Efficient Context-Aware Barring Scheme for Low-Latency 2-Step RACH in 5G Networks

Nie, Dawei; Yu, Wenjuan; Foh, Chuan Heng; Ni, Qiang; Chen, Luan; Berri, Sara; Chorti, Arsenia; Sun, Hongjian

Abstract

The random access channel (RACH) procedure is critical for uplink synchronization and connection establishment in massive machine-type communication (mMTC). While 3GPP Release 16 introduced the 2-step RACH to reduce signaling overhead, latency incurred due to collisions remains a significant challenge in latency-critical mMTC scenarios. This paper proposes an enhanced 2-step RACH framework that integrates access class barring (ACB) with an action space-reduced contextual multi-armed bandit (AR-CMAB) agent to optimize performance. The proposed scheme dynamically adjusts the barring rate based on real-time traffic conditions, significantly reducing collisions, avoiding backoff delays, and minimizing overall access latency. Simulation results demonstrate that the AR-CMAB agent converges much faster than the benchmark scheme while achieving near-optimal latency, outperform-ing existing methods under varying traffic conditions. Index Terms-Two-step random access channel, contex-tual multi-armed bandit, access class barring.

Citation

Nie, D., Yu, W., Foh, C. H., Ni, Q., Chen, L., Berri, S., Chorti, A., & Sun, H. (2025, May). Efficient Context-Aware Barring Scheme for Low-Latency 2-Step RACH in 5G Networks. Presented at IEEE INFOCOM 2025: IEEE International Conference on Computer Communications - Workshop, London

• Presentation Conference Type: Conference Paper (published)
• Conference Name: IEEE INFOCOM 2025: IEEE International Conference on Computer Communications - Workshop
• Start Date: May 19, 2025
• End Date: May 22, 2025
• Acceptance Date: Jan 16, 2025
• Deposit Date: Feb 25, 2025
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Public URL: https://durham-repository.worktribe.com/output/3546113
• Publisher URL: https://ieeexplore.ieee.org/xpl/conhome/1000359/all-proceedings