Full-Stack ns-3 Framework for the Evaluation of 5G-NR Beam Management in Non-Standalone Downlink Millimeter-Wave Networks

Abstract

To address the end-to-end implications of realistic beam management control operations, in this paper we present a full-stack 5G-NR-compliant ns-3 framework which implements realistic scheduling, transmission, and reception of 5G-NR downlink control signals, namely synchronization signal block (SSB) and channel state information-reference signal (CSI-RS). The framework is based on a non-standalone downlink 5G-NR millimeter wave (mm-wave) network, enabling control signal transmission via an LTE network connection for handover coordination and overcoming radio link failure (RLF). Our framework provides customizable interfaces to a threshold-based beam management operation. Furthermore, we propose three 5G-NR-compliant beam management strategies and analyze their performance using site-specific propagation and pedestrian mobility data. Overall, our results show the end-to-end implications of realistic beam management operations required to maintain high-rate mobile user performance, with frequent signal-to-noise ratio variations reflected as significant drops in the achievable throughput and high delay spikes. This highlights the importance of the presented ns-3 framework compared to the ideal, instantaneous beam scanning supported in existing ns-3 mm-wave modules, for realistic 5G-NR beam management evaluation. To this end, we provide open access to the ns-3 code to facilitate the research efforts of the wireless community.