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

• US 8,145,201 B2
• Filed: 05/22/2006
• Issued: 03/27/2012
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Raytheon BBN Technlogies Corp. (Rtx Corporation)
• Original Assignee: Raytheon BBN Technlogies Corp. (Rtx Corporation)
• Inventors: Redi, Jason Keith
• Primary Examiner(s): Eng, George
• Assistant Examiner(s): MANOHARAN, MUTHUSWAMY GANAPATHY
• Application Number:
  US11/439,320
• Publication Number:
  US 20060229083A1
• Time in Patent Office: 2,136 Days
• Field of Search: 370/338
• 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 52/0219 where the power saving management affects multiple 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

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. The communications control processor can also take into account requests for reserved bandwidth.

Claims

1. A method of reserving wireless communication bandwidth in an ad hoc network in which nodes are capable of routing data by forwarding data to other nodes in the network, the method comprising:

transmitting, by a first node to a plurality of receiving nodes, first scheduling data sufficient for a receiving node in the plurality of receiving nodes to predict times at which the first node will be available to receive wireless communications from the plurality of receiving nodes (“

receiving times”

); and

transmitting, by the first node to the plurality of receiving nodes, second scheduling data including an identified set of nodes, wherein the second scheduling data is sufficient for the receiving node to predict times reserved for communications from the identified set of nodes to the first node (“

reserved times”

), during which times;

(1) the receiving node can transmit to the first node only if the receiving node is in the identified set of nodes, and

(2) the receiving node can transmit to a node other than the first node only communications with a transmission range that is reduced in distance or limited in direction to reduce interference with wireless communications from the identified set of nodes to the first node;

thereby reserving times for nodes in the identified set of nodes to communicate with the first node, wherein the first node, the receiving node, and the nodes in the set of nodes share a common algorithm for predicting the receiving times and the reserved times based on the first and second scheduling data;

powering up a receiver of the first node during the receiving times, such that the first node can receive communications from one of the receiving nodes; and

fully powering down a receiver of the first node during times other than the receiving times, such that the first node does not receive communications via the receiver.

2. The method of claim 1, wherein the first node is in the set of nodes.

3. The method of claim 1, wherein the set of nodes includes only one node.

4. The method of claim 1, wherein the set of nodes includes a plurality of nodes.

5. The method of claim 4, wherein the set of nodes is defined by a network address mask.

6. The method of claim 1, wherein the common algorithm for predicting the receiving times and the reserved times is a pseudorandom number generator.

7. The method of claim 1, wherein the first scheduling data comprises a first value corresponding to the percentage of time that the first node will be available for receiving wireless communications.

8. The method of claim 7, wherein second scheduling data includes a second value corresponding to a percentage of time which is less than the first value.

9. The method of claim 8, wherein the common algorithm for predicting the receiving times and the reserved times is a pseudorandom number generator.

10. The method of claim 9, wherein the first node is available to receive wireless communications from only the set of nodes if the output of the pseudorandom number generator, using at least a portion of the first or second scheduling data as an input, is less than the second value.

11. The method of claim 9, wherein the first node is available to receive wireless communications from any node if the output of the pseudorandom number generator, using at least a portion of the first or second scheduling data as an input, is greater than the second value but less than the first value.

12. The method of claim 1, comprising:

transmitting by the first node a wireless communication to a third node requesting the third node to reserve bandwidth for receiving wireless communication from the first node.

13. The method of claim 1, comprising:

determining, by the first node, the second scheduling data based on a request to reserve a specified bandwidth for wireless transmission from nodes in the set of nodes.

14. A method of communication over an ad hoc network in which nodes are capable of routing data by forwarding data to other nodes in the network, the method comprising:

receiving at a first node first scheduling data from a second node sufficient for the first node to predict when the second node will be available to receive wireless communications from the first node (“

receiving times”

);

receiving at the first node second scheduling data including an identified set of nodes from the second node, wherein the second scheduling data is sufficient for the first node to determine times reserved for communication from the identified set of nodes to the second node (“

reserved times”

), during which times;

(1) the first node can transmit to the second node only if the first node is in the identified set of nodes, and

(2) the first node can transmit to a node other than the second node only wireless communications with a transmission range that is reduced in distance or limited in direction to reduce interference with wireless communications from the identified set of nodes to the second node, thereby reserving bandwidth of the second node to receive wireless communication from the identified set of nodes;

wherein the first node, the second node, and the nodes in the set of nodes share a common algorithm for predicting the times based on the first and second scheduling data;

transmitting, from the first node to the second node, a data packet during a reserved time determined based on the common algorithm; and

refraining from transmitting, from the first node to the second node, a data packet during times other than reserved times for the first node determined based on the common algorithm.

15. The method of claim 14, wherein the first scheduling data comprises a seed value for a pseudorandom number generator.

16. The method of claim 14, wherein the first scheduling data comprises a cycle state for generating an output from a pseudorandom number generator.

17. The method of claim 14, wherein the second scheduling data comprises a reservation threshold.

18. The method of claim 17, comprising comparing an output from a pseudorandom number generator, based at least in part on the scheduling data, with the reservation threshold.

19. The method of claim 18, comprising, in response to determining that the output of the pseudorandom number generator is less than the reservation threshold, transmitting a data packet from the first node to the second node.

20. The method of claim 18, comprising, in response to determining that the output of the pseudorandom number generator is greater than the reservation threshold, refraining from transmitting a data packet from the first node to the second node.

21. The method of claim 14, comprising transmitting a message at a reduced power level to avoid interfering with the second node receiving communications from a node in the set of nodes.

22. The method of claim 14, comprising transmitting via a directional antenna to avoid interfering with the second node receiving communications from a node in the set of nodes.

23. The method of claim 14, wherein the second scheduling data includes an identifier corresponding to the set of nodes allowed to transmit data packets during reserved time slots.

24. The method of claim 23, wherein the identifier comprises a network address mask.

25. The method of claim 23, wherein the identifier comprises one of a MAC address and an IP address.

26. The method of claim 14, further comprising powering up a receiver of the second node during the predicted times at which the second node will be available to receive wireless communications from the first node, such that the second node can receive communications from the first node.

27. The method of claim 14, further comprising powering down a receiver of the second node during times other than the predicted times at which the second node will be available to receive wireless communications from the first node, such that the second node cannot receive communications from the first node.