THE TRANSMISSION OF IDENTICAL TIME-ALIGNED SIGNALS FROM MULTIPLE CELLS, INCLUDING THE CASE OF FM BOOSTER BROADCAST SERVICES, IS REFERRED TO AS A SINGLE FREQUENCY NETWORK (SFN).
Properly designed SFNs result in increased signal strength and reduced interference at the receiver, in vehicles on the coverage contour, and to portable devices in buildings. It is the underlying foundation for our product offerings.
The GBS technical team has been involved in SFN design and deployment for many years, from Land Mobile Radio to PCS to Broadcast involving thousands of sites. Our patented FM analog stereo SFN design is successfully deployed across the United States. We even funded an NPR Labs – Towson University analog FM listening study (one of the largest ever) to enhance its SFN knowledge base gained in ZoneCasting Geo-Targeted research and development trials.
SFNs are becoming increasingly popular with digital broadcast technologies such as DAB, ATSC 3.0 and HD Radio using OFDM modulation because it simplifies the engineering. Analog FM radio must legally co-exist with digital in the U.S. and other countries and it is a limiting design criteria in analog/digital hybrid systems. Once we have designed an analog FM network, the digital HD Radio signal is completely integrated! And we keep the digital to analog signal ratio consistent for FCC compliance and avoiding interference to the analog host or adjacent FM channels.