Reduced power synchronization of wireless devices
View Patent ↗Synchronizing at least one wireless sensor includes sending at least one reference message along with a request for acquired data from an access point to the at least one wireless sensor, where the reference message includes a first timestamp indicating when the reference message was sent according to time of a clock of the access point, receiving from the at least one wireless sensor a response that includes the requested data, the first timestamp, and at least one other timestamp corresponding to time of a clock of the at least one wireless sensor, and determining a relative clock offset of the at least one wireless sensor using the timestamps.
1. A method of synchronizing at least one wireless sensor of a plurality of wireless sensors, comprising:
sending at least one reference message along with a request for acquired data from an access point to the at least one wireless sensor of the plurality of wireless sensors, wherein the reference message includes a first timestamp indicating when the reference message was sent according to time of a clock of the access point, and wherein each of the plurality of wireless sensors collects data in synchronization with other of the plurality of wireless sensors;
receiving from the at least one wireless sensor a response that includes the requested data, the first timestamp, and at least one other timestamp corresponding to time of a clock of the at least one wireless sensor;
determining a relative clock offset of the at least one wireless sensor using the timestamps; and
discarding data from at least one of the plurality of wireless sensors that does not correspond to data from other ones of the plurality of wireless sensors, wherein discarding data includes determining a latest start time for data collection for all of the plurality of wireless sensors and determining an earliest end time for all of the plurality of wireless sensors and discarding data that is prior to the latest start time and after the earliest end time.
2. The method according to claim 1 , wherein the at least one other timestamp includes a second timestamp corresponding to time of the clock of the at least one wireless sensor when the reference message is received by the at least one wireless sensor and a third timestamp corresponding to time of the clock of the at least one wireless sensor when the response is sent.
3. The method according to claim 1 , wherein determining a relative clock offset includes using a fourth timestamp corresponding to when the response was received according to time of the clock of the access point.
4. The method according to claim 1 , further comprising:
providing to at least one of the wireless sensors a command to acquire data.
5. The method according to claim 4 , wherein the command is provided in connection with sending the at least one reference message.
6. The method according to claim 1 , further comprising:
sending at least one other reference message having a timestamp indicating when the reference message was sent according to time of the clock of the access point, wherein the reference message does not include a request for data.
7. The method according to claim 6 , wherein the at least one other reference message is sent after sending the reference message that includes the request for data.
8. A non-transitory computer-readable medium storing software that synchronizes at least one wireless sensor of a plurality of wireless sensors, the software comprising:
executable code that sends at least one reference message along with a request for acquired data from an access point to the at least one wireless sensor of the plurality of wireless sensors, wherein the reference message includes a first timestamp indicating when the reference message was sent according to time of a clock of the access point, and wherein each of the plurality of wireless sensors collects data in synchronization with other of the plurality of wireless sensors;
executable code that receives from the at least one wireless sensor a response that includes the requested data, the first timestamp, and at least one other timestamp corresponding to time of a clock of the at least one wireless sensor;
executable code that determines a relative clock offset of the at least one wireless sensor using the timestamps; and
executable code that discards data from at least one of the plurality of wireless sensors that does not correspond to data from other ones of the plurality of wireless sensors, wherein discarding data includes determining a latest start time for data collection for all of the plurality of wireless sensors and determining an earliest end time for all of the plurality of wireless sensors and discarding data that is prior to the latest start time and after the earliest end time.
9. The non-transitory computer-readable medium according to claim 8 , wherein the at least one other timestamp includes a second timestamp corresponding to time of the clock of the at least one wireless sensor when the reference message is received by the at least one wireless sensor and a third timestamp corresponding to time of the clock of the at least one wireless sensor when the response is sent.
10. The non-transitory computer-readable medium according to claim 8 , wherein determining a relative clock offset includes using a fourth timestamp corresponding to when the response was received according to time of the clock of the access point.
11. The non-transitory computer-readable medium according to claim 8 , wherein the software further comprises:
executable code that provides to at least one of the wireless sensors a command to acquire data.
12. The non-transitory computer-readable medium according to claim 11 , wherein the command is provided in connection with sending the at least one reference message.
13. The non-transitory computer-readable medium according to claim 8 , wherein the software further comprises:
executable code that sends at least one other reference message having a timestamp indicating when the reference message was sent according to time of the clock of the access point, wherein the reference message does not include a request for data.
14. The non-transitory computer-readable medium according to claim 13 , wherein the at least one other reference message is sent after sending the reference message that includes the request for data.