Beam Management in mmWave 5G NR: an Intra-Cell Mobility Study
Filipa Fernandes, Christian Rom, Johannes Harrebek, Gilberto Berardinelli
Abstract
5th Generation (5G) millimeter wave (mmWave) communications rely on directive and narrow beams to circumvent its challenging propagation conditions. Therefore, Medium Access Control (MAC)-based Beam Management (BM) becomes essential to secure adequate beam alignment between the User Equipment (UE) and the Next Generation Node Base Station (gNodeB) beams. For dynamic environments, this can be challenging, potentially compromising control procedures such as Beam Tracking (BT) under the current 5G New Radio (NR) deployments for FR2. This paper presents a sensitivity study on the stability of the gNodeB selected beam - measured by the beam's time-of-stay (ToS) - and the resulting link quality under different operational conditions with respect to UE mobility, propagation environment and operational bands. Results show that the suitability of 5G NR BM procedures can be significantly affected by UE angular speed, channel's angular spread and availability of channel-adaptive BM parametrization.