Methods and Apparatus for Scanning for Mesh Nodes

• US 20090274083A1
• Filed: 04/23/2009
• Published: 11/05/2009
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wentink, Maarten Menzo
• Granted Patent: US 9,445,253 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 40/005 Routing actions in the presence of nodes in sleep or doze mode
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• 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 are provided for scanning for mesh nodes. A communication device monitors a shared communication channel to detect receive window start frames indicating that a mesh node is awake and available to receive data. The scanning device transmits a probe request during the awake window.

Claims

1. A method for scanning for a mesh network, comprising:

determining an awake window associated with a mesh node in power save mode;

sending a probe request to the mesh node during the awake window; and

receiving a probe response from the mesh node in power save mode.

2. The method of claim 1, wherein the procedure is repeated for multiple mesh nodes in power save mode.

3. The method of claim 1, wherein a broadcast probe request is transmitted without waiting for an awake window to occur.

4. The method of claim 1, wherein the probe request is transmitted to the power save node as a unicast frame.

5. The method of claim 1, wherein a scanning station sends a broadcast probe request to detect mesh nodes that are not in power save mode.

6. The method of claim 1, wherein determining an awake window comprises monitoring a shared communications channel to detect a receive window start frame indicating an upcoming awake window.

7. The method of claim 6, wherein the receive window start frame includes mesh network identifying information, and wherein the method further comprises:

examining the mesh network identifying information prior to sending the probe request.

8. The method of claim 6, wherein the receive window start frame is a beacon frame.

9. The method of claim 7, wherein the identifying information is the first characters of the mesh network'"'"'s mesh ID.

10. The method of claim 1, wherein a scanning station is pre-configured to search for a pre-determined mesh node.

11. The method of claim 1, wherein at least one mesh node not in power save mode periodically transmits a plurality of receive window start frames indicating a permanent awake period.

12. The method of claim 1, wherein the receive window start frame is a beacon frame that indicates that the mesh node is not in power save mode.

13. The method of claim 1, wherein at least one mesh node in power save mode periodically transmits a plurality of receive window start frames, and wherein determining an awake window comprises detecting a receive window start frame.

14. The method of claim 13, wherein each receive window start frame indicates an upcoming awake window.

15. An apparatus, comprising:

a processor; and

a network scanning module, the network scanning module configured to detect a receive window start frame.

16. The apparatus of claim 15, wherein the network scanning module comprises:

a scanning engine for passively monitoring a shared communication channel to detect a receive window start frame; and

a probe exchange engine for transmitting a probe request during an awake window associated with a mesh node upon detection of a receive window start frame.

17. The apparatus of claim 16, wherein the probe request is a broadcast message.

18. The apparatus of claim 16, wherein the probe request is a unicast message.

19. The apparatus of claim 16, wherein the probe exchange engine is configured to transmit a probe request upon detection of a receive window start frame.

20. The apparatus of claim 15, wherein the receive window start frame includes mesh network identifying information.

21. The apparatus of claim 20, wherein the mesh network identifying information is the first characters of the mesh network'"'"'s mesh ID.

22. The apparatus of claim 15, wherein the network scanning module is pre-configured to search for a predetermined mesh node.

23. The apparatus of claim 15, further comprising a power saving module for implementing the power save mode.

24. An apparatus, comprising:

means for determining an awake window associated with a mesh node in a power save mode; and

means for sending a probe request to the mesh node during the awake window; and

means for receiving a probe response from the mesh node in power save mode.