I. Introduction
The use of millimeter-wave (mm-wave) spectrum is seen as key for unlocking the full potential of 5G-and-beyond cellular networks, offering a large amount of continuous wide bandwidth for capacity enhancements [1]. However, the move to mm-wave frequencies comes with significant challenges in terms of increased propagation losses, blockage susceptibility and a limited multipath environment [2]. Multi-antenna arrays can compensate this by electronically steering the antenna beams with the required gains in the desired directions. However, the use of directional pencil-beam communications makes mm-wave coverage heavily reliant on either line-of-sight (LOS) or strong non-LOS (NLOS) links, where the distinct link opportunities become sparse, both in numbers and angular reach [3]. Novel beam management approaches are thus required for addressing the challenge of high and robust coverage for future mm-wave mobile networks.