System and method for synchronizing components in a mesh network

• US 7,664,055 B2
• Filed: 03/21/2005
• Issued: 02/16/2010
• Est. Priority Date: 03/21/2005
• Status: Expired due to Fees

• Current Assignee: RF Monolithics, Inc. (Murata Manufacturing Co Limited)
• Original Assignee: RF Monolithics, Inc. (Murata Manufacturing Co Limited)
• Inventors: Nelson, Dan R.
• Primary Examiner(s): Rao; Seema S
• Assistant Examiner(s): DUONG, CHRISTINE T
• Application Number:
  US11/084,991
• Publication Number:
  US 20060209878A1
• Time in Patent Office: 1,793 Days
• Field of Search: 370/351, 370/376, 370/458, 370/459, 370/460, 370503-520
• US Class Current: 370/256
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/036 Updating the topology between route computation elements, e.g. between OpenFlow controllers
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 88/14 Backbone network devices

Abstract

A method includes receiving a first message at a router in a mesh network and synchronizing the router to a plurality of time slots using the first message. The method also includes repeatedly incrementing a network reference value at each time slot up to a maximum value and then decrementing the network reference value at each time slot down to a minimum value. In addition, the method includes broadcasting a second message at the router when the network reference value has a specific value that is associated with a unique identifier of the router.

Claims

1. A method, comprising:

receiving a first message at least one of a plurality of routers in a mesh network;

synchronizing the plurality of routers to a plurality of time slots using the first message;

repeatedly incrementing a network reference value at each of multiple time slots up to a maximum value and then repeatedly decrementing the network reference value at each of multiple time slots down to a minimum value, wherein the maximum value corresponds to the number of routers; and

broadcasting a second message at the router when the network reference value matches a specific value that is associated with a unique identifier of the router;

wherein the network reference value is incremented up to the maximum value in alternate sequences of a plurality of sequences and is decremented down to the minimum value in remaining sequences of the plurality of sequences, and

wherein broadcasting the second message comprises broadcasting subsequent second messages at each of the plurality of routers in each of at least some of the sequences when the network reference value matches the specific value of the router during the sequences.

2. The method of claim 1, wherein synchronizing the router to the plurality of time slots comprises:

identifying a first time associated with the first message;

adding the first time and a known second time to produce a total time, each time slot having a length equal to the total time; and

setting a slot timer to the total time for a new time slot.

3. The method of claim 2, further comprising:

resetting the slot timer to the total time at an end of each time slot.

4. The method of claim 2, further comprising:

receiving a third message at the router; and

calibrating the slot timer so as to be synchronized with the third message.

5. The method of claim 1, wherein the network reference value is incremented up to the maximum value in successive time slots and is decremented down to the minimum value in successive time slots.

6. The method of claim 1, wherein the first message is broadcast by one of:

a central controller in the mesh network and another router in the mesh network.

7. The method of claim 1, wherein the router comprises a mobile router.

8. A computer program embodied on a computer readable medium and operable to be executed, the computer program comprising computer readable program code for:

receiving a first message at least one of a plurality of routers in a mesh network;

synchronizing the plurality of routers to a plurality of time slots using the first message;

repeatedly incrementing a network reference value at each of multiple time slots up to a maximum value and then repeatedly decrementing the network reference value at each of multiple time slots down to a minimum value, wherein the maximum value corresponds to the number of routers; and

broadcasting a second message at the router when the network reference value matches a specific value that is associated with a unique identifier of the router;

wherein the network reference value is incremented up to the maximum value in alternate sequences of a plurality of sequences and is decremented down to the minimum value in remaining sequences of the plurality of sequences, and

wherein broadcasting the second message comprises broadcasting subsequent second messages at each of the plurality of routers in each of at least some of the sequences when the network reference value matches the specific value of the router during the sequences.

9. The computer program of claim 8, wherein the computer readable program code for synchronizing the router to the plurality of time slots comprises computer readable program code for:

identifying a first time associated with the first message;

adding the first time and a known second time to produce a total time, each time slot having a length equal to the total time; and

setting a slot timer to the total time for a new time slot.

10. The computer program of claim 9, further comprising computer readable program code for:

resetting the slot timer to the total time at an end of each time slot.

11. The computer program of claim 9, further comprising computer readable program code for:

receiving a third message at the router; and

calibrating the slot timer so as to be synchronized with the third message.

12. The computer program of claim 8, wherein the network reference value is incremented up to the maximum value in successive time slots and is decremented down to the minimum value in successive time slots.

13. The computer program of claim 8, wherein the first message is broadcast by one of:

a central controller in the mesh network and another router in the mesh network.

14. The computer program of claim 8, wherein the router comprises a mobile router.

15. A mesh network, comprising:

a plurality of routers capable of communicating with a plurality of user endpoints; and

a central controller capable of defining a plurality of time slots and communicating with at least one of the routers in at least one of the time slots;

each router further capable of;

receiving a first message in one of the time slots;

synchronizing the plurality of routers to the plurality of time slots using the first message;

repeatedly incrementing a network reference value at each of multiple time slots up to a maximum value and then repeatedly decrementing the network reference value at each of multiple time slots down to a minimum value, wherein the maximum value corresponds to the number of routers; and

broadcasting a second message at the router when the network reference value matches a specific value that is associated with a unique identifier of the router;

wherein the network reference value is incremented up to the maximum value in alternate sequences of a plurality of sequences and is decremented down to the minimum value in remaining sequences of the plurality of sequences, and

wherein each router is capable of broadcasting subsequent second messages in each of at least some of the sequences when the network reference value matches the specific value of the router during the sequences.

16. The mesh network of claim 15, wherein each router is capable of synchronizing to the plurality of time slots by:

identifying a first time associated with the first message;

adding the first time and a known second time to produce a total time, each time slot having a length equal to the total time; and

setting a slot timer to the total time for a new time slot.

17. The mesh network of claim 16, wherein each router is further capable of:

resetting the slot timer to the total time at an end of each time slot.

18. The mesh network of claim 16, wherein each router is further capable of:

receiving a third message at the router; and

calibrating the slot timer so as to be synchronized with the third message.

19. The mesh network of claim 15, wherein the network reference value is incremented up to the maximum value in successive time slots and is decremented down to the minimum value in successive time slots.

20. The mesh network of claim 15, wherein at least some of the routers are mobile routers.