Too many questions have been thrown at me concerning decoders and the many practical uses they might be put into. However, the dimension of most questions strongly suggests that most intending digital TV decoders do not yet understand what decoders are. For clear of doubts, this post will define and simplify the mystery surrounding what decoders are. If you really wish to understand what your decoders really do and how they generate the image and audio displayed on your TV screen, then this post is definitely for you.
What is a Decoder?
Any device which receives encrypted or protected data and decrypts or unlocks such data, bringing you to know the contents of such data is a decoder. Simply put, a decoder transforms encoded data and decodes it for you. When you watch TV channels, the setup box through which you receive the TV signals breaks down the complicated TV signals before presenting them to you in a format which your TV understands and displays.
Types of Decoders
Basically, there are two types of decoders – the digital decoder and the analog decoder. In as much as the analog decoders are no longer in use in most parts of the world due to massive digitization of TV signal globally, they were once the major setup boxes used during the black and white TV era.
Today, technology has gone digital, and so do decoders. TV signals in transmission are now in digital formats and only digital decoders can consequently capture and decrypt such signals. Of course, the gains of TV signal digitization are too many to mention.
Apart from enhanced video and audio quality, digitization of TV signals and consequently decoders have given room for the incorporation of more TV channels and radio programs, better interactivity features, channels customization, addition of voice and data communication etc. Considering the many features obtainable from signal digitization leaves much to be desired about the nature of signal sources and how it affects the types of digital decoders we have. Resultantly, we have two major signal sources for TV signals – satellite TV signal source and the terrestrial TV signal source. These leave us with two types of digital decoders – the digital satellite decoder and the digital terrestrial decoder.
The Digital Satellite Decoder
This is the most common type of digital TV decoder used in developed, developing and under-developed countries of the world. These decoders use the satellite-like dish pan as signal receptors, positioned to face the sky at some angle. The technology of the digital satellite decoder and dish setup allows your satellite dish to directly communicate with TV satellites in space and relates received signals to the waiting satellite TV decoders. In professional terms, the technology of signal transmission is known as Direct-to-Home Digital Video Broadcast (DTH DVB). This type is seen in the DStv model of dish and decoders used in most parts of Africa, including Nigeria.
There are many other types of satellite TV decoders and services in Nigeria and Africa. We have seen the MyTV, StarSat, NileSat, ArabSat, and so many others. All of these operate via similar technology, different TV satellites, parameters and settings. It is interesting to note that although there may be free TV channels on all these digital satellite TV systems, they are all Pay-Tv services. This means that you must pay money and subscribe to their services before you are given access to view their TV programs.
The Digital Terrestrial Decoder
When you see high towering masts or antennas transmitting or receiving TV signals, this is terrestrial in nature. This type of technology uses highly raised poles or masts to propagate its signals. They do not transmit through satellites directly to your homes. That is why you do not need a satellite dish to receive such signals. Their decoders are configured to decrypt signals of this terrestrial nature.
Therefore, you cannot use a digital terrestrial TV decoder to decrypt signals from a digital satellite source. Even among terrestrial services, only the prescribed decoders can successfully unlock signals from a particular terrestrial source. Hence, one cannot use GOtv decoders on Startimes antennas and vice versa. In the same vein, DStv decoders cannot be used to view TV signals from MyTV satellites and vice versa. Any attempt to do otherwise is illegal and I condemn it in strong terms.