METHOD AND APPARATUS FOR OBTAINING SYNCHRONIZATION FOR COMMUNICATION BETWEEN DEVICES

• US 20120320776A1
• Filed: 06/19/2012
• Published: 12/20/2012
• Est. Priority Date: 06/20/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LIM, Chi-Woo, YU, Hyun-Kyu, KIM, Kyung-Kyu, JEONG, Su-Ryong
• Granted Patent: US 8,909,276 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 76/14 Direct-mode setup

Abstract

A method and an apparatus for obtaining synchronization of a terminal for communication between devices when a base station collapses are provided. The method includes, when a preamble signal is not received from the base station, maintaining a first synchronization for a predetermined time using a timer, transmitting a first preamble signal at a first synchronization point, performing a synchronization procedure with at least one neighbor terminal based on the first preamble signal, and, after the synchronization procedure, performing communication with the at least one neighbor terminal. In addition, when a preamble signal is not received from a base station, a first preamble signal from a relevant neighbor terminal is monitored for a predetermined time. When the first preamble signal is not received from the relevant neighbor terminal for the predetermined time, a second preamble signal is transmitted at an arbitrary point.

Claims

1. A method for obtaining synchronization of a terminal for communication between devices when a base station collapses, the method comprising:

when not receiving a preamble signal from the base station, maintaining, at the terminal, a first synchronization for a predetermined time using a timer;

transmitting, at the terminal, a first preamble signal at a first synchronization point;

performing, at the terminal, a synchronization procedure with at least one neighbor terminal based on the first preamble signal; and

after the synchronization procedure, performing communication with the at least one neighbor terminal.

2. The method of claim 1, wherein the first preamble signal implicitly indicates that the base station has collapsed and is transmitted at the same point as a transmission point of the preamble signal by the base station.

3. The method of claim 1, further comprising, after the performing of the synchronization procedure with the at least one neighbor terminal using the first preamble signal:

monitoring the preamble signal received from the base station; and

when receiving the preamble signal from the base station, performing synchronization based on the preamble signal received from the base station to communicate with the base station.

4. The method of claim 1, further comprising:

maintaining, at the terminal, base station synchronization for a predetermined time when the base station collapses, or

receiving, at the terminal, the first preamble signal from an arbitrary terminal inside a cell area of a base station that has not collapsed to maintain synchronization.

5. A method for obtaining synchronization of a terminal for communication between devices when a base station collapses, the method comprising:

when not receiving a preamble signal from the base station, monitoring a first preamble signal from a relevant neighbor terminal for a predetermined time;

when not receiving the first preamble signal from the relevant neighbor terminal for the predetermined time, transmitting a second preamble signal at an arbitrary point;

performing a synchronization procedure with at least one neighbor terminal based on the second preamble signal; and

after the synchronization procedure, performing communication with the at least one neighbor terminal.

6. The method of claim 5, wherein the first preamble signal and the second preamble signal implicitly indicate that the base station has collapsed,

the first preamble signal is transmitted at the same point as a transmission point of the preamble signal by the base station, and

the second preamble signal is transmitted at a point that does not coincide with the transmission point of the preamble signal by the base station.

7. The method of claim 5, further comprising, after the performing of the synchronization procedure with the at least one neighbor terminal using the second preamble signal:

monitoring the preamble signal received from the base station or the first preamble signal received from the relevant neighbor terminal; and

when receiving the preamble signal from the base station, performing synchronization based on the preamble signal received from the base station to communicate with the base station.

8. The method of claim 7, further comprising, when receiving the first preamble signal from the relevant neighbor terminal, performing synchronization based on the first preamble signal received from the relevant neighbor terminal to communicate with the relevant neighbor terminal.

9. The method of claim 8, further comprising, after performing a synchronization procedure with the relevant neighbor terminal using the first preamble signal:

monitoring the preamble signal received from the base station; and

when receiving the preamble signal from the base station, performing synchronization based on the preamble signal received from the base station to communicate with the base station.

10. The method of claim 7, further comprising, when not receiving the preamble signal from the base station and the first preamble signal from the relevant neighbor terminal, maintaining synchronization with at least one neighbor terminal using the second preamble signal.

11. An apparatus of a terminal for obtaining synchronization for communication between devices when a base station collapses, the apparatus comprising:

a transmitter for, when a preamble signal is not received from the base station, allowing the terminal to maintain a first synchronization for a predetermined time using a timer and for allowing the terminal to transmit a first preamble signal at a first synchronization point; and

a controller for allowing the terminal to perform a synchronization procedure with at least one neighbor terminal based on the first preamble signal and for allowing the terminal, after the synchronization procedure, to perform communication with the at least one neighbor terminal.

12. The apparatus of claim 11, wherein the first preamble signal implicitly indicates that the base station has collapsed and is transmitted at the same point as a transmission point of the preamble signal by the base station.

13. The apparatus of claim 11, wherein the controller performs the synchronization procedure with the at least one neighbor terminal using the first preamble signal, then

monitors the preamble signal received from the base station, and

when receiving the preamble signal from the base station, performs synchronization based on the preamble signal received from the base station to communicate with the base station.

14. The apparatus of claim 11, wherein the transmitter receives the first preamble signal from an arbitrary terminal inside a cell area of a base station that has not collapsed to maintain synchronization.

15. An apparatus of a terminal, for obtaining synchronization for communication between devices when a base station collapses, the apparatus comprising:

a controller for, when a preamble signal is not received from the base station, monitoring a first preamble signal from a relevant neighbor terminal for a predetermined time; and

a transmitter for, when the first preamble signal is not received from the relevant neighbor terminal for the predetermined time, transmitting a second preamble signal at an arbitrary point,

wherein the controller performs a synchronization procedure with at least one neighbor terminal using the second preamble signal, and after the synchronization procedure, performs communication with the at least one neighbor terminal.

16. The apparatus of claim 15, wherein the first preamble signal and the second preamble signal implicitly indicate that the base station has collapsed,

the first preamble signal is transmitted at the same point as a transmission point of the preamble signal by the base station, and

the second preamble signal is transmitted at a point that does not coincide with the transmission point of the preamble signal by the base station.

17. The apparatus of claim 15, wherein the controller performs the synchronization procedure with the at least one neighbor terminal using the second preamble signal, then

monitors the preamble signal received from the base station or the first preamble signal received from the relevant neighbor terminal, and

when receiving the preamble signal from the base station, performs synchronization based on the preamble signal received from the base station to communicate with the base station.

18. The apparatus of claim 17, wherein, when receiving the first preamble signal from the relevant neighbor terminal, the controller performs synchronization based on the first preamble signal received from the relevant neighbor terminal to communicate with the relevant neighbor terminal.

19. The apparatus of claim 18, wherein the controller performs a synchronization procedure with the relevant neighbor terminal using the first preamble signal, then

monitors the preamble signal received from the base station, and

when receiving the preamble signal from the base station, performs synchronization based on the preamble signal received from the base station to communicate with the base station.

20. The apparatus of claim 17, wherein, when not receiving the preamble signal from the base station and the first preamble signal from the relevant neighbor terminal, the controller maintains synchronization with at least one neighbor terminal using the second preamble signal.