Patent ID: 7466266

Claim:
An apparatus comprising: a signal generator to generate an radio-frequency (RF) signal comprising a ranging signal comprising a component of a television signal; a wireless transmitter to wirelessly transmit the RF signal; and a self-check unit comprising a receiver to receive the RF signal, and to recover the ranging signal from the RF signal, a pseudorange circuit to determine a pseudorange based on the ranging signal, and a self-test circuit to generate a self-test output based on the pseudorange; wherein the self-test circuit comprises a wireless receiver to wirelessly receive a second RF signal comprising a second ranging signal comprising a component of a television signal, and to recover the second ranging signal from the second RF signal, and a second pseudorange circuit to determine a second pseudorange based on the second ranging signal, wherein a station comprising a transmitter of the second RF signal generates a third pseudorange based on the ranging signal and a fourth pseudorange based on the second ranging signal, wherein a range between the station and the apparatus is determined based on the pseudoranges.