为解决海量机器类通信(mMTC,massive machine type communications)场景下,机器类通信设备(MTCD,machine type communication device)采用传统随机接入方案时,往往出现网络严重拥塞,导致大量MTCD无法成功接入网络问题,提出了一种基于前导码重传辅助的动态接入类别限制(PRT-ACB,preamble retransmission access class barring)方案.利用MTCD的前导码重传次数,将每个随机接入机会(RAO,random access opportunity)中尝试发起接入的MTCD划分为高、低优先级,结合每个RAO中负载数估计模型,分别为其设定随每个RAO中的接入负载动态变化的高、低优先级限制因子和可用前导码池,使更多MTCD能在未达到最大前导码传输次数前成功接入网络.仿真结果表明,所提方案能有效提升MTCD的接入成功概率,降低MTCD接入网络所需时延.所提方案可以作为缓解海量通信设备同时接入网络造成拥塞的一种解决方案.
Preamble retransmission assisted control-based mMTC dynamic random access
To address the issue of severe network congestion in the scenario of massive machine-type communications(mMTC),where machine-type communication devices(MTCD)employing traditional random access schemes often encountered challenges leading to a large number of MTCD failing to access the network successfully,a novel approach called preamble retransmission-based dynamic access class barring(PRT-ACB)was proposed.By utilizing the number of MTCD preamble retransmissions,the MTCD attempting to initiate access in each random access opportunity(RAO)were categorized into different sets of high and low priority.In conjunction with an estimation model for the number of pay-loads in each RAO,high and low-priority limiting factors and available preamble pools were dynamically adjusted based on the access load in each RAO.This allowed more MTCD to successfully access the network before reaching the maxi-mum number of preamble transfers.Simulation results have demonstrated that the proposed scheme effectively enhances the MTCD successful access rate and reduces the time delay required for MTCD to access the network.The proposed scheme can serve as a solution to alleviate the congestion caused by a massive influx of communication devices attempt-ing simultaneous network access.
machine type communication devicerandom accesscongestion controlthe number of preamble retransmissions