Multi-User Preemptive Scheduling for Critical Low Latency Communications in 5G Networks

TL;DR

This paper introduces a novel multi-user preemptive scheduling strategy for 5G networks that optimizes both spectral efficiency and ultra-reliable low-latency communication, ensuring URLLC latency requirements with minimal impact on eMBB throughput.

Contribution

It proposes a joint scheduling approach that prioritizes URLLC traffic and dynamically overwrites eMBB transmissions when necessary, balancing latency and spectral efficiency.

Findings

Significant improvement in URLLC latency performance.

Enhanced spectral efficiency for eMBB traffic.

Effective handling of sporadic URLLC traffic during transmissions.

Abstract

5G new radio is envisioned to support three major service classes: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications. Emerging URLLC services require up to one millisecond of communication latency with 99.999% success probability. Though, there is a fundamental trade-off between system spectral efficiency (SE) and achievable latency. This calls for novel scheduling protocols which cross-optimize system performance on user-centric; instead of network-centric basis. In this paper, we develop a joint multi-user preemptive scheduling strategy to simultaneously cross-optimize system SE and URLLC latency. At each scheduling opportunity, available URLLC traffic is always given higher priority. When sporadic URLLC traffic appears during a transmission time interval (TTI), proposed scheduler seeks for fitting the URLLC-eMBB traffic in a multi-user transmission. If the available spatial degrees of freedom are limited within a TTI, the URLLC traffic instantly overwrites part of the ongoing eMBB transmissions to satisfy the URLLC latency requirements, at the expense of minimal eMBB throughput loss. Extensive dynamic system level simulations show that proposed scheduler provides significant performance gain in terms of eMBB SE and URLLC latency.