Method for performing D2D communication in wireless communication system and device therefor

• US 10,182,468 B2
• Filed: 07/01/2015
• Issued: 01/15/2019
• Est. Priority Date: 07/01/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Taehun, Lee, Youngdae, Kim, Jaehyun, Jung, Sunghoon, Ryu, Jinsook, Kim, Hyunsook, Kim, Laeyoung
• Primary Examiner(s): Faroul, Farah
• Application Number:
  US15/322,716
• Publication Number:
  US 20170156175A1
• Time in Patent Office: 1,294 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 for performing device-to-device (D2D) communication in a wireless communication system, the method performed by a User Equipment (UE) and comprising:

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

receiving allocation of a resource for the D2D communication;

transmitting a D2D signal using the allocated resource;

receiving a system information block (SIB) after transmitting the D2D signal; and

not performing an RRC recovery-related operation if the SIB includes information related to a resource pool even if RRC connection failure occurs within a predetermined time before tracking area update (TAU) grant or TAU rejection is received.

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 SIB is either SystemInformationBlockType18 or SystemInformationBlockType19.

4. The method according to claim 1, wherein the RRC recovery related operation comprises transmitting a TAU request to a mobile management entity.

5. The method according to claim 1, further comprising transmitting D2D data using a portion of the resource pool if the UE has D2D data for transmission.

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

7. 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.

8. 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.

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

10. A User Equipment (UE) performing device-to-device (D2D) communication in a wireless communication system, the UE comprising:

a transceiver configured to transmit and receive signals; and

a processor configured to;

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

receive an allocated resource for the D2D communication;

transmit a D2D signal using the allocated resource;

receive a system information block (SIB) after transmitting the D2D signal; and

not perform an RRC recovery-related operation if the SIB includes information related to a resource pool even if RRC connection failure occurs within a predetermined time before tracking area update (TAU) grant or TAU rejection is received.

11. The UE according to claim 10, wherein the RRC connection failure occurs when there are no pending user uplink data.

12. The UE according to claim 10, wherein the SIB is either SystemInformationBlockType18 or SystemInformationBlockType19.

13. The UE according to claim 10, wherein the RRC recovery related operation comprises transmitting a TAU request to a mobility management entity.

14. The UE according to claim 10, further comprising transmitting D2D data using a portion of the resource pool if the UE has D2D data for transmission.

15. The UE according to claim 10, wherein information indicating the RRC connection failure is transmitted from an RRC layer to a Non-Access-Stratum layer.

16. The UE according to claim 10, wherein a transmission mode is 1 when the service request is transmitted and a transmission mode indicated by the SIB is mode 2.

17. The UE according to claim 10, wherein a discovery type is type 2 when the service request is transmitted and a discovery type indicated by the SIB is type 1.

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