Method and apparatus for new radio multicast broadcast service reception
The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments herein disclose methods and systems for efficient and reliable reception for New Radio Multicast Broadcast Service (NR MBS). Embodiments herein disclose a DRX approach and HARQ transmission and retransmission for MBS packets in order to support power efficient and reliable delivery of 5G MBS. Embodiments herein disclose mechanisms that work for the PTM and PTP based delivery framework for NR MBS.
1 . A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
receiving, from a base station, a radio resource control (RRC) message including a discontinuous reception (DRX) configuration for a multicast broadcast service (MBS) corresponding to a group-radio network temporary identifier (G-RNTI) or a group-configured scheduling-RNTI (G-CS-RNTI) and a hybrid automatic repeat request (HARQ) feedback configuration for the MBS;
monitoring, during an active time for the MBS, a physical downlink control channel (PDCCH) addressed to the G-RNTI or the G-CS-RNTI for the MBS based on the DRX configuration; and
receiving, from the base station, the PDCCH addressed to the G-RNTI or the G-CS-RNTI for the MBS,
wherein the DRX configuration for the MBS comprises a drx-onDurationTimerpoint-to-multipoint (PTM) for the MBS, a drx-Inactivity TimerPTM for the MBS, a drx-HARQ-RTT-TimerDLPTM for the MBS, a drx-RetransmissionTimerDLPTM for the MBS, a DRX cycle for the MBS, and a DRX start offset for the MBS,
wherein, if a medium access control (MAC) protocol data unit (PDU) is received in a configured downlink (DL) assignment for the MBS, the drx-HARQ-RTT-TimerDLPTM for the MBS is started for a corresponding HARQ process in a first symbol after an end of a transmission carrying a DL HARQ feedback,
wherein the HARQ feedback configuration configures the DL HARQ feedback as a negative acknowledgement (NACK)-only mode for the MBS,
wherein the DRX cycle for the MBS is a PTM long DRX cycle for the MBS,
wherein the active time comprises a duration in which at least one of the drx-onDurationTimerPTM for the MBS, the drx-Inactivity TimerPTM for the MBS or the drx-RetransmissionTimerDLPTM for the MBS is running,
wherein the DL HARQ feedback is mapped to either a unicast physical uplink control channel (PUCCH) or an MBS PUCCH, and wherein the RRC message configures whether the unicast PUCCH or the MBS PUCCH is used.
2 . The method of claim 1 , further comprising:
starting or restarting the drx-InactivityTimerPTM for the MBS in a first symbol after an end of the PDCCH, if the PDCCH indicates a new transmission for the MBS.
3 . The method of claim 1 , further comprising:
starting the PTM long DRX cycle for the MBS based on the DRX cycle for the MBS and the DRX start offset for the MBS.
4 . The method of claim 1 ,
wherein enabling or disabling of the DL HARQ feedback is based on at least one of the following:
an RRC signaling enabling or disabling the MBS; or
a downlink control information (DCI) enabling or disabling the MBS addressed by the G-RNTI or the G-CS-RNTI.
5 . A user equipment (UE) comprising:
at least one transceiver;
at least one processor communicatively coupled to the at least one transceiver; and
at least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the UE to:
receive, from a base station, a radio resource control (RRC) message including a discontinuous reception (DRX) configuration for a multicast broadcast service (MBS) corresponding to a group-radio network temporary identifier (G-RNTI) or a group-configured scheduling-RNTI (G-CS-RNTI) and a hybrid automatic repeat request (HARQ) feedback configuration for the MBS,
monitor, during an active time for the MBS, a physical downlink control channel (PDCCH) addressed to the G-RNTI or the G-CS-RNTI for the MBS based on the DRX configuration, and
receive, from the base station, the PDCCH addressed to the G-RNTI or the G-CS-RNTI for the MBS,
wherein the DRX configuration for the MBS comprises a drx-onDurationTimerpoint-to-multipoint (PTM) for the MBS, a drx-Inactivity TimerPTM for the MBS, a drx-HARQ-RTT-TimerDLPTM for the MBS, a drx-RetransmissionTimerDLPTM for the MBS, a DRX cycle for the MBS, and a DRX start offset for the MBS,
wherein, if a medium access control (MAC) protocol data unit (PDU) is received in a configured downlink (DL) assignment for the MBS, the drx-HARQ-RTT-TimerDLPTM for the MBS is started for a corresponding HARQ process in a first symbol after an end of a transmission carrying a DL HARQ feedback,
wherein the HARQ feedback configuration configures the DL HARQ feedback as a negative acknowledgement (NACK)-only mode for the MBS,
wherein the DRX cycle for the MBS is a PTM long DRX cycle for the MBS,
wherein the active time comprises a duration in which at least one of the drx-onDurationTimerPTM for the MBS, the drx-Inactivity TimerPTM for the MBS, or the drx-RetransmissionTimerDLPTM for the MBS is running,
wherein the DL HARQ feedback is mapped to either a unicast physical uplink control channel (PUCCH) or an MBS PUCCH, and
wherein the RRC message configures whether the unicast PUCCH or the MBS PUCCH is used.
6 . The UE of claim 5 , wherein the instructions further cause the UE to:
start or restart the drx-InactivityTimerPTM for the MBS in a first symbol after an end of the PDCCH, if the PDCCH indicates a new downlink transmission for the MBS.
7 . The UE of claim 5 , wherein the instructions further cause the UE to:
start the PTM long DRX cycle for the MBS based on the DRX cycle for the MBS and the DRX start offset for the MBS.
8 . The UE of claim 5 ,
wherein an enabling or disabling of the DL HARQ feedback is based on at least one of the following:
an RRC signaling enabling or disabling the MBS; or
downlink control information (DCI) enabling or disabling the MBS addressed by the G-RNTI) or the G-CS-RNTI.