How the TV works
While TV is a tool you use every day, you really have no idea how it works. How do the broadcasts work? What are the differences, technically, between digital terrestrial and digital satellite? Don’t worry, I’m here to help you clarify your ideas. In this guide, in fact, I will go to explain in detail how the TV works .
In addition to explaining how TV broadcasts work in practice, I will explain what is meant by Smart TV and what are the differences between these devices and so-called normal (non-Smart) TVs. Don’t worry, they are really simple concepts and you don’t need to have studied electronics to understand them.
I am sure that, by the end of reading this guide, you will be able to explain the operation of these devices and the main channel transmission systems to your relatives and friends as well. When you are ready, then, I would say to start. Sit back and get ready to find out how TV broadcasts work. I just have to wish you good continuation!
Index
- How TV broadcasts work
- How digital TV works
- How satellite TV works
- How cable TV works
- How Internet TV works
- How Smart TV works
How TV broadcasts work
The TV is a device for receiving television signals , which also has various applications as regards the display of signals from accessories such as multimedia players (eg Blu-Ray players or TV Boxes ) or video game consoles . Here we are, right?
The television (the actual device) is mainly made up of the following components: a signal decoder , a display , which can have different construction characteristics (through LCD , LED , OLED panels ), one or more speakers and a remote control .
Nowadays, since the analog signal is turned off, the most popular television signals are digital terrestrial (abbreviated to DDT ), satellite signal , cable TV , mainly broadcast in the United States, and streaming broadcasts via the Internet . Let’s take a closer look at how each of these systems works.
How digital TV works
The digital terrestrial or DDT is the type most commonly used in Italian signal, which has been gradually to replace the signal analog . The signal transmission system is similar to the satellite one , but does not require a dish as the signal comes from antennas installed on the ground.
The connection standards of digital terrestrial are decidedly more advantageous than those of analog, as they allow to ensure a greater choice of channels thanks to the lower bandwidth required to transmit a single channel.
The image quality is also higher and can transmit video in 16: 9 and resolution Full HD . Furthermore, digital terrestrial is able to carry multiple audio tracks at the same time, allowing the viewer to change, for example, the language of a film in real time.
The less interference are handled smoothly by DTT, which does not lose quality. However, when the signal becomes too weak , unlike what happened for analog signals, it completely loses its readability by the decoder.
Almost all the TVs on the market at the moment adopt internal decoders with digital terrestrial decoding technology, but in the last period we are moving to new transmission standards. In Italy, the main transmission standard of digital terrestrial is DVB-T , which uses an image transport stream called MPEG-2 .
TVs that do not have support for digital terrestrial, need a special decoder , capable of decoding this type of signal, to be connected externally via HDMI or SCART.
DVB-T technology, however, is in a sense already the past. From October 2021, in fact, a process of transition to a new transmission standard, called DVB-T2 , is expected in Italy .
This standard is necessary to transmit images through the new MPEG-4 technology with HEVC / H.265 codec , and this will lead, by 2023, to the shutdown of non-HD channels , making TVs and decoders that do not support this type of technology obsolete. . Find the complete roadmap here .
The transition to the DVB-T2 standard is necessary to free up the transmission frequencies of 700 MHz , which will be destined for 5G telephone technology . Also in this case, to adapt your TVs to receive new channels, it will be necessary to purchase specific decoders or TVs : I have talked about it more precisely in the guide, which I invite you to read, to understand if your TV is suitable for viewing of DVB-T2 broadcasts .
Know that there are several bonuses offered by the state for the purchase of devices that can support the transition to the new broadcast standards. I recommend that you take a look at this guide to understand how to get the TV Bonus .
For more information on DVB-T and DVB-T2 technologies, you can also consult Wikipedia .
How satellite TV works
The satellite , such as digital TV, using a broadcast standard channel DVB ( Digital Video Broadcasting ), called DVB-S or DVB-S2 . The satellite signal is spread through, precisely, satellites , whose reception is guaranteed by special dishes .
To receive the satellite channel, in fact, you need to install a dish and an illuminator (or LBN ), or to hook yourself to the common dish of your condominium. The signal is connected via a coaxial cable , which must be connected behind the TV (if it has an integrated satellite tuner) or to a special satellite decoder .
The satellite transmission technology is very similar to digital terrestrial ( MPEG-2 ) and allows you to view images in HD or Ultra HD (up to 4K , that is 4096 x 2160 pixels), carrying even more audio tracks . The “weak point” of satellite transmission mainly concerns the interference that arise in the event of rain or bad weather.
Satellite TV is mainly used for the broadcasting of encrypted pay channels , which can be viewed upon subscription (as is the case, for example, for Sky ) and insertion of a card into the decoder or CAM + smart card support (or CI / Common Interface ) of the TV. In any case, the satellite decoders that you find on the market also allow you to watch the channels that broadcast in the clear (defined Free to Air ).
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In case you want to learn more, I suggest you read my guide on how satellite TV works , in which I show you how to also receive the free channels offered by the tivùsat service , which allows you to access the main Italian free-to-air broadcasters via satellite.
For more information on DVB-S and DVB-S2 technologies, you can take a look at Wikipedia instead .
How cable TV works
The cable TV is a broadcasting standard television signal typically used in the United States and in Switzerland . So, in case you are going to find out how TV works in America , I recommend that you read the next lines.
This type of technology uses common electrical telecommunication cables ( coaxial cables ) as a means of transporting the signal . Upstream of the signal there is a single receiving antenna , to which the cables that arrive inside the individual homes are connected.
The signal picked up by the antennas is reprocessed and converted into certain frequencies, which can be encrypted , if the owner of the channel intends to make it available for a fee. The signal is received by the TV, if it has a cable signal decoder , or by a suitable decoder .
This system is used to provide the signal even in the so-called “shadow areas” , in which the satellite or digital terrestrial signal cannot be perceived. The quality of the cable signal, therefore, is higher in those areas where it is difficult to pick it up through common antennas.
The European cable connection standard is called DVB-C , while the American one is called ATSC and is characterized by an MPEG-2 or MPEG-4 digital video stream , capable of transmitting in 16: 9 up to a resolution of 1920 x 1080 pixels . To cover particularly long cable sections, special redistribution boxes have been developed .
In the last period, especially in the United States, the infrastructures for cable transmissions are being enhanced through the use of fiber optic cables , which increase the speed, quality and range of the signal. For more information, take a look at Wikipedia .
How Internet TV works
The Internet TV broadcasts are developing in an ever more widespread, thanks to technological progress as the new types of ultra-fast connection via optical fiber .
The type of transmission diffused through the Internet is called streaming and guarantees excellent graphic rendering in the presence of a stable connection . This type of service has now entered the daily lexicon, as many paid platforms use streaming for the transmission of their contents live and on-demand .
As for on-demand broadcasts , just talk about well-known services such as Netflix , Amazon Prime Video and Disney + , which guarantee the use of films, TV series and much more, even in 4K , through monthly subscriptions , to understand well about what are we talking about.
The quality of the service is guaranteed by a type of technology called “buffer” , which allows you to enjoy content saved in the servers of the broadcasters without the need to download them into the internal memory of the TV. Short portions of video are decompressed and reproduced by a codec , a few seconds after reception, in order to avoid micro connection interruptions, guaranteeing continuity of vision .
The live stream , however, is offered by platforms such as NOW , Sky Go or, with regard to sporting events, DAZN . This type of transmission needs a stable and fast connection to work in the best way.
The live streaming , in fact, it is closely linked to the stability of the network , since the transmissions are compressed and decoded in real time . The buffer between actual transmission and decompression on TV and other devices is approximately 10 seconds .
Viewing content via the Internet on TV is possible through the purchase of special devices capable of connecting to the network, such as a dongle , TV box or set-top box . These devices have an operating system very similar to that of smartphones and tablets and allow the download of the streaming apps of the broadcasters.
Among the most famous dongles, for example, there is Chromecast , a “key” produced by Google in two versions: the basic one , able to play content only from smartphones, tablets and PCs through supported apps with a maximum resolution in Full HD, and the one with Google TV , sold with remote control, which allows the direct installation of apps and allows you to view content even in 4K. Check out my Chromecast guide if you’re interested in learning more about how it works.
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Another very “rated” dongle is the Amazon Fire TV Stick , which allows you to view streaming content by installing the app using the supplied remote control and featuring support for Alexa voice commands . The main versions are the Lite one which supports a resolution up to 1080p and the 4K / 4K Max ones which allow viewing of Ultra HD / 4K content .
As regards the multimedia boxes, the Fire TV Cube , a cubic-shaped device that integrates all the functions of the Fire TV Stick 4K, in addition to those of an Amazon Echo speaker, should be reported .
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Apple TV is Apple’s multimedia box, with a dedicated app store and remote control. It is available in the HD version, with 32 GB internal memory, which allows viewing up to a maximum resolution of 1080p , and in the 4K version, in sizes of 32 GB and 64 GB , capable of reproducing Ultra HD / 4K content . Thanks to AirPlay technology, it also allows screen mirroring of iPhone, iPad and Mac.
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It is not always necessary to buy a separate dongle or multimedia box, since some TVs allow you to download applications through internal stores. I’m talking about Smart TVs , which I will go into in depth shortly .
How Smart TV works
The Smart TV are devices that allow the viewing of broadcast satellite , digital terrestrial , cable and thanks to the possibility of Internet connection, even in streaming and which are characterized by the presence of an operating system and one store inside for downloading applications.
The connection to the Internet can be ensured by an Ethernet network card that allows connection via cable and, in many cases, also by a Wi-Fi network card for wireless connection. Smart TVs have all the typical characteristics of non-Smart TVs, with LCD , LED or OLED displays, display sizes expressed in inches and various resolutions (up to 8K ).
The operating systems present on the Smart TVs can be developed by the manufacturers themselves (such as Samsung Smart Hub or LG Web OS ) or by third parties, as in the case of Google ‘s Android TV , which through its Play Store allows you to download almost all the applications available. even on smartphones and tablets animated by the same platform.
The application support is the real strength of the Smart TV, which means this type of service allows the user to view streaming content , such as YouTube , Netflix , Amazon Prime Video , Disney + and DAZN , but there are also apps with functions different , which allow you to view, for example, weather updates or news .
In case you want to learn more, I suggest you take a look at my guides about the operation of Smart TVs and the best Smart TVs on the market to date.
In any case, know that it is possible to make Smart even TVs that are not , through the purchase of special devices called dongles , which I told you about in the previous chapter .
