Method and apparatus for merging independently synchronized networks

• US 7,649,873 B2
• Filed: 04/03/2006
• Issued: 01/19/2010
• Est. Priority Date: 10/13/2005
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Michels, James P., Calcev, George, Bonta, Jeffrey D.
• Primary Examiner(s): Nguyen; Lee
• Application Number:
  US11/278,436
• Publication Number:
  US 20070086426A1
• Time in Patent Office: 1,387 Days
• Field of Search: 370/338, 370/350, 370/503, 375/356, 455 412- 413, 455/502
• US Class Current: 370/338
• CPC Class Codes: H04J 3/0641 Change of the master or reference, e.g. take-over or failure of the master
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

During operation, nodes that receive beacons from a different network will synchronize to the different network when a predetermined condition is met. Synchronization to the differing network will only take place if the node receiving the beacon from a different network does not have access to a fixed network coordinator and the predetermined condition is met. The predetermined condition may comprise such things as a Network ID for the different network being larger than the Network ID for the current network, or alternatively, the size of the different network being larger than a size of the current network.

Claims

1. A method for a node currently synchronized to a first network, having a first Network ID to synchronize to a second network having a second Network ID, the method comprising the steps of:

receiving a beacon containing the second Network ID;

determining that the second Network ID differs from the first Network ID;

determining that a condition exists that requires merging the first network with the second network;

synchronizing to the second network when the condition exists, otherwise maintaining synchronization to the first network; and

determining if the first network is synchronized to a fixed network coordinator; and

wherein the step of synchronizing to the second network when the condition exists comprises the step of synchronizing to the second network only when it is determined that the first network is not synchronized to the fixed network coordinator and when the condition exists.

2. The method of claim 1 wherein the step of determining that the condition exists comprises the step of determining that the second Network ID is larger than the first Network ID.

3. The method of claim 1 wherein the step of determining that the condition exists comprises the step of determining that the second network is larger than the first network.

4. The method of claim 1 wherein the step of determining that the condition exists comprises the step of determining conditions taken from the group consisting of determining that the second Network ID is larger than the first Network ID and determining that the second network is larger than the first network.

5. The method of claim 1 wherein the first and the second Network IDs comprise a first and a second base station ID.

6. The method of claim 1 wherein the step of determining that the condition exists comprises the step of determining that the second Network ID is larger than the first Network ID.

7. The method of claim 1 wherein the step of determining that the condition exists comprises the step of determining that the second network is larger than the first network.

8. The method of claim 1 wherein the step of determining that the condition exists comprises the step of determining conditions taken from the group consisting of determining that the second Network ID is larger than the first Network ID and determining that the second network is larger than the first network.

9. The method of claim 1 wherein the step of synchronizing to the second network occurs after a transition timer expires.

10. A method for a node currently synchronized to a first network, having a first Network ID to synchronize to a second network having a second Network ID, the method comprising the steps of:

receiving a beacon containing the second Network ID and an indication as to whether or not the second network utilizes a fixed network coordinator;

determining that the second Network ID differs from the first Network ID;

synchronizing to the second network when the first network does not have a fixed network coordinator and a condition exists from the group consisting of;

the Network ID of the second network is larger than the network ID of the first network;

the second network utilizes a fixed network coordinator; and

the second network is larger than the first network.

11. The method of claim 10 wherein the first and the second Network IDs comprise a first and a second base station ID.

12. An apparatus comprising:

a receiver receiving a beacon containing a second Network ID;

logic circuitry determining that the second Network ID differs from a first Network ID and also determining that a condition exists that requires merging the first network with the second network, and synchronizing to a second network when the condition exists, otherwise maintaining synchronization to a first network; and

wherein the logic circuitry additionally determines if the first network is synchronized to a fixed network coordinator and synchronizes to only when it is determined that the first network is not synchronized to the fixed network coordinator and when the condition exists.

13. The apparatus of claim 12 wherein the condition comprises the second Network ID being larger than the first Network ID.

14. The apparatus of claim 12 wherein the condition comprises the second network being larger than the first network.

15. The apparatus of claim 12 wherein the condition is taken from the group consisting of the second Network ID being larger than the first Network ID and the second network being larger than the first network.

16. The apparatus of claim 12 wherein the first and the second Network IDs comprise a first and a second base station ID.

17. The apparatus of claim 12 wherein the condition comprises the second Network ID being larger than the first Network ID.

18. The apparatus of claim 12 wherein the condition comprises the second network being larger than the first network.