6 GHz frequency bands. To overcome this issue, efficient usage of highly directional beamformed transmission and reception using a larger number of antenna elements is crucial at the gNB and the UE. To achieve large beamforming gain with reasonable implementation complexity, hybrid beamforming was found to be a suitable solution. The analog beams on each panel/subarray are adapted through phase shifters and/or amplitude scaling. Digital beamforming is adapted by apply- ing different digital precoders across panels/subarrays. At the gNB, downlink transmission with analog beamforming, that is, transmitter beam pointing toward a certain direction can only cover a limited area due to its relatively narrow beam-width. Therefore, the gNB needs to utilize multiple transmit beams to cover the entire cell. Similarly, in the uplink the gNB needs to utilize multiple receive beams to receive the uplink transmissions from the entire cell. 4.1.6.2 Beam Management The new radio provides a set of mechanisms by which the UEs and the gNB can establish highly directional transmission links, typically using large-scale phased arrays, to benefit from the resulting beamforming gain and to sustain an acceptable communication quality. Directional links, nevertheless, require fine alignment of the transmitter and receiver beams that can be only achieved through a set of procedures known as beam management. The beam management procedures are essential to perform a variety of radio access network functions including the initial access for idle users, which allows a mobile UE to establish a physical connection with a gNB and beam tracking for connected users, which enables beam adaptation schemes, or handover, path selection and radio link failure (RLF) recovery procedures. In LTE, these control procedures are performed using omnidirectional 510 Chapter 4 transmission, and beamforming or other directional transmissions can only be performed after a physical link (user-plane) is established. In certain conditions such as operation in the mmW