Power management for audience measurement meters

1. A method comprising:

monitoring, using a processor, an activation state of a media presentation device; and

controlling, using the processor, activation of an audience measurement meter different from the media presentation device based on the monitored activation state of the media presentation device, the audience measurement meter to monitor the media presentation device when the activation state is an active state, the controlling comprising:

in response to determining that the media presentation device has been active during at least a portion of a time interval prior to a first time, (1) sending a wake-up signal to activate the audience measurement meter and (2) interrogating the audience measurement meter to obtain audience measurement data associated with the time interval prior to the first time; and

in response to determining that the media presentation device has been inactive over the time interval prior to the first time, determining that interrogation of the audience measurement meter to obtain audience measurement data associated with the time interval prior to the first time is to be skipped.

2. A method as defined in claim 1 wherein monitoring the activation state of the media presentation device comprises:

measuring power consumption of the media presentation device;

determining that the activation state is the active state when the measured power consumption exhibits a positive slope change; and

determining that the activation state is an inactive state when the measured power consumption exhibits a negative slope change.

3. A method as defined in claim 1 wherein monitoring the activation state of the media presentation device comprises:

monitoring an audio output of the media presentation device;

determining that the activation state is the active state when an audio signal is detected at the monitored audio output; and

determining that the activation state is an inactive state when no audio signal is detected at the monitored audio output.

4. A method as defined in claim 1 wherein controlling the activation of the audience measurement meter further comprises:

sending the wake-up signal to the audience measurement meter in response to determining that the media presentation device is in the active state; and

sending a sleep signal to the audience measurement meter in response to determining that the media presentation device is in an inactive state.

5. A method as defined in claim 4 further comprising:

setting the audience measurement meter to an enabled state in response to receiving the wake-up signal, the wake-up signal being communicated via at least one of a wired local area network (LAN), a wireless LAN, a universal serial bus (USB) or an input/output (I/O) pin; and

setting the audience measurement meter to a sleep state in response to receiving the sleep signal, the sleep signal being communicated via at least one of the wired LAN, the wireless LAN, the USB or the I/O pin.

6. A method as defined in claim 1 further comprising:

sending a sleep signal to the audience measurement meter after the audience measurement data is obtained.

7. A method comprising:

measuring, using a processor, power consumption of a media presentation device;

determining, using the processor, that an activation state of the media presentation device is an active state when the measured power consumption is greater than a first threshold;

determining, using the processor, that the activation state is an inactive state when the measured power consumption is less than a second threshold different from the first threshold; and

controlling, using the processor, activation of an audience measurement meter based on the monitored activation state of the media presentation device, the audience measurement meter to monitor the media presentation device when the activation state is the active state.

8. A tangible computer readable medium comprising machine readable instructions which, when executed, cause a machine to at least:

monitor an activation state of a media presentation device;

control activation of an audience measurement meter different from the media presentation device based on the monitored activation state of the media presentation device, the audience measurement meter to monitor the media presentation device when the activation state is an active state;

in response to the media presentation device having been active during at least a portion of a time interval prior to a first time, (1) send a wake-up signal to activate the audience measurement meter and (2) interrogate the audience measurement meter to obtain audience measurement data associated with the time interval prior to the first time; and

in response to the media presentation device having been inactive over the time interval prior to the first time, determine that interrogation of the audience measurement meter to obtain audience measurement data associated with the time interval prior to the first time is to be skipped.

9. A tangible computer readable medium as defined in claim 8 wherein to monitor the activation state of the media presentation device, the machine readable instructions, when executed, further cause the machine to:

measure power consumption of the media presentation device;

determine that the activation state is the active state when the measured power consumption is greater than a first threshold; and

determine that the activation state is an inactive state when the measured power consumption is less than at least one of the first threshold or a second threshold.

10. A tangible computer readable medium as defined in claim 8 wherein to monitor the activation state of the media presentation device, the machine readable instructions, when executed, further cause the machine to:

monitor an audio output of the media presentation device;

determine that the activation state is the active state when an audio signal is detected at the monitored audio output; and

determine that the activation state is an inactive state when no audio signal is detected at the monitored audio output.

11. A tangible computer readable medium as defined in claim 8 wherein to control the activation of the audience measurement meter, the machine readable instructions, when executed, further cause the machine to:

send the wake-up signal to the audience measurement meter in response to determining that the media presentation device is in the active state; and

send a sleep signal to the audience measurement meter in response to determining that the media presentation device is in an inactive state.

12. A tangible computer readable medium as defined in claim 11 wherein the machine readable instructions, when executed, further cause the machine to:

set the audience measurement meter to an enabled state in response to receiving the wake-up signal, the wake-up signal being communicated via at least one of a wired local area network (LAN), a wireless LAN, a universal serial bus (USB) or an input/output (I/O) pin; and

set the audience measurement meter to a sleep state in response to receiving the sleep signal, the sleep signal being communicated via at least one of the wired LAN, the wireless LAN, the USB or the I/O pin.

13. A tangible computer readable medium as defined in claim 8 wherein the machine readable instructions, when executed, further cause the machine to:

determine whether the media presentation device has been inactive over the time interval prior to the first time.

14. A tangible computer readable medium as defined in claim 8 wherein the machine readable instructions, when executed, further cause the machine to:

send a sleep signal to the audience measurement meter after the audience measurement data is obtained.

15. An apparatus comprising:

a state monitor to monitor an activation state of a media presentation device; and

a processor to:

control activation of an audience measurement meter different from the media presentation device based on the monitored activation state of the media presentation device, the audience measurement meter to monitor the media presentation device when the activation state is an active state;

in response to the media presentation device having been active during at least a portion of a time interval prior to a first time, (1) send a wake-up signal to activate the audience measurement meter and (2) interrogate the audience measurement meter to obtain audience measurement data associated with the time interval prior to the first time; and

in response to the media presentation device having been inactive over the time interval prior to the first time, determine that interrogation of the audience measurement meter to obtain audience measurement data associated with the time interval prior to the first time is to be skipped.

16. An apparatus as defined in claim 15 wherein to monitor the activation state of the media presentation device, the state monitor is to:

measure power consumption of the media presentation device;

determine that the activation state is the active state when the measured power consumption is greater than a first threshold; and

determine that the activation state is an inactive state when the measured power consumption is less than at least one of the first threshold or a second threshold.

17. An apparatus as defined in claim 15 wherein to monitor the activation state of the media presentation device, the state monitor is to:

monitor an audio output of the media presentation device;

determine that the activation state is the active state when an audio signal is detected at the monitored audio output; and

determine that the activation state is an inactive state when no audio signal is detected at the monitored audio output.

18. An apparatus as defined in claim 15 wherein to control activation of the audience measurement meter, the processor is to:

send the wake-up signal to the audience measurement meter in response to determining that the media presentation device is in an active state; and

send a sleep signal to the audience measurement meter in response to determining that the media presentation device is in an inactive state.

19. An apparatus as defined in claim 18 wherein the processor is further to:

set the audience measurement meter to an enabled state in response to receiving the wake-up signal, the wake-up signal being communicated via at least one of a wired local area network (LAN), a wireless LAN, a universal serial bus (USB) or an input/output (I/O) pin; and

set the audience measurement meter to a sleep state in response to receiving the sleep signal, the sleep signal being communicated via at least one of the wired LAN, the wireless LAN, the USB or the I/O pin.

20. An apparatus as defined in claim 15 wherein the processor is further to:

determine whether the media presentation device has been inactive over the time interval prior to the first time.

21. An apparatus as defined in claim 15 wherein the processor is further to:

send a sleep signal to the audience measurement meter after the audience measurement data is obtained.