# US 2021/0345433 A1 · Method and apparatus for configuring sidelink communication in a wireless communication system

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- Number: US 2021/0345433 A1
- Document ID: US20210345433A1
- Status: Published application
- Kind: A1
- Application number: 17/378,691
- Filed: 2021-07-17
- Published: 2021-11-04
- Earliest claimed: 2019-06-25
- Assignees: ASUSTeK COMPUTER INC.
- Applicants: ASUSTek Computer Inc.
- Inventors: Li-Te Pan; Richard Lee-Chee Kuo
- Web page: https://patentgrep.com/patent/US20210345433A1

## CPC

- H04W 76/18: Management of setup rejection or failure
- H04W 72/04: Wireless resource allocation
- H04W 76/14: Direct-mode setup
- H04W 76/27: Transitions between radio resource control [RRC] states
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A method and apparatus are disclosed from the perspective of a first UE (User Equipment) in RRC_CONNECTED to detect configuration failure. In one embodiment, the method includes the first UE transmitting a first PC5 RRC (Radio Resource Control) message to a second UE, wherein the first PC5 RRC message includes an AS (Access Stratum)-layer configuration for a unicast link established with the second UE. The method also includes the first UE transmitting a fourth RRC message to a network node if a configuration failure of the AS-layer configuration is detected, wherein the fourth RRC message indicates the configuration failure occurs.

## Claims

### Claim 1

A method for a first UE (User Equipment) to detect configuration failure, comprising:
transmitting a first PC5-S message to establish a unicast link with a second UE;
receiving a second PC5-S message from the second UE to complete establishment of the unicast link;
transmitting a first PC5 RRC (Radio Resource Control) message to the second UE, including configuration information;
receiving a second PC5 RRC failure message directly from the second UE to indicate the second UE cannot comply with the configuration information; and
transmitting a RRC message to a network node to indicate a configuration failure in response to reception of the second PC5 RRC failure message, wherein the RRC message includes a specific failure cause value.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first PC5 RRC message includes an AS (Access Stratum)-layer configuration for the unicast link.

### Claim 3 (depends on 2)

The method of claim 2, wherein the second UE cannot comply with the AS-layer configuration.

### Claim 4 (depends on 1)

The method of claim 1, further comprising:
transmitting a first RRC message to the network node, wherein the first RRC message includes a request for a SLRB (Sidelink Radio Bearer) configuration.

### Claim 5 (depends on 4)

The method of claim 4, further comprising:
receiving a second RRC message from the network node, wherein the second RRC message includes the SLRB configuration.

### Claim 6 (depends on 5)

The method of claim 5, further comprising:
transmitting a third RRC message to the network node, wherein the third RRC message is a complete message in response to reception of the second RRC message.

### Claim 7 (depends on 1)

The method of claim 1, wherein the specific failure cause value is a cause value indicating a configuration failure on the unicast link.

### Claim 8 (depends on 1)

The method of claim 1, wherein the network node is a base station.

### Claim 9 (depends on 1)

The method of claim 1, wherein the first PC5-S message is a Direct Communication Request message.

### Claim 10 (depends on 1)

The method of claim 1, wherein the second PC5-S message is a Direct Communication Accept message.

### Claim 11

A first UE (User Equipment), comprising:
a processor; and
a memory operatively coupled to the processor, wherein the processor is configured to execute a program code to:
transmit a first PC5-S message to establish a unicast link with a second UE;
receive a second PC5-S message from the second UE to complete establishment of the unicast link;
transmit a first PC5 RRC (Radio Resource Control) message to the second UE, including configuration information;
receive a second PC5 RRC failure message directly from the second UE to indicate the second UE cannot comply with the configuration information; and
transmit a RRC message to a network node to indicate a configuration failure in response to reception of the second PC5 RRC failure message, wherein the RRC message includes a specific failure cause value.

### Claim 12 (depends on 11)

The first UE of claim 11, wherein the first PC5 RRC message includes an AS (Access Stratum)-layer configuration for the unicast link.

### Claim 13 (depends on 12)

The first UE of claim 12, wherein the second UE cannot comply with the AS-layer configuration.

### Claim 14 (depends on 11)

The first UE of claim 11, wherein the processor is further configured to execute a program code to:
transmit a first RRC message to the network node, wherein the first RRC message includes a request for a SLRB (Sidelink Radio Bearer) configuration.

### Claim 15 (depends on 14)

The first UE of claim 14, wherein the processor is further configured to execute a program code to:
receive a second RRC message from the network node, wherein the second RRC message includes the SLRB configuration.

### Claim 16 (depends on 15)

The first UE of claim 15, wherein the processor is further configured to execute a program code to:
transmit a third RRC message to the network node, wherein the third RRC message is a complete message in response to reception of the second RRC message.

### Claim 17 (depends on 11)

The first UE of claim 11, wherein the specific failure cause value is a cause value indicating a configuration failure on the unicast link.

### Claim 18 (depends on 11)

The first UE of claim 11, wherein the network node is a base station.

### Claim 19 (depends on 11)

The first UE of claim 11, wherein the first PC5-S message is a Direct Communication Request message.

### Claim 20 (depends on 11)

The first UE of claim 11, wherein the second PC5-S message is a Direct Communication Accept message.