Methods and apparatus for power saving for mesh nodes

• US 9,088,946 B2
• Filed: 04/23/2009
• Issued: 07/21/2015
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wentink, Maarten Menzo
• Primary Examiner(s): SMARTH, GERALD A
• Application Number:
  US12/429,114
• Publication Number:
  US 20090274082A1
• Time in Patent Office: 2,280 Days
• Field of Search: 370/311
• US Class Current: 1/1
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and apparatus for implementing power saving in mesh nodes include transmitting a receive window start frame prior to each awake period. The receive window start frame is a short frame, and nodes in the mesh network passively monitor for this frame. Upon detection, a mesh node can transmit data to its destination during its awake period.

Claims

1. A method for receiving data from a peer node comprising:

transmitting, by a first node to the peer node, a receive window start frame prior to each of one or more scheduled awake periods of the first node and the peer node, wherein the receive window start frame indicates an upcoming awake period and includes a beacon change field indicating whether a change has been made to a beacon;

periodically transmitting the beacon, said beacon comprising information about the first node; and

receiving data from the peer node during a scheduled awake period.

2. The method of claim 1, wherein the first node and the peer node are connected by a mesh link.

3. The method of claim 1, wherein each awake period is defined as a fixed number of timeslots.

4. The method of claim 1, wherein each awake period is defined as a fixed period of time.

5. The method of claim 1, wherein the receive window start frame includes a length field identifying the length of the upcoming awake period.

6. The method of claim 5, wherein the length is expressed in units of time.

7. The method of claim 5, wherein the length is expressed as a number of backoff slots.

8. The method of claim 1, wherein said receive window start frame is substantially smaller in size than said beacon.

9. The method of claim 1, wherein the beacon change field comprises a counter value which is updated after each significant beacon change.

10. A method of transmitting data to a power save node in a mesh network, comprising:

receiving at a first node, from the power save node, a receive window start frame indicating an upcoming awake period of the power save node, the receive window start frame being transmitted by the power save node prior to each of one or more scheduled awake periods of the first node and the power save node, and wherein the receive window start frame includes a beacon change field indicating whether a change has been made to a beacon;

periodically receiving the beacon, said beacon comprising information about the power save node; and

transmitting the data to the power save node during a scheduled awake period.

11. The method of claim 10, wherein the awake period is a fixed number of backoff slots.

12. An apparatus operating as a mesh node comprising:

a processor;

a power saving module, said power saving module comprising a start frame generator for generating and transmitting a frame indicating to other mesh nodes that the mesh node has an upcoming awake period, wherein the mesh node is available to receive data during the awake period, wherein the frame is transmitted prior to each of one or more scheduled awake periods of the mesh node and the other mesh nodes, and includes a beacon change field indicating whether a change has been made to a beacon; and

a beacon generator for generating the beacon comprising information about the mesh node.

13. The apparatus of claim 12, wherein the power saving module further comprises:

a scheduler for exchanging awake period information with the other mesh nodes; and

a receive window start frame generator for generating the frame indicating the mesh node has an upcoming awake period and is available to receive data.

14. The apparatus of claim 12, wherein the awake period is defined as a fixed number of timeslots.

15. The apparatus of claim 12, wherein the awake period is defined as a fixed period of time.

16. The apparatus of claim 12, wherein the frame indicating the upcoming awake period includes a length field identifying the length of the upcoming awake period.

17. The apparatus of claim 16, wherein the length is expressed as a number of time slots.

18. The apparatus of claim 16, wherein the length is expressed in units of time.

19. The apparatus of claim 12, wherein said frame indicating the mesh node is awake is substantially smaller in size than said beacon.

20. The apparatus of claim 12, wherein the beacon change field comprises a counter value which is updated after each significant beacon change.

21. An apparatus operating as a mesh node, comprising:

a processor;

a receiver for detecting a receive window start frame associated with a destination mesh node, the receive window start frame indicating an upcoming awake period of the destination mesh node, the receive window start frame being transmitted by the destination mesh node to the mesh node prior to each of one or more scheduled awake periods of the destination mesh node and the mesh node, and for periodically receiving a beacon, said beacon comprising information about the destination mesh node; and

a transmitter for transmitting data to the destination mesh node during a scheduled awake period,

wherein said receive window start frame includes a beacon change field indicating whether a change has been made to the beacon.

22. The apparatus of claim 21, wherein the awake period is a fixed number of timeslots.

23. An apparatus operating as a mesh node in a mesh network, comprising:

means for transmitting, from the mesh node to one or more other nodes in the mesh network, a receive window start frame prior to each of one or more scheduled awake periods of the mesh node and one or more other nodes, the receive window start frame indicating an upcoming awake period and includes a beacon change field indicating whether a change has been made to a beacon;

means for periodically transmitting the beacon, said beacon comprising information about the mesh node; and

means for receiving data from the one or more other nodes in the mesh network during the scheduled awake period.

24. An apparatus operating as a mesh node in a mesh network, comprising:

means for receiving a receive window start frame indicating an upcoming awake period of a destination mesh node, the receive window start frame being transmitted by the destination mesh node to the mesh node prior to each of one or more scheduled awake periods, wherein the receive window start frame includes a beacon change field indicating whether a change has been made to a beacon;

means for periodically receiving the beacon, said beacon comprising information about the destination mesh node; and

means for transmitting data to the destination mesh node during the awake period, wherein said receive window start frame includes a beacon change field indicating whether a change has been made to the beacon.