Systems and methods of selective scanning for ad-hoc networks

Patent metadata

Field	Value
Publication number	US-9307507-B2
Application number	US-201313836178-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Nov 30, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

Methods, devices, and computer program products for selective scanning of ad-hoc networks are described herein. In one aspect, a method includes receiving a message identifying a number of times the message has been forwarded. The method further includes selectively scanning for other ad-hoc networks based on the identified number. In one aspect, a root device for an ad-hoc network is responsible for generating synchronization messages for nodes of the ad-hoc network. The synchronization message includes a count of the number of times the synchronization message has been forwarded. When the hop count reaches a limit, the synchronization message is no longer retransmitted or forwarded by receiving nodes. Nodes receiving this message may recognize they are positioned near the edge of the ad-hoc network. In at least one embodiment, these nodes may selectively scan for other ad-hoc networks based on the hop count reaching or exceeding a predetermined threshold.

First claim

What is claimed is:

1. A method of wireless communication by a leaf device in a first ad-hoc communications network, comprising:
determining a discovery interval and a paging interval for the first ad-hoc communications network;
receiving, by a device, a message from the first ad-hoc communications network identifying a number of times the message has been forwarded;
remaining awake and processing messages outside the discovery interval and paging interval in response to the number of times the message has been forwarded exceeding a threshold, wherein processing messages outside the discovery window and paging interval comprises:
scanning, by the device, for other ad-hoc networks, and joining a second ad-hoc network based on the scanning; and
entering a sleep state outside the discovery interval and the paging interval in response to the number of times the message has been forwarded being below the threshold.

2. The method of claim 1 , further comprising incrementing the number of times the received message has been forwarded and forwarding the received message if the identified number is less than a maximum number of hops.

3. The method of claim 1 , further comprising not forwarding the message if the identified number is greater than or equal to a maximum number of hops.

4. The method of claim 1 , further comprising joining a second ad-hoc network based on the selective scanning.

5. The method of claim 1 , wherein the device is a leaf device of the ad-hoc network if the identified number of times is greater than or equal to a maximum number of hops.

6. The method of claim 1 , wherein the received message comprises a synchronization message transmitted by a root device.

7. The method device of claim 1 , wherein whether to selectively scan is further based on configuration data.

8. The method of claim 1 , wherein selectively scanning for other ad-hoc networks comprises receiving messages outside an availability window for the ad-hoc communications network.

9. The method of claim 1 , wherein the selective scanning is based on a remaining battery life of the device.

10. The method of claim 8 , wherein selectively scanning for other ad-hoc networks further comprises determining if a particular discovery packet or other message received outside the availability window matches a criteria defined by configuration data.

11. A leaf device for wireless communication in a first ad-hoc communications network, comprising:
a processor configured to determine a discovery interval and a paging interval for the first ad-hoc communications network;
a receiver configured to receive a message from the ad-hoc communications network identifying a number of times the message has been forwarded, and
wherein the processor is further configured to:
remain awake and process messages outside the discovery interval and paging interval in response to the number of times the message has been forwarded exceeding a threshold, wherein processing messages outside the discovery window and paging interval comprises:

scanning for other ad-hoc networks in response to the identified number being greater than or equal to a maximum number of hops, and joining a second ad-hoc network based on the scanning; and
entering a sleep state outside the discovery interval and the paging interval in response to the number of times the message has been forwarded being below the threshold.

12. The device of claim 11 , wherein the processor is further configured to:
increment the number of times the received message has been forwarded and forward the received message if the identified number is less than a maximum number of hops.

13. The device of claim 11 , wherein the processor is further configured to not forward the message if the identified number is greater than or equal to a maximum number of hops.

14. The device of claim 11 , wherein the processor is further configured to join a second ad-hoc network based on the selective scanning.

15. The device of claim 11 , wherein the device is a leaf device of the ad-hoc network if the identified number of times is greater than or equal to a maximum number of hops.

16. The device of claim 11 , wherein the received message comprises a synchronization message transmitted by a root device.

17. The device of claim 11 , wherein whether to selectively scan is further based on configuration data.

18. The device of claim 11 , wherein the processor is further configured to selectively scan for other ad-hoc networks by receiving messages outside an availability window for the ad-hoc communications network.

19. The device of claim 11 , wherein the selective scanning is based on a remaining battery life of the device.

20. The device of claim 18 , wherein the processor is further configured to selectively scan by determining if a particular discovery packet or other message received outside the availability window includes matches a criteria defined by configuration data.

21. A leaf device for wireless communication in an ad-hoc communications network, comprising:
means for determining a discovery interval and a paging interval for the first ad-hoc communications network;
means for receiving a message from the ad-hoc communications network identifying a number of times the message has been forwarded;
means for remaining awake and processing messages outside the discovery interval and paging interval in response to the number of times the message has been forwarded exceeding a threshold, wherein processing messages outside the discovery window and paging interval comprises:
means for scanning, by the device, for other ad-hoc networks, and joining a second ad-hoc network based on the scanning; and
means for entering a sleep state outside the discovery interval and the paging interval in response to the number of times the message has been forwarded being below the threshold.

22. The device of claim 21 , further comprising means for incrementing the number of times the received message has been forwarded and forwarding the received message if the identified number is less than a maximum number of hops.

23. The device of claim 21 , further comprising means for not forwarding the message if the identified number is greater than or equal to a maximum number of hops.

24. The device of claim 21 , further comprising means for joining a second ad-hoc network based on the selective scanning.

25. The device of claim 21 , wherein the device is a leaf device of the ad-hoc network if the identified number of times is greater than or equal to a maximum number of hops.

26. The device of claim 21 , wherein the received message comprises a synchronization message transmitted by a root device.

27. The device of claim 21 , wherein the means for selectively scanning selectively scans for other ad-hoc networks by receiving messages outside an availability window for the ad-hoc communications network.

28. The device of claim 21 , wherein the means for selective scanning is configured to base the selective scanning on a remaining battery life of the device.

29. The device of claim 27 , wherein the means for selectively scanning determines if a particular discovery packet or other message received outside the availability window matches a criteria defined by configuration data.

30. A non-transitory, computer readable medium comprising instruction

Assignees

• Qualcomm Inc

Inventors

• Zhou Yan
• Cherian George
• Abraham Santosh Paul

Classifications

• H04W40/12

  based on transmission quality or channel quality · CPC title

• H04W40/22

  using selective relaying for reaching a BTS [Base Transceiver Station] or an access point · CPC title

• H04L45/28

  using route fault recovery · CPC title

• H04W84/20

  Leader-follower arrangements · CPC title

• H04W56/0015 Primary

  one node acting as a reference for the others · CPC title