Patent ID: 11889372
Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A wireless communication device that performs handover from a source cell to a target cell in a wireless communication system, the wireless communication device comprising:
at least one transmitter and at least one receiver; and
circuitry associated with the at least one transmitter and the at least one receiver, the circuitry operable to:
perform a beam tracking procedure for one or more neighbor cells to provide, for each neighbor cell, a list of tracked beams for the neighbor cell;
receive a handover command from a source radio access node that instructs the wireless communication device to perform a handover from a source cell served by the source radio access node to a target cell served by a target radio access node, wherein the target cell is one of the one or more neighbor cells for which the beam tracking procedure is performed;
select a beam of the target cell from the list of tracked beams for the target cell based on random access resource configuration and/or a quality threshold; and

perform random access on the selected beam;, wherein selecting the beam of the target cell from the list of tracked beams for the target cell comprises the circuitry being further operable to:
determine that there are no dedicated random access channel resources allocated for contention-free random access for the best beam in the list of tracked beams for the target cell; and
upon determining that there are no dedicated random access channel resources allocated for contention-free random access for the best beam in the list of tracked beams for the target cell:
determine a difference between a quality of the best beam in the list of tracked beams for the target cell and a quality of a k-th best beam in the list of tracked beams for the target cell, the k-th best beam being a beam for which dedicated random access channel resources are allocated; and
determine whether the difference is less than a threshold, where the selected beam of the target cell is the k-th best beam if the difference is less than the threshold.