National Association of Broadcasters Engineering Handbook, 11th Edition

Chapter8.5

Single-Frequency Networks for DTV Systems

Walter Fischer

Rohde & Schwarz

In the past, typical broadcast networks transmitted different local content on each transmitter site. That was true for FM transmitter stations and analog TV transmitter stations as well as most ATSC stations. Today such a principle is called multifrequency networks. Analog TV signals in particular would create ghost pictures if we transported and received those signals via different signal paths. That was one of the reasons for using directional antennas in analog TV. Back then, the availability of free frequencies was not as big a problem as nowadays. Today frequencies are an expensive and rare resource that has to be carefully saved and handled. When digital ...