Electronic shelf label (ESL) efficient reconnect
According to various aspects and techniques to enable methods and systems for a first communication device to determine an approximate number of other communication devices that have lost contact with a host communication device. This includes determining a common future time window using a last known global time stamp and determining a transmit time within the common future time window. This also includes receiving samples that are captured during the common future time window on a predefined communication channel, as well as analyzing the received samples to estimate the total number of other communication devices.
1. A method for a first communication device to determine an approximate number of other communication devices that have lost contact with a host communication device comprising:
determining a common future time window using a last known global time stamp;
determining a transmit time within the common future time window;
capturing received samples during the common future time window on a predefined communication channel; and
analyzing the received samples to estimate a total number of other communication devices that have lost contact with the host communication device.
2. The method of claim 1 , wherein the transmit time is uniformly distributed to fit within the common future time window.
3. The method of claim 1 , wherein the transmit time is selected to determine a plurality of un-connected communication devices based on a power-level profile of the received samples.
4. The method of claim 3 , wherein the plurality of un-connected communication devices represents a large number of un-connected communication devices.
5. The method of claim 1 , wherein analyzing the received samples excludes a time period when a communication device was transmitting.
6. The method of claim 1 , wherein analyzing the received samples includes determining a Received Signal Strength Indication (RSSI).
7. An apparatus for a first communication device to determine an approximate number of other communication devices that have lost contact with a host radio device comprising:
a processor for determining a common future time window using a last known global time stamp;
a transmitter and receiver for determining a transmit time within the common future time window;
a processor memory for capturing received samples during the common future time window on a predefined communication channel; and
an analyzer for analyzing the received samples to estimate a total number of other communication devices that have lost contact with the host radio device.
8. The apparatus of claim 7 , wherein the transmit time is uniformly distributed to fit within the common future time window.
9. The apparatus of claim 8 , wherein the transmit time is selected to determine a plurality of un-connected communication devices based on a power-level profile of the received samples.
10. The apparatus of claim 7 , wherein a number of un-connected communication devices represent a large number of un-connected radio devices.
11. The apparatus of claim 7 , wherein analyzing the received samples excludes a time period where a communication device was transmitting.
12. The apparatus of claim 7 , wherein analyzing the received samples includes determining a Received Signal Strength Indication (RSSI).
13. A communication device comprising:
means for determining a common future time window using a last known global time stamp;
means for determining a transmit time within the common future time window;
means for capturing received samples during the common future time window on a predefined communication channel; and
means for analyzing the received samples to estimate a total number of other communication devices that have lost contact with a host communication device.
14. A non-transitory computer-readable storage medium having computer-executable instructions recorded thereon, the computer-executable instructions configured to cause a communication device having one or more processors to:
determine a common future time window using a last known global time stamp;
determine a transmit time within the common future time window;
capture received samples during the common future time window on a predefined communication channel; and
analyze the received samples to estimate a total number of other communication devices that have lost contact with a host communication device.