What is the difference between analogue television and digital television? Analog and digital signal. Types of signals and how they work

With the development of digital technologies, there is gradually a smooth migration of television viewers from analogue to digital television.

This happens not only because of large-scale advertising campaigns launched by Internet providers to popularize and sell IPTV, but also because users certainly like such television.

Why? Let's figure it out.

Differences between digital TV and analogue

I won’t spoil things here about digital and analog signals, who cares? No one. Let's take a closer look at the practical difference in use.

Equipment

So, to watch analog television you need a regular terrestrial antenna (in an apartment, on the roof) or a cable television connected to some company. Due to the specifics of how an analog signal works (after all, I had to write about signals), the image can be distorted in every possible way under the influence of external sources of interference.

In turn, to watch digital television, a regular antenna is not enough. You will have to install a receiver (encrypted digital signal decoder) near the TV, which will convert the received data into an image and display the picture on the TV screen.

A good example is Interactive TV from Rostelecom, which I wrote about in great detail in the article.

Digital satellite TV is a little different from the previous example. And if you want to watch satellite television, you will have to install a satellite dish (“dish”) on the wall of your private or apartment building. This time, the Tricolor TV company can be cited as an example.

Naturally, the satellite TV provider will provide you with all the necessary equipment and install an antenna. But the number of channels will depend on the selected service package.

Image quality

Without a doubt, digital television is the leader in this regard in all respects. Here are some obvious advantages of digital:

• Does not lose signal quality if transmitted over very long distances;
• The image cannot contain glare, “snow”, picture distortion and other common defects when watching analog television;
• Possibility of connecting channels in HD quality. One could safely put this item first on the list, since a high-definition image is the dream of any TV viewer who has a large diagonal TV screen.

Other options

Undoubtedly, in addition to image quality, IPTV has many other advantages:

Somehow I’ve gotten really into trouble with my writing, it’s time to finish.

Digital TV is better and higher quality than analogue

Summarizing all of the above, we can conclude that analog television has practically become obsolete, since it is inferior to digital television in almost everything except cost (“analogue” can be watched for free).

Some of the readers may have thought: “I’ll buy a TV with a built-in TV tuner, set it up to receive satellite TV and watch digital for free.” No, my dears, it’s not that simple. Firstly, there will be free (unencrypted) channels “one, two and gone,” and secondly, you still need to be able to find the right satellite and configure the equipment.

In general, Russia will not have a complete transition to digital TV for a very long time. 10-20 years, or even more. Although, many countries are striving for this, including our great Motherland. In the meantime, there is only one way out - to buy good digital television from Internet providers and highly specialized companies.

That's all, thanks for your attention.

Comments:

Every modern home must have a TV - the main source of information and entertainment content. A TV can be the cheapest and simplest, or the most expensive and packed with an endless number of functions. But a TV is simply of no use if it is not connected to television broadcasting. Therefore, the question arises: “What to choose: cable television or digital? And which of these is better?

Cable television is an analogue of the television broadcasting model; the television signal is distributed along a cable that goes to the consumer and also transmits sound. This method began to actively spread in the 1980s in Europe and America. It became widespread in Russia only in the late 80s and early 90s. Initially, coaxial cable was used, later it was replaced by fiber optic cable, which has a number of advantages. This method of broadcasting allows the consumer to watch more than sixty channels with high quality and not be afraid of interference.

What is digital television?

Digital television is a broadcasting method in which a television signal containing image and sound is encoded using digital channels. At the moment, the most popular data encoding method is MPEG. This method has a number of advantages: noise immunity, reduced transmitter power, a much larger number of programs in one frequency range, excellent sound and image quality, many useful functions, and the ability to select a language. If you decide to connect digital television, then you just need to buy a small set-top box, but even that is not necessary, since many modern TVs have long supported the DVB-T2 standard.

It is worth understanding that comparing digital and cable television is pointless and there is no point in it. Cable television is essentially one of the ways to deliver information to subscribers, while digital television is a type of providing video and audio signals. Television via satellite or terrestrial is placed on a par with cable, while digital is compared with analog.

What are the main pros and cons of digital television?

Pros:

1. Great picture and sound.
2. Cheap equipment (in fact, you only need a set-top box, but some TVs themselves can already receive a DVB-T2 signal).
3. High resistance to interference.
4. A huge number of channels.
5. Good technical support due to its popularity.

Minuses:

1. Reception within a limited radius (it is possible to watch outside the home, but only on the phone and at the rates of the cellular operator)
2. When the signal is poor, the quality of sound and image drops significantly.

What are the main pros and cons of cable television?

Pros:

1. Good sound and picture quality, which is far superior to analog, although not the same as digital.
2. Resistance to interference, this parameter is approximately at the same level as that of digital.
3. A large number of channels, but this is also inferior to digital.

Minuses:

1. Depends heavily on the operator.
2. It is impossible to conduct it in a village or village. Even in some cities, in remote areas, it will be problematic for the subscriber to install a cable, which is undoubtedly a minus.
3. Installation prices vary from operator to operator and can range from inexpensive to exorbitant prices.

What are the differences between digital and cable television?

Firstly, subscribers receive the signal in the form in which it was generated; there is no distortion during digital broadcasting. Thanks to this, the quality of sound and image does not suffer. Cable television is highly susceptible to external factors.

Secondly, digital television is much more mobile than cable television. You can watch digital television on your tablet or phone while on the road or just outside. Isn't it convenient?

Thirdly, digital television can provide a simply unrealistic number of channels than cable. This number can exceed a hundred, but it all depends, of course, on the tariff. Of course, this is a big plus for digital television.

Fourthly, digital television is much cheaper than cable television.

What are the similarities between digital and cable television?

Firstly, digital television has the ability to connect via cable. Digital television is very convenient in the sense that it can be connected in several ways, including cable.

Secondly, both types of broadcasting are dependent on weather conditions and signal strength. Do not forget that in bad weather or a poor signal, the quality of the picture and sound will drop significantly.

These are all the differences and similarities between cable and digital broadcasting. I hope this article will help you make your choice and you will enjoy watching TV.

Transmitting images and sound over vast distances is a long-standing dream of mankind. Before the advent of writing, people passed plot drawings on papyrus to each other. In ancient legends, ancient people talked about magical artifacts with the help of which you can communicate and see your interlocutor from another country. Russian folk tales mention a blue plate with a pouring apple, which can show what is happening in a particular place.

In the 20th century, this miracle became a reality. Modern people cannot imagine their life without television. On average, each person spends 5 hours a day watching television.

History of origin

The creation of modern television was made possible thanks to the efforts of several generations of scientists, inventors and engineers. In 1933, scientist V. Zvorykin invented a cathode tube. This device is the main part of most TV models. Three years later, the first electric television receiver was created. It was a wooden box with a small screen.

In the Soviet Union, the first mass-produced TV model appeared in 1949. It was called KVN 49. The device included a special lens that magnified the image. It was necessary to pour distilled water into it.

In the early 50s of the last century, the Central Studio was organized on Shabolovka, which broadcast throughout the Soviet Union. The first color television in the USSR was created in 1967. In the same year, broadcasts of Soviet television programs began in color.

Analog TV

Analog television is one of the broadcasting options in which the signal is transmitted in analog format. An example of such a signal is the transmission of sound in wired telephones. An electronic membrane detects air vibrations during a conversation and transmits it over a distance using a similar electrical signal.

Analog TV is connected using a regular terrestrial antenna. It can be indoor or outdoor. Cable television operators also provide this type of signal connection service. To install analog cable television, you will need a standard cable.

Digital television

What is the difference between analogue and digital television? Modern TVs are capable of displaying images in high quality. Digital broadcasting became available only in the 90s of the last century. It uses an encrypted signal. An example of a digital signal is the transmission of messages using Morse code. Dots and dashes are replaced with numbers 1 and 0.

Development of television systems

Digital technology has long been used as part of the television system in analogue television. The signal was converted to analog and transmitted to television receivers. After some time, hybrid television networks appeared. Fully digital systems emerged in the late 1980s. This type of television ensures signal transmission without distortion or interference. The digital broadcasting method allows you to receive a signal without loss of quality even in a moving car. Unlike a continuous analog signal, a digital signal is transmitted in several portions, which are separated by pauses. This virtually eliminates its distortion. If the signal reaches the receiver, it is received in its original quality. But sometimes blurry squares may appear on the screen. Also, other useful information in the form of teletext can be transmitted through this channel.

Connecting to digital TV

Old-style televisions can be connected to digital television using a special device - a receiver. This device converts the signal to analog.

You will also need a decimeter antenna. The set-top box can transmit a signal to several receivers at once. But at the same time, the same program will be broadcast on each device. To broadcast different channels, you need to purchase a set-top box for each TV. At the same time, it must support the modern DVB-T2 format. The connection process does not require special knowledge and skills. Any student can handle it. The disadvantages of this connection method include the use of two control panels.

Transition to digital television

Analogue television is an outdated type of signal transmission. The possibilities for its development have been exhausted. This signal is inferior to digital in terms of image quality and number of available channels. Its quality depends on the distance from the transmitting television tower. The analog signal travels over a distance of no more than 100 km. Digital television has much more advantages.

Ten digital channels can fit on one frequency occupied by an analog channel. This set is called multiplex. Many countries have gone completely digital. According to the international agreement of June 17, 2015, most states undertake to release frequencies that interfere with digital television broadcasts in neighboring countries. Many of them have already done this. However, some states are in no hurry to switch to digital. Their government fears mass protests. Often analogue TV is the most effective means of warning the population in the event of natural disasters.

Shutdown in Russia

When will analogue television be switched off in Russia? In the Russian Federation, the transition to digital is planned for early 2019. This date was postponed several times, and it was unclear when analogue television would be switched off in Russia. The corresponding decision was made back in 2009. The government planned to complete the gradual transition to digital television in 2015. But due to the difficult economic situation, this period was extended for several years.

Many TV viewers are concerned about the question of when analogue television will be turned off in Russia. To implement the transition, it is necessary to provide access to digital television to 95 percent of the country's population. For this purpose, 2 packages of free TV channels and radio stations were created. The first package included 10 federal channels. The second multiplex was created with funds from television companies. Before 2010, 40 percent of Russians received no more than 4 channels on their TVs. Free digital “buttons” have become publicly available throughout Russia. Almost any Russian can watch television programs in high quality.

The creation of a third package of free channels is currently being discussed. It should include regional programs. But experts believe that launching this package is not economically feasible. To create it, you need to free up additional frequencies. This will only become possible after turning off analogue television. The only region where third multiplexes are already available is Crimea. He inherited the Ukrainian infrastructure.

When will analogue television be switched off in Russia? Next year the state will stop subsidizing it. This means that analogue channels will be able to continue operating only at their own expense. Most of them are already broadcast in digital format. To understand which channels will be muted after the transition, you just need to turn on the TV. Channels that will end analogue in 2019 will have an "A" next to their logo.

Conclusion

Switching to a new TV format is a long and expensive process. Regional channels will be the first to suffer from the shutdown of analogue television broadcasting. Many of them do not have expensive equipment for broadcasting in digital format. Only in a few regions they are already duplicated. Also, after the transition to digital, low-income segments of the population may be left without television altogether. An indoor antenna for analog television will become a useless item. Charitable organizations can solve the problem by covering the costs of purchasing the necessary equipment. It is also planned to provide government subsidies in the form of free distribution of digital TV set-top boxes to those in need.

The average person doesn’t think about the nature of signals, but sometimes he does about the difference between analogue and digital broadcasting or formats. By default, it is believed that analog technologies are becoming a thing of the past, and will soon be completely replaced by digital ones. It’s worth knowing what we give up in favor of new trends.

Analog signal- a data signal described by continuous functions of time, that is, its oscillation amplitude can take any value within the maximum.

Digital signal- a data signal described by discrete functions of time, that is, the amplitude of oscillations takes only strictly defined values.

In practice, this allows us to say that an analog signal is accompanied by a large amount of noise, while a digital signal successfully filters it out. The latter is capable of restoring the original data. In addition, a continuous analog signal often carries a lot of unnecessary information, which leads to its redundancy - several digital signals can be transmitted instead of one analog signal.

If we talk about television, and it is this area that worries most consumers with its transition to “digital,” then we can consider the analog signal to be completely obsolete. However, for now, analog signals can be received by any equipment designed for this purpose, while digital signals require special equipment. True, with the spread of digital television, there are fewer and fewer analogue televisions and the demand for them is catastrophically decreasing.

Another important characteristic of a signal is security. In this regard, analog demonstrates complete defenselessness against outside influences or intrusions. The digital one is encrypted by assigning it a code from radio pulses, so that any interference is excluded. It is difficult to transmit digital signals over long distances, so a modulation-demodulation scheme is used.

Conclusions website

1. The analog signal is continuous, the digital signal is discrete.
2. When transmitting an analog signal, there is a higher risk of clogging the channel with interference.
3. The analog signal is redundant.
4. The digital signal filters out noise and restores the original data.
5. The digital signal is transmitted in encrypted form.
6. Multiple digital signals can be sent instead of one analog signal.

What is Analog and Digital broadcasting?

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(basic concepts of analogue and digital broadcasting)

Recently, more and more information has begun to appear on the information network about the transition from analogue to digital broadcasting, in connection with this, many questions arise on this topic, giving rise to all sorts of rumors and assumptions. In this article, I want to explain the difference between “analog” and “digital” broadcasting, in a language that is accessible and understandable to the common user (at least as far as possible).
First, let's figure out what an “analog” signal is.

Analog signal

As always, I will explain using a simple example. As an example, let's take the transfer of voice information from one person to another.
During a conversation, our vocal cords emit a certain vibration of varying tonality (frequency) and volume (sound signal level). This vibration, having traveled a certain distance, enters the human ear, affecting there the so-called auditory membrane. This membrane begins to vibrate with the same frequency and strength of vibration that our sound cords emitted, with the only difference that the strength of vibration weakens somewhat due to overcoming the distance.
So, the transmission of voice speech from one person to another can easily be called analog signal transmission, and here’s why.
The point here is that our vocal cords emit the same sound vibration that the human ear itself perceives (we hear what we say), that is, the transmitted and received sound signal has a similar pulse shape and the same frequency spectrum sound vibrations, or in other words, “analogous” sound vibration.
Here, I think it’s clear.

Now, let's look at a more complex example. And for this example, let’s take a simplified diagram of a telephone, that is, the telephone that people used long before the advent of cellular communications.
During a conversation, speech sound vibrations are transmitted to the sensitive membrane of the handset (microphone). Then, in the microphone, the sound signal is converted into electrical impulses, and then travels through wires to the second handset, in which, using an electromagnetic transducer (speaker or earphone), the electrical signal is converted back into a sound signal.
In the example above, again, “analog” signal conversion is used. That is, sound vibration has the same frequency as the frequency of the electrical impulse in the communication line, and also, sound and electrical impulses have a similar shape (that is, similar).
In the transmission of a television signal, the analogue radio-television signal itself has a rather complex pulse shape, as well as a fairly high frequency of this pulse, because it transmits both audio information and video over long distances.

I think we've sorted it out with the "analog signal".

Over time, the number of TV channels increased, the number of subscribers at telephone exchanges increased, and the Internet appeared. As a result, the bandwidth of analog information transmission no longer meets modern requirements. This applies to both terrestrial, wired and broadcast signal transmission and reception lines, and, of course, satellite communication lines.

Now, let's figure out what a “digital” signal is.

Digital signal

As an example of a “digital signal”, let’s take the principle of transmitting information using the fairly well-known “Morse code”. For those who are not familiar with this type of transmission of text information, below I will briefly explain the basic principle.
Previously, when signal transmission over the air (using a radio signal) was just developing, the technical capabilities of transmitting and receiving equipment did not allow transmitting a speech signal over long distances. Therefore, instead of speech information, text information was used. Since the text consists of letters, these letters were transmitted using short and long pulses of a tonal electrical signal.
This transfer of text information was called transfer of information using Morse code.
The tone signal, due to its electrical properties, had a greater throughput than the speech signal, and as a result, the range of the transmitting and receiving equipment increased.
The units of information in such signal transmission were conventionally called “dot” and “dash”. A short tone meant a dot, and a long tone meant a dash. Here, each letter of the alphabet consisted of a specific set of dots and dashes. So, for example, the letter A was designated by the combination ".-" (dot-dash), and the letter B "- ..." (dash-dot-dot-dot), and so on.
That is, the transmitted text was encoded using dots and dashes in the form of short and long segments of a tone signal. If the words "MORSE CODE" are expressed using dots and dashes, it will look like this: (deleted)

Digital signal versus Morse code

The digital signal is based on a very similar principle of encoding information, only the units of information themselves are different.
Any digital signal consists of so-called "binary code". Here, logical 0 (zero) and logical 1 (one) are used as units of information.
If we take an ordinary pocket flashlight as an example, then if you turn it on, it will seem to mean a logical one, and if you turn it off, it will mean a logical zero.
In digital electronic circuits, logical units of 1 and 0 are taken to be a certain level of electrical voltage in volts. So, for example, a logical one will mean 4.5 volts, and a logical zero will mean 0.5 volts. Naturally, for each type of digital microcircuit, the voltage values ​​of logical zero and one are different.
Any letter of the alphabet, as in the example with the Morse code described above, in digital form, will consist of a certain number of zeros and ones, arranged in a certain sequence, which in turn are included in packets of logical pulses. So, for example, the letter A will be one packet of impulses, and the letter B will be another packet, but in the letter B the sequence of zeros and ones will be different than in the letter A (that is, a different combination of the arrangement of zeros and ones).
In digital code, you can encode almost any type of transmitted electrical signal (including analog), and it doesn’t matter whether it is a picture, video signal, audio signal, or text information, and you can transmit these types of signals almost simultaneously (in a single digital stream ).
A digital signal, due to its electrical properties (as in the example with a tone signal), has a greater information transmission capacity than an analog signal. Also, a digital signal can be transmitted over a greater distance than an analogue one, without reducing the quality of the transmitted signal.

Which antenna to choose?

What antenna is needed to receive digital terrestrial television?

To receive terrestrial digital television, you need a UHF antenna.

Is an indoor antenna sufficient for high-quality reception?
The quality of signal reception depends on the distance of the transmitter and its power. The closer you are to it, the better the reception.

What antenna models allow you to receive digital terrestrial television? How much do these antennas cost?
As an example:

Alpha H 311 DVB-T



ASP 8 SUPER DVB-T

Is it possible to get a high-quality TV signal without a special antenna?
Yes, it is possible, only if you are in close proximity to the signal source. In this case, of course, you won’t need an antenna, but you still need to screw a small piece of wire to the antenna input on the TV for more accurate signal reception.

Where and how is it possible to install the antenna?
You can choose the installation location: paint, wall, window frame, balcony. Most often, in multi-storey buildings, antennas are installed on the roof of the building; if we consider private houses, then they often use masts with a diameter of 40-50 mm, a height of about 5-6 meters, or less, but it all depends on the location of the antenna relative to the signal transmitter. The better the installation, the better the signal reception, you should avoid it for now.

Where to buy an antenna for an over-the-air digital television signal?
You can purchase an antenna in home appliance hypermarkets, as well as in any store that sells on-air equipment or on the radio market. But, before making a purchase, check with the seller whether this antenna receives the UHF range.
What is the difference between an active and passive antenna? Which one to choose?
The difference is that the active antenna has a signal reception amplifier operating from the network. An active antenna receives better at a distance from the transmitter, while a passive antenna, on the contrary, works better in close proximity to it. The effectiveness of an active antenna decreases if you are located near a TV tower; it begins to “choke.” Therefore, in such situations, it is better to use a passive antenna.

What is the difference between the MV and UHF bands?
Terrestrial television signals are transmitted using ultra-short radio waves, abbreviated as VHF, in the frequency range from 48 to 862 MHz. This frequency band is conventionally divided into 5 ranges, combined into two groups:
- meter or HF (VHF), bands I, II, III; (47-160 MHz)
- UHF or UHF (UHF), bands IV, V. (470-862 MHz)
There are some differences in the distribution of television channels between terrestrial television bands in different countries. In the standard used in the CIS countries, the meter range includes 1-12 channels, the decimeter range 21-60 channels.

TV channels included in the RTRS-1 package

The composition of the RTRS-1 digital TV channel package complies with the decrees of the President of Russia on all-Russian mandatory public television channels: No. 715 of June 24, 2009, No. 456 of April 17, 2012, No. 167 of April 24, 2013.

TV channels included in the RTRS-2 package

Key indicators of the digital broadcasting network

The advisory support center is located on the ground floor of a 2-story building in the central part of the city near the Glinka City Garden, the Heroes' Memorial Square and Lenin Square in close proximity to public transport stops located on the street. Dzerzhinsky.

Objects of test digital broadcasting of the RTRS-1 package

Objects of test digital broadcasting of the RTRS-2 package