Methods, devices, and systems for configuring sidelink DRX
The present disclosure describes methods, system, and devices for configuring a sidelink discontinuous reception (DRX). One method includes obtaining, by a first user equipment (UE), a DRX profile information of a second UE from an upper layer of the first UE; and sending, by the first UE based on the obtained DRX profile information of the second UE, a PC5 message to the second UE or receiving the PC5 message from the second UE. Another method includes sending, by the first UE, DRX configuration assistance information to a second UE; and receiving, by the first UE, a DRX configuration sent from the second UE.
1 . A method for wireless communication, comprising:
obtaining, by a first user equipment (UE), information of whether a second UE supports discontinuous reception (DRX) or the second UE does not support the DRX from an upper layer of the first UE, wherein the information is associated with a destination layer-2 (L2) ID associated to the second UE prior to completing a layer-2 link establishment procedure with the second UE;
obtaining, by the first UE, a DRX configuration from a network or pre-configuration, the DRX configuration comprising a set of DRX parameters, wherein the set of DRX parameters comprises at least one of the following:
a DRX cycle;
a slot offset;
an on-duration timer; or
a start offset;
receiving, by the first UE based on the information of whether the second UE supports the DRX or does not support the DRX, a PC5 message from the second UE; and
in response to the information indicating that the second UE supports the DRX, monitoring, by the first UE, the PC5 message from the second UE based on the DRX configuration,
wherein:
the first UE receives the PC5 message from the second UE during the layer-2 link establishment procedure.
2 . The method according to claim 1 , wherein:
the PC5 message comprises at least one of the following:
a direct communication request message; or
a direct communication accept message.
3 . The method according to claim 1 , wherein:
before the first UE sends the DRX configuration to the second UE via a PC5-RRC message, or before the first UE receives the DRX configuration of the first UE and sends a DRX configuration complete message to the second UE via a PC5-RRC message:
the first UE monitors the PC5 message from the second UE based on the DRX configuration, wherein the DRX configuration is acquired from the network or is pre-configured.
4 . The method according to claim 1 , wherein:
in response to the information indicating that the second UE does not support the DRX or does not know whether the second UE supports the DRX, and the first UE supporting the DRX:
the first UE monitors a reception resource pool for sidelink groupcast or broadcast to receive a PC5 message.
5 . A method for wireless communication, comprising:
obtaining, by a first user equipment (UE), information of whether a second UE supports DRX or the second UE does not support the DRX from an upper layer of the first UE, wherein the information is associated with a destination layer-2 (L2) ID associated to the second UE prior to completing a layer-2 link establishment procedure with the second UE; and
sending, by the first UE based on the information of whether the second UE supports the DRX or does not support the DRX, a PC5 message to the second UE,
wherein:
the PC5 message from the first UE is received during the layer-2 link establishment procedure.
6 . The method according to claim 5 , wherein:
the PC5 message comprises at least one of the following:
a direct communication request message; or
a direct communication accept message.
7 . The method according to claim 5 , further comprising:
after sending the PC5 message, starting, by the first UE, a timer; and
during the timer running, staying, by the first UE, active to monitor a sidelink (SL) channel,
wherein a value of the timer is received from a network or is pre-configured.
8 . The method according to claim 7 , wherein:
the PC5 message comprises at least one of the following: a PC5-RRC message; a PC5-S message; or a PC5-data message.
9 . The method according to claim 7 , wherein:
a time duration after the first UE sends the PC5 message, the second UE starts a timer.
10 . The method according to claim 5 , further comprising:
in response to sending the PC5 message, starting, by the first UE, a round trip time (RTT) timer;
in response to the RTT timer expiring, starting, by the first UE, a timer; and
during the timer running, staying, by the first UE, active to monitor a SL channel.
11 . The method according to claim 10 , wherein:
a value of the timer is received from a network or is pre-configured.
12 . An apparatus comprising:
a memory storing instructions; and
a processor in communication with the memory, wherein, when the processor executes the instructions, the processor is configured to cause the apparatus to perform:
obtaining information of whether a second UE supports discontinuous reception (DRX) or the second UE does not support the DRX from an upper layer of the apparatus, wherein the information is associated with a destination layer-2 (L2) ID associated to the second UE prior to completing a layer-2 link establishment procedure with the second UE;
obtaining a DRX configuration from a network or pre-configuration, the DRX configuration comprising a set of DRX parameters, wherein the set of DRX parameters comprises at least one of the following:
a DRX cycle;
a slot offset;
an on-duration timer; or
a start offset;
receiving, based on the information whether the second UE supports the DRX or does not support the DRX, a PC5 message from the second UE; and
in response to the information indicating that the second UE supports the DRX, monitoring the PC5 message from the second UE based on the DRX configuration,
wherein:
the apparatus receives the PC5 message from the second UE during the layer-2 link establishment procedure.
13 . The apparatus according to claim 12 , wherein:
the PC5 message comprises at least one of the following:
a direct communication request message; or
a direct communication accept message.
14 . The apparatus according to claim 12 , wherein:
before the apparatus sends the DRX configuration to the second UE via a PC5-RRC message, or before the apparatus receives the DRX configuration of the apparatus and sends a DRX configuration complete message to the second UE via a PC5-RRC message:
the apparatus monitors the PC5 message from the second UE based on the DRX configuration, wherein the DRX configuration is acquired from the network or is pre-configured.
15 . The apparatus according to claim 12 , wherein:
in response to the information indicating that the second UE does not support the DRX or does not know whether the second UE supports the DRX, and the apparatus supporting the DRX:
the apparatus monitors a reception resource pool for sidelink groupcast or broadcast to receive a PC5 message.