Power efficient communications

1. A method of power-efficient communications, comprising:

determining available output power of an energy harvesting electrical power source;

drawing power using a data processing apparatus from the energy harvesting electrical power source and performing by the data processing apparatus one or more of:

transmitting data at a data transmission rate determined, at least in part, by the available output power of the energy harvesting electrical power source, the transmitting data configured to enable a ratio of peak-to-average power consumption of available output power from the energy harvesting electrical power source used in transmitting data to be minimized and to enable energy consumption of the available output power from the energy harvesting electrical power source to be maximized per unit time; and

receiving data at a data reception rate determined, at least in part, by the available output power, the receiving data configured to enable a ratio of peak-to-average power consumption of the available output power from the energy harvesting electrical power source used in receiving data to be minimized and to enable energy consumption of the available output power of the energy harvesting electrical power source to be maximized per unit time.

2. The method of claim 1 , further comprising:

minimizing a ratio of peak-to-average power consumed in transmitting the data in order to maximize a portion of the available output power usable to transmit data.

3. The method of claim 2 , where minimizing the ratio of peak-to-average power provides for one or more of:

increasing one or more of the data transmission rate and a transmission range;

increasing one or more of the data reception rate and a reception range; and

reducing power consumption of a transmitter of the data processing apparatus that transmits the data.

4. The method of claim 3 , further comprising one or more of:

increasing the data transmission rate of a transmitter; and

increasing a transmission range of the transmitter.

5. The method of claim 3 , where minimizing the ratio of peak-to-average power provides for increasing a reception range of a receiver that receives the data and further comprising:

reducing power consumption of the receiver.

6. The method of claim 5 , further comprising:

controlling a reception range of the receiver by selectively turning on a low noise amplifier (LNA) of the receiver to increase the reception range of the receiver.

7. The method of claim 3 , where minimizing the ratio of peak-to-average power further comprises reducing power used by a receiver to receive the data.

8. The method of claim 7 , further comprising one or more of:

increasing the data reception rate of receiver, and

increasing a reception range of the receiver.

9. The method of claim 8 , further comprising:

selectively turning on a low noise amplifier (LNA) of the receiver to increase the reception range of the receiver.

10. The method of claim 7 , where reducing power used by the receiver to receive the data further comprises one or more of:

selectively controlling operation of the receiver to minimize the ratio of peak-to-average power used by a synthesizer and a transmit signal path of the receiver during a receive period of the receiver; and

selectively controlling operation of a microcomputer and the receiver to minimize the ratio of peak-to-average power used by the microcomputer and the receiver.

11. The method of claim 10 , the method further comprising:

the receiver waking up from a receiver sleep mode and receiving a data packet while

the microcomputer is in a microcomputer sleep mode;

the receiver placing the received data packet in a receive buffer of the receiver;

the receiver going into a receiver sleep mode;

the microcomputer waking up and processing the received data packet; and

the microcomputer going into the microcomputer sleep mode.

12. The method of claim 3 , where reducing the power consumption of the transmitter to transmit the data further comprises one or more of:

selectively controlling operation of the transmitter to minimize the ratio of peak-to-average power used by a synthesizer and a transmit signal path of the transmitter during a transmit period of the transmitter; and

selectively controlling operation of a microcomputer and the transmitter to minimize the ratio of peak-to-average power used by the microcomputer and the transmitter.

13. The method of claim 12 , further comprising:

the microcomputer placing a prepared data packet in a transmit buffer of the transmitter while the transmitter is in a transmitter sleep mode;

the microcomputer going into a microcomputer sleep mode;

the transmitter waking up and transmitting the prepared data packet in the transmit buffer; and

following transmittal of the prepared data packet, the transmitter going into the transmitter sleep mode.

14. The method of claim 1 , further comprising:

determining the data reception rate of data transmitted by a first network device and received by a second network device; and

estimating a range between said first and second network devices from the data reception rate.

15. The method of claim 14 , further comprising:

determining the range between said first and second network devices from an estimated transmit power of the first network device.

16. The method of claim 14 , where an RSSI value is not needed to estimate the range.

17. The method of claim 1 , where determining available output power of the energy harvesting electrical power source comprises predicting a future value of the available output power of the electrical power source.

18. The method of claim 17 , further comprising prior to transmitting data:

changing one or more of the transmit power of a transmitter and a data transmission rate of the transmitter in accordance with the predicted future value of the available output power of the energy harvesting electrical power source.

19. The method of claim 18 , further comprising:

notifying a receiver of the data processing apparatus of the changed data transmission rate of the transmitter.

20. The method of claim 17 , where predicting a future value of the available output power of the energy harvesting electrical power source further comprises one or more of:

using a plurality of prior values of the available output power of the energy harvesting electrical power source; and

using a predictive algorithm having one or more of a curve-fitting technique, a linear extrapolation, a non-linear extrapolation, and a heuristic.

21. The method of claim 20 , where in accordance with the predictive algorithm, further comprising:

a transmitter of the data processing apparatus collecting at a plurality of times T-n the available output power P-n of the energy harvesting electrical power source;

determining a linear rate of change m of the available output power in accordance with

m

=

(

P

0

-

P

-

1

)

(

T

0

-

T

-

1

)

⁢

W

⁢

/

⁢

s

(

1

)

selecting a time T 1 to determine a predicted change in the available output power; and

estimating at time T 0 the available output power P 1 available at time T 1 in accordance with

P 1 =m ( T 1 −T 0 ) +P 0 W.

22. The method of claim 1 , further comprising optimizing the data transmission rate over a communication link, comprising:

transmitting a plurality of consecutive data packets over the communication link at a test data transmission rate;

determining whether each data packet of the plurality of consecutive data packets was successfully transmitted at the test data transmission rate;

if each data packet of the plurality of consecutive data packets were successfully transmitted at the test data transmission rate, increasing the test data transmission rate by a predetermined multiplier to an increased test data transmission rate if the test data transmission rate is not a maximum data transmission rate of the communication link; and

if one or more of the data packets of the plurality of consecutive data packets were not successfully transmitted at the test data transmission rate, then upon determination that a first data packet of the one or more of the data packets of the plurality of consecutive data packets was not successfully transmitted reducing the test data transmission rate by a predetermined divider to a reduced test data transmission rate and transmitting the first data packet of the one or more data packets of the plurality of consecutive data packets at the reduced test data transmission rate.

23. The method of claim 22 , where determining whether the plurality of consecutive data packets were successfully transmitted comprises determining whether an acknowledge message is received for each data packet of the plurality of consecutive data packets transmitted.

24. The method of claim 22 , further comprising prior to the transmitting the plurality of data packets over the communication link:

determining a maximum data transmission rate of the communication link; and

transmitting the plurality of data packets over the communication link at the maximum determined data transmission rate.

25. The method of claim 1 , further comprising:

the data processing apparatus drawing from the energy harvesting electrical power source no more than a present power sourcing ability of the energy harvesting electrical power source.

26. The method of claim 1 , further comprising:

monitoring the energy harvesting electrical power source to determine a present power sourcing ability of the energy harvesting electrical power source.