Method for transmitting/receiving discovery signals in D2D communication and devices for supporting same

• US 9,955,336 B2
• Filed: 09/25/2014
• Issued: 04/24/2018
• Est. Priority Date: 09/25/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jung, Sunghoon, Lee, Youngdae
• Primary Examiner(s): Foud, Hicham
• Application Number:
  US15/025,092
• Publication Number:
  US 20160242022A1
• Time in Patent Office: 1,307 Days
• Field of Search: None
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

Provided are a method for transmitting/receiving discovery signals in a wireless communication system and user equipment for supporting same. The method involves receiving a discovery request signal from user equipment, and determining whether or not to transmit a discovery response signal in response to the discovery request signal on the basis of the determination of the validity of proximity of the user equipment.

Claims

1. A method for transmitting a discovery response signal, in a wireless communication system, the method performed by a first user equipment (UE), which supports a device-to-device (D2D) communication, and comprising:

receiving, from a second UE which supports the D2D communication, a first discovery request signal;

transmitting, to the second UE, a first discovery response signal as a response to the first discovery request signal;

receiving, from the second UE, a discovery check signal as a response to the first discovery response signal;

receiving, from the second UE, a second discovery request signal;

determining whether or not to transmit a second discovery response signal to the second UE as a response to the second discovery request signal based on a validity of proximity for the first UE; and

transmitting the second discovery response signal to the second UE based on the determination when the validity of proximity for the first UE is determined to be not valid,

wherein the validity of proximity for the first UE is determined based on a time interval between a point of time at which the discovery check signal has been received and a point of time at which the validity of proximity has been determined, and

wherein the time interval is scaled according to a mobility of the first UE.

2. The method of claim 1, wherein the second discovery response signal is not transmitted when the validity of proximity for the first UE is determined to be valid.

3. The method of claim 1, wherein the time interval is measured by a timer.

4. The method of claim 1, wherein the validity of proximity for the first UE is determined to be valid when the time interval is equal to or less than a threshold.

5. The method of claim 4, wherein the threshold is a predetermined threshold or a threshold determined by a network.

6. The method of claim 4, wherein when the mobility of the first UE is a high mobility, the time interval is scaled down, and

when the mobility of the first UE is a low mobility, the time interval is scaled up.

7. The method of claim 1, wherein the validity of proximity for the first UE is determined to be not valid when the time interval is larger than a threshold.

8. The method of claim 7, wherein the threshold is a predetermined threshold or a threshold determined by a network.

9. The method of claim 7, wherein when the mobility of the first UE is a high mobility, the time interval is scaled down, and

when the mobility of the first UE is a low mobility, the time interval is scaled up.

10. A first user equipment (UE) which supports a device-to-device (D2D) communication, the first UE comprising:

a radio frequency (RF) transceiver configured to transmit and receive radio signals; and

a processor coupled to the RF transceiver,

wherein the processor is configured to;

receive, from a second UE which supports the D2D communication, a first discovery request signal;

transmit, to the second UE, a first discovery response signal as a response to the first discovery request signal;

receive, from the second UE, a discovery check signal as a response to the first discovery response signal;

receive, from the second UE, a second discovery request signal;

determine whether or not to transmit a second discovery response signal to the second UE as a response to the second discovery request signal based on a validity of proximity for the first UE; and

transmit the second discovery response signal to the second UE based on the determination when the validity of proximity for the first UE is determined to be not valid,

wherein the validity of proximity for the first UE is determined based on a time interval between a point of time at which the discovery check signal has been received and a point of time at which the validity of proximity has been determined, and

wherein the time interval is scaled according to a mobility of the first UE.