Joint Uplink and Downlink Resource Configuration for Ultra-reliable and Low-latency Communications

TL;DR

This paper proposes a joint uplink and downlink resource configuration method for URLLC in 5G networks, minimizing total bandwidth while satisfying strict QoS constraints through a novel packet delivery mechanism and optimization approach.

Contribution

It introduces a joint optimization framework for uplink and downlink bandwidths in URLLC, incorporating a new packet delivery mechanism and a two-step solution method.

Findings

Significant bandwidth reduction achieved through joint optimization.

Effective queueing and transmission delay management for URLLC.

Validation via simulations showing performance improvements.

Abstract

Supporting ultra-reliable and low-latency communications (URLLC) is one of the major goals for the fifth-generation cellular networks. Since spectrum usage efficiency is always a concern, and large bandwidth is required for ensuring stringent quality-of-service (QoS), we minimize the total bandwidth under the QoS constraints of URLLC. We first propose a packet delivery mechanism for URLLC. To reduce the required bandwidth for ensuring queueing delay, we consider a statistical multiplexing queueing mode, where the packets to be sent to different devices are waiting in one queue at the base station, and broadcast mode is adopted in downlink transmission. In this way, downlink bandwidth is shared among packets of multiple devices. In uplink transmission, different subchannels are allocated to different devices to avoid strong interference. Then, we jointly optimize uplink and downlink bandwidth configuration and delay components to minimize the total bandwidth required to guarantee the overall packet loss and end-to-end delay, which includes uplink and downlink transmission delays, queueing delay and backhaul delay. We propose a two-step method to find the optimal solution. Simulation and numerical results validate our analysis and show remarkable performance gain by jointly optimizing uplink and downlink configuration.