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Digital television

Digital television


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There have been talks about digitalizing television for about ten years. Experts predict the imminent demise of analog TV and the onset of the era of digital broadcasting.

During this time, the digital format really became the main one in the field of satellite broadcasting, however, in the cable and in the air segment, despite all the forecasts, the position of digital television is still extremely weak. The very transition to a new form opens up new perspectives for broadcasters.

In digital format, data transmission channels will become unified and multi-service. It will be possible to install, store and transfer information without loss of quality.

When creating subscriber devices, it will be possible to use proven digital technologies and so on. It was these capabilities, first formulated in the late 90s, that allowed experts to predict the decline of analog television.

However, the introduction of innovations was prevented by a difficult situation on the market, consumers could not fully understand what they should be paid for, what is a myth in beautiful slogans, and what is true. Therefore, we will consider the main statements about the unconditional transition to a new technology.

In digital television, data transmission channels are used more efficiently. This statement is true. With digital coding, not one, but up to 16 television programs are transmitted in one frequency channel. This phenomenon is one of the main advantages of digital television. For telecom operators, this phenomenon is very important, it allows either to significantly reduce the payment for the channels used or significantly increase the number of channels. Now people watch television using three ways - satellite, ether, cable. If we compare the cost of equipment maintenance, the highest is for satellite operators, which spend significant funds on signal delivery to the subscriber. But with digital methods, these costs are noticeably reduced, which also reduces the cost of the service. Of course, the introduction of digital technologies plays into the hands of both operators and consumers. Today digital technologies DVB-S and MPEG-2 in satellite broadcasting have already been introduced all over the world. Today the issue of introducing a new generation of formats - DVB-S2 and MPEG-4 is on the agenda. For cable operators, the situation is different, they do not spend significant funds on maintaining the communication channel, they usually do not have a shortage of frequencies. If an operator wants to increase the number of channels, then he can simply use new frequencies, so there is no noticeable gain from the introduction of digital technologies, and besides, the cost of implementation is quite high. This is why cable operators are just starting to offer digital television, a tribute to both progress and fashion. The most difficult situation is faced by terrestrial operators, who have a shortage of frequency resources and incur high costs for maintaining broadcasting equipment. Therefore, it is the broadcasters who are most interested in the implementation of digital, which will reduce costs in the main areas and increase the number of programs. But the introduction of the digital format in broadcasting requires enormous costs. The state estimates the transfer of the state network to a figure of $ 1.5 billion, and we should not forget that the population will need to be equipped with digital decoders, which is estimated at 50 million pieces. The end user usually does not really care what technology he uses and how many channels he receives in one frequency, but quality and price play an important role.

With the help of digital television, the number of programs distributed can be significantly increased. This statement just continues the previous one, being one of the incentives for the introduction of numbers. The statement is true, but how attractive is it to operators? It is much easier for cable operators to modify their network and thereby increase the number of channels, rather than investing in expensive equipment and losing subscribers when switching to a new standard. But for broadcasting broadcasters, such a transition is very attractive, since it will significantly expand their capabilities. The increase in the number of channels may also interest subscribers, but this should be attributed to residents of remote areas. By the way, to a large extent this segment is already occupied by satellite operators, for example, Tricolor. So, financing of the transition will hardly be carried out at the expense of such subscribers.

With digital broadcasting, the picture quality is noticeably better. This statement is rather controversial, since the quality of the image is determined by the quality of the weakest link in the chain from signal conditioning to the television receiver. For example, a cable from a decoder to a TV can noticeably distort the image. Yes, and today there are few TVs that can show a really high-quality picture, so it is not surprising that most people do not show a noticeable improvement. In good reception conditions, it is difficult even for an expert to distinguish the image transmission format. But when the conditions worsen, a difference appears - with analog broadcasting, snow appears, the sound starts to hiss, but in digital format the picture remains unchanged for some time, then it begins to disintegrate into cubes and freeze. Whether such behavior is an advantage is a rhetorical question, since the presence in Russia of a large number of places with poor reception in general can negate the advantages of the new format. You should also take into account such a parameter as the dynamics of the image. In analog broadcasting, each frame carries complete information about the picture, therefore, a sharp change in the scene does not lead to the loss of information, but in digital broadcasting, full information is only in the key frames. The rest of the time, information about changes in the picture is simply transmitted, with an increase in compression, information is transmitted less often. This leads to the fact that in dynamic scenes there is a noticeable loss of information, since the image does not have time to update. By the way, the transition to digital is especially critical for the United States, which use the 1954 NTSC standard, but even for this leading country, the transition time is constantly shifting. Europe, on the other hand, plans to switch to digital broadcasting no earlier than 2014.

Digital broadcasting will significantly reduce the energy consumption of terrestrial transmitters. This is true because a transmitter using the same or less power will be able to broadcast many more programs. This is beneficial for the state and for on-air broadcasters, since the cost of maintaining equipment will decrease, and the social package of programs can be significantly increased. However, for subscribers of other segments (satellite and cable), this phenomenon does not matter.

Digital broadcasting will improve the reception of terrestrial channels in urban areas. For work in urban environments, given the strong signal reflections from houses, the DVB-T format has been developed, for which this statement is true. However, experience has shown that in cities that have introduced digital terrestrial broadcasting, a reliable signal for stationary users still cannot be obtained without external antennas or cable networks. But the possibility of receiving a television signal on mobile devices of motorists and travelers can really become a promising business.

Digital broadcasting means interactivity. Interactivity is often mentioned when digital broadcasting is mentioned, but it is not. In fact, broadcasting itself has nothing to do with interactivity and does not provide it. For the transmission of a digital television signal, IP networks can indeed be used, which are interactive from the beginning, this possibility can also be applied to programs. As a result, interactivity is achieved with the help of a data transmission network, head-end equipment, properties of terminal user devices. This phenomenon is of great interest to operators, as new services appear that attract potential subscribers. But for the majority of traditional operators, this opportunity remains inaccessible, since its implementation requires significant network reconstruction. The experience of introducing interactivity has shown that the required costs for organizing services and their maintenance did not arouse significant interest of users, therefore, there are practically no incentives for traditional operators to introduce this service.

After the transition to digital, television will become paid. It is just that the transition to digital broadcasting will not necessarily involve coding, but for cable operators, open broadcasting does not offer advantages, which is critical for paid channels. But with the introduction of closed paid broadcasting, it turns out that almost all decoders have the ability to decode a digital signal. Naturally, it will be logical to implement paid systems already on a digital basis, then the transition to digital broadcasting will be a consequence of the introduction of pay TV, and not its reason. Yes, and on-air broadcasters have tried to create this myth. In the UK, it was initially decided that terrestrial channels should be paid and compete with cable, but this approach completely discredited itself, the same situation arose in Italy and Spain. But the very fact has confirmed even more in the minds of consumers the idea of ​​paid digital broadcasting. This experience has led broadcasters to understand that widespread adoption of digital television is only possible with the provision of free packages first. Strengthening the concept of a new format on the market will make it possible to introduce paid packages over time.

The introduction of digital standards will end the confusion with analog standards. The entire era of analogue broadcasting was remembered for the leapfrog of standards, it came to the point that almost every country had its own kind of analogue television broadcasting. Experts reasonably believed that with the introduction of digital broadcasting, a single world standard would be created, which would allow unifying equipment and exchanging programs. However, the reality turned out to be different, there was a division by technology within countries. For different transmission media, appropriate standards have been developed - for cable operators DVB-C, for satellite operators - DVB-S, for terrestrial operators - DVB-T. The use of different standards for broadcasting and cable broadcasting turned out to be unjustified, leading to undesirable consequences in the development of terrestrial broadcasting. Initially, the terrestrial and cable environments were very similar in characteristics, and the cable network was first created for relaying broadcasting. But the higher characteristics of the cable network, the absence of a number of interference characteristic of the air in it, led to the creation of a separate DVB-C standard, which significantly differs from DVB-T. For broadcasting, additional protection mechanisms are provided, and the bandwidth of its channel is only 17% less than in cable. The payment for this 17% was the presence of a new standard, which led to the appearance of different demodulators for analog and cable broadcasting. The "beautiful" technical solution had a bad impact on the market as a whole, complicating the introduction of digital terrestrial broadcasting. And it is beneficial for cable operators themselves to use a DVB-C decoder, since it usually provides access control systems, which are not available in DVB-T receivers. Therefore, simpler terrestrial systems are being introduced into modern televisions.

Digital TV is just a good quality picture. In fact, digital television offers a number of new services for the consumer. First, the subscriber can choose the package and tariff plan he needs. Secondly, it simplifies its maintenance (enabling, disabling, switching to another package). All this happens literally in a matter of seconds. Thirdly, the consumer gets high-quality stereo sound and even Dolby Digital. Fourthly, there is the EPG service, which provides a TV program to any channel directly on the TV screen. The user can group the channels to his liking, block some of them from the access of children, you can change the subtitle language on the channels. Also, do not forget about HDTV - high definition television, a new service that is possible exclusively in digital form. Today this service is rapidly gaining popularity. True, for HDTV, you will also need an appropriate television receiver.


Watch the video: How to set up your TV digital-ready English (June 2022).


Comments:

  1. Evrain

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  2. Kigakinos

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  3. Dustyn

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  4. Nakasa

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  5. Kazill

    Very informative. Thanks.



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