Energy efficient forwarding in ad-hoc wireless networks

• US 7,020,501 B1
• Filed: 11/30/2001
• Issued: 03/28/2006
• Est. Priority Date: 11/30/2001
• Status: Expired due to Term

• Current Assignee: III Holdings 1, LLC (Intellectual Ventures LLC)
• Original Assignee: BBNT Solutions LLC (Rtx Corporation)
• Inventors: Elliott, Brig Barnum, Pearson, David Spencer
• Primary Examiner(s): Feild, Joseph
• Assistant Examiner(s): PEREZ, JULIO R
• Application Number:
  US09/998,946
• Time in Patent Office: 1,579 Days
• Field of Search: 455/574, 455/13.4, 455/343.1, 455/343.4, 455/426, 455/435.2, 455/52, 455/552, 455/554, 455/554.1, 455/555, 370/338
• US Class Current: 455/574
• 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 52/0216 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

A system for conserving energy in a multi-node network (110) includes nodes (205) configured to organize themselves into tiers (305, 310, 315). The nodes (205) are further configured to produce a transmit/receive schedule at a first tier (310) in the network (110) and control the powering-on and powering-off of transmitters and receivers in nodes (205) in a tier adjacent (315) to the first tier (310) according to the transmit/receive schedule.

Claims

1. A method of conserving energy in a node in a wireless network, comprising:

receiving, at the node, a first powering-on schedule from another node in the network;

selectively powering-on at least one of a transmitter and receiver based on the received first schedule;

producing a second powering-on schedule based on the first powering-on schedule; and

transmitting the second powering-on schedule from the node to other nodes in the network when the transmitter is in a powered-on state.

2. The method of claim 1, wherein the wireless network comprises an ad-hoc, multi-node wireless network.

3. The method of claim 1, wherein the wireless network comprises a wireless sensor network.

4. A node in a wireless network, comprising:

a transmitter;

a receiver configured to receive a powering-on schedule from another node in the network; and

a processing unit configured to;

selectively power-on at least one of the transmitter and receiver based on the received powering-on schedule,

produce a second powering-on schedule based on the first powering-on schedule, and

transmit the second powering-on schedule to other nodes in the wireless network when the transmitter is in a powered-on state.

5. A computer-readable medium containing instructions for controlling at least one processor to perform a method of conserving energy in a node in a wireless network, the method comprising:

receiving, at the node, a powering-on schedule from another node in the network;

selectively powering-on at least one of a transmitter and receiver based on the received schedule;

producing a second powering-on schedule based on the first powering-on schedule; and

transmitting the second powering-on schedule from the node to other nodes in the network when the transmitter is in a powered-on state.

6. A method of conveying messages in a sensor network, comprising:

organizing a sensor network into a hierarchy of tiers;

transmitting one or more transmit/receive scheduling messages throughout the network; and

transmitting and receiving data messages between nodes in adjacent tiers based on the one or more transmit/receive scheduling messages,

wherein at least one sensor node in a tier of the network receives data messages from sensor nodes in a higher tier and forwards the data messages to a sensor node in a lower tier.

7. The method of claim 6, wherein the transmit/receive scheduling messages comprise time schedules for powering-on and powering-off transmitters and receivers at each of the nodes in the adjacent tiers.

8. The method of claim 6, wherein a destination of the data messages comprises at least one data collection point.

9. The method of claim 8, wherein the at least one data collection point resides in a lowest tier of the network.

10. A method of conserving power at a first node in a network, wherein the first node is an intermediate node on a path between one or more other nodes and a second node, the method comprising:

powering-on, at the first node, a receiver to listen for a scheduling message;

receiving the scheduling message from the second node in the network, wherein the scheduling message specifies a first communication schedule that indicates times at which the first and second nodes may communicate with one another and a second communication schedule that indicates times at which the first node may communicate with each of the one or more other nodes; and

selectively powering-on and powering-off the receiver and a transmitter based on the first and second communication schedules.

11. The method of claim 10, further comprising:

organizing the first node, second node, and one or more other nodes in the network into a hierarchy of tiers.

12. The method of claim 11, further comprising:

transmitting data messages to the one or more nodes in a lower tier of the network when the transmitter is powered-on.

13. The method of claim 11, further comprising:

transmitting scheduling messages to the second node in a higher tier of the network when the transmitter is powered-on.

14. A first node on a path between one or more other nodes and a second node in an ad-hoc, wireless network, comprising:

a transmitter;

a receiver configured to receive a scheduling message from the second node in the network, wherein the scheduling message specifies a first communication schedule that indicates times at which the first and second nodes may communicate with one another and a second communication schedule that indicates times at which the first node may communicate with each of the one or more other nodes; and

a processing unit configured to;

power-on the receiver to listen for the scheduling message, and

subsequent to receipt of the scheduling message, selectively power-on and power-off the receiver and the transmitter based on the first and second communication schedules.

15. A computer-readable medium containing instructions for controlling at least one processor to perform a method of conserving power at a first node on a path between one or more other nodes and a second node in a network, the method comprising:

powering-on a receiver to listen for a scheduling message;

receiving the scheduling message from the second node, wherein the scheduling message specifies a first communication schedule that indicates times at which the first and second nodes may communicate with one another and a second communication schedule that indicates times at which the first node may communicate with each of the one or more other nodes; and

selectively powering-on and powering-off the receiver and a transmitter based on the first and second communication schedules.

16. A data structure encoded on a computer-readable medium, comprising:

first data comprising identifiers of sensor nodes affiliated with a parent node in a network; and

second data comprising a first time schedule for transmitting messages from the parent node to the affiliated sensor nodes and a second time schedule for receiving messages at the parent node from each of the affiliated sensor nodes.

17. The data structure of claim 16, further comprising:

third data comprising a third time schedule allocating times for the affiliated sensor nodes to transmit to, and receive messages from, other sensor nodes in the sensor network.

18. The data structure of claim 16, further comprising:

third data comprising an identifier for the parent node.

19. A method, comprising:

receiving messages, at a first node, from neighboring nodes in a network notifying the first node of the neighboring nodes'"'"' presence in the network;

determining a first communication schedule that indicates times for communicating with each of the neighboring nodes;

determining a second communication schedule that indicates times for each of the neighboring nodes to communicate with other nodes in the network; and

transmitting a message to each of the neighboring nodes, wherein the message includes the first communication schedule and the second communication schedule.