Method and apparatus for uplink synchronization maintenance with P2P communication in wireless communication networks

• US 7,336,638 B2
• Filed: 04/16/2004
• Issued: 02/26/2008
• Est. Priority Date: 05/19/2003
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Cheng, Jiang, Sun, Li
• Primary Examiner(s): Anderson; Matthew D.
• Assistant Examiner(s): Aminzay; Shaima Q.
• Application Number:
  US10/556,613
• Publication Number:
  US 20060258383A1
• Time in Patent Office: 1,411 Days
• Field of Search: 455/436, 455/414.1, 455/11.1, 455/502, 455/522, 455/415, 455/416, 455/428, 455/439, 455/442, 455/455, 455/509, 455/511, 455/514, 455/515, 455/516, 455/518, 455/519, 455/528, 455/526, 455/517, 370/278, 370/311, 370/328, 370/330, 370/331, 370/335, 370/336, 370/338, 370/342, 370/412, 370/280, 370/337
• US Class Current: 370/338
• CPC Class Codes: H04W 52/383 power control in peer-to-peer links
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time

Abstract

A method for maintaining uplink synchronization in P2P (Peer to Peer) communication, performed by a user equipment in wireless communication systems, comprising: negotiating with a wireless communication network system about the schedule and parameters for controlling the uplink synchronization of the user equipment by the procedure of establishing P2P direct link; transmitting testing signals to the network system via a customized uplink channel according to the negotiated parameters; receiving the control information transmitted via a customized downlink channel from the network system according to the negotiated schedule; and maintaining uplink synchronization of the user equipment in P2P communication according to the control information. Uplink synchronization can be realized through the customized channel, so the present invention can overcome the problem of overload brought by implementing uplink synchronization through the downlink common control channel and system performance degradation caused by increasing the transmitting power of the user equipment to transmit P2P signals.

Claims

1. A method for maintaining uplink synchronization in P2P (Peer to Peer) communication performed by user equipment (UE) in wireless communication systems, comprising:

(a) negotiating with a UTRAN (Universal mobile telecommunications system Terrestrial Radio Access Network) of a wireless communication network system to determine a schedule and parameters for controlling the uplink synchronization for the user equipment, during a procedure of establishing a P2P direct link between the UE and another UE;

(b) transmitting testing signals from the UE to the UTRAN of the network system via a customized uplink channel according to the negotiated schedule and parameters, wherein the negotiated schedule and parameters include at least (i) an interval corresponding to an intermittent and regular interval for sending testing signals from the UE to the UTRAN for executing unlink synchronization estimation and control, and (ii) a number corresponding to a number of continuous traffic bursts to be included in the testing signals and used for the unlink synchronization estimation and control;

(c) receiving control information transmitted via a customized downlink channel from the UTRAN of the network system according to the negotiated schedule; and

(d) maintaining uplink synchronization for the user equipment with the UTRAN during P2P communication of the UE with the another UE, according to the control information;

wherein the customized uplink channel and downlink channel are channels between the user equipment and the UTRAN of the network system allotted to the user equipment by the UTRAN of the network system and used intermittently to control and maintain unlink synchronization of the UE with the UTRAN during the P2P communication of the UE with the another UE.

2. The method according to claim 1, wherein step (d) includes:

adjusting a timing advance (TA) for the UE transmitting P2P signals during the P2P communication and for the UE transmitting said testing signals to the UTRAN via the customized unlink channel, so as to control the user equipment to maintain uplink synchronization with the UTRAN of the network system during P2P communication of the UE with the another UE, according to said control information.

3. The method according to claim 1, wherein step (d) includes:

adjusting a transmission power of the user equipment to transmit said testing signals via the customized unlink channel according to said control information.

4. The method according to claim 1, wherein step (d) includes:

adjusting said negotiated parameters at the UE in response to control information, wherein said negotiated parameters at least include one of the following two parameters;

(i) the interval in which to transmit said testing signals from the UE to the UTRAN of the network system; and

(ii) the number of traffic bursts continuously transmitted to the UTRAN of the network system in the testing signals for use in unlink synchronization estimation for controlling uplink synchronization.

5. The method according to claim 4, wherein step (b) includes:

transmitting said testing signals to the UTRAN of the network system via said customized uplink channel when said negotiated interval is overrun, according to said negotiated interval.

6. The method according to claim 4, wherein step (b) includes:

continuously transmitting said number of traffic bursts to the UTRAN of the network system, according to the negotiated number of continuous traffic bursts used in uplink synchronization control.

7. The method according to claim 1, wherein said customized uplink channel and downlink channel are one kind of a dedicated channel (DCH) and an uplink/downlink shared channel.

8. A method for user equipment (UE) in P2P (peer-to-peer) communication to maintain uplink synchronization in wireless communication systems, performed by a UTRAN (Universal mobile telecommunications system Terrestrial Radio Access Network) of a wireless communication network system, comprising:

(i) customizing an uplink channel and a downlink channel between the UTRAN of the network system and the user equipment for the user equipment;

(ii) negotiating between the UTRAN and the user equipment about a schedule and parameters for controlling the uplink synchronization for the UE;

(iii) receiving testing signals at the UTRAN from the user equipment via the customized uplink channel, according to said negotiated schedule and parameters;

(iv) estimating control information at the UTRAN for uplink synchronization for the user equipment, according to the received testing signals; and

(v) transmitting the control information from the UTRAN to the user equipment via said customized downlink channel, so that the user equipment can maintain uplink synchronization with the UTRAN during P2P communication with another UE.

9. The method according to claim 8, wherein said negotiated parameters include at least one of the following two parameters:

an interval in which the UE transmits and the UTRAN of the network system receives said testing signals from said UE via the customized uplink channel so as to control uplink synchronization; and

a number of continuous traffic bursts to be used by the UTRAN of the network system in the estimating of control information for uplink synchronization control.

10. The method according to claim 9, wherein step (iii) includes:

receiving said testing signals transmitted via said customized uplink channel from the user equipment when the negotiated interval is overrun, according to said negotiated interval.

11. The method according to claim 9, wherein step (iii) includes:

receiving said number of continuous traffic bursts from the user equipment via said customized uplink channel.

12. The method according to claim 8, wherein said control information at least includes synchronization shift information of the user equipment, power control information used to transmit said testing signals from the UE to the UTRAN of the network system, and one of the negotiated parameters after adjustment.

13. The method according to claim 12, wherein the negotiated parameters after adjustment, included in said control information, are determined by evaluating the state of the P2P link between the user equipment and the other user equipment, according to said testing signals.

14. The method according to claim 13, wherein said state of P2P link at least includes one of a change of distance between the user equipment and the other user equipment and a change of transmitting power with which the user equipment and the other user equipment transmit P2P signals.

15. The method according to claim 8, wherein said customized uplink channel and downlink channel are one kind of a dedicated channel (DCH) and an uplink/downlink shared channel (USCH/DSCH).

16. A user equipment (UE) for maintaining uplink synchronization in P2P (Peer to Peer) communication in wireless communication systems, comprising:

a parameter negotiating means, for negotiating with a UTRAN (Universal mobile telecommunications system Terrestrial Radio Access Network) of a wireless communication network system about a schedule and parameters for controlling uplink synchronization of the user equipment (UE) during a procedure of establishing a P2P direct link with another UE;

a transmitting means, for transmitting testing signals to the UTRAN of the network system via a customized uplink channel according to the negotiated schedule and parameters;

a receiving means, for receiving control information transmitted via a customized downlink channel from the UTRAN of the network system, according to the negotiated schedule; and

a synchronization maintaining means, for maintaining uplink synchronization with the UTRAN during P2P communication of the user equipment with the other UE;

wherein the customized uplink channel and downlink channel are channels between the user equipment and the UTRAN of the network system customized by the UTRAN of the network system for the UE, wherein the customized unlink channel and down link channel are used intermittently to control and maintain unlink synchronization of the UE with the UTRAN during the P2P communication of the UE with the other UE.

17. The user equipment according to claim 16, wherein said synchronization maintaining means includes:

an adjusting means, for adjusting a timing advance (TA) for the UE transmitting P2P signals to the other UE and for the UE transmitting testing signals to the UTRAN, and

a transmitting power with which to transmit testing signals and said negotiated parameters, so as to maintain uplink synchronization between the user equipment and the UTRAN of the network system during P2P communication of the UE with the other UE, according to said control information.

18. The user equipment according to claim 16, wherein said negotiated parameters at least include one of the following two parameters:

an interval in which to transmit said testing signals from the UE to the UTRAN of the network system; and

a number of continuous traffic bursts included in said testing signals transmitted to the UTRAN of the network system for use in unlink synchronization estimation for controlling uplink synchronization.

19. A UTRAN (Universal mobile telecommunications system Terrestrial Radio Access Network) of a wireless communication network system in wireless communication systems, capable of performing a method to maintain uplink synchronization for a user equipment (UE) in P2P (peer-to-peer) communication with another UE, comprising:

a customizing means, for customizing an uplink channel and a downlink channel for the user equipment between the UTRAN of the network system and the user equipment;

a negotiating means, for negotiating with the user equipment about a schedule and parameters for controlling the uplink synchronization of the user equipment;

a receiving means, for receiving testing signals transmitted via said customized uplink channel from the user equipment, according to said negotiated schedule and parameters;

an estimating means, for estimating control information for uplink synchronization of the user equipment, according to said received testing signals; and

a transmitting means, for transmitting the control information to the user equipment, wherein responsive to the control information the user equipment operates to maintain uplink synchronization with the UTRAN during P2P communication of the UE with another UE, according to the negotiated schedule.

20. The UTRAN of the network system according to claim 19, wherein said negotiated parameters include at least one of the following two parameters:

an interval in which the UTRAN of the network system receives said testing signals from said customized uplink channel so as to estimate an uplink synchronization control; and

a number of continuous traffic bursts used by the UTRAN of the network system in estimating the uplink synchronization control.

21. The UTRAN of the network system according to claim 19, wherein said control information at least includes (i) synchronization shift information of the user equipment, (ii) power control information used by the UE to transmit said testing signals to the UTRAN of the network system, and (iii) one of the negotiated parameters after adjustment.

22. The UTRAN of the network system according to claim 21, further comprising an evaluating means, for determining whether to adjust said negotiated parameters by evaluating the state of the P2P link between the user equipment and the other user equipment, according to said testing signals.