Method for energy efficient prospective peer discovery in an ad hoc network

• US 7,613,156 B2
• Filed: 06/08/2006
• Issued: 11/03/2009
• Est. Priority Date: 06/08/2006
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Vasudevan, Venugopal, Narasimhan, Nitya, Horozov, Tzvetan T., Rittle, Loren J.
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Hannon, Christian A
• Application Number:
  US11/422,954
• Publication Number:
  US 20070286136A1
• Time in Patent Office: 1,244 Days
• Field of Search: 455/41.2, 455/41.3, 455/500, 370/254, 370/255, 370/256, 370/277, 370/311, 370/312, 370/338, 370/331
• US Class Current: 370/338
• 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 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 76/10 Connection setup
• 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

Energy-efficient discovery techniques are provided for a client node to discover at least one peer provider node in an ad hoc network. For example, the client node can be configured to turn on its first ad hoc interface while in a discovery mode to establish a channel for a first time period. The client node can then transmit a first beacon to advertise its presence to other nodes within the transmission range of the client node to acquire service information from at least one of a plurality of prospective peer provider nodes within the transmission range of the client node. At least one of the prospective peer provider nodes is configured to turn on its second ad hoc interface for a second period of time to listen for beacons from other nodes. The second period of time is less than or equal to the first period of time.

Claims

1. A method for a client node to discover a peer provider node in an ad hoc network, comprising:

activating a first ad hoc interface in the client node while in a discovery mode to establish a channel for a first time period;

transmitting a first beacon to advertise presence of the client node including a request to acquire service information from at least one prospective peer provider node within the transmission range of the client node;

receiving, during the first time period at the client node, a second beacon from the at least one prospective peer provider node;

analyzing information in the second beacon to determine if the at least one prospective peer provider node offers the service the client node is requesting; and

transmitting a response message from the client node to the at least one prospective peer provider node when the at least one prospective peer provider node offers the service requested by the client node,

wherein the response message indicates that the at least one prospective peer provider node is to keep a second ad hoc interface active for a period of time.

2. A method according to claim 1, further comprising:

activating the second ad hoc interface in the at least one prospective peer provider node for a second period of time to listen for beacons from other nodes, wherein the second period of time is less than or equal to the first period of time; and

transmitting the second beacon from the at least one prospective peer provider node at the beginning of the second period of time to advertise services which the at least one of the plurality of prospective peer provider node can provide to other nodes,

wherein the second beacon comprises a service extension field comprising a list of services that are currently running on the at least one prospective peer provider node or that the at least one prospective peer provider node is capable of running.

3. A method according to claim 2, wherein the second ad hoc interface is activated in response to either:

receiving another beacon, or

at regular predetermined time intervals.

4. A method according to claim 1, wherein the first beacon comprises:

a first field indicating the first period of time the client node will keep the channel on for, and

a second field indicating a service the client node is requesting,

wherein the first time period is of sufficient duration to ensure that a prospective peer provider node within the transmission range of the client node can detect and respond to the first beacon, and

wherein the first time period is of sufficient duration to ensure that, if a response beacon is transmitted by a prospective peer provider node, the client node will detect a response beacon within the first time period.

5. A method according to claim 1, wherein the second beacon further comprises:

a first field specifying a duration of the second time period (α

) during which the second ad hoc interface will be on and a duration of the third time period (β

) during which the second ad hoc interface will be off;

a MAC beacon field which specifies the IEEE 802.11 MAC beacon;

an IP extension field which specifies the IP address of the particular node that is transmitting the second beacon; and

a second field comprising a number of neighbor nodes a particular prospective peer provider node has seen recently within a particular time period.

6. A method according to claim 5, further comprising:

receiving a second beacon from a first prospective peer provider node;

receiving a second beacon from a second prospective peer provider node;

evaluating each of the second beacons; and

choosing either the first prospective peer provider node or the second prospective peer provider node based on the fields specified in each of the second beacons.

7. A method according to claim 5, wherein a duration of the second time period (α

) and a duration of the third time period (β

) define a duty cycle for the particular node.

8. A method according to claim 5, further comprising:

determining, at each prospective peer provider node, a duration of the second time period (α

) and a duration of the third time period (β

) based on the particular service(s) being offered by the particular prospective peer provider node.

9. A method according to claim 8, wherein the duration of the second time period (α

) can be adjusted based on the particular radio protocol being used, and

wherein the duration of the third time period (β

) can be adjusted based on the real time requirements of the particular service(s) being offered by the particular node.

10. A method according to claim 5, wherein a sum of the second time period (α

) and the third time period (β

) is less than or equal to the value of the first time period (Y_max) on all nodes.

11. A method according to claim 1, wherein the first beacon comprises a first application service beacon and the second beacon comprises a second application service beacon.

12. A method according to claim 1, wherein the beginning of the first time period is synchronized with the beginning of the second time period based on a time constant provided from a cellular network or service.

13. A method according to claim 12, wherein the end of the first time period is synchronized with the end of the second time period based on a time constant provided from a cellular network or service.

14. A method according to claim 1, wherein the client node turns off the first ad hoc interface and enters sleep mode when it does not receive a response from a prospective peer provider node within the first time period.

15. A method according to claim 1, further comprising:

communicating, between the client node and the at least one prospective peer provider node, information associated with the service requested by the client node; and

turning off the second ad hoc interface once the at least one prospective peer provider node has communicated the information associated with the service requested by the client node.

16. A method according to claim 1, wherein the prospective peer provider nodes not receiving a response message from the client node turn off their second ad hoc interfaces at the end of the second time period.

17. An ad hoc network, comprising:

at least one prospective peer provider node; and

a client node configured to;

turn on a first ad hoc interface in the client node while in a discovery mode to establish a channel for a first time period;

transmit a first beacon to advertise presence of the client node including a request to acquire service information from at least one prospective peer provider node within the transmission range of the client node;

receive, during the first time period at the client node, a second beacon from the at least one prospective peer provider node;

analyze information in the second beacon to determine if the at least one prospective peer provider node offers the service the client node is requesting; and

transmit a response message from the client node to the at least one prospective peer provider node when the at least one prospective peer provider node offers the service requested by the client node,

wherein the response message indicates that the at least one prospective peer provider node is to keep a second ad hoc interface active for a period of time.

18. An ad hoc network according to claim 17, wherein the at least one of the prospective peer provider nodes is configured to:

activate the second ad hoc interface in the at least one of the prospective peer provider nodes for a second period of time to listen for beacons from other nodes, wherein the second period of time is less than or equal to the first period of time; and

transmit the second beacon during the second period of time to advertise services the prospective peer provider node can provide to other nodes

wherein the second beacon comprises a service extension field comprising a list of services that are currently running on the prospective peer provider node or that the prospective peer provider node is capable of running.

19. An ad hoc network according to claim 17, wherein the first beacon comprises:

a first field indicating the first period of time the client node will keep the channel on for, and

a second field indicating a service the client node is requesting,

wherein the first time period is of sufficient duration to ensure that a prospective peer provider node within the transmission range of the client node can detect and respond to the first beacon, and

wherein the first time period is of sufficient duration to ensure that, if a response beacon is transmitted by a prospective peer provider node, the client node will detect a response beacon within the first time period.

20. An ad hoc network according to claim 17, wherein the second beacon further comprises:

a first field specifying a duration of the second time period (α

) during which the second ad hoc interface will be on and a duration of the third time period (β

) during which the second ad hoc interface will be off;

a MAC beacon field which specifies the IEEE 802.11 MAC beacon;

an IP extension field which specifies the IP address of the particular node that is transmitting the second beacon; and

a second field comprising a number of neighbor nodes a particular prospective peer provider node has seen recently within a particular time period.

21. An ad hoc network according to claim 20, wherein the client node is further configured to:

receive a second beacon from a first prospective peer provider node;

receive a second beacon from a second prospective peer provider node;

evaluate each of the second beacons, and choose either the first prospective peer provider node or the second prospective peer provider node based on the fields specified in each of the second beacons.

22. An ad hoc network according to claim 20, wherein a duration of the second time period (α

) and a duration of the third time period (β

) define a duty cycle for the particular node.

23. An ad hoc network according to claim 20, wherein each of the prospective peer provider nodes is configured to determine a duration of the second time period (α

) and a duration of the third time period (β

) based on the particular service(s) being offered by the particular prospective peer provider node.

24. An ad hoc network according to claim 23, wherein the duration of the second time period (α

) can be adjusted based on the particular radio protocol being used, and wherein the duration of the third time period (β

) can be adjusted based on the real time requirements of the particular service(s) being offered by the particular node.

25. An ad hoc network according to claim 20, wherein a sum of the second time period (α

) and the third time period (β

) is less than or equal to the value of the first time period (Y_max) on all nodes.

26. An ad hoc network according to claim 17, wherein the first beacon comprises a first application service beacon and the second beacon comprises a second application service beacon.

27. An ad hoc network according to claim 17, wherein the beginning of the first time period is synchronized with the beginning of the second time period based on a time constant provided from a cellular network or service.

28. An ad hoc network according to claim 27, wherein the end of the first time period is synchronized with the end of the second time period based on a time constant provided from a cellular network or service.

29. An ad hoc network according to claim 17, wherein the second ad hoc interface is activated in response to either:

receiving another beacon, or

at regular predetermined time intervals.

30. An ad hoc network according to claim 17, wherein the client node turns off the first ad hoc interface and enters sleep mode when it does not receive a response beacon from a prospective peer provider node within the first time period.

31. An ad hoc network according to claim 17, wherein the at least one prospective peer provider node is configured to communicate information associated with the service requested by the client node, and to turn off the second ad hoc interface once the at least one prospective peer provider node has communicated the information associated with the service requested by the client node.

32. An ad hoc network according to claim 17, wherein the prospective peer provider nodes not receiving a response message from the client node turn off their second ad hoc interfaces at the end of the second time period.