# US 12,225,581 B2 · Consistent sidelink listen before talk failure

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,225,581 B2
- Document ID: US12225581B2
- Status: Granted
- Kind: B2
- Application number: 18/653,605
- Filed: 2024-05-02
- Published: 2024-09-05
- Granted: 2025-02-11
- Earliest claimed: 2021-11-03
- Assignees: InterDigital Patent Holdings, Inc.
- Applicants: InterDigital Patent Holdings, Inc.
- Inventors: Faris Alfarhan; Martino M. Freda; J. Patrick Tooher; Tao Deng; Tuong Duc Hoang; Moon-il Lee
- Web page: https://patentgrep.com/patent/US12225581B2

## CPC

- H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA]
- H04W 72/25: between terminals via a wireless link, e.g. sidelink
- H04W 92/18: between terminal devices
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A wireless transmit/receive unit (WTRU) may perform a listen before talk (LBT) procedure associated with a sidelink (SL) bandwidth. The SL bandwidth may include a resource block (RB) set. The WTRU may determine a CSLF associated with the RB set of the SL bandwidth based on the LBT procedure. The WTRU may determine a resource for reporting the CSLF, for example, based on a priority rule. The priority rule may indicate that a licensed resource has a higher priority than an unlicensed resource. The priority rule may indicate that, if a consistent LBT failure is not detected on an unlicensed uplink (UL) resource, the unlicensed UL resource has a higher priority than an unlicensed SL resource. The WTRU may send a medium access control (MAC) control element (CE) using the determined resource. In examples, the MAC CE may indicate the RB set.

## Claims

### Claim 1

A wireless transmit/receive unit (WTRU), comprising:
a processor configured to:
receive configuration information associated with a sidelink (SL) listen before talk (LBT) procedure, wherein the configuration information indicates a time period and a maximum counter value;
perform, based on the configuration information, the SL LBT procedure;
determine to trigger a consistent SL LBT failure (CSLF) associated with a set of resources of a resource pool, wherein the determination to trigger the CSLF is based on the SL LBT procedure, and wherein a number of LBT failures associated with the set of resources of the resource pool reaches the maximum counter value;
based on the determination to trigger the CSLF, start a timer, wherein the timer is associated with the time period:
during the time period that the timer is running, select a first resource for a first SL transmission, wherein the first resource is selected from the resource pool excluding the set of resources associated with the CSLF;
trigger a CSLF medium access control (MAC) control element (CE);
send the CSLF MAC CE; and
after the timer expires, cancel the CSLF associated with the set of resources.

### Claim 2 (depends on 1)

The WTRU of claim 1, wherein the CSLF MAC CE is sent via the first SL transmission.

### Claim 3 (depends on 1)

The WTRU of claim 1, wherein the processor is further configured to select a second resource for a second SL transmission from a plurality of resources that includes the set of resources.

### Claim 4 (depends on 3)

The WTRU of claim 3, wherein the processor is further configured to:
send the first SL transmission using the first resource; and
send the second SL transmission using the second resource.

### Claim 5 (depends on 1)

The WTRU of claim 1, wherein the CSLF MAC CE indicates the CSLF associated with the set of resources, and wherein the processor is further configured to:
receive an uplink (UL) grant; and
send the CSLF MAC CE according to the UL grant.

### Claim 6 (depends on 1)

The WTRU of claim 1, wherein the processor is further configured to:
determine a bandwidth part (BWP) for the first SL transmission, wherein the BWP comprises the resource pool from which the first resource is selected for the first SL transmission.

### Claim 7 (depends on 1)

The WTRU of claim 1, wherein the processor is further configured to operate according to an SL resource allocation mode 2, and wherein the processor is further configured to:
determine that an LBT failure occurs on the set of resources;
increment a counter value for the set of resources by one;
determine that the number of LBT failures is equal to or greater than the maximum counter value; and
send the CSLF MAC CE indicating the CSLF associated with the set of resources.

### Claim 8 (depends on 1)

The WTRU of claim 1, wherein the start of the timer indicates a start of a CSLF report and recovery procedure configured for the WTRU.

### Claim 9 (depends on 1)

The WTRU of claim 1, wherein the configuration information indicates one or more resource pools for the SL LBT procedure, wherein the resource pool is a first resource pool of the one or more resource pools, and a second resource pool of the one or more resource pools includes the set of resources, and where the processor is further configured to use the first resource pool for the selection of the first resource for the first SL transmission during the time period and, after the expiration of the timer, switch to the second resource pool for a selection of a second resource for a second SL transmission.

### Claim 10 (depends on 9)

The WTRU of claim 9, wherein the first resource and the second resource are the same.

### Claim 11 (depends on 9)

The WTRU of claim 9, wherein the first resource and the second resource are different.

### Claim 12 (depends on 1)

The WTRU of claim 1, wherein the set of resources comprises a resource block (RB) set.

### Claim 13

A method performed by a wireless transmit/receive unit (WTRU), comprising:
receiving configuration information associated with a sidelink (SL) listen before talk (LBT) procedure, wherein the configuration information indicates a time period and a maximum counter value;
performing, based on the configuration information, the SL LBT procedure;
determining to trigger a consistent SL LBT failure (CSLF) associated with a set of resources of a resource pool, wherein the determination to trigger the CSLF is based on the SL LBT procedure, and wherein a number of LBT failures associated with the set of resources of the resource pool reaches the maximum counter value;
based on the determination to trigger the CSLF, starting a timer, wherein the timer is associated with the time period:
during the time period that the timer is running, selecting a first resource for a first SL transmission, wherein the first resource is selected from the resource pool excluding the set of resources associated with the CSLF;
triggering a CSLF medium access control (MAC) control element (CE);
sending the CSLF MAC CE; and
after the timer expires, cancelling the CSLF associated with the set of resources.

### Claim 14 (depends on 13)

The method of claim 13, wherein the CSLF MAC CE is sent via the first SL transmission.

### Claim 15 (depends on 13)

The method of claim 13, further comprising selecting a second resource for a second SL transmission from a plurality of resources that includes the set of resources.

### Claim 16 (depends on 13)

The method of claim 13, wherein the CSLF MAC CE indicates the CSLF associated with the set of resources, and wherein the method further comprises:
receiving an uplink (UL) grant; and
sending the CSLF MAC CE according to the UL grant.

### Claim 17 (depends on 13)

The method of claim 13, wherein the method further comprises:
determining a bandwidth part (BWP) for the first SL transmission, wherein the BWP comprises the resource pool from which the first resource is selected for the first SL transmission.

### Claim 18 (depends on 13)

The method of claim 13, wherein the method further comprises:
determining that an LBT failure occurs on the set of resources;
incrementing a counter value for the set of resources by one;
determining that the number of LBT failures is equal to or greater than the maximum counter value; and
sending the CSLF MAC CE indicating the CSLF associated with the set of resources.

### Claim 19 (depends on 13)

The method of claim 13, wherein a start of the time period indicates the start of a CSLF report and recovery procedure configured for the WTRU.

### Claim 20 (depends on 13)

The method of claim 13, wherein the configuration information indicates one or more resource pools for the SL LBT procedure, wherein the resource pool is a first resource pool of the one or more resource pools, and a second resource pool of the one or more resource pools includes the set of resources, and where the method further comprises using the first resource pool for the selection of the first resource for the first SL transmission during the time period and, after the expiration of the timer, switching to the second resource pool for a selection of a second resource for a second SL transmission.