Method and apparatus of performing random access procedure for data transmission in wireless communication system

A user equipment (UE) in a wireless communication system, the UE comprising:

• at least one processor;
• and
• at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, cause the UE to perform operations comprising:
• based on a first data that can be transmitted in a Radio Resource Control (RRC)_INACTIVE state becoming available, triggering a first random access (RA) procedure for transmitting the first data in the RRC_INACTIVE state;
• and
• based on a second data that cannot be transmitted in the RRC_INACTIVE state becoming available while the first RA procedure is ongoing, transmitting a RRC message for transitioning to a RRC CONNECTED state,
• wherein, based on the second data becoming available after a contention resolution succeeds, a ciphering is applied to the RRC message, and
• wherein, based on the second data becoming available before the contention resolution succeeds, the first RA procedure is stopped and a second RA procedure for transitioning to the RRC CONNECTED state is started.

An apparatus of a user equipment (UE), the apparatus comprising:

• at least one processor;
• and
• at least one computer memory storing instructions that, when executed by the at least one processor, cause the UE to perform operations comprising:
• based on a first data that can be transmitted in a Radio Resource Control (RRC) INACTIVE state becoming available, triggering a first random access (RA) procedure for transmitting the first data in the RRC_INACTIVE state;
• and
• based on a second data that cannot be transmitted in the RRC_INACTIVE state becoming available while the first RA procedure is ongoing, transmitting a RRC message for transitioning to a RRC CONNECTED state,
• wherein, based on the second data becoming available after a contention resolution succeeds, a ciphering is applied to the RRC message, and
• wherein, based on the second data becoming available before the contention resolution succeeds, the first RA procedure is stopped and a second RA procedure for transitioning to the RRC CONNECTED state is started.

A non-transitory computer readable storage medium storing at least one computer program comprising instructions that, when executed by at least one processor of a user equipment (UE), cause the UE to perform operations comprising:

• based on a first data that can be transmitted in a Radio Resource Control (RRC)_INACTIVE state becoming available, triggering a first random access (RA) procedure for transmitting the first data in the RRC_INACTIVE state;
• and
• based on a second data that cannot be transmitted in the RRC_INACTIVE state becoming available while the first RA procedure is ongoing, transmitting a RRC message for transitioning to a RRC CONNECTED state,
• wherein, based on the second data becoming available after a contention resolution succeeds, a ciphering is applied to the RRC message, and
• wherein, based on the second data becoming available before the contention resolution succeeds, the first RA procedure is stopped and a second RA procedure for transitioning to the RRC CONNECTED state is started.