USER EQUIPMENT AND METHOD FOR PERFORMING CONFIGURED GRANT BASED SMALL DATA TRANSMISSION
A method and a user equipment (UE) for performing a Configured Grant-based Small Data Transmission (CG-SDT) is provided. The method includes performing an initial transmission of the CG-SDT via a first configured Uplink (UL) grant associated with a Hybrid Automatic Repeat Request (HARQ) process; determining whether a feedback from the BS has been received for the first configured UL grant associated with the HARQ process; and performing a retransmission for the initial transmission of the CG-SDT via a second configured UL grant if the feedback has not been received.
1 . A method for a User Equipment (UE) to perform a Configured Grant-based Small Data Transmission (CG-SDT) to a Base Station (BS), the method comprising:
performing an initial transmission of the CG-SDT via a first configured Uplink (UL) grant associated with a Hybrid Automatic Repeat Request (HARQ) process;
determining whether a feedback from the BS has been received for the first configured UL grant associated with the HARQ process; and
performing a retransmission for the initial transmission of the CG-SDT via a second configured UL grant if the feedback has not been received.
2 . The method of claim 1 , wherein the initial transmission of the CG-SDT comprises a Common Control Channel (CCCH) message.
3 . The method of claim 1 , wherein the feedback is received on a Physical Downlink Control Channel (PDCCH) addressed to a Cell-Radio Network Temporary Identifier (C-RNTI).
4 . The method of claim 1 , wherein the retransmission for the initial transmission of the CG-SDT is performed if the feedback is not received and a configured CG-SDT retransmission timer is not running.
5 . The method of claim 1 , wherein a Medium Access Control (MAC) layer of the UE indicates a failure of performing a Small Data Transmission (SDT) procedure to a Radio Resource Control (RRC) layer of the UE if a configured grant timer for the HARQ process expires and the feedback has not been received after the initial transmission of the CG-SDT.
6 . The method of claim 1 , further comprising:
stopping a CG-SDT retransmission timer for the HARQ process if the UE receives a specific UL grant.
7 . The method of claim 6 , wherein the specific UL grant is received on a Physical Downlink Control Channel (PDCCH) addressed to a Cell-Radio Network Temporary Identifier (C-RNTI).
8 . The method of claim 1 , further comprising:
stopping a configured grant timer for the HARQ process if the UE receives a specific UL grant.
9 . The method of claim 8 , wherein the specific UL grant is received on a Physical Downlink Control Channel (PDCCH) addressed to a Cell-Radio Network Temporary Identifier (C-RNTI).
10 . The method of claim 1 , further comprising:
starting or restarting a CG-SDT retransmission timer for the HARQ process when the initial transmission of the CG-SDT or the retransmission for the initial transmission of the CG-SDT is performed.
11 . A User Equipment (UE) in a wireless communication system for performing a Configured Grant-based Small Data Transmission (CG-SDT) to a Base Station (BS), the 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 a computer-executable program that, when executed by the at least one processor, causes the UE to:
perform an initial transmission of the CG-SDT via a first configured Uplink (UL) grant associated with a Hybrid Automatic Repeat Request (HARQ) process;
determine whether a feedback from the BS has been received for the first configured UL grant associated with the HARQ process; and
perform a retransmission for the initial transmission of the CG-SDT via a second configured UL grant if the feedback has not been received.
12 . The UE of claim 11 , wherein the initial transmission of the CG-SDT comprises a Common Control Channel (CCCH) message.
13 . The UE of claim 11 , wherein the feedback is received on a Physical Downlink Control Channel (PDCCH) addressed to a Cell-Radio Network Temporary Identifier (C-RNTI).
14 . The UE of claim 11 , wherein the retransmission for the initial transmission of the CG-SDT is performed if the feedback is not received and a configured CG-SDT retransmission timer is not running.
15 . The UE of claim 11 , wherein a Medium Access Control (MAC) layer of the UE indicates a failure of performing a Small Data Transmission (SDT) procedure to a Radio Resource Control (RRC) layer of the UE if a configured grant timer for the HARQ process expires and the feedback has not been received after the initial transmission of the CG-SDT.
16 . The UE of claim 11 , wherein the computer-executable program, when executed by the at least one processor, further causes the UE to:
stop a CG-SDT retransmission timer for the HARQ process if the UE receives a specific UL grant.
17 . The UE of claim 16 , wherein the specific UL grant is received on a Physical Downlink Control Channel (PDCCH) addressed to a Cell-Radio Network Temporary Identifier (C-RNTI).
18 . The UE of claim 11 , wherein the computer-executable program, when executed by the at least one processor, further causes the UE to:
stop a configured grant timer for the HARQ process if the UE receives a specific UL grant.
19 . The UE of claim 18 , wherein the specific UL grant is received on a Physical Downlink Control Channel (PDCCH) addressed to a Cell-Radio Network Temporary Identifier (C-RNTI).
20 . The UE of claim 11 , wherein the computer-executable program, when executed by the at least one processor, further causes the UE to:
start or restart a CG-SDT retransmission timer for the HARQ process when the initial transmission of the CG-SDT or the retransmission for the initial transmission of the CG-SDT is performed.