Wireless communication method and user equipment for random access operations

1. A wireless communication method performed by a User Equipment (UE), the wireless communication method comprising:

receiving, from a Base Station (BS), a Radio Resource Control (RRC) reconfiguration message including information related to a reconfiguration with synchronization, the information including a Contention Free Random Access (CFRA) configuration for a 2-step Random Access (RA), the CFRA configuration configuring a resource and a maximum number of Message-A (MSGA) preamble transmissions;

starting a timer upon receiving the RRC reconfiguration message including the information related to the reconfiguration with synchronization, the timer being configured by the information;

initiating an RA procedure after starting the timer, with an RA type set to a 2-step RA type, for the reconfiguration with synchronization, the RA procedure comprising transmitting an MSGA preamble;

discarding the resource in a case that a value of a preamble transmission counter reaches the maximum number of MSGA preamble transmissions;

discarding the resource in a case that the timer expires; and

discarding the resource in a case that the UE sets the RA type from the 2-step RA type to a 4-step RA type for the RA procedure.

2. The wireless communication method of claim 1 , wherein the resource includes at least one of a Physical Uplink Shared Channel (PUSCH) resource and a CFRA resource for the 2-step RA.

3. The wireless communication method of claim 1 , wherein the resource is a dedicated resource for the UE.

4. The wireless communication method of claim 1 , further comprising:

stopping the timer upon successful completion of the RA procedure; and

discarding the resource further in a case of the successful completion of the RA procedure.

5. The wireless communication method of claim 1 , further comprising:

stopping the RA procedure in a case that the UE resets a Medium Access Control (MAC) entity of the UE; and

discarding the resource further in a case that the RA procedure is stopped.

6. The wireless communication method of claim 1 , further comprising resetting the value of the preamble transmission counter when the RA procedure is initiated.

7. The wireless communication method of claim 1 , further comprising incrementing the value of the preamble transmission counter when a time window expires, wherein the time window is a time period for the UE to monitor a Random Access Response (RAR) for the RA procedure with the 2-step RA type.

8. The wireless communication method of claim 1 , wherein the maximum number of MSGA preamble transmissions is indicated by an Information Element (IE) denoted as msgA-TransMax in the CFRA configuration for the 2-step RA.

9. A User Equipment (UE) comprising:

at least one processor; and

at least one memory coupled to the at least one processor, wherein the at least one memory stores computer-executable instructions that, when executed by the at least one processor, cause the UE to:

receive, from a Base Station (BS), a Radio Resource Control (RRC) reconfiguration message including information related to a reconfiguration with synchronization, the information including a Contention Free Random Access (CFRA) configuration for a 2-step Random Access (RA), the CFRA configuration configuring a resource and a maximum number of Message-A (MSGA) preamble transmissions;

start a timer upon receiving the RRC reconfiguration message including the information related to the reconfiguration with synchronization, the timer being configured by the information;

initiate an RA procedure after starting the timer, with an RA type set to a 2-step RA type, for the reconfiguration with synchronization, the RA procedure comprising transmitting an MSGA preamble;

discard the resource in a case that a value of a preamble transmission counter reaches the maximum number of MSGA preamble transmissions;

discard the resource in a case that the timer expires; and

discard the resource in a case that the UE sets the RA type from the 2-step RA type to a 4-step RA type for the RA procedure.

10. The UE of claim 9 , wherein the resource includes at least one of a Physical Uplink Shared Channel (PUSCH) resource and a CFRA resource for the 2-step RA.

11. The UE of claim 9 , wherein the resource is a dedicated resource for the UE.

12. The UE of claim 9 , wherein the computer-executable instructions, when executed by the at least one processor, further cause the UE to:

stop the timer upon successful completion of the RA procedure; and

discard the resource further in a case of the successful completion of the RA procedure.

13. The UE of claim 9 , wherein the computer-executable instructions, when executed by the at least one processor, further cause the UE to:

stop the RA procedure in a case that the UE resets a Medium Access Control (MAC) entity of the UE; and

discard the resource further in a case that the RA procedure is stopped.

14. The UE of claim 9 , wherein the computer-executable instructions, when executed by the at least one processor, further cause the UE to:

reset the value of the preamble transmission counter when the RA procedure is initiated.

15. The UE of claim 9 , wherein the computer-executable instructions, when executed by the at least one processor, further cause the UE to:

increment the value of the preamble transmission counter when a time window expires, wherein the time window is a time period for the UE to monitor a Random Access Response (RAR) for the RA procedure with the 2-step RA type.

16. The UE of claim 9 , wherein the maximum number of MSGA preamble transmissions is indicated by an Information Element (IE) denoted as msgA-TransMax in the CFRA configuration for the 2-step RA.