Independent sidelink (SL) discontinuous reception (DRX)

Patent metadata

Field	Value
Publication number	US-11758481-B2
Application number	US-202117153097-A
Country	US
Kind code	B2
Filing date	Jan 20, 2021
Priority date	Mar 26, 2020
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A method of wireless communications by a sidelink UE (user equipment) includes receiving a first signal as part of a discontinuous reception (DRX) wake-up procedure at the beginning of a sidelink discontinuous reception (DRX) ON duration. The method also includes transmitting a response to the first signal as part of a DRX wake-up procedure. The method further includes starting a timer after sending the response. The method still further includes entering a sleep state upon not receiving a physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) before the timer expires.

First claim

What is claimed is:

1. A method of wireless communications by a sidelink UE (user equipment), comprising:
receiving a first signal as part of a discontinuous reception (DRX) wake-up procedure at the beginning of a sidelink DRX ON duration;
transmitting a response to the first signal as part of a DRX wake-up procedure;
starting a timer after sending the response; and
entering a sleep state upon not receiving a physical sidelink channel before the timer expires.

2. The method of claim 1 , further comprising:
receiving the physical sidelink channel before the timer expires; and
starting a sidelink inactivity timer in response to receiving the physical sidelink channel.

3. The method of claim 2 , in which the sidelink inactivity timer, a sidelink DRX ON duration timer, and a sidelink DRX retransmission timer are preconfigured for each link, for each link type, for each traffic type, or for each UE.

4. The method of claim 1 , in which a sidelink DRX CycleStartOffset and sidelink DRX ON duration timer are set such that every sidelink DRX ON duration coincides with at least one preconfigured physical sidelink channel resource.

5. The method of claim 1 , in which a minimum value of a sidelink DRX hybrid automatic repeat request (HARQ) round trip time (RTT) timer is preconfigured for each link, for each link type, for each traffic type, or for each UE, and an actual value of the sidelink DRX HARQ RTT timer is dynamically adjusted to ensure at least one physical sidelink channel resource coincides with the duration of an incoming sidelink DRX retransmission timer.

6. The method of claim 1 , further comprising staying awake during a random access procedure until a last random access message is sent or received.

7. The method of claim 1 , in which no preconfigured physical sidelink channel resource coincides with a duration of the respective timer, the method further comprising sleeping during an inactivity timer, a sidelink DRX ON duration timer, or a sidelink DRX retransmission timer.

8. The method of claim 1 , in which a sidelink DRX cycle setting is the same for communications with each of a plurality of transmitting UEs.

9. The method of claim 1 , in which a sidelink DRX ON duration timer starts after drx-SlotOffset from a beginning of a subframe, where the subframe is such that [(subframe number (SFN)×10)+subframe number] modulo (drx-LongCycle)=drx-StartOffset for long DRX cycle, and [(SFN×10)+subframe number] modulo (drx-ShortCycle)=(drx-StartOffset) modulo (drx-ShortCycle) for short DRX cycle (if configured);
a sidelink inactivity transmit (TX) timer starts at a transmission of the physical sidelink channel;
a sidelink inactivity receive (RX) timer starts at reception of the physical sidelink channel;
a sidelink DRX HARQ RTT TX timer starts at the transmission of the physical sidelink channel;
a sidelink DRX HARQ RTT RX timer starts at a transmission of a negative acknowledgment (NACK) on a received physical sidelink channel;
a sidelink DRX retransmission TX timer starts at expiry of the sidelink DRX HARQ RTT TX timer; and
a sidelink DRX retransmission RX timer starts at the expiry of the sidelink DRX HARQ RTT RX timer.

10. The method of claim 1 , in which the physical sidelink channel comprises a physical sidelink control channel (PSCCH).

11. The method of claim 1 , in which the physical sidelink channel comprises a physical sidelink shared channel (PSSCH).

12. A sidelink (SL) UE (user equipment) for wireless communication, comprising:
a memory, and
at least one processor operatively coupled to the memory, the memory and the at least one processor configured:
to receive a first signal as part of a discontinuous reception (DRX) wake-up procedure at the beginning of a sidelink DRX ON duration;
to transmit a response to the first signal as part of a DRX wake-up procedure;
to start a timer after sending the response; and
to enter a sleep state upon not receiving a physical sidelink channel before the timer expires.

13. The UE of claim 12 , in which the at least one processor is further configured:
to receive the physical sidelink channel before the timer expires; and
to start a sidelink inactivity timer in response to receiving the physical sidelink channel.

14. The UE of claim 13 , in which the sidelink inactivity timer, a sidelink DRX ON duration timer, and a sidelink DRX retransmission timer are preconfigured for each link, for each link type, for each traffic type, or for each UE.

15. The UE of claim 12 , in which a sidelink DRX CycleStartOffset and sidelink DRX ON duration timer are set such that every sidelink DRX ON duration coincides with at least one preconfigured physical sidelink channel resource.

16. The UE of claim 12 , in which a minimum value of a sidelink DRX hybrid automatic repeat request (HARQ) round trip time (RTT) timer is preconfigured for each link, for each link type, for each traffic type, or for each UE, and an actual value of the sidelink DRX HARQ RTT timer is dynamically adjusted to ensure at least one physical sidelink channel resource coincides with the duration of an incoming sidelink DRX retransmission timer.

17. The UE of claim 12 , in which the at least one processor is further configured to stay awake during a random access procedure until a last random access message is sent or received.

18. The UE of claim 12 , in which no preconfigured physical sidelink channel resource coincides with a duration of the respective timer, the at least one processor further configured to sleep during an inactivity timer, a sidelink DRX ON duration timer, or a sidelink DRX retransmission timer.

19. The UE of claim 12 , in which a sidelink DRX cycle setting is the same for communications with each of a plurality of transmitting UEs.

20. The UE of claim 12 , in which a sidelink DRX ON duration timer starts after drx-SlotOffset from a beginning of a subframe, where the subframe is such that [(subframe number (SFN)×10)+subframe number] modulo (drx-LongCycle)=drx-StartOffset for long DRX cycle, and [(SFN×10)+subframe number] modulo (drx-ShortCycle)=(drx-StartOffset) modulo (drx-ShortCycle) for short DRX cycle (if configured);
a sidelink inactivity transmit (TX) timer starts at a transmission of the physical sidelink channel;
a sidelink inactivity receive (RX) timer starts at reception of the physical sidelink channel;
a sidelink DRX HARQ RTT TX timer starts at the transmission of the physical sidelink channel;
a sidelink DRX HARQ RTT RX timer starts at a transmission of a negative acknowledgment (NACK) on a received physical sidelink channel;
a sidelink DRX retransmission TX timer starts at expiry of the sidelink DRX HARQ RTT TX timer; and
a sidelink DRX retransmission RX timer starts at the expiry of the sidelink DRX HARQ RTT RX timer.

21. The UE of claim 12 , in which the physical sidelink channel comprises a physical sidelink control channel (PSCCH).

22. The UE of claim 12 , in which the physical sidelink channel comprises a physical sidelink shared channel (PSSCH).

23. A sidelink (SL) UE (user equipment) for wireless communication, comprising:
means for receiving a first signal as part of a discontinuous reception (DRX) wake-up procedure at the beginning of a sidelink DRX ON duration;
means for transmitting a response to the first signal as part of a DRX wake-up procedure;
means for starting a timer after sending the response; and
means for entering a sleep state upon not receiving a physical sidelink channel

Assignees

• Qualcomm Inc

Inventors

• Ding Ling
• Li Junyi
• Akkarakaran Sony
• Ryu Jung Ho
• Zhang Qian
• Bai Tianyang
• Venugopal Kiran
• Damnjanovic Jelena
• Luo Tao

Classifications

• H04W76/14 Primary

  Direct-mode setup · CPC title

• H04W52/0235 Primary

  where the received signal is a power saving command · CPC title

• H04L1/1851

  using multiple timers · CPC title

• H04W52/0216

  using a pre-established activity schedule, e.g. traffic indication frame · CPC title

• H04W76/28

  Discontinuous transmission [DTX]; Discontinuous reception [DRX] · CPC title