METHOD FOR PERFORMING D2D COMMUNICATION IN WIRELESS COMMUNICATION SYSTEM AND DEVICE THEREFOR

• US 20170156175A1
• Filed: 07/01/2015
• Published: 06/01/2017
• Est. Priority Date: 07/01/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: RYU, Jinsook, KIM, Hyunsook, KIM, Laeyoung, LEE, Youngdae, KIM, Jaehyun, JUNG, Sunghoon, KIM, Taehun
• Granted Patent: US 10,182,468 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 76/18 Management of setup rejection or failure
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/38 triggered by timers

Abstract

One embodiment of the present invention relates to a method by which a terminal performs device-to-device (D2D) communication in a wireless communication system, the method comprising the steps of: converting into a radio resource control (RRC) connection state through the transmission of a service request; being allocated a resource for the D2D communication; transmitting a D2D signal through the allocated resource; and receiving a system information block (SIB) after transmitting the D2D signal, wherein if the SIB includes information on a resource pool, the terminal does not perform an RRC recovery-related operation even if RRC connection failure occurs.

Claims

1. A method by which a UE performs device-to-device (D2D) communication in a wireless communication system, the method comprising the steps of:

switching to a radio resource control (RRC) connection state through the transmission of a service request;

being allocated a resource for the D2D communication;

transmitting a D2D signal through the allocated resource; and

receiving a system information block (SIB) after transmitting the D2D signal, wherein if the SIB includes information on a resource pool, the UE does not perform an RRC recovery-related operation even if RRC connection failure occurs.

2. The method according to claim 1, wherein the RRC connection failure occurs when there are no pending user uplink data.

3. The method according to claim 1, wherein the RRC connection failure occurs within a predetermined time before TAU (tracking area update) grant or TAU rejection is received.

4. The method according to claim 3, wherein the SIB is either SystemInformationBlockType18 or SystemInformationBlockType18.

5. The method according to claim 1, wherein the RRC recovery related operation transmits a TAU request to an MME (mobility management entity).

6. The method according to claim 1, further comprising transmitting D2D data by using a part of the resource pool if the UE has D2D data to be transmitted.

7. The method according to claim 1, wherein information indicating the RRC connection failure is transmitted from an RRC layer to a NAS (Non-Access-Stratum) layer.

8. The method according to claim 1, wherein a transmission mode is 1 when the service request is transmitted, and a transmission mode indicated by the SIB is mode 2.

9. The method according to claim 1, wherein a discovery type is type 2 when the service request is transmitted, and a discovery type indicated by the SIB is type 1.

10. The method according to claim 1, wherein the D2D signal is either a discovery signal or a communication signal.

11. A UE for performing device-to-device (D2D) communication in a wireless communication system, the UE comprising:

a transceiver; and

a processor,

wherein the processor configured to switch to a radio resource control (RRC) connection state through the transmission of a service request, be allocated a resource for the D2D communication, transmits a D2D signal through the allocated resource, and receives a system information block (SIB) after transmitting the D2D signal, and

wherein if the SIB includes information on a resource pool, the UE does not perform an RRC recovery-related operation even if RRC connection failure occurs.