Digital TV: history of formation and main advantages

Television today is considered the most popular mass media. There is not a single state left in the world that is not covered by TV broadcasting. It is not for nothing that at the end of 1996 the UN General Assembly proclaimed November 21 as World Television Day. But few people know that this invention is a little over a hundred years old. Humanity has dreamed of transmitting images over distances since ancient times, inventing fairy tales about running apples on plates and magic mirrors. However, more than one millennium passed before these fantasies became reality. Therefore, it is probably interesting for everyone to trace the stages of the origin, formation and development of television, starting from those times when the screens shone not with blue, but with a completely different light.

Who invented television and when?

Unlike the invention of radio, which occurred almost simultaneously in many countries of the world, each state independently created and voiced its own version of the history of the emergence of television. It is not surprising that each country has its own legend about the many years of united work of scientists who created a unique technology.

The phenomenon of the photoelectric effect was first described by the German physicist Heinrich Hertz. In 1887, during his research, he accidentally discovered that when substances are exposed to electromagnetic radiation, electrons are released, but he could not explain this phenomenon.

A year later, in February 1888, the Russian scientist Alexander Stoletov managed to conduct an experiment that clearly demonstrated this same phenomenon and identified several patterns. However, no use was found for it.

And only in 1907, the Russian physicist Boris Rosing was able to theoretically substantiate the possibility of obtaining images using a cathode ray tube created by the German physicist Karl Braun. He even put the idea into practice, as a result of which he managed to obtain an image in the form of one point that did not change its position.

The principle of operation of the very first TV

And yet, the first television is considered to be a device created by the German engineer Paul Nipkow.
In 1884, he managed to develop a mechanical scanning device, which served as the basis for the production of a device called the “mechanical television.” The basis was an opaque disk, which made it possible to convert the “picture” into an electrical impulse. Its diameter was no more than 50 cm, and holes were drilled on the surface along the Archimedes spiral. Their number reached 200, although usually there were from 30 to 100. Opposite the disk, a photocell was mounted on one side, and a neon lamp on the other. At

As the circle rotated, light rays penetrated through the holes and hit the photocell, resulting in an image being projected.

The first devices were compact in size; the screen contained only 300 dots. This made it possible to reproduce only crude and primitive images. But although the quality left much to be desired - only silhouettes and shadow play, it was possible to discern what exactly the TV was showing.

Having achieved stunning success, the engineer patented his discovery, and his system was called the “Nipkow disk.” It was the main component and was used in the production of mechanical televisions. Since they remained small-line, their production ceased in the late 40s of the last century.

However, it was thanks to the “Nipkow disk” that the Swedish engineer John Bird managed to create a system capable of transmitting a moving picture. This made it possible to broadcast recognizable images of human faces. The unique development gave impetus to the creation of electronic devices.

However, officially, humanity owes the birth of the first electronic television to specialists from the American research laboratory RCA - Radio Corporation of America. A device suitable for practical use was created in 1936, and already in 1939 mass production of television equipment was established. The model was a wooden box equipped with a 5-inch diagonal screen and was named RCS TT-5.

The first television broadcast networks began operating in the early 1950s, and an advertising-based business model was immediately launched, which subsequently led to the further development of the television industry.

The advent of color television

Experiments with electron beams for receiving and transmitting images over certain distances began to be carried out in the 20s of the last century in the USA, Japan and the USSR. In 1933, a Russian-born American engineer invented the cathode tube, which is still the main component of modern televisions. However, five years earlier he also managed to develop a color television system. Due to the complexity of implementation, the practical application of the technology became possible only by 1950.

The first commercially available color TV was created by the same American laboratory RCA in 1954. At first, the models were equipped with 15-inch screens. Somewhat later, screens with diagonals of 19 and 21 inches were developed. Television equipment was desirable, but not everyone could buy it - the cost of the model reached $1,000 or more. However, soon it became possible to purchase equipment on credit, which marked the beginning of the mass distribution of color television broadcasting. The rapid growth of the receiving and transmitting television network occurred in the 50s of the 20th century. During this period, citizens began to actively use both black and white and color television models.

At first, color broadcasting was carried out on Rainbow TV devices, which had a rotating filter. And since the frequency range was incompatible with those used for conventional broadcasting, it was decided to develop and create equipment with simultaneous color transmission. In 1960, specialists from the laboratory of the Leningrad Electrotechnical Institute named after. Bonch-Bruevich, a prototype was made and soon after that the first experimental session took place.

Since tests of color TV systems were carried out in other countries of the world, in March 1965, an agreement was signed between the USSR and France on cooperation in the development of color TV based on the SECAM system. Without shelving the document, already in 1966 it was decided to introduce the SECAM-111 system in the USSR. The first programs began to be broadcast in Moscow on October 1, 1967, and on November 7, a color broadcast of the parade and workers’ demonstration took place on Red Square.

The introduction of color television has opened up broad prospects for improving the quality of broadcast programs and mastering new broadcasting standards. Before the advent of digital TV, the signal was transmitted via cable and radio relay communication channels. Special repeaters were used on airplanes. Television was divided into channels, which, as their number increased, were combined into packages. Some are still offered to the public in a paid format (about 30%).

On the approaches to the problem

In 1975, the VNIIT (All-Union Research Institute of Television) carried out exploratory research work “Forecast” to determine further ways to build color television equipment. In the process of its implementation, it was necessary to analyze the state and trends in the development of TV technology in the world and propose ways for its development in the USSR. At this time, in the country's television centers they worked on 2nd generation equipment (on transistors), and in the laboratories of the research institute they developed 3rd generation equipment (on microcircuits) using the SECAM system. The task of the search research work was to determine the main features of 4th generation TV equipment.

By this time, the first TV devices appeared abroad, which converted television signals into digital form and processed them. This innovation was based on the latest advances in microelectronics, thanks to which a memory device on integrated circuits was created that allows storing an entire frame of an image if the signal is presented in digital form. The acceptable dimensions of this device (less than one standard equipment cabinet) made it possible to use it to solve two pressing problems of broadcast TV: synchronizing signals from different sources and converting them from the American 525/60 standard to the European 625/50 standard and back. Digital processing turned out to be very useful for many applied applications of TV, and therefore the VNIIT departments dealing with non-broadcast television became interested in it.

The pioneers of digital TV were Doctor of Physical and Mathematical Sciences. Ilya Ioannovich Tsukkerman and Ph.D. Vyacheslav Pavlovich Mandrazhi. Under their leadership, the first domestic digital devices were developed - blocks for encoding TV images and introducing them into a computer for analysis, which included 6-bit analog-to-digital converters (ADC). Subsequently, I.I. Zuckerman and his collaborators (Ph.D. Boris Moiseevich Kats, Sergei Vitalievich Sardyko, etc.) developed algorithms and experimental digital devices to reduce the redundancy of digital signals (source coding), to filter them in order to improve quality, etc.

Subsequent work in this direction made it possible, in particular, to create equipment to increase the sensitivity of telescopes through digital signal processing and image formation using the photon counting method. But, not being a participant in these works, I will not be able to describe them here as they deserve.

Reporting on the results of the research project “Forecast” in our head office (5th Main Directorate of the Ministry of Communications Industry), I discussed the possibility of using digital technology in the equipment of 4th generation telecentres with the deputy chief engineer of the head office P.K. Kirillov. It was he who became the first person who expressed to me his firm opinion that this equipment should be digital (Pavel Konstantinovich Kirillov came to the main board from the Moscow Research Television Institute, where he was deputy director. Later he went to work in the industrial department of the apparatus of the CPSU Central Committee ).

Since I was in charge of the above-mentioned “Forecast” topic, based on its results I was asked to open a research project “Determination of ways to build 4th generation color TV transmitting equipment” (code - “Drawing”, 1976-1978). When drawing up the terms of reference for the research project “Drawing”, we wrote down in it the requirement for digital coding of TV signals inside the television center. Knowing the entire subsequent history, we can now say that for 1975 this was a very premature decision, since the element base of that time, and the entire level of technology, were not yet ready for such a sharp leap forward. But we were driven by the desire to stay at the forefront of global technical progress, there were hopes for a more rapid development of the element base, and we were extremely attracted by the opportunities that digital technology opened up. The transition to the digital 4th generation was a consensus decision of both many (but not all!) leading specialists and all of my then bosses (otherwise it could not have been accepted). Among them were: department head Yakov Abramovich Shapiro, who was the head of the development of television centers of the 1st, 2nd and 3rd generations; deputy chief engineer Viktor Timofeevich Esin, who oversaw all broadcast TV at VNIIT, and director of the institute Igor Aleksandrovich Rosselevich. The task was truly enormous: unlike applied TV, in broadcasting it was not about individual digital devices or small closed systems, but ultimately about the transfer to digital technology of such large technical systems as a television center.

During this period, an article was published by VNIIT employees Doctors of Science I.A. Rosselevichai I.I. Tsukkerman, candidates of sciences E.K. Ovchinnikova and B.M. Pevzner, engineers SV. Sardyko and V.E. Timofeeva “Digital coding of television images and prospects for its use on the body. 1976. Vol. 4). As far as I know, this was the first domestic article on digital TV. In it, in particular, the point of analog-to-digital conversion of TV signals (camera channel output) was selected, the optimal structure of the further path was determined, the fundamental advantages of digital coding and specific tasks of upcoming development were indicated.

During the three-year research work “Drawing”, we had to deal primarily with the development of ADCs and digital-to-analog converters (DACs), since commercially produced devices with 8-bit encoding and the speed required for broadcast TV did not yet exist. This work was entrusted to the Odessa branch of VNIIT (developers: Vadim Evgenievich Timofeev and Sergey Adolfovich Goryev). Much effort was also spent on developing digital codes for TV signals, since there were no international standards for digital coding yet. (The well-known Recommendation 601 of the CCIR was adopted only in 1982, and the more detailed Recommendation 656 - in 1986.) By the end of the “Drawing” topic, laboratory mock-ups of the main devices of the digital TV path had been created, but it became clear that it would be experimental to implement them based on - design development for mass production of telecentre equipment is not yet possible. The commission that accepted the completed research work agreed with our proposal to open another research project. However, this decision was met with very disapproval at the institute. As a rule, R&D should be followed by R&D (experimental design work) with the transfer of drawings to mass production, and taking into account the search topic “Forecast”, we got the third R&D in a row! Reporting at the scientific and technical council of VNIIT on the results of the “Drawing” topic, I spoke about the unavailability of the element base, the lack of a standard for digital coding, and other difficulties associated with the novelty of digital technology, and in the end it was decided to conduct another one three-year research project. However, director I.A. Rosselevich gave me a remark that I still remember well: “Oh, if I were younger, I would make you do OCD right away!” He was then 60.

The emergence of digital television

The history of digital television includes several stages of development, among which the transition to international broadcasting standards is considered the main one. By this time, the possibilities of transmitting television broadcasting had already expanded, resulting in the following:

• terrestrial – the television signal is transmitted through antennas and towers;
• cable - the signal arrives via a cable connected to the television receiver;

• 
  satellite – the signal is broadcast from a satellite and arrives at the set-top box (receiver) through a parabolic antenna (dish).

To transmit an encoded signal, hybrid analog-digital television systems were created, and digital technology began to be used.
The first proposals for this equipment began to arrive in 1990, and from that moment on the number of projects only increased. As a result, already in 1993, the last analog systems were withdrawn from consideration, and a year later, four groups of companies united in the “Grand Alliance” and created a project that became the basis of the MPEG-2 standard. At the same time, the DVB (Digital Video Broadcasting) project was developed in Europe - Digital Video Broadcasting, based on the mentioned standard. Today, signal encoding is carried out according to three world standards:

• European;
• American;
• Japanese.

The main advantage of broadcasting in this format is the low level of interference and the ability to receive high-resolution images. The world is actively replacing analog television with digital television.

Digital TV came to Russia a little later in 1999 after the State Communications Committee approved the “Concept for the introduction of terrestrial digital audio and television broadcasting systems in the Russian Federation.” This process was supposed to be carried out in two stages. As a result, the project was successfully implemented, and at the moment Russia has completely switched to digital broadcasting.

With the development of data exchange technology through encoded signals and the increasing capabilities of data transmission channels, Internet broadcasting has gained popularity. This option is considered economical in terms of cost and convenient due to the combination of almost all types of media content into one package of services and access to viewing it at any time of the day.

Digital TV: history of formation and main advantages

Since its inception in the last century, television has come a long way and achieved impressive results. It has covered almost the entire population of the Earth, expanded its functions and capabilities for transmitting television programs through various channels: cable, satellite and terrestrial. And finally, we have come to the stage of implementing a massive transition to a completely digital broadcast format. In Russia, the transition to digital was completely completed at the end of 2019.

The need to switch to digital television became tangible 20-30 years ago. But then some technical obstacles stood in the way of digital television, and only in the late eighties and early nineties of the twentieth century were they overcome. With the help of a special commission of experts and the development of technology, the problems of compressing video signals for transmitting moving images were successfully solved. All these successes were largely associated with high achievements in microelectronics. After this, the fate of analog television was sealed, and the transition to digital broadcasting became not so much possible as inevitable.

Analogue television was broadcast according to the Stockholm plan, developed back in 1961, which determined the principle of frequency planning and frequency assignment. A regional conference was held in June 2006 to review the digital terrestrial broadcasting plan. All experts recognized the undeniable advantage of digital television, which, according to their estimates, is six times superior to analogue.

With digital broadcasting, the quality of the television signal is much higher than with analogue; in addition, the digital signal is much more noise-resistant. The amount of electricity consumed by a digital transmitter, per one broadcast transmission, is also reduced several times. This will allow you to significantly save energy when using a digital transmitter than when using an analogue one, with the same broadcast area.

Better and more stable TV signal reception can be obtained both by using an outdoor stationary antenna and by using an indoor antenna, since the digital signal is less susceptible to interference and noise. The signal can be received both by special digital receivers and analogue ones with a digital set-top box. Thus, the introduction of new digital technologies does not at all cancel out the old ones, which allows them to exist in parallel with each other.

Thus, we can summarize and point out the main advantages of digital TV:

• increasing image quality;
• a single digital coding standard that eliminates the need for numerous incompatible color television systems;
• possibility of using stereo sound;
• small amount of electricity consumed by transmission equipment;
• increasing the number of television programs on one channel;
• ensuring sufficient mobile TV signal reception in large cities, which will lead to a higher quality image.

But the processes of complete digitalization of television have not yet been completed. At the moment, the service of paid access to high-quality television channels as part of “Triple Play” packages, within which subscribers receive broadband access to the Internet along with home telephony and television, has gained mass demand. A separate driver for the development of modern TV is IPTV and paid OTT services.

The era of digital and smart television

Despite the fact that digital television was created in the early 1990s, by the early 2000s it had become commonplace. The availability of viewing programs in this format is due to the advent of inexpensive but high-performance computers. Therefore, today video content is transmitted in high definition and widescreen aspect ratio.

The massive popularization of such equipment at the beginning of 2010 prompted the largest manufacturers not only to think about it, but also to begin developing and producing “smart” TVs, which, having a standard set of options, acquired built-in Internet functions and interactive web version 2.0.

According to statistics (as of 2021), about 70% of TVs sold worldwide are “smart”. At the same time, it is expected that in the coming years such technology will become even more popular, and, accordingly, accessible. Therefore, there is a high probability that it will very quickly displace conventional TV receivers and even more modern models from the market.

Already today, televisions broadcast exclusively in 3D format and are controlled via satellites. Smart functionality allows you to automatically save films and programs that are popular with viewers. This allowed many users to create a list of their favorite programs, creating their own channel, and enjoy watching at any time of the day.

The history of television in our country

In parallel with developed countries, active development of television equipment was carried out on the territory of the Soviet Union. It is enough to look at the chronology of events of those decades to understand how seriously the government approached the development of television broadcasting.

Television broadcasting was temporarily suspended only during the Great Patriotic War, but work in the field of creating advanced television equipment did not stop. Soviet scientists and inventors P.V. Timofeev, S.I. Kataev, L.A. Kubetsky, P.V. Shmakov, G.V. Braude, A.A. Chernyshev and others made an invaluable contribution to the development of television.

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Close to the future

In fact, in 1979-1881, not one, but two parallel research projects were carried out - “Etching” (as a continuation of “Drawing”) and “Estamp” to create a digital mixer and a video effects unit based on frame memory. The head of the Estamp research project was Ph.D. Albert Konstantinovich Bukharov, and the leading developers are Igor Vladimirovich Nagibin and Vyacheslav Vasilyevich Rybakov.

In the course of these two coordinated works, a working model of an end-to-end digital TV path from the camera channel output to the television center output was made. It implemented all the necessary functions for creating a color television broadcast, including new effects that are only possible in digital form. On a model of the tract, not only were all the blocks tested in their interaction, but also examinations were carried out to subjectively assess the quality of the images. Much work on the assembly and testing of this complex was carried out by Tatyana Firsovna Yelinekene.

Based on these works, it was finally decided to organize R&D to develop a 4th generation television center. The director appointed deputy chief engineer V.T. as the chief designer of the new theme, which was given the code “Studio”. Yesin, and I became his first deputy. This was a large five-year work, occupying the second place in volume among all the works of the institute. In addition to VNIIT, it was attended by VNIIRPA, which developed all the 4th generation sound equipment (this work was led by Ph.D. Viktor Semenovich Nemanov), Kirovograd and Aleksandrovsky radio plants, as well as several educational institutes. VNIIRPA ordered the production of audio equipment in Hungary and Czechoslovakia; this equipment was mainly analog (with a digital control system), and this article does not talk about it.

Already the very first stage of work - drawing up a technical specification and agreeing it with the customer - turned out to be a complex and lengthy process. Our regular customer - the State Television and Radio Broadcasting Center of the USSR, which was represented by the main production and technical department (GPTU, chief engineer V.M. Palitsky) and leading specialists of the Moscow Television Center (TTC) - demanded the implementation of all the world-known achievements of TV broadcasting technology and technology, and also ensure maximum ease of use. The requirements are, in general, quite legal, but their implementation led to a significant increase in the volume and cost of equipment and its energy consumption.

On the “Studio” theme, a hardware-studio unit was developed (Deputy Chief Designer for ASB Tatyana Moiseevna Lyakhova), a digital sector of the central hardware room of the television center (Deputy Chief Designer for AC Semyon Abramovich Sherman), as well as digital connecting lines between hardware rooms. The ASB is the main hardware room of the television center; television programs are generated in it. Its digital telecontrol system, which allows the connection of a control computer, made it possible to easily assemble a hardware-software unit (HSU) on its basis for editing and automatically broadcasting the current television program. Thus, almost all the components of the future television center were created at the Studio R&D.

As part of a separate R&D project “TKA-4”, the task was set to develop a 4th generation telecine projection room (the leading developer of the telecine projector was Vladimir Nikolaevich Roldugin, now the general director (“Film and Television Equipment.” 1977. No. 9) it was proposed to transmit both in each line color signal with 8-bit encoding. This led to a clock frequency of 18.75 MHz and a digital flow of 150 Mbit/s. This code was implemented in laboratory layouts on the topics “Etching” and “Printmaking.” But in 1981 it became clear that CCIR would adopt higher sampling rates of 13.5 MHz for the luma signal and 6.75 MHz for the chrominance signal, which gave a clock frequency of 27 MHz and a bit rate of 216 Mbit/s.

Digital code synchronization parameters were developed by the CCIR much later. But Soviet specialists took an active part in the work of the ICKR, monitored all incoming contributions, and we took the risk of developing the equipment of the “Studio” order in 1982-1984 in accordance with the standards being prepared, which were officially adopted by the ICKR only in 1982 and 1986.

To be continued

Published: Broadcasting Magazine.
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