TIMING SYNCHRONIZATION COORDINATION ON A SHARED COMMUNICATION MEDIUM

• US 20170223651A1
• Filed: 01/31/2017
• Published: 08/03/2017
• Est. Priority Date: 02/02/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: RADULESCU, Andrei Dragos, KADOUS, Tamer Adel, PATEL, Chirag Sureshbhai, LUO, Tao, SADEK, Ahmed Kamel
• Granted Patent: US 10,219,235 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/02 Hybrid access
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Techniques for intra- and inter-operator coordination on a shared communication medium are disclosed. A central coordination server may send an operating mode information message to coordinate operation of different points on the communication medium. An access point may receive such an operating mode information message and adjust one or more communication parameters. An access point may determine a level of timing synchronization with neighboring access points and send a synchronization advertisement message to an access terminal. An access terminal may receive a synchronization advertisement message and perform one or more measurements of the neighboring access points.

Claims

1. A communication method, comprising:

determining a level of timing synchronization between a first access point and one or more neighboring access points; and

sending, from the first access point to an access terminal, a synchronization advertisement message that identifies the level of timing synchronization.

2. The method of claim 1, wherein the level of timing synchronization corresponds to a level of timing synchronization associated with a Discovery Reference Signal (DRS) Transmission Window (DTxW).

3. The method of claim 2, wherein the synchronization advertisement message includes a measurement timing indicator that indicates a location of one or more DTxW measurement opportunities for the access terminal to perform measurements on the one or more neighboring access points.

4. The method of claim 2, wherein the synchronization advertisement message includes a neighborhood synchronization indicator that indicates a level of DTxW synchronization among the one or more neighboring access points.

5. The method of claim 1, wherein the determining comprises:

receiving a backhaul signal from the one or more neighboring access points or from a remote server;

monitoring over-the-air signaling from the one or more neighboring access points;

or

self-determining based on an absence of synchronization information.

6. The method of claim 1, further comprising synchronizing, at the first access point, reference signal timing with at least one of the one or more neighboring access points based on the determining.

7. The method of claim 6, wherein the reference signal timing corresponds to timing of a Discovery Reference Signal (DRS) Transmission Window (DTxW).

8. The method of claim 7, wherein the synchronizing comprising synchronizing the DTxW of the first access point and the at least one of the one or more neighboring access points to within a margin.

9. The method of claim 8, wherein the synchronizing comprises:

synchronizing a first DTxW of the first access point, on a first frequency over which the first access point serves the access terminal, with the DTxW of the at least one of the one or more neighboring access points to within a first margin; and

synchronizing a second DTxW of the first access point, on a second frequency over which the first access point does not serve the access terminal, with the DTxW of the at least one of the one or more neighboring access points to within a second margin,

wherein the second margin is smaller than the first margin.

10. The method of claim 1, wherein the level of timing synchronization corresponds to a level of timing synchronization associated with subframe boundaries or radio frame boundaries.

11. A communication apparatus, comprising:

at least one processor;

at least one memory coupled to the at least one processor, the at least one processor and the at least one memory being configured to determine a level of timing synchronization between a first access point and one or more neighboring access points; and

at least one transceiver configured to send, from the first access point to an access terminal, a synchronization advertisement message that identifies the level of timing synchronization.

12. The apparatus of claim 11, wherein the level of timing synchronization corresponds to a level of timing synchronization associated with a Discovery Reference Signal (DRS) Transmission Window (DTxW).

13. The apparatus of claim 11, wherein the at least one processor and the at least one memory are configured to determine the level of timing synchronization by:

receiving a backhaul signal from the one or more neighboring access points or from a remote server;

monitoring over-the-air signaling from the one or more neighboring access points;

or

self-determining based on an absence of synchronization information.

14. The apparatus of claim 11, the at least one processor and the at least one memory are further configured to synchronize, at the first access point, reference signal timing with at least one of the one or more neighboring access points based on the determining.

15. The apparatus of claim 11, wherein the level of timing synchronization corresponds to a level of timing synchronization associated with subframe boundaries or radio frame boundaries.

16. A communication method, comprising:

receiving, at an access terminal from a first access point, a synchronization advertisement message that identifies a level of timing synchronization between the first access point and one or more neighboring access points; and

performing, by the access terminal, one or more measurements of the one or more neighboring access points based on the level of timing synchronization.

17. The method of claim 16, wherein the level of timing synchronization corresponds to a level of timing synchronization associated with a Discovery Reference Signal (DRS) Transmission Window (DTxW).

18. The method of claim 17, wherein the synchronization advertisement message includes a measurement timing indicator that indicates a location of one or more DTxW measurement opportunities for the access terminal to perform the one or more measurements.

19. The method of claim 17, wherein the synchronization advertisement message includes a neighborhood synchronization indicator that indicates a level of DTxW synchronization among the one or more neighboring access points.

20. The method of claim 16, wherein the one or more measurements comprise one or more Radio Resource Management (RRM) measurements.

21. The method of claim 16, wherein the one or more measurements of the one or more neighboring access points are performed by the access terminal during a Discovery Reference Signal (DRS) Transmission Window (DTxW) of the first access point in response to the synchronization advertisement message indicating a substantial level of synchronization between the first access point and the one or more neighboring access points.

22. The method of claim 16, wherein the one or more measurements of the one or more neighboring access points are performed by the access terminal during a Discovery Reference Signal (DRS) Transmission Window (DTxW) of at least one of the one or more neighboring access points in response to the synchronization advertisement message indicating a location of the DTxW of the at least one of the one or more neighboring access points.

23. The method of claim 16, wherein the one or more measurements of the one or more neighboring access points are performed by the access terminal autonomously in response to the synchronization advertisement message indicating a less than substantial level of synchronization between the first access point and the one or more neighboring access points.

24. A communication apparatus, comprising:

at least one transceiver configured to receive, at an access terminal from a first access point, a synchronization advertisement message that identifies a level of timing synchronization between the first access point and one or more neighboring access points;

at least one processor;

at least one memory coupled to the at least one processor, the at least one processor and the at least one memory being configured to perform, by the access terminal, one or more measurements of the one or more neighboring access points based on the level of timing synchronization.

25. The apparatus of claim 24, wherein the level of timing synchronization corresponds to a level of timing synchronization associated with a Discovery Reference Signal (DRS) Transmission Window (DTxW).

26. The apparatus of claim 25, wherein the synchronization advertisement message includes a measurement timing indicator that indicates a location of one or more DTxW measurement opportunities for the access terminal to perform the one or more measurements.

27. The apparatus of claim 25, wherein the synchronization advertisement message includes a neighborhood synchronization indicator that indicates a level of DTxW synchronization among the one or more neighboring access points.

28. The apparatus of claim 24, wherein the at least one processor and the at least one memory are configured to perform the one or more measurements of the one or more neighboring access points during a Discovery Reference Signal (DRS) Transmission Window (DTxW) of the first access point in response to the synchronization advertisement message indicating a substantial level of synchronization between the first access point and the one or more neighboring access points.

29. The apparatus of claim 24, wherein the at least one processor and the at least one memory are configured to perform the one or more measurements of the one or more neighboring access points during a Discovery Reference Signal (DRS) Transmission Window (DTxW) of at least one of the one or more neighboring access points in response to the synchronization advertisement message indicating a location of the DTxW of the at least one of the one or more neighboring access points.

30. The apparatus of claim 24, wherein the at least one processor and the at least one memory are configured to perform the one or more measurements of the one or more neighboring access points autonomously in response to the synchronization advertisement message indicating a less than substantial level of synchronization between the first access point and the one or more neighboring access points.