Location aware device

摘要

A device having a signal module configured to transmit a first type of signal and a second type of signal and to receive the first type of signal and the second type of signal. The device also includes a timer and a controller configured to operate the signal module and timer. The controller is operable to determine a location of the device with respect to another device based upon the time elapsed between transmission and receipt of the first type of signal and transmission and receipt of the second type of signal.