Originally featured on BroadcastEngineering.com
OMVC releases Mobile DTV propagation model for high VHF channels
The Open Mobile Video Coalition — in one of its last moves before being integrated into NAB — released a predictive model Dec. 21 for reception of high VHF (channels 7 through 13) mobile DTV signals.
The model gives broadcasters a tool to predict future coverage of Mobile DTV signals from existing or new facilities for viewers in cars with mounted antennas, those using handheld receivers outdoors and consumers watching handheld devices indoors.
“Mobile TV is designed to be transmitted alongside the same digital TV broadcasts that bring local news, weather, traffic, sports and favorite programs to viewers in high-definition. But the signal qualities of Mobile TV are quite different than HDTV transmissions, because reception antennae in Mobile TV receivers are usually lower to the ground and always on the move,” said OMVC executive director Anne Schelle in a press release announcing the predictive model.
According to Schelle, the new predictive model for high VHF Mobile DTV reception uses a “semi-empirical” method that blends actual reception data collected in the field and theory. “With information about the local terrain, antenna height, frequency and polarization as well as details about the receiver and atmospheric conditions, we can predict signal strength for mobile broadcasts with this model,” said Schelle.
The results are local maps that show where Mobile DTV reception can be expected to be robust. Subsequent field testing with automobiles showed the predictive model to accurately correlate to actual conditions.