控机制的系统性能;与基站调控机制相比,本自适应转换机制能减少系统周期性广播的资源消耗.

英文摘要：

An adaptive dynamic persistence level transition scheme for random access protocols in multimedia cellular mobile communication systems was proposed.In this scheme,the transition points were defined as the intersections of the throughput curves of each persistence level.Dynamic persistence level changed as the average delay was equal to or larger than the delay of current transition point.The scheme principle as well as the theoretical transition points were analyzed in detail.Analytical and simulation results showed that,by adopting the adaptive transition scheme,the quality of service （QoS） of high priority multimedia traffic was guaranteed when the system load was heavy,and the QoS could reach the performance of the system adopting the UMTS transition scheme controlled by base station.Moreover,the system broadcast resources could also be reduced compared with the traditional transition scheme controlled by base station.