User equipment and method for small data transmission
A user equipment (UE) and a method for small data transmission (SDT) are provided. The method includes receiving a Radio Resource Control (RRC) release message from a Base Station (BS), the RRC release message indicating an SDT configuration including a Configured Grant (CG) configuration and a timer; initiating a transmission on an Uplink (UL) resource while the UE is in an RRC_INACTIVE state, the UL resource being either configured by the CG configuration or scheduled by a UL grant from the BS; starting or restarting the timer after initiating the transmission; and monitoring a Physical Downlink Control Channel (PDCCH) addressed to a specific Radio Network Temporary Identifier (RNTI) on a specific search space while the timer is running.
1. A method performed by a User Equipment (UE) for small data transmission (SDT), the method comprising:
receiving a Radio Resource Control (RRC) release message from a Base Station (BS), the RRC release message indicating an SDT configuration including a Configured Grant (CG) configuration and a timer;
initiating a transmission on an Uplink (UL) resource while the UE is in an RRC_INACTIVE state, the UL resource being either configured by the CG configuration or scheduled by a UL grant from the BS;
starting or restarting the timer after initiating the transmission; and
monitoring a Physical Downlink Control Channel (PDCCH) addressed to a specific Radio Network Temporary Identifier (RNTI) on a specific search space while the timer is running.
2. The method of claim 1 , further comprising:
stopping the timer upon receiving an indication from the BS.
3. The method of claim 2 , wherein the indication indicates Downlink Feedback Information (DFI).
4. The method of claim 2 , wherein the indication indicates a specific UL grant for a new transmission associated with a Hybrid Automatic Repeat Request (HARM) process used for the transmission.
5. The method of claim 1 , further comprising:
stopping the timer when a Time Alignment (TA) timer expires.
6. The method of claim 1 , further comprising:
stopping the timer when the CG configuration is released.
7. The method of claim 1 , further comprising:
initiating a Random Access (RA) procedure when the timer expires.
8. The method of claim 1 , wherein the specific search space is indicated by the SDT configuration.
9. The method of claim 1 , wherein the specific RNTI includes at least one of a Cell-RNTI (C-RNTI) and a Configured Scheduling-RNTI (CS-RNTI).
10. The method of claim 1 , wherein the timer is included in the CG configuration.
11. A user equipment (UE) for small data transmission (SDT), the UE comprising:
one or more processors; and
at least one memory coupled to at least one of the one or more processors, wherein the at least one memory stores a computer-executable program that, when executed by the at least one of the one or more processors, causes the UE to:
receive a Radio Resource Control (RRC) release message from a Base Station (BS), the RRC release message indicating an SDT configuration including a Configured Grant (CG) configuration and a timer;
initiate a transmission on an Uplink (UL) resource while the UE is in an RRC_INACTIVE state, the UL resource being either configured by the CG configuration or scheduled by a UL grant from the BS;
start or restart the timer after initiating the transmission; and
monitor a Physical Downlink Control Channel (PDCCH) addressed to a specific Radio Network Temporary Identifier (RNTI) on a specific search space while the timer is running.
12. The UE of claim 11 , wherein the computer-executable program, when executed by the processor, further causes the UE to:
stop the timer upon receiving an indication from the BS.
13. The UE of claim 12 , wherein the indication indicates Downlink Feedback Information (DFI).
14. The UE of claim 12 , wherein the indication indicates a specific UL grant for a new transmission associated with a Hybrid Automatic Repeat Request (HARQ) process used for the transmission.
15. The UE of claim 11 , wherein the computer-executable program, when executed by the processor, further causes the UE to:
stop the timer when a Time Alignment (TA) timer expires.
16. The UE of claim 11 , wherein the computer-executable program, when executed by the processor, further causes the UE to:
stop the timer when the CG configuration is released.
17. The UE of claim 11 , wherein the computer-executable program, when executed by the processor, further causes the UE to:
initiate a Random Access (RA) procedure when the timer expires.
18. The UE of claim 11 , wherein the specific search space is indicated by the SDT configuration.
19. The UE of claim 11 , wherein the specific RNTI includes at least one of a Cell-RNTI (C-RNTI) and a Configured Scheduling-RNTI (CS-RNTI).
20. The UE of claim 11 , wherein the timer is included in the CG configuration.