Patent ID: 11477712

Abstract:
This document describes methods, devices, systems, procedures, and means of maintaining communication and signaling interfaces during network role transitions, such as a secondary node change or a handover. A source secondary base station holds a source donor Central Unit (Source CU) for its own Distributed Unit (source DU) and for the Distributed Unit(s) of the node base station(s) (node DU). The source secondary base station connects to the node base station via a first F1 interface. The node DU triggers handover of the node base station and connected User Equipment (UE) from the source secondary base station to a target secondary base station. The node base station creates Transport Network Layer (TNL) connectivity toward a target donor Central Unit (Target CU) and exchanges application layer configuration data with the Target CU via a wireless backhaul link implemented utilizing the TNL connectivity. The node base station then sets up a second F1 interface with the Target CU and handover of the node base station and connected User Equipment (UE) from the source secondary base station to a target secondary base station is performed.