Methods and apparatus for using received signal strength information in a wireless system
Methods and apparatus for processing and using signals transmitted by a device, e.g., a low cost beacon transmitter device, to facilitate making location determinations with regard to the transmitting device and/or making a decision of when or how to use location information generated based on received signals are described. In accordance with some features the processing performed on the received signal strength measurements is based on whether or not the device from which the signals are received is in motion. The size of a sample period used as a processing window when determining device location is based, in some embodiments, on the rate of motion. When and/or how to use location determinations are performed is also based on motion in some embodiments. Machine learning updates of location determination parameters, based on received signals, are disabled when the signals are from devices determined to be in motion.
1. A method comprising:
determining a measure of motion of a wireless device by determining one or more signal strength values of one or more signals from the wireless device;
determining a duration of a time period for the determined signal strength values of the one or more signals, wherein the duration of the time period is based on the measure of motion;
computing a measure of a location of the wireless device based on the determined signal strength values of the one or more signals corresponding to the determined duration of the time period; and
communicating the computed measure of a location to a computing device to indicate the location of the wireless device.
2. The method of claim 1 , wherein determining the duration of the time period further comprises at least one of:
setting the duration of the time period to a first duration based on determining that the wireless device is not in motion; or
setting the duration of the time period to a second duration based on determining that the wireless device is in motion, wherein the second duration is shorter than the first duration.
3. The method of claim 2 , wherein computing the measure of the location of the wireless device comprises at least one of:
based on setting the duration of the time period to the first duration, determining the measure of the location of the wireless device based on a first number of determined signal strength values of the one or more signals received during the first duration; or
based on setting the duration of the time period to the second duration, determining the measure of the location of the wireless device based on a second number of determined signal strength values of the one or more signals received during the second duration, wherein the second number of determined signal strength values is comparatively less than the first number of determined signal strength values.
4. The method of claim 1 , wherein determining the measure of motion comprises:
measuring a rate of change of the determined signal strength values of the one or more signals;
determining, based on determining that the rate of change of the determined signal strength values of the one or more signals is below a first threshold, the wireless device is not in motion;
determining, based on determining that the rate of change of the determined signal strength values of the one or more signals is above the first threshold and below a second threshold, the wireless device is in motion at a first rate of motion; and
determining, based on determining that the rate of change of the determined signal strength values of the one or more signals is above the second threshold, the wireless device is in motion at a second rate of motion, wherein the second rate of motion is a faster rate of motion than the first rate of motion.
5. The method of claim 4 , further comprising:
conditionally updating a machine learning model based on the determined measure of motion.
6. The method of claim 5 , wherein conditionally updating the machine learning model further comprises inhibiting an update to the machine learning model based on determining that the wireless device is not in motion.
7. The method of claim 1 , wherein determining the duration of the time period for the determined signal strength values further comprises determining a signal strength averaging window, wherein the signal strength averaging window is based on the measure of motion.
8. The method of claim 7 , wherein determining the signal strength averaging window comprises at least one of:
determining a first signal strength averaging window based on determining that the wireless device is not in motion; or
determining a second signal strength averaging window based on determining that the wireless device is in motion, wherein the second signal strength averaging window includes comparatively fewer number of time slots than the first signal strength averaging window.
9. The method of claim 7 , wherein the signal strength averaging window includes one or more time slots, and wherein each time slot of the one or more time slots includes a measure of signal strength deviation during the respective time slot.
10. A system, comprising:
memory; and
one or more programmable processors in communication with the memory, and configured to:
determine a measure of motion of a wireless device by determining one or more signal strength values of one or more signals from the wireless device;
determine a duration over a time period for the determined signal strength values of the one or more signals, wherein the duration of the time of the time period is based on the measure of motion;
compute a measure of a location of the wireless device based on the determined signal strength values of the one or more signals corresponding to the determined duration of the time period; and
communicate computed measure of a location to a computing device to indicate the location of the wireless device.
11. The system of claim 10 , wherein to determine the duration of a time period, the one or more programmable processors are further configured to perform at least one of:
set the duration of the time period to a first duration based on a determination that the wireless device is not in motion; or
set the duration of the time period to a second duration based on determining that the wireless device is in motion, wherein the second duration is shorter than the first duration.
12. The system of claim 11 , wherein to compute the measure of the location of the wireless device, the one or more programmable processors are further configured to perform at least one of:
based on setting the duration of the time period to the first duration, determine the measure of the location of the wireless device based on a first number of determined signal strength values of the one or more signals received during the first duration; or
based on setting the duration of the time period to the second duration, determine the measure of the location of the wireless device based on a second number of determined signal strength values of the one or more signals received during the second duration, wherein the second number of determined signal strength values is comparatively less than the first number of determined signal strength values.
13. The system of claim 10 , wherein the one or more programmable processors are further configured to:
measure a rate of change of the determined signal strength values of the one or more signals;
determine, based on determining that the rate of change of the determined signal strength values of the one or more signals is below a first threshold, the wireless device is not in motion; and
determine, based on determining that the rate of change of the determined signal strength values of the one or more signals is above the first threshold and below a second threshold, the wireless device is in motion at a first rate of motion; and
determine, based on determining that the rate of change of the determined signal strength values of the one or more signals is above the second threshold, the wireless device is in motion at a second rate of motion, wherein the second rate of motion is a faster rate of motion than the first rate of motion.
14. The system of claim 13 , wherein the one or more programmable processors are further configured to:
conditionally update a machine learning model based on the determined measure of motion.
15. The system of claim 14 , wherein to conditionally update the machine learning model, the one or more programmable processors are further configured to:
inhibit an update to the machine learning model based on determining that the wireless device is not in motion.
16. The system of claim 10 , wherein to determine the duration of the time period for the determined signal strength values, the one or more programmable processors are further configured to determine a signal strength averaging window, wherein the signal strength averaging window is based on the measure of motion.
17. The system of claim 16 , wherein to determine the signal strength averaging window, the one or more programmable processors are further configured to perform one of:
determine a first signal strength averaging window based on determining that the wireless device is not in motion; or
determine a second signal strength averaging window based on determining that the wireless device is in motion, wherein the second signal strength averaging window includes comparatively fewer time slots than the first signal strength averaging window.
18. The system of claim 17 , wherein the signal strength averaging window includes one or more time slots, and wherein each time slot of the one or more time slots includes a measure of signal strength deviation during the respective time slot.
19. Non-transitory computer-readable storage media comprising instructions that, when executed, cause one or more processors to:
determine a measure of motion of a wireless device by determining one or more signal strength values of one or more signals from the wireless device;
determine a duration over a time period for the determined signal strength values of the one or more signals, wherein the duration of the time period is based on the measure of motion;
compute a measure of a location of the wireless device based on the determined signal strength values of the one or more signals corresponding to the determined duration of the time period; and
communicate the measure of a location to a computing device to indicate the location of the wireless device.
20. The non-transitory computer-readable storage media of claim 19 , wherein to determine the duration of the time period the instructions further cause the one or more processors to perform at least one of:
set the duration of the time period to a first duration based on determining that the wireless device is not in motion; or
set the duration of the time period to a second duration based on determining that the wireless device is not in motion, wherein the second duration is shorter than the first duration.