机器类设备基于不同时延需求分组的随机接入方法

针对大规模机器类通信中拥塞导致的时延敏感设备时延高和接入成功率低的问题，提出将小区中设备按时延要求分组，对不同组设备引入不同的退避模型，分析时延敏感设备的时延和吞吐量，按照不同组中设备的时延需求动态分配前导数目，同时通过调整接入类限制因子实现吞吐量的优化。仿真结果表明，在给定时延敏感设备的时延限制条件时，与统一退避的机制对比，所提分组机制的时延敏感设备能够满足时延要求，并且提高了接入效率。

A random access method based on device grouping with different time delay requirements in machine type communication

In order to solve the problem of high delay and low access success rate caused by congestion in large-scale machine type communication(MTC),this paper groups the devices according to the delay requirements and analyzes the delay and throughput of delay-sensitive devices by introducing different back-off models for different groups.The number of preambles is dynamically allocated according to the delay requirements of different groups,and the throughput is optimized by adjusting the access class barring factor.By comparing with the mechanism of uniform backoff,the simulation results show that the delay-sensitive devices can achieve latency requirement and the access efficiency is improved when the latency of the delay sensitive devices is limited.