Operation and device for instructing sleep for power saving of groupcast terminal in NR V2X
Proposed is a method for operating a first device ( 100 ) in a wireless communication system. The method may comprise the steps of: transmitting an MAC PDU to a second device and a third device in a group in which groupcast communication is performed, the MAC PDU being transmitted through a PSSCH on the basis that an SL DRX on-duration timer in an SL DRX configuration is operating; monitoring an HARQ feedback related to the PSSCH on the basis of a PSFCH resource; receiving the HARQ feedback related to the PSSCH from the second device on the basis that the SL DRX on-duration timer is operating; and transmitting an early termination message to the second device on the basis that the HARQ feedback is not received from the third device within a time interval in which the SL DRX on-duration timer is operating.
1 . A method for performing, by a first device, wireless communication, the method comprising:
obtaining information related to a set of resource blocks (RBs) for a physical sidelink feedback channel (PSFCH) transmission;
obtaining a sidelink (SL) discontinuous reception (DRX) configuration related to a destination layer (L) 2 ID, including information related to a timer for an active time;
transmitting, to a second device and a third device in a group where groupcast communication is performed, first sidelink control information (SCI) for scheduling of a physical sidelink shared channel (PSSCH) through a physical sidelink control channel (PSCCH), based on an SL DRX on-duration timer of the SL DRX configuration being running;
transmitting, to the second device and the third device, a medium access control (MAC) protocol data unit (PDU) and second SCI through the PSSCH, based on the SL DRX on-duration timer being running;
allocating at least one RB among the set of RBs for the PSSCH;
determining an index of a PSFCH resource among the at least one RB, for a PSFCH reception, based on a source ID of the first device;
monitoring a hybrid automatic repeat request (HARQ) feedback related to the PSSCH based on the PSFCH resource;
receiving, from the second device, the HARQ feedback related to the PSSCH, based on the SL DRX on-duration timer being running; and
transmitting, to the second device, an early termination message, based on a HARQ feedback being not received from the third device within a time interval during which the SL DRX on-duration timer is running.
2 . The method of claim 1 , wherein the timer for the active time is started by the second device based on a reception of the second SCI.
3 . The method of claim 2 , wherein the timer for the active time is stopped by the second device based on a reception of the early termination message.
4 . The method of claim 3 , wherein the second device operates in a sleep mode, based on the timer for the active time being stopped based on the reception of the early termination message.
5 . The method of claim 1 , further comprising:
starting the timer for the active time based on the transmission of the second SCI.
6 . The method of claim 5 , further comprising:
stopping the timer for the active time based on the transmission of the early termination message.
7 . The method of claim 6 , wherein the first device operates in a sleep mode, based on the timer for the active time being stopped based on the transmission of the early termination message.
8 . The method of claim 1 , wherein the active time of the SL DRX configuration includes an interval during which the timer for the active time being running.
9 . The method of claim 1 , wherein the timer for the active time is an SL DRX inactivity timer or an SL DRX retransmission timer.
10 . The method of claim 1 , wherein the early termination message is transmitted at an expiration time point of the SL DRX on-duration timer.
11 . The method of claim 1 , wherein the early termination message is transmitted after an expiration time point of the SL DRX on-duration timer.
12 . The method of claim 1 , wherein the early termination message is transmitted through third SCI or a MAC control element (CE).
13 . The method of claim 1 , wherein the MAC PDU is a HARQ feedback enabled MAC PDU.
14 . A first device for performing wireless communication, the first device comprising:
one or more memories storing instructions;
one or more transceivers; and
one or more processors connected to the one or more memories and the one or more transceivers, wherein the one or more processors execute the instructions to:
obtain information related to a set of resource blocks (RBs) for a physical sidelink feedback channel (PSFCH) transmission;
obtain a sidelink (SL) discontinuous reception (DRX) configuration related to a destination layer (L) 2 ID, including information related to a timer for an active time;
transmit, to a second device and a third device in a group where groupcast communication is performed, first sidelink control information (SCI) for scheduling of a physical sidelink shared channel (PSSCH) through a physical sidelink control channel (PSCCH), based on an SL DRX on-duration timer of the SL DRX configuration being running;
transmit, to the second device and the third device, a medium access control (MAC) protocol data unit (PDU) and second SCI through the PSSCH, based on the SL DRX on-duration timer being running;
allocate at least one RB among the set of RBs for the PSSCH;
determine an index of a PSFCH resource among the at least one RB, for a PSFCH reception, based on a source ID of the first device;
monitor a hybrid automatic repeat request (HARQ) feedback related to the PSSCH based on the PSFCH resource;
receive, from the second device, the HARQ feedback related to the PSSCH, based on the SL DRX on-duration timer being running; and
transmit, to the second device, an early termination message, based on a HARQ feedback being not received from the third device within a time interval during which the SL DRX on-duration timer is running.
15 . A device adapted to control a first user equipment (UE), the device comprising:
one or more processors; and
one or more memories operably connectable to the one or more processors and storing instructions, wherein the one or more processors execute the instructions to:
obtain information related to a set of resource blocks (RBs) for a physical sidelink feedback channel (PSFCH) transmission;
obtain a sidelink (SL) discontinuous reception (DRX) configuration related to a destination layer (L) 2 ID, including information related to a timer for an active time;
transmit, to a second UE and a third UE in a group where groupcast communication is performed, first sidelink control information (SCI) for scheduling of a physical sidelink shared channel (PSSCH) through a physical sidelink control channel (PSCCH), based on an SL DRX on-duration timer of the SL DRX configuration being running;
transmit, to the second UE and the third UE, a medium access control (MAC) protocol data unit (PDU) and second SCI through the PSSCH, based on the SL DRX on-duration timer being running;
allocate at least one RB among the set of RBs for the PSSCH;
determine an index of a PSFCH resource among the at least one RB, for a PSFCH reception, based on a source ID of the first UE;
monitor a hybrid automatic repeat request (HARQ) feedback related to the PSSCH based on the PSFCH resource;
receive, from the second UE, the HARQ feedback related to the PSSCH, based on the SL DRX on-duration timer being running; and
transmit, to the second UE, an early termination message, based on a HARQ feedback being not received from the third UE within a time interval during which the SL DRX on-duration timer is running.