ATSC is short for Advanced Television Systems Committee. An ATSC receiver is a device through which digital television signals are received for use by a television. Without an ATSC receiver of some variety, a television set cannot receive digital signals. This system exists in most of North America and some Asian countries.
When television is produced, TV broadcasting towers emit video and audio signals. These signals are picked up by ATSC receivers in digital format, and then the receiver relays them to the television screen. Most ATSC receivers are also tuners, which means they are able to decode the digital signals as well. Sometimes ATSC receivers are referred to a tuners, but this is a misnomer, as tuning is only one of the several functions the ATSC receiver performs.
An ATSC receiver performs its functions in much the same way as a computer processor does, at least in terms of receiving information and reformatting it for use by the television. While a computer processor receives commands and processes them in a language the operating system understands by using Boolean characters, the primary function of the ATSC receiver is somewhat analogous. It receives signals from the television broadcast tower over the air and converts them into the digital format.
However, unlike most computer signals, over-the-air signals received by an ATSC receiver are not encrypted. As a result, the tuner takes almost no time to covert these signals into digital format. An ATSC receiver or tuner can be present in DVD players, set top boxes that are used for television viewing or VCRs.
When an ATSC receiver is connected to a TV, the need for the picture tube is obviated because the transmission is made directly from the internally or externally placed tuner onto the television screen. In this sense, it is somewhat similar to the irrelevance of the speed of the microprocessor in a computer in which only the Internet is being used. The microprocessor is needed for the computer to function, but the speed of the Net is not related to it.
The receiver works in a logical manner by transmiting data in digital format. It sequentially performs the following functions: demodulation, transport stream de-multiplexing, decompression, error correction, analog to digital conversion, audio video synchronization and media reformatting. This process happens very quickly, resulting in the seamless streaming of data.
In February 17, 2009 all broadcasters stopped relaying signals via the older analog signals in the U.S. In televisions that were built after March 1, 2007, built-in or integrated ATSC receivers were mandatory. An external receiver is necessary for those television sets bought prior to this date.