Radio Resource Management Scheme for URLLC and eMBB Coexistence in a Cell-Less Radio Access Network

Abstract

We address the latency challenges in a high-density and high-load scenario for an ultrareliable and low-latency communication (URLLC) network which may coexist with enhanced mobile broadband (eMBB) services in the evolving wireless communication networks. We propose a new radio resource management (RRM) scheme consisting of a combination of time domain (TD) and frequency domain (FD) schedulers specific for URLLC and eMBB users. We also develop a user ranking algorithm from a radio unit (RU) perspective, which is employed by the TD scheduler to increase the efficiency of scheduling in terms of resource consumption in large-scale networks. Therefore, the optimized and novel resource scheduling scheme reduces latency for the URLLC users (requesting a URLLC service) in an efficient resource utilization manner to support scenarios with high user density. At the same time, this RRM scheme, while minimizing the latency, it also overcomes another important challenge of eMBB users (requesting an eMBB service), namely the throughput of those who coexist in such highly loaded scenario with URLLC users. The effectiveness of our proposed scheme including time and frequency domain (TD and FD) schedulers is analyzed. Simulation results show that the proposed scheme improves the latency of URLLC users and throughput of the eMBB users compared to the baseline scheme. The proposed scheme has a 29% latency improvement for URLLC and 90% signal-to-interference-plus-noise ratio (SINR) improvement for eMBB users as compared with conventional scheduling policies. INDEX TERMSCell-less, Radio access network, URLLC, RRM, 5G and beyond networks. Recently, a new radio access network (RAN) architecture known as cell-less (or cell-free) [4], [5] is proposed to provide high spectral efficiency, flexible and cost-efficient deployment, ensure high quality of service and benefit from low path loss propagation conditions. In the cell-less architecture, the cell boundaries are removed from the user equipment (UE) view point. In most of the recent literature illustrating the advantages of cell-less massive multiple-input-multipleoutput (mMIMO) over legacy architectures, the relevant key performance indicators (KPIs) for eMBB service type are VOLUME xx, 2022