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Digital Television: The Revival of Single-Frequency Networks

Digital Television: The Revival of Single-Frequency Networks

The upcoming launch of the new digital television technology ATSC 3.0 brought about the reintroduction of single-frequency networks or SFN networks.

Apparently, this technology of single-frequency networks has been around since the 1920s, when it was first implemented. It initially consisted of closely situated radio stations that shared a single frequency.  During the 1950s and in the years thereafter, the operation extended to the TV industry.

The so-called “boosters” transmitted off-the-air TV stations to smaller areas, communities, and even individuals that were beyond the main signal’s reach.

These tools were located on the ridges, with the receiving antenna geared toward the preferred station. An amplifier fed the transmitting antenna that was turned toward the area without TV signals.

In today’s popular digital television industry, the SFN technology gained fame owing to its receivers’ capability of rejecting unwanted TV signals.

As broadcast television evolved, the operation of signal boosters was legalized, but with limitations. Any interference to the direct consumers within the station’s main service area had to be prevented.

TV industry consultant S. Merrill Weiss established the world’s very first ATSC 1.0 single-frequency network in Pennsylvania. He wanted to provide a more effective coverage for the city’s TV station. It has since spread out to the neighboring areas.

He previously filed 29 single-frequency network applications. Out of which, 19 were subsequently approved. Weiss believes all 19 were built.

According to Weiss, the ATSC 1.0 depended on the design of the equalizer, which has varying performances per receiver. On the other hand, the ATSC 3.0 is based on the modulation. Hence, the receivers are expected to respond identically. Multiple signal carriers also boost its function.

Scientist Yiyan Wu of Canada’s Communications Research Centre also said that the ATSC 3.0’s modulation offers optimum protection as it has a longer and more efficient guard interval.

The ATSC 1.0 only used adaptable equalization, handling only about 64 microseconds of echo. The ATSC 3.0 can manage about 150 microseconds. Insofar as single-frequency networks are concerned, the longer the echo, the more power you can generate.

Adam Alderson
the authorAdam Alderson
Adam is an aspiring writer and an artist who plays with his band on the weekends. He loves to write about cord cutting and digital industry focused articles. His favorite movie is "Home Alone". He loves watching his home team Birmingham City FC play while listening to House Music. Favorite Teams - Basketball: Spurts, Football: NY Jets, Soccer: Birmingham City FC.

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