Enhanced Contention-Based Random Access for 5G NR and Beyond: Supporting NES

Abstract

This manuscript investigates the challenges arising from the interaction between cell discontinuous transmission/reception (DTX/DRX) for network energy saving (NES) and contention-based random access (CBRA) in 5G new radio (NR) networks and beyond. While cell DTX/DRX significantly reduces network power consumption, it can negatively impact CBRA performance by increasing access delay and reducing the success rate. To address these issues, we propose two enhanced CBRA schemes with mathematical modeling and Monte Carlo simulation results demonstrating significant improvements in CBRA performance under dense 5G NR and 6G NES environments. The first scheme introduces a Secondary MSG1 Opportunity to dynamically allocate radio resources and mitigate collisions. The second scheme employs Multiple Uplink (UL) Grant Occasions for MSG3 to reduce contention among User Equipments (UEs). We detail the operation of the proposed CBRA schemes and analyze their potential to improve CBRA performance in 5G NR and beyond, while effectively supporting NES.