lt of the measurements to the network. The network then makes a decision as to whether the device has to be handed-over to a 252 Chapter 2 new cell. It should be noted that the reporting is provided through RRC signaling and not layer 1 measurement and reporting framework used for beam management. Apart from some cases in small cell network architectures where the cells are relatively synchronized, the device must perform a new uplink synchronization with respect to the target cell prior to handover. To obtain synchronization to a new cell, the UE has to perform a contention- free random-access procedure using resources specifically assigned to the device with no risk of collision with the goal of attaining synchronization to the target cell. Thus, only first two steps of the random-access procedure are needed which includes the preamble transmission and the corresponding random-access response providing the device with updated transmission timing [17]. In RRC_CONNECTED state, a network-controlled mobility scheme is used which has two variants: cell-level mobility and beam-level mobility. In cell-level mobility explicit RRC signaling is used to trigger a handover. For inter-gNB handover, the signaling procedures consist of four components as follows [8]: 1. The source gNB initiates handover and issues a Handover Request message over Xn interface. 2. The target gNB performs admission control and provides the RRC configuration as part of the Handover ACK message. 3. The source gNB provides the RRC configuration to the UE in the Handover Command. The Handover Command message includes at least the cell ID and all information required to access the target cell SO that the UE can access the target cell without detect- ing its SI. In some cases, the information required for contention-based and contention- free random-access procedure can be included in the Handover Command message. The access information to the target cell may include beam-specific information. 4. The UE moves the RRC connection to the target gNB and r