Techniques for selecting and reselecting sidelink relay

Patent metadata

Field	Value
Publication number	US-2023053351-A1
Application number	US-202017759706-A
Country	US
Kind code	A1
Filing date	Feb 29, 2020
Priority date	Feb 29, 2020
Publication date	Feb 23, 2023
Grant date	—

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may determine to operate as a relay UE based on a set of thresholds configured for the first UE. The UE may transmit a relay discovery announcement on a communication channel of a sidelink to indicate support for relay communications. A remote UE may monitor for and receive the relay discovery announcement on the sidelink communications channel. The remote UE may select the relay UE based on a set of criteria for selecting a candidate relay UE. The remote UE and the relay UE may establish the relay communications based on the relay discovery announcement transmitted on the communications channel of the relay sidelink.

First claim

1 . A method for wireless communications at a first user equipment (UE), comprising:
determining to operate as a relay UE based at least in part on a set of thresholds configured for the first UE; transmitting a relay discovery announcement on a sidelink channel indicating support for relay communications based at least in part on the determination to operate as the relay UE; and establishing the relay communications with a second UE based at least in part on the transmission of the relay discovery announcement on the sidelink channel.

2 . The method of claim 1 , further comprising:
receiving, from the second UE on the sidelink channel, a relay request to operate as the relay UE for the second UE, wherein the determination to operate as the relay UE is based at least in part on receiving the relay request.

3 . The method of claim 2 , further comprising:
indicating, to the second UE, load information for the first UE, battery information for the first UE, a quality of service level supported for the relay communications, or a combination thereof, wherein the relay request is received based at least in part on the indication.

4 . The method of claim 1 , further comprising:
receiving a radio resource control message from a base station indicating a plurality of sets of thresholds comprising the set of thresholds.

5 . The method of claim 4 , wherein the plurality of sets of thresholds comprises a first set of thresholds used when the first UE is not connected to a remote UE and a second set of thresholds used when the first UE is connected to at least one remote UE.

6 . The method of claim 5 , wherein a difference between a high threshold and a low threshold of the first set of thresholds is smaller than the difference between the high threshold and the low threshold of the second set of thresholds.

7 . The method of claim 1 , wherein the determination to operate as the relay UE is further based at least in part on a mobility state of the first UE.

8 . The method of claim 1 , further comprising:
reporting, to a base station, a reference signal measurement, load information for the first UE, battery information for the first UE, or any combination thereof; and receiving, from the base station, an indication to transmit the relay discovery announcement based at least in part on the reporting.

9 . The method of claim 8 , wherein the load information comprises a channel busy rate for the sidelink channel for the first UE.

10 . The method of claim 8 , wherein the reference signal measurement, the load information, the battery information, or any combination thereof, is transmitted in a measurement report for radio resource management.

11 . The method of claim 1 , further comprising:
indicating, to the second UE, a quality of service level supported by the first UE for relay communications based at least in part on the transmission of the relay discovery announcement, wherein the quality of service level is indicated by a medium access control element or by an application code associated with a discovery announcement message.

12 . (canceled)

13 . The method of claim 1 , further comprising:
receiving, from a base station, a set of quality of service levels, wherein the relay discovery announcement is transmitted on the sidelink channel based at least in part on the set of quality of service levels comprising the quality service level of the relay communications.

14 . The method of claim 1 , further comprising:
receiving, from a base station, a radio resource control configuration for a set of resources to transmit the relay discovery announcement on the sidelink channel.

15 . The method of claim 1 , further comprising:
receiving, from a base station, downlink control information scheduling the first UE a set of resources to transmit the relay discovery announcement on the sidelink channel.

16 . The method of claim 1 , further comprising:
transmitting, to a base station, a relay discovery announcement request comprising a quality of service level supported by the first UE for relay communications; and receiving, from the base station, a relay discovery announcement response for the relay discovery announcement request, wherein the transmission of the relay discovery announcement is based at least in part on receiving the relay discovery announcement response.

17 . The method of claim 1 , further comprising:
including an indicator in a packet data convergence protocol (PDCP) packet of the relay discovery announcement that the relay discovery announcement is associated with relay discovery.

18 . The method of claim 1 , further comprising:
receiving, from the second UE on the sidelink channel, a measurement report of the sidelink channel based at least in part on an L3 filtering of a reference signal measurement.

19 . A method for wireless communications at a second user equipment (UE), comprising:
monitoring for a relay discovery announcement on a sidelink channel to establish relay communications with a first UE operating as a relay UE, wherein the relay communications are associated with a quality of service level; receiving the relay discovery announcement via a broadcast on the sidelink channel from the first UE, wherein the first UE supports the quality of service level for the relay communications; and establishing the relay communications with the first UE based at least in part on receiving the relay discovery announcement.

20 . The method of claim 19 , further comprising:
determining to establish relay communications with a base station; transmitting a relay discovery announcement request comprising a quality of service level for the relay communications; receiving a relay discovery announcement response based at least in part on transmitting the relay discovery announcement request; and transmitting a relay request on the sidelink channel to the first UE for the first UE to operate as the relay UE based at least in part on the relay discovery announcement response, wherein the relay discovery announcement is received based at least in part on transmitting the relay request.

21 . The method of claim 19 , further comprising:
receiving an indication that the first UE supports the quality of service level for the relay communications.

22 . The method of claim 21 , wherein the indication is received via a medium access control element or by an application code associated with a relay discovery message.

23 . The method of claim 19 , further comprising:
selecting the first UE as the relay UE for the relay communications.

24 . (canceled)

25 . The method of claim 23 , further comprising:
receiving an indication of a load of the first UE, wherein the first UE is selected based at least in part on the load of the first UE being below a load threshold.

26 . (canceled)

27 . The method of claim 23 , further comprising:
receiving an indication of a battery level of the first UE, wherein the first UE is selected based at least in part on the battery level being above a battery threshold.

28 . (canceled)

29 . The method of claim 19 , wherein the second UE is connected to a third UE for the relay communications, the method further comprising:
determining the third UE cannot support the quality of service level for the relay communications, wherein the relay communications

Assignees

• Qualcomm Inc

Inventors

• Cheng Peng
• Cheng Hong
• Baghel Sudhir Kumar
• Horn Gavin Bernard
• Chen Wanshi
• Paladugu Karthika
• Ozturk Ozcan
• Hosseini Seyedkianoush

Classifications

• H04W76/14

  Direct-mode setup · CPC title

• H04W40/10 Primary

  based on available power or energy · CPC title

• Y02D30/70

  in wireless communication networks · CPC title

• H04W40/12

  based on transmission quality or channel quality · CPC title

• H04W40/22 Primary

  using selective relaying for reaching a BTS [Base Transceiver Station] or an access point · CPC title