DISCOVERY SIGNAL TRANSMITTED IN DIRECT COMMUNICATION SYSTEM, AND METHOD OF TRANSMITTING/RECEIVING THE DISCOVERY SIGNAL

• US 20140112235A1
• Filed: 10/21/2013
• Published: 04/24/2014
• Est. Priority Date: 10/22/2012
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: JUNG, Soojung, KIM, Sung Kyung, CHO, Seungkwon, YOON, Chanho, KIM, Hyung Jin, CHANG, Sung Cheol, KWON, DongSeung
• Granted Patent: US 9,408,137 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 76/14 Direct-mode setup

Abstract

A discovery signal that a first device joining in direct communication broadcasts through a radio channel is provided. The discovery signal includes a first field representing whether the discovery signal is a signal for discovering a device or a signal for discovering a service, and a second field including one of device identifier information of the first device and service information of a service that the first device provides according to a value of the first field.

Claims

1. A method in which a first device joining in device to device direct communication transmits a discovery signal, the method comprising:

transmitting a first discovery signal for discovering a device; and

transmitting a second discovery signal for discovering a service,

wherein the first discovery signal comprises;

a first field representing whether the first discovery signal is a signal for discovering a device or a signal for discovering a service; and

a second field comprising one of device identifier information (Device ID) of the first device and service information of a service that the first device provides according to a value of the first field,

wherein the second discovery signal is formed in the same format as that of the first discovery signal.

2. The method of claim 1, further comprising selecting a first resource for transmitting the first and second discovery signals from among a plurality of resources, before the transmitting of a first discovery signal.

3. The method of claim 2, wherein the plurality of resources are provided periodically, and

a position of the selected first resource in each period is constant.

4. The method of claim 3, wherein the transmitting of a first discovery signal comprises periodically broadcasting the first discovery signal N times (N is a natural number) using the selected first resource, and

the transmitting of a second discovery signal comprises periodically broadcasting the second discovery signal M times (M is a natural number) using the selected first resource after the first discovery signal is broadcasted N times.

5. The method of claim 2, wherein the selected first resource is a resource of a determined position according to a hopping pattern,

the transmitting of a first discovery signal comprises broadcasting the first discovery signal using the selected first resource, and

the transmitting of a second discovery signal comprises broadcasting the second discovery signal using the selected first resource.

6. The method of claim 5, wherein the transmitting of a second discovery signal comprises

periodically broadcasting the second discovery signal M times (M is a natural number) using the selected first resource after the first discovery signal is periodically broadcasted N times (N is a natural number), and

the N and the M are varied.

7. The method of claim 1, wherein the transmitting of a second discovery signal comprises:

masking the service information using the Device ID;

inserting the masked service information into the second field; and

broadcasting the second discovery signal.

8. The method of claim 7, wherein the broadcasting of the second discovery signal comprises

broadcasting the second discovery signal through a radio channel using a discovery resource for transmitting the first and second discovery signals.

9. The method of claim 1, wherein the first device operates in an ultraframe structure that is formed with a plurality of superframes, and

A discovery resource is provided through F (F is a natural number) frames within the ultraframe.

10. The method of claim 9, wherein the F frames each comprise a plurality of discovery resources.

11. The method of claim 10, wherein the plurality of discovery resources each correspond to any one resource class of K (K is a natural number) resource classes having different cycles.

12. The method of claim 11, further comprising selecting any one discovery resource for transmitting the first and second discovery signals from among the plurality of discovery resources, before the transmitting of a first discovery signal.

13. The method of claim 10, wherein a plurality of discovery resources that are included in a first frame of the F frames correspond to a first resource class having a first cycle, and

a plurality of discovery resources that are included in a second frame of the F frames correspond to a second resource class having a second cycle.

14. The method of claim 13, further comprising selecting any one discovery resource for transmitting the first and second discovery signals from among the plurality of discovery resources that are included in the first frame, before the transmitting of a first discovery signal.

15. A method in which a first device joining in direct communication receives a discovery signal, the method comprising:

receiving the discovery signal;

determining whether the received discovery signal is a signal for discovering a device or a signal for discovering a service based on a value that is stored at a first field of the received discovery signal;

acquiring, when the discovery signal is a signal for discovering a device, device identifier information (Device ID) that is stored at a second field of the discovery signal; and

acquiring, when the discovery signal is a signal for discovering a service, service information that is stored at the second field of the discovery signal,

wherein the discovery signal comprises;

the first field representing whether the discovery signal is a signal for discovering a device or a signal for discovering a service; and

the second field comprising one of the Device ID of a device that transmits the discovery signal and the service information of a service that a device that transmits the discovery signal provides according to a value of the first field.

16. The method of claim 15, further comprising unmasking the acquired service information using the acquired Device ID.

17. A discovery signal that a first device joining in direct communication broadcasts through a radio channel, the discovery signal comprising:

a first field representing whether the discovery signal is a signal for discovering a device or a signal for discovering a service; and

a second field comprising one of device identifier information (Device ID) of the first device and service information of a service that the first device provides according to a value of the first field.

18. The discovery signal of claim 17, wherein the service information comprises:

service type information representing a type of the service;

service identifier information of the service;

service status information representing a providing status of the service; and

time information that is related to the service status information.

19. The discovery signal of claim 18, wherein the service type information represents one of unicast transmission, multicast transmission, and broadcast transmission.

20. The discovery signal of claim 18, wherein the service status information represents one of a start status of the service, a continue status of the service, and an end status of the service, and

the time information represents a start time of the service when the service status information represents the start status, and the time information represents an end time of the service when the service status information represents the end status.