Method and apparatus for mobility procedure in a wireless communication system

A User Equipment (UE), comprising:

• a control circuit;
• a processor installed in the control circuit;
• and
• a memory installed in the control circuit and operatively coupled to the processor, wherein the processor is configured to execute a program code stored in the memory to perform operations, the operations comprising:
• receiving, from a first cell, a first signaling indicative of one or more random access resources of a second cell;
• receiving, from the first cell, a second signaling indicative of switching a Special Cell (SpCell) of the UE to the second cell, wherein the second signaling comprises at least one of a Physical Downlink Control Channel (PDCCH) signaling or a Medium Access Control (MAC) Control Element (CE);
• and
• initiating a random access procedure on the second cell in response to receiving the second signaling, wherein the random access procedure is performed by the UE using the one or more random access resources.

A non-transitory computer-readable medium comprising processor-executable instructions that when executed by a User Equipment (UE) cause performance of operations, the operations comprising:

• receiving, from a first cell, a first signaling indicative of one or more random access resources of a second cell;
• receiving, from the first cell, a second signaling indicative of switching a Special Cell (SpCell) of the UE to the second cell, wherein the second signaling comprises at least one of a Physical Downlink Control Channel (PDCCH) signaling or a Medium Access Control (MAC) Control Element (CE);
• and
• initiating a random access procedure on the second cell in response to receiving the second signaling, wherein the random access procedure is performed by the UE using the one or more random access resources.