Methods and apparatus for reduced energy communication in an ad hoc network

• US 20060135145A1
• Filed: 03/10/2005
• Published: 06/22/2006
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Raytheon BBN Technologies Corp. (Rtx Corporation)
• Original Assignee: BBNT Solutions LLC (Rtx Corporation)
• Inventors: Redi, Jason Keith
• Granted Patent: US 7,330,736 B2
• Time in Patent Office: Days
• US Class Current: 455/420
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• 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

The invention relates to communications devices for reduced energy communications in an ad hoc network. The communication device includes a first low powered transceiver for initiating communications with other communications devices and a second transceiver for transmitting data messages to the other communications devices once communication is initiated. The communication device also includes a communications control processor for determining times at which the other communications devices will be available to receive communications based on scheduling data received from those communication devices.

Claims

1. A communication device comprising:

a first transceiver for transmitting a communication initiation message using low power transmissions to initiate communication with a second communication device in an ad hoc network;

a second transceiver for transmitting data packets to the second communication device subsequent to initiating communications using the low power transmissions;

a communications control processor in communication with the first transceiver and the second transceiver;

configured for;

receiving scheduling data from the second communication device sufficient to predict a time at which the second communication device will be accepting data communications;

causing the first transceiver to transmit the communication initiation message to the second communication device at the predicted time;

causing the second transceiver to transmit at least one of the data packets to the second communication device subsequent to transmitting the communication initiation message.

2. The communication device of claim 1, wherein the communications control processor is configured to await receipt of an initiation acknowledgement message from the second communication device prior to causing the second transceiver to transmit at least one data packet to the second communication device.

3. The communication device of claim 1, wherein the communications control processor predicts the time at which the second communication device will be accepting the data communications based on a pseudorandom number generator shared between the communication device and the second communication device.

4. The communication device of claim 3, wherein the scheduling data includes a seed datum and a cycle state for the pseudorandom number generator.

5. The communication device of claim 1, wherein the scheduling data includes a unicast threshold indicating an availability of the second communication device to receive unicast communications.

6. The communication device of claim 1, wherein the scheduling data includes a multicast threshold indicating an availability of the second communication device to receive multicast communications.

7. The communication device of claim 1, wherein the scheduling data includes a dynamic threshold which can be dynamically changed by the second communication device to provide for variable availability of the second communication device.

8. The communication device of claim 7, wherein the dynamic threshold is based, at least in part, on a network traffic level.

9. The communication device of claim 7, wherein the dynamic threshold is based at least in part on a level of change in the network topology.

10. The communication device of claim 1, wherein the communication control processor is configured to:

await a data acknowledgement message from the second communication device following the transmitting of the data packet by the second transceiver; and

in response to failing to receive the data acknowledgment message after a predetermined amount of time, determining a time to cause the second transceiver to retransmit the data packet.

11. The communication device of claim 1, wherein the communication control processor is configured to:

request acknowledgement of receipt of the communication initiation message from the second communication device; and

in response to failing to receive an initiation acknowledgement message in a predetermined amount of time, waiting until a later time to transmit the data packet.

12. A communication device comprising:

a first low powered transceiver for receiving data communication initiation messages from a second communication device in an ad hoc network;

a second transceiver for receiving data packets from the second communication device in the ad hoc network subsequent to the first transceiver receiving the data communication initiation message;

a communications control processor in communication with the first lower- powered transceiver and the second transceiver for;

causing the second transceiver to transmit scheduling data to the second communication device sufficient to inform the second communication device of the times at which the communication device will be available for receiving data messages;

powering-up the first low-powered transceiver based on the scheduling data to allow receipt of incoming communication initiation messages; and

in response to the first low-powered transceiver receiving a communication initiation message, powering up the second transceiver to receive an incoming data packet.

13. The communication device of claim 12, wherein the communications control processor determines whether it should power-up the first lower-powered transceiver based on the output of a pseudorandom number generator shared between the communication device and the second communication device.

14. The communication device of claim 12, wherein the communications control processor determines whether it should power-up the first lower-powered transceiver based on a dynamic threshold indicating an availability of the communication device to receive communications, wherein the dynamic threshold can be varied by communication control processor to provide variable availability.

15. The communication device of claim 14, wherein the dynamic threshold is based at least in part on a network traffic level.

16. The communication device of claim 14, wherein the dynamic threshold is based at least in part on a level of change in a topology of the network.

17. The communication device of claim 14, wherein the scheduling data includes a seed datum and a cycle state for the pseudorandom number generator.

18. The communication device of claim 12, wherein the scheduling data includes a multicast threshold indicating an availability of the communication device to receive multicast communications.

19. The communication device of claim 12, wherein the scheduling data includes a unicast threshold indicating an availability of the communication device to receive unicast communications.

20. The communication device of claim 12, wherein the communication control processor determines whether it successfully received a data packet and informs the second communication device of the determination.

21. A method of transmitting data from a first communication device to a second communication device in an ad hoc network comprising:

predicting a time at which the second communication device of the ad hoc network will accept data packets based on scheduling data received from the second communication device;

transmitting by the first communication device of the ad hoc network a communication initiation message to the second communication device at the predicted time using a first low-powered transceiver;

transmitting, by the first communication device, after the transmission of the communication initiation message, a data packet to the second communication device using a second transceiver.

23. The method of receiving data of claim 21, comprising:

powering down the first lower-powered transceiver according to the determined schedule; and

powering down the second transceiver after receiving the data packet.

24. The method of receiving data of claim 21, comprising the first communication device transmitting an acknowledgement message to the second communication device indicating successful receipt of the data packet.

25. The method of claim 21, wherein the determination of the schedule includes the use of a pseudorandom number generator.

26. The method of claim 21, wherein the determination of the schedule includes the use of a dynamic threshold.

27. The method of claim 25, wherein the dynamic threshold is changed based on one of a traffic level in the network and a level of change of a network topology.

22. A method of receiving data at a first communication device from a second communication device in an ad hoc network comprising:

transmitting, by the first communication device, scheduling data to the second communication device sufficient to inform the second communication device of at least one time at which the first communication device will be available to receive a data packet;

powering-up a first transceiver by the first communication device based on the scheduling data; and

in response to the first transceiver receiving a communication initiation message, powering up a second transceiver by the first communication device to receive an incoming data packet.

28. A communication device comprising:

a first transceiver for transmitting data packets to a second communication device;

a communications control processor in communication with the transceiver for;

receiving scheduling data from a second communication device sufficient to predict, using a shared pseudorandom number generator, a time at which the second communication device will be accepting data communications; and

causing the first transceiver to transmit a data packet to the second communication device at about the predicted time.

29. The communication device of claim 28, wherein the communications control processor awaits receipt by the first transceiver of an initiation acknowledgement message prior to causing the transmitting of the data packet.

30. The communication device of claim 28, wherein the scheduling data includes a seed datum and a cycle state for the pseudorandom number generator.

31. The communication device of claim 28, wherein the scheduling data includes a unicast threshold indicating an availability of the second communication device to receive unicast communications.

32. The communication device of claim 28, wherein the scheduling data includes a multicast threshold indicating an availability of the second communication device to receive multicast communications.

33. The communication device of claim 28, wherein the scheduling data includes the use of a dynamic threshold.

34. The communication device of claim 33, wherein the dynamic threshold is based at least in part on a network traffic level.

35. The communication device of claim 34, wherein the dynamic threshold is based at least in part on a level of change in a network topology.

36. The communication device of claim 28, wherein the communications control processor:

awaits receipt of a data acknowledgement message by the first transceiver following the transmission of a data packet; and

in response to the first transceiver failing to receive a data acknowledgment message after a predetermined amount of time, determines a time to retransmit the data packet.

37. The communication device of claim 28, wherein the communication control processor:

causes the first transceiver to request acknowledgement of receipt of the communication initiation message from the second communication device; and

in response to the first transceiver failing to receive an initiation acknowledgement message in a predetermined amount of time, waits until a later time to transmit the data packet.

38. A method of transmitting a data packet from a first communication device to a second communication device:

receiving scheduling data from the second communication device at the first communication device;

predicting, using the scheduling data and a shared pseudorandom number generator, a time at which the second communication device is available to receive data packets;

transmitting a data packet to the second communication device at about the predicted time.