Signalling method for direct communication between terminals

• US 9,265,071 B2
• Filed: 07/09/2013
• Issued: 02/16/2016
• Est. Priority Date: 07/10/2012
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Chang, Sung Cheol, Yun, Mi Young, Kim, Seokki, Kim, Won-Ik, Lee, Hyun, Kim, Sung Kyung, Yoon, Chul Sik
• Primary Examiner(s): Dao, Minh D
• Application Number:
  US13/937,898
• Publication Number:
  US 20140017991A1
• Time in Patent Office: 952 Days
• Field of Search: 455/7, 455/13.1, 455/9, 455/10, 455/436, 455/439, 370/331, 370/332, 370/329, 370/350
• US Class Current: 1/1
• CPC Class Codes: H04W 76/00 Connection management
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 76/23 Manipulation of direct-mode connections
• CPC Class Codes: H04W 76/38 triggered by timers

Abstract

A signaling method for a terminal that performs direct communication between terminals terminal is disclosed. A transmitting terminal transmits a link establishment request message for establishing a link to a receiving terminal, and the receiving terminal transmits a link establishment response message responding to this message to the transmitting terminal. The link establishment request message includes a field indicating a flow to use if the receiving terminal acquires a token.

Claims

1. A signaling method for a first terminal to perform direct communication with a second terminal, the signaling method comprising:

transmitting a first link establishment request message for establishing a direct communication link to the second terminal;

generating, by the second terminal, a first link establishment response message that includes a first field indicating a flow for use; and

receiving the first link establishment response message for establishing a direct communication link from the second terminal.

2. The signaling method of claim 1, wherein the first link establishment request message further comprises a second field indicating “

Flow Establishment Request for Token Handover”

.

3. The signaling method of claim 2, wherein the first link establishment response message further comprises a third field indicating “

Flow Establishment Confirm for Token Handover”

.

4. The signaling method of claim 1, wherein the first link establishment request message is transmitted through an RTS (request to send) data part, and the first link establishment response message is transmitted through a CTS (clear to send) data part.

5. The signaling method of claim 1, further comprising:

detecting the loss of the direct communication link; and

upon detecting the loss of the direct communication link, releasing the direct communication link.

6. The signaling method of claim 5, wherein the detecting comprises detecting that the loss of the direct communication link has occurred, if no signal is received on a subchannel, which is one of channels established between the first terminal and the second terminal, a predetermined number of times or more.

7. The signaling method of claim 5, wherein the releasing comprises transmitting a link release command message for releasing the direct communication link to the second terminal.

8. The signaling method of claim 1, further comprising:

establishing the direct communication link between the first and second terminals;

running the direct communication link on multiple dedicated channels; and

releasing at least one of the multiple dedicated channels.

9. The signaling method of claim 1, further comprising:

using the first field indicating a flow included in the first link establishment response message to support a token handover procedure in a unidirectional connection between the first terminal and the second terminal.

10. The signaling method of claim 9, further comprising:

if a direction of the unidirectional connection is changed by the token handover procedure, establishing a flow by using the first field included in the first link establishment response message.

11. A signaling method for a first terminal to perform direct communication between terminals, the signaling method comprising:

transmitting a first link establishment request message for establishing a direct communication link to a second terminal;

receiving a first link establishment response message for establishing a direct communication link from the second terminal, the first link establishment response message comprising a first field indicating a flow that the second terminal will use;

running the direct communication link on multiple dedicated channels; and

releasing at least one of the multiple dedicated channels, wherein the releasing of at least one dedicated channel comprises;

receiving a report on the states of the multiple dedicated channels from the second terminal, and selecting one to release from the multiple channels; and

transmitting a resource change command message including a field for identifying the resources of the dedicated channel to release to the second terminal.

12. A signaling method for a first terminal that performs direct communication with a plurality of second terminals, the signaling method comprising:

transmitting a token advertisement message for announcing a token to the plurality of second terminals;

generating a token request message that includes a first field indicating a flow for use of a third terminal;

receiving said token request message from said third terminal wanting to have a token, among the plurality of second terminals; and

transmitting a token response message responding to the token request message.

13. The signaling method of claim 12, further comprising:

making a multicast connection between the third terminal and the second terminals by using the flow which is indicated by the first field.

14. The signaling method of claim 12, further comprising:

transmitting a token handover message informing about a token handover to the plurality of second terminals.

15. The signaling method of claim 12, further comprising:

making a unidirectional multicast connection by using the first field by the third terminal which has acquired the token.

16. A signaling method for a first terminal to perform direct communication with a plurality of second terminals, the signaling method comprising:

transmitting a MAC header to the plurality of second terminals;

transmitting a preamble to the plurality of second terminals;

repeatedly transmitting a link establishment command message for establishing a direct communication link to the plurality of second terminals through an RTS (request to send) data part; and

generating, by the second terminals, a response message to be sent from the plurality of second terminals, said response message including a first field indicating a flow for use.

17. The signaling method of claim 16, further comprising:

detecting the loss of the direct communication link; and

upon detecting the loss of the direct communication link, releasing the direct communication link.

18. The signaling method of claim 17, wherein the detecting comprises detecting that the loss of the direct communication link has occurred, if a signal transmitted on a subchannel, which is one of channels established between the first terminal and the plurality of second terminals, has a lower value than a clear channel threshold.

19. A signaling method for a relay terminal that relays direct communication between a first terminal and a second terminal, the signaling method comprising:

receiving a relay request message requesting relay information from the first terminal; and

generating a response message that includes a first field indicating a flow for use by the second terminal or the relay terminal,

transmitting said response message responding to the relay request message to the first terminal through the relay terminal as a relay response message.

20. The signaling method of claim 19, further comprising:

transmitting the relay request message to the second terminal; and

receiving the relay response message including the field from the second terminal.

21. The signaling method of claim 19, wherein

the relay request message comprises a field indicating “

Flow Establishment Request for Token Handover”

, and

the relay response message further comprises a field indicating “

Flow Establishment Confirm for Token Handover”

.

22. A signaling method for a relay terminal that relays direct communication between a first terminal and a plurality of second terminals, the signaling method comprising:

receiving a token handover message for handing over a token from the first terminal;

transmitting a token advertisement message for announcing a token to the plurality of second terminals;

generating a token request message that includes a field indicating a flow for use of a third terminal or the relay terminal, said third terminal being one of said plurality of second terminals;

receiving said token request message from said third terminal; and

transmitting a token response message responding to the token request message to the third terminal.

23. The signaling method of claim 22, further comprising transmitting a link establishment command message including the flow to the plurality of second terminals and the third terminal.

24. The signaling method of claim 22, further comprising:

setting up new multicast relay connection by the relay terminal; and

establishing the flow indicated by the first field, said flow being used for the third terminal after acquiring the token.