CPC G06Q 10/0833 (2013.01) | 11 Claims |
1. A tracking device comprising:
a first antenna that transmits response signals in a first frequency band; and
a transmission module that modulates a response signal for transmission in the first frequency band and outputs the modulated response signal to the first antenna for transmission in accordance with a communication protocol, the response signal including a message indicating a device identifier of the tracking device, wherein the transmission module includes a bulk acoustic wave reference oscillator that produces an output frequency, the bulk acoustic wave reference oscillator including a bulk acoustic wave delay reference, a time difference detector configured to detect an echo of the bulk acoustic wave delay reference, wherein the transmission module modulates the response signal such that the response signal has a carrier frequency based on the output frequency of the bulk acoustic wave reference oscillator.
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