一种基于业务区分的随机接入方案

通过对移动通信系统关键技术的发展趋势和网络实时业务服务质量（QoS）需求的分析，提出了一种适用于时分－正交频分多址接入系统（TD-OFDMA）的简单高效的随机接入方案。在该方案中，网络终端利用特有的优先随机接入信道（FRRACH）对不同时延特性的业务采用不同的随机接入机制，从而有效地避免分组碰撞，保障实时业务的QoS需求。理论分析和仿真结果表明，该方案在成功接入概率、接入时延以及资源利用率等方面的性能较目前常用的随机接入方案有着较大的改善。

A New Service-oriented Random Access Scheme

By the analysis of the development of key technologies and quality of service(QoS) requirements of the real-time traffic in mobile communication systems,a simple and efficient random access scheme which is suitable for TD-orthogonal frequency division multiple access(TD-OFDMA) systems is proposed.In this scheme,the network terminals adopt different random access processing methods by utilizing the special first refusal random access channel(FRRACH) according to the delay sensitivity of the traffic.The new scheme efficiently avoids the packet collision and guarantees QoS requirements for the real-time traffic.Theoretical analysis and simulation results show the new scheme is superior to current random access schemes with respect to resource efficiency in random access process,successful access probability and average delay.