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.