COMMUNICATION PROTOCOL FOR ENERGY-HARVESTING DEVICES

• US 20130121176A1
• Filed: 11/16/2011
• Published: 05/16/2013
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Addepalli, Sateesh K., Vasseur, Jean-Philippe, Sudhaakar, Raghuram S.
• Granted Patent: US 9,313,275 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H05B 47/19 via wireless transmission

Abstract

In one embodiment, an energy-harvesting communication device of a communication network accumulates energy, e.g., electromagnetic energy. Upon detecting that the accumulated energy surpasses a sufficient threshold, the communication device may transmit a message into the communication network using the accumulated energy as an unreliable and unsynchronized broadcast transmission to any available receiver within the communication network.

Claims

1. A method, comprising:

accumulating energy at an energy-harvesting communication device of a communication network;

detecting when the accumulated energy surpasses a sufficient threshold; and

in response to the accumulated energy surpassing the sufficient threshold, transmitting, using the accumulated energy, a message from the device into the communication network as an unreliable and unsynchronized broadcast transmission to any available receiver within the communication network.

2. The method as in claim 1, further comprising:

determining, prior to transmitting, whether to transmit the message; and

in response to determining not to transmit, activating a receiver mode on the communication device to listen for and correspondingly relay received transmissions from within the communication network.

3. The method as in claim 2, further comprising:

preventing the communication device from expending the accumulated energy below the sufficient threshold while in the receiver mode.

4. The method as in claim 2, further comprising:

listening periodically for received transmissions during receiver mode.

5. The method as in claim 1, further comprising:

applying a random back-off timer to transmitting the message.

6. The method as in claim 1, wherein transmitting the message comprises:

transmitting a plurality of copies of the message, each copy separated by a random back-off time.

7. The method as in claim 1, further comprising:

delaying at least a minimum amount of time between message transmissions.

8. The method as in claim 1, further comprising:

in response to the accumulated energy surpassing the sufficient threshold, measuring a sensed value by the communication device, wherein the message contains the sensed value.

9. The method as in claim 8, further comprising:

deferring transmitting the message until a sufficient change to the sensed value occurs.

10. The method as in claim 1, wherein transmitting comprises:

including a specific device destination address in the transmitted message.

11. The method as in claim 1, further comprising:

receiving a directive to activate a receiver mode on the communication device, wherein the communication device has an auxiliary power supply in addition to the accumulated energy; and

in response

activating the receiver mode on the communication device to listen for and correspondingly relay received transmissions from within the communication network.

12. The method as in claim 1, wherein accumulating energy comprises:

harvesting electromagnetic energy.

13. An apparatus, comprising:

energy-harvesting circuitry configured to accumulate energy;

one or more network interfaces to communicate within a communication network;

a processor coupled to the network interfaces and adapted to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

detect when the accumulated energy surpasses a sufficient threshold; and

in response to the accumulated energy surpassing the sufficient threshold, transmit a message into the communication network using the accumulated energy, the message transmitted as an unreliable and unsynchronized broadcast transmission to any available receiver within the communication network.

14. The apparatus as in claim 13, wherein the process when executed is further operable to:

determine, prior to transmitting, whether to transmit the message; and

activate a receiver mode on the communication device to listen for and correspondingly relay received transmissions from within the communication network in response to determining not to transmit.

15. The apparatus as in claim 14, wherein the process when executed is further operable to:

prevent expenditure of the accumulated energy below the sufficient threshold while in the receiver mode.

16. The apparatus as in claim 13, wherein the process when executed to transmit the message is further operable to:

transmit a plurality of copies of the message, each copy separated by a random back-off time.

17. The apparatus as in claim 13, further comprising:

sensor circuitry configured to measure a sensed value; and

wherein the process when executed is further operable to;

measure a sensed value with the sensor circuitry in response to the accumulated energy surpassing the sufficient threshold, wherein the message contains the sensed value.

18. The apparatus as in claim 13, further comprising:

an auxiliary power supply in addition to the accumulated energy and;

wherein the process when executed is further operable to;

receive a directive to activate a receiver mode; and

in response

activate the receiver mode to listen for and correspondingly relay received transmissions from within the communication network.

19. The apparatus as in claim 13, wherein the energy-harvesting circuitry comprises electromagnetic energy harvesting circuitry.

20. The apparatus as in claim 19, wherein the electromagnetic energy harvesting circuitry comprises a self-tunable tank circuit adapted to accumulate energy from electromagnetic fields.

21. The apparatus as in claim 20, wherein the self-tunable tank circuit comprises a super-capacitor arranged in a charge pump configuration.

22. A tangible, non-transitory, computer-readable media having software encoded thereon, the software, when executed by a processor on an energy-harvesting communication device, operable to:

detect when accumulated energy at the energy-harvesting communication device surpasses a sufficient threshold; and

in response to the accumulated energy surpassing the sufficient threshold, transmit a message into the communication network using the accumulated energy, the message transmitted as an unreliable and unsynchronized broadcast transmission to any available receiver within the communication network.

23. The computer-readable media as in claim 22, wherein the software when executed is further operable to:

determine, prior to transmitting, whether to transmit the message; and

activate a receiver mode to listen for and correspondingly relay received transmissions from within the communication network in response to determining not to transmit.

24. The computer-readable media as in claim 22, wherein the software when executed is further operable to:

measure a sensed value in response to the accumulated energy surpassing the sufficient threshold, wherein the message contains the sensed value.