机器类型通信中随机接入信道的拥塞控制策略

摘要

在基于3GPP长期演进技术的机器类型通信( MTC)应用背景下,针对无线接入网络中随机接入信道的拥塞问题,提出一种改进的拥塞控制策略,MTC器件利用基站广播信息自适应调整各自的接入时间,避免由于大量MTC器件同时发起随机接入而引起接入碰撞的问题,实现基站的负载均衡及信道资源的合理分配。基于最大熵原理证明各MTC器件接入时间的均匀分布是最优分布。仿真实验结果表明,与接入类别限制策略相比,该策略可缓解随机接入信道的拥塞状况,提高MTC器件的随机接入成功率,降低接入时延,从而提升网络整体性能及服务质量。%This paper proposes an improved congestion control strategy to alleviate the congestion of random access channel in radio access network of Machine Type Communication(MTC) based on 3GPP-Long Term Evolution(LTE). In order to reach the base-station’ s load balancing in the time interval and allocate the channel resources rationally,it schedules the access time of MTC devices through the base-station’ s broadcasted information,and thereby avoids access collisions caused by massive number of MTC devices access the base-station simultaneously. It also proofs that uniform distribution of the access time is the optimal choice by maximum entropy principle. Simulation experimental results show that the strategy can alleviate the channel congestion significantly and increase the random access success rate of MTC devices,reduce the delay,and thus improve the network’ s performance and guarantee the network’ s Quality of Service ( QoS) compared with Access Class Barring( ACB) strategy.