Abstract: Methods having corresponding apparatus and computer-readable media comprise: receiving television signals and a message at an apparatus, wherein the television signals include an NTSC television signal and an ATSC television signal, wherein the message represents first and second arrival times representing absolute times of arrival at the apparatus of a first wavefront of the NTSC and ATSC television signals, respectively; measuring third and fourth arrival times, based on a local clock, after receiving the message, wherein the third and fourth arrival times represent times of arrival at the apparatus of a second wavefront of the NTSC and ATSC television signals, respectively; and providing a clock correction signal for the local clock based on the first arrival time, the second arrival time, the third arrival time, and the fourth arrival time.

Abstract: Apparatus having corresponding methods comprises a reference clock; a receiver to receive a wireless television signal, wherein the wireless television signal is transmitted by a television transmitter according to a transmitter clock; and a clock offset unit to determine a clock offset between the reference clock and the transmitter clock based on the wireless television signal.

Abstract: Apparatus having corresponding methods comprises a reference clock; a receiver to receive a wireless television signal, wherein the wireless television signal is transmitted by a television transmitter according to a transmitter clock; and a clock offset unit to determine a clock offset between the reference clock and the transmitter clock based on the wireless television signal.