Sidelink DRX and network-assisted sidelink beam failure detection and recovery

Patent metadata

Field	Value
Publication number	US-11832329-B2
Application number	US-202117344755-A
Country	US
Kind code	B2
Filing date	Jun 10, 2021
Priority date	Jun 12, 2020
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

Certain aspects of the present disclosure provide techniques for network-assisted sidelink beam failure recovery. In certain aspects, a method performed by a base station may generally include receiving from a first UE a sidelink beam failure recovery (BFR) signal, indicating that a first communication link between the first UE and a second UE has failed; determining, based on the sidelink BFR signal, a set of resources for performing a sidelink beam failure recovery procedure to reestablish the first communication link between the first UE and the second UE; and transmitting information to the first UE and the second UE indicating the set of resources for performing the sidelink beam failure recovery procedure.

First claim

The invention claimed is:

1. A method for wireless communication performed by a base station, comprising:
receiving from a first UE a sidelink beam failure recovery (BFR) signal, indicating that a first communication link between the first UE and a second UE has failed, wherein the first communications link comprises a beamformed sidelink between the first UE and the second UE;
based on the sidelink BFR signal, determining a set of resources for performing a sidelink beam failure recovery procedure to reestablish the first communication link between the first UE and the second UE, wherein the set of resources for performing the sidelink beam failure recovery procedure comprise time-frequency resources for transmission of at least one of one or more sidelink synchronization signal blocks (SSBs) or one or more sidelink random access channel (RACH) messages; and
transmitting information to the first UE and the second UE indicating the set of resources for performing the sidelink beam failure recovery procedure.

2. The method of claim 1 , further comprising determining a period of time of an access discontinuous reception (DRX) mode of the second UE during which the second UE is in an awake state, wherein transmitting information to the first UE and the second UE comprises transmitting the information to at least the second UE during the period of time of the access DRX mode during which the second UE is in the awake state.

3. The method of claim 1 , further comprising transmitting a semi-persistent scheduling (SPS) grant to the second UE, configuring the second UE with semi-persistently scheduled resources for receiving data transmissions via a second communication link between the second UE and the base station.

4. The method of claim 3 , further comprising determining that the second UE is operating in a sleep state of an access discontinuous reception (DRX) mode.

5. The method of claim 4 , wherein:
transmitting information to the first UE and the second UE comprises transmitting a data transmission to the second UE that includes an indication for the second UE to wake up from the sleep state of the access DRX mode and the information indicating the set of resources for performing the sidelink beam failure recovery procedure to reestablish the first communication link between the first UE and the second UE; and
the data transmission comprises a media access control (MAC) control element (CE) transmitted on a physical shared data channel (PDSCH).

6. The method of claim 1 , further comprising:
receiving at least one of:
a sidelink beam failure recovery complete message from at least the first UE or the second UE, indicating that the first communication link between the first UE and the second UE has been reestablished; or
a sidelink beam failure recovery incomplete message from at least the first UE or the second UE, indicating that the first communication link between the first UE and the second UE was not reestablished; and

forwarding the sidelink beam failure recovery complete message or the sidelink beam failure recovery incomplete message to either the first UE or the second UE depending on the UE from which the sidelink beam failure recovery complete message is received.

7. The method of claim 1 , wherein the sidelink BFR signal is received in a scheduling request transmitted on a physical uplink control channel (PUCCH).

8. A method for wireless communication performed by a first user equipment (UE), comprising:
communicating with a second UE on a first communications link between the first UE and the second UE and with a base station on a second communications link between the first UE and the base station, wherein the first communications link comprises a beamformed sidelink between the first UE and the second UE;
detecting that the first communication link between the first UE and a second UE has failed;
transmitting a sidelink beam failure recovery (BFR) signal to the BS, indicating that a first communication link between the first UE and a second UE has failed; and
receiving, based on the sidelink BFR signal, information from the BS indicating a set of resources for performing a sidelink beam failure recovery procedure to reestablish the first communication link between the first UE and the second UE, wherein the set of resources for performing the sidelink beam failure recovery procedure comprise time-frequency resources for transmission of at least one of one or more sidelink synchronization signal blocks (SSBs) or one or more sidelink random access channel (RACH) messages.

9. The method of claim 8 , wherein detecting that the first communication link between the first UE and a second UE has failed comprises:
transmitting a signal to the second UE via the first communications link; and
determining that an acknowledgement message is not received from the second UE, acknowledging that the second UE received the signal from the first UE, within a threshold period of time; and
detecting that the first communication link between the first UE and a second UE has failed based on the acknowledgement message is not received from the second UE within the threshold period of time.

10. The method of claim 8 , further comprising operating in at least an access discontinuous reception (DRX) mode.

11. The method of claim 10 , wherein:
the access DRX mode is associated with the second communication link between the first UE and the BS; and
operating in the access DRX mode comprises periodically operating in a sleep state of the access DRX mode associated with the second communications link and periodically operating in an awake state of the access DRX mode associated with the second communication link.

12. The method of claim 11 , further comprising:
operating in a sidelink DRX mode associated with the first communication link between the first UE and the second UE, wherein operating in a sidelink DRX mode periodically operating in the sleep state associated with the first communications link and periodically operating in the awake state associated with the first communications link; and
in response to transmitting the sidelink BFR signal, remaining in the sleep state of the sidelink DRX mode associated with the first communication link until the information indicating the set of resources for performing the sidelink beam failure recovery procedure are received from the BS.

13. The method of claim 8 , further comprising performing the sidelink beam failure recovery procedure to reestablish the first communication link between the first UE and the second UE based on the information received from the BS.

14. The method of claim 13 , wherein performing the sidelink beam failure recovery procedure comprises transmitting the one or more sidelink SSBs using the set of resources for performing the sidelink beam failure recovery procedure.

15. The method of claim 14 , wherein performing the sidelink beam failure recovery procedure further comprises:
receiving, based on the transmitted one or more sidelink SSBs, the one or more sidelink RACH messages from the second UE using the set of resources for performing the sidelink beam failure recovery procedure;
transmitting a sidelink RACH response message to the second UE based, at least in part, on the one or more sidelink RACH messages received from the second UE; and
reestablishing the first communication link between the first UE and the second UE based, at least in part, on the sidelink RACH response message.

16. The method of claim 15 , wherein:
performing the sidelink beam failure recovery procedure further comprises at least one of:

Assignees

• Qualcomm Inc

Inventors

• Ryu Jung Ho
• Akkarakaran Sony
• Li Junyi
• Luo Tao

Classifications

• H04B7/06964

  Re-selection of one or more beams after beam failure · CPC title

• H04B7/06954

  Sidelink beam training with support from third instance, e.g. the third instance being a base station · CPC title

• H04W74/0833

  Random access procedures, e.g. with 4-step access · CPC title

• H04W76/19 Primary

  Connection re-establishment · CPC title

• H04W52/0225

  using monitoring of external events, e.g. the presence of a signal · CPC title