• Why can't sound waves be transmitted over long distances?
• Decipher the drawing.

• What is the detection process for?
• A. for signal transmission over long distances;
• B. to detect objects;
• B. To isolate a low-frequency signal;
• D. To convert a low-frequency signal.

• The process of detecting objects using radio waves is called...
• A. scan
• B. radar
• B. Broadcasting
• D. Modulation
• D. detection

HISTORY OF DEVELOPMENT OF TELEVISION

• At the origins stands Willoughby Smith, who invented the photoelectric effect in selenium.

HISTORY OF DEVELOPMENT OF TELEVISION

• The next stage of the discovery is associated with the name of the Russian scientist Boris Rosing, who patented the electrical method for transmitting images.

HISTORY OF DEVELOPMENT OF TELEVISION

• P. Nipkov, D. Byrd, J. Jenkins, I. Adamyan, L. Theremin also contributed to the discovery. They independently create transmitters for broadcasting images in different countries.

Scottish engineer John Baird succeeded in transmitting a black and white image of a ventriloquist doll in 1925. The image was scanned in 30 lines vertically, five images per second were transmitted. For the first time in history, details of the transmitted image could be discerned.

HISTORY OF DEVELOPMENT OF TELEVISION

• In 1880, the scientist Porfiry Ivanovich Bakhmetiev (Russia) and almost at the same time the physicist Adriano de Paiva (Portugal) formulated one of the basic principles of television - the decomposition of an image into separate elements for their sequential sending to a distance. Bakhmetiev theoretically substantiated the process of operation of the television system, which he called the "telephotographer", but did not build the device itself.

HISTORY OF DEVELOPMENT OF TELEVISION

• The next round of technology development is associated with the advent of electronic television. M. Dickman and G. Glage registered the creation of a tube for transmitting images.

HISTORY OF DEVELOPMENT OF TELEVISION

• But the first patent for the technology, which is still used in televisions today, was received by Boris Rosing in 1907.

HISTORY OF DEVELOPMENT OF TELEVISION

• in 1931, engineer V. Zworykin creates an iconoscope, which is considered the first television.

HISTORY OF DEVELOPMENT OF TELEVISION

• Based on this invention, the American inventor Philo Farnsworth creates a kinescope.

HISTORY OF DEVELOPMENT OF TELEVISION

• The principle of operation of television is a special projection of the image on a photosensitive plate in a cathode ray tube. For a long time, the history of television has been associated with the improvement of this tube, which led to an increase in the quality of the picture and to an increase in the screen surface. But with the advent of digital broadcasting, the principle has changed, now a kinescope with a ray tube is no longer needed. It uses a completely different way of transmitting an image. It is encoded and transmitted using digital channels and through Internet systems.

Black and white and color television

• Color kinescope device. 1 - Electron guns. 2 - Electron beams. 3 - Focusing coil. 4 - Deflecting coils. 5 - Anode. 6 - Mask, due to which the red beam hits the red phosphor, etc. 7 - Red, green and blue grains of the phosphor. 8 - Mask and phosphor grains (enlarged).

According to the method of signal transmission, television can be divided into:

terrestrial, in this case the television receiver receives a signal from a television tower, this is the most familiar and common way of broadcasting;

cable, in this case, the signal comes from the transmitter via a cable connected to the TV;

satellite - the signal is transmitted from the satellite and is captured by a special antenna, which transmits the image to a special set-top box connected to the TV;

Internet TV, in this case the signal is transmitted through the Network.

According to the method of encoding information, television is divided into analog and digital.

Fill in the table at home (p. 58 + Internet)

Modern means connections

Means of communication

How the work is done

additional information

In the modern world, there are various means of communication that are constantly evolving and improving. Even such a traditional type of communication as a postal message (delivery of messages in writing) has undergone significant changes. This information is delivered by railroads and airplanes instead of the old mail coaches.

With the development of science and technology, new types of communication appear. So in the 19th century, a wire telegraph appeared, through which information was transmitted using Morse code, and then the telegraph was invented, in which dots and dashes were replaced by letters. But this type of communication required long transmission lines, laying cables under the ground and water, in which information was transmitted by means of electrical signals. The need for transmission lines remained in the transmission of information by telephone.

At the end of the 19th century, radio communication appeared - the wireless transmission of electrical signals over long distances using radio waves ( electromagnetic waves with a frequency in the Hz range). But for the development of this type of communication, it was necessary to increase its range, and for this it was necessary to increase the power of transmitters and the sensitivity of receivers receiving a weak radio signal. These problems were gradually solved with the advent of new inventions - vacuum tubes in 1913, and after the Second World War they began to be replaced by semiconductors. integrated circuits. Powerful transmitters and sensitive receivers appeared, their sizes decreased, and their parameters improved. But the problem remained - how to make radio waves go around the globe.

And the property of electromagnetic waves was used to be partially reflected at the interface between two media (waves were reflected weakly from the surface of the dielectric, and almost without loss from the conducting surface). As such a reflective surface, the layer of the earth's ionosphere, the upper layer of the atmosphere consisting of ionized gases, began to be used).

Back in 1902, English mathematician Oliver Heaviside and American electrical engineer Arthur Edwin Kennelly almost simultaneously predicted that an ionized layer of air exists above the Earth - a natural mirror that reflects electromagnetic waves. This layer was called the ionosphere. The Earth's ionosphere was supposed to make it possible to increase the range of propagation of radio waves to distances exceeding the line of sight. Experimentally, this assumption was proven in Radio frequency pulses were transmitted vertically upwards and returned signals were received. Measurements of the time between sending and receiving pulses made it possible to determine the height and number of reflection layers.

Reflected from the ionosphere, short waves return to the Earth, leaving hundreds of kilometers of the "dead zone" under them. Having traveled to the ionosphere and back, the wave does not “calm down”, but is reflected from the surface of the Earth and again rushes to the ionosphere, where it is reflected again, etc. Thus, repeatedly reflected, the radio wave can go around the globe several times. It was found that the reflection height depends primarily on the wavelength. The shorter the wave, the higher its reflection occurs and, consequently, the larger the “dead zone”. This dependence is true only for the short-wavelength part of the spectrum (up to approximately 25–30 MHz). For shorter wavelengths, the ionosphere is transparent. Waves penetrate it through and through and go into outer space. It can be seen from the figure that the reflection depends not only on the frequency, but also on the time of day. This is due to the fact that the ionosphere is ionized by solar radiation and gradually loses its reflectivity with the onset of darkness. The degree of ionization also depends on solar activity, which varies throughout the year and from year to year in a seven-year cycle.

This layer perfectly reflects radio waves from a length of meters. Repeatedly and alternately reflected from the ion of the sphere and the surface of the earth, short radio waves go around the globe, transmitting information to the most remote parts of the planet. After being telephone invented and found ways to implement long-range radio communications, naturally there was a desire to combine these two achievements. It was necessary to solve the problem of transmitting low-frequency electrical vibrations created by the vibration of the telephone receiver membrane under the influence of the human voice. And it was solved by mixing these low frequency vibrations with the high frequency electrical vibrations of the radio transmitter. The form of high-frequency radio waves changed in strict accordance with what sounds gave rise to low-frequency electrical vibrations. Sound vibrations began to propagate at the speed of radio waves. In the radio receiver, the mixed radio signal was separated and low-frequency sound vibrations reproduced the transmitted sounds.

Significant achievements in the development of communications were the invention of the phototelegraph and television communications. Video signals are transmitted with the help of these means of communication. Now, with the help of phototelegraphy, the text of newspapers and various information are transmitted over great distances. The number of television channels that occupy the region of ultra-high radio frequencies from 50 to 900 MHz is constantly growing. Each television channel is about 6 MHz wide. Within the operating frequency of the channel, 3 signals are transmitted: audio, transmitted according to the method frequency modulation; video signal transmitted by the method of amplitude modulation; synchronization signal.

Naturally, for the implementation of television communications, two transmitters are already needed: one for sound, the other for video signals. The next step in the improvement of television communications was the invention of color television. But modern requirements for communication facilities all the time require their further improvement, now the introduction of digital information, image, sound transmission systems is beginning, which in the future will replace the current analog television. Television receivers of the new generation allow you to receive digital and analog transmissions. Familiar TV screens and displays are being replaced by liquid crystal displays. Liquid crystal silicone displays using thin-film technology can dramatically reduce energy consumption due to the fact that the backlight of the screen is not needed. Sharp has already created televisions with new features that have access to the Internet and allow you to use e-mail. The use of digital systems, liquid crystals, and optical fibers in communication means made it possible at the turn of the century to solve several extremely important problems for humans at once: reducing energy consumption, reducing (or, conversely, increasing) the size of equipment, multifunctionality, and accelerating information exchange.

With the help of such communication satellites, a variety of information is transmitted: from radio and television broadcasts to top-secret military information. A communications satellite was recently launched to carry out financial transactions Russian banks, which will greatly speed up the passage of payments in such a vast territory as our country. Entire satellite communications networks are being created that will make it possible to easy access Russian regional users to global information flows. Network subscribers in the regions will receive satellite channel communications the following services: fax, telephone, Internet, radio and TV programs.

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Presentation on the topic: Means of communication

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Answer the questions What is called an infrastructure complex? What unites the infrastructure complex? What sectors are included in the infrastructure complex? What is the difference between the production and non-production spheres of the complex? What area of ​​the complex can be attributed to the topic of our lesson?

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Postal communication In the old days in Russia, communication between the capital and peripheral cities, as well as between the troops participating in hostilities, was carried out with the help of special rider messengers. This method was improved by the Tatars, having created on the roads at a distance of 30 - 40 km. special stations ("pits"), where the coachmen could rest and change horses. In the 17th century, Moscow was connected by such "pits" with Novgorod, Pskov, Smolensk, Arkhangelsk and Nizhny Novgorod. The first regular post office for sending government papers and letters from merchants was established in 1666. Under Peter I, maximum deadlines (norms) for delivering correspondence were established. Under Catherine II, a peculiar tax was introduced for letters and parcels, depending on the weight and distance of their transportation. In the 19th century, postal institutions were transferred to the Ministry of the Interior. The main function of mail was to send simple and registered letters, postcards (introduced in 1872) and parcels. Money, including copper, silver and gold coins, could be sent in small quantities in special packages and leather bags. They, like valuable parcels, were insured. Since 1897, they began to accept postal, and then telegraphic money transfers. The post office also took over the delivery of periodicals, charging for this, depending on the frequency of publication of newspapers or magazines, from 6 to 18% of the total subscription price. The following data testifies to the dynamic development of the postal service. If in 1897 in Russia there were only 2.1 thousand postal and telegraph institutions, then in 1913 their number increased to 11 thousand, and the total length of postal routes increased to 261 thousand km.

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Telephone communication The telephone first appeared in Russia in 1880. Initially, the government planned to establish a state monopoly on the device. telephone communication. However, due to the high cost of building and operating telephone exchanges, private capital began to be attracted to their creation. According to the concluded contracts, telephone exchanges and lines built at the expense of private companies, after 20 years of operation, became state property. By the beginning of the 20th century, there were 77 state and 11 private telephone exchanges in Russia. Telephone charges in the public sector were half those in the private sector. In total, in 1913, 300 thousand telephone sets were installed in Russian cities.

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Peculiarities of telephone communications The main indicator of the development of the public telecommunication services market is telephone density (TP), that is, the number of telephones per 100 inhabitants, which is directly correlated with GDP per capita. According to official statistics, at the end of the 90s, the telephone fleet in Russia consisted of more than 31 million devices, that is, there were 21 telephones per 100 Russians, while the same number of residents of the United States and Western European countries - from 60 to 70 telephones . In Russia, at the beginning of the third millennium, 54,000 telephones were not installed. settlements, there were b million people on the waiting list and about 50 million potential phone owners. Tariffs for local telephone communication for the population were lower than the actual cost

slide number 7

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Radio and television communications At the end of the 19th century, radio communications appeared - the wireless transmission of electrical signals over long distances using radio waves (electromagnetic waves with a frequency in the range of 105-1012 Hz). Later, powerful transmitters and sensitive receivers appeared, their sizes decreased, and their parameters improved. Significant achievements in the development of means of communication were the inventions of the phototelegraph and television communications. Video signals are transmitted with the help of these means of communication. For television communication, two transmitters are already needed: one for sound, the other for video signals. The next step in the improvement of television communications was the invention of color television.

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Telegraph communications The first telegraph line appeared in Russia in 1835. It connected St. Petersburg with Kronstadt and was intended for the needs of the military department. Four years later, the construction of the second line was completed, which connected the northern capital with Warsaw. Since the mid-1950s, where the railways were being built, the German company Siemens has been laying a telegraph equipped with new electromagnetic technology. By the beginning of the 20th century, the length of state telegraph lines amounted to 127 thousand miles. By that time, underwater telegraph cables had been laid connecting Russia with Denmark and Sweden. Russian telegraph lines were connected to telegraph lines in China and Japan. If in 1897 14 million internal telegrams were sent, then in 1912 more than 36 million were already sent.

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Description of the slide:

Telegram - a message sent by telegraph, one of the first types of communication using electrical transmission of information. Telegrams are transmitted, as a rule, by wire, using Morse code. Telegrams are printed on a paper tape, which is then pasted onto a sheet of paper for ease of reading. Telegraph (from the Greek tele - “far away” + grapho - “I write”) - in modern meaning- a means for transmitting a signal over wires or other telecommunication channels.

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Satellite connection Satellite communication is one of the types of radio communication based on the use of artificial earth satellites as repeaters. Satellite communication is carried out between earth stations, which can be both stationary and mobile. Network subscribers in the regions will receive the following services via a satellite communication channel: fax, telephone, Internet, radio and TV programs.

"The Russian army in the next two years should be fully equipped with modern digital communications" D.A. Medvedev, 25.05.2010.

The head of state set three priority tasks for

Ministry of Defense:

until 2012 to replace in the Armed Forces

outdated analog communications digital as

at command posts and in the field.

stimulate development and production in Russia

the latest telecommunications equipment and

software

development of communication subsystems in the field of public

security and law enforcement, which could actually reduce the number of crimes.

Glonass

Global Navigation Satellite System (GLONASS, GLONASS ) - Russian system navigation, developed by order of the Ministry of Defense of the Russian Federation. One of two systems of global satellite navigation functioning today.

GLONASS is intended for operational navigation and time support for an unlimited number of ground, sea, air and space-based users. Access to civilian GLONASS signals anywhere in the world, on the basis of a decree of the President of the Russian Federation, is provided to Russian and foreign consumers free of charge and without restrictions.

Second generation GLONASS satellite

The developer and manufacturer of the satellites is JSC "ISS" named after Academician M. F. Reshetnev, the city of Zheleznogorsk. Krasnoyarsk region.

The GLONASS system determines the location of an object with an accuracy of up to 4.5 meters, but in early 2012 the accuracy will be increased from 4.5 meters to 2.5-2.8 meters. And after the two satellites for correcting the signal of the Luch system are put into operation, the accuracy of the GLONASS navigation signal will increase to one meter. (Previously, the system only determined the location of an object with an accuracy of 50 m.

Army in 3D

In a training battle, a reconnaissance motorized rifle unit must obtain as much information as possible in a unit of time.

Everything must be taken into account: the location of the enemy, the features of the terrain, the presence of ditches, hollows, communications. One visual observation is not limited here, aerial reconnaissance, which is carried out by an unmanned aerial vehicle, will be a good addition.

All information received about the situation on the battlefield is displayed on a special interactive electronic map.

It allows you to watch the full picture of the battle. One could only dream of such opportunities when using ordinary paper maps. According to Anton Apanasenko, who is the acting commander of the reconnaissance battalion, published on the Vesti website, it used to take a lot of time to build various graphs, build terrain patterns used to determine the visibility zones of objects. When using an electronic map, all this information is updated in a few mouse clicks every second.

The development of military electronic maps is carried out by the 38th Central Aerial Photo-Topographic Detachment, located in Noginsk, Moscow Region. A huge number of satellite images flock here, after which they are tied to the terrain in the coordinate system. The photographs are used to create maps. Detachment commander Alexei Anisov notes that the unit uses equipment and software only Russian-made, directly used in the process of creating topographic maps in electronic form. IN this moment For this, digital versions of satellite aerial photographs are used.

slide 2

Answer the questions

What is an infrastructure complex? What unites the infrastructure complex? What sectors are included in the infrastructure complex? What is the difference between the production and non-production spheres of the complex? What area of ​​the complex can be attributed to the topic of our lesson?

slide 3

Communication is a branch of the economy that provides the reception and transmission of information.

What do you think the postal service does?

slide 4

Postal service

In the old days in Russia, communication between the capital and peripheral cities, as well as between the troops participating in hostilities, was carried out with the help of special rider messengers. This method was improved by the Tatars, having created on the roads at a distance of 30 - 40 km. special stations ("pits"), where the coachmen could rest and change horses. In the 17th century, Moscow was connected by such "pits" with Novgorod, Pskov, Smolensk, Arkhangelsk and Nizhny Novgorod. The first regular post office for sending government papers and letters from merchants was established in 1666. Under Peter I, maximum deadlines (norms) for delivering correspondence were established. Under Catherine II, a peculiar tax was introduced for letters and parcels, depending on the weight and distance of their transportation. In the 19th century, postal institutions were transferred to the Ministry of the Interior. The main function of the post office was to send ordinary and registered letters, postcards (introduced in 1872) and parcels. Money, including copper, silver and gold coins, could be sent in small quantities in special packages and leather bags. They, like valuable parcels, were insured. Since 1897, they began to accept postal, and then telegraphic money transfers. The post office also took over the delivery of periodicals, charging for this, depending on the frequency of publication of newspapers or magazines, from 6 to 18% of the total subscription price. Electric traditional communication The following data testifies to the dynamic development of postal communication. If in 1897 in Russia there were only 2.1 thousand postal and telegraph institutions, then in 1913 their number increased to 11 thousand, and the total length of postal routes increased to 261 thousand km.

slide 5

Telephone communications

The telephone first appeared in Russia in 1880. Initially, the government planned to establish a state monopoly on telephone communications. However, due to the high cost of building and operating telephone exchanges, private capital began to be attracted to their creation. According to the concluded contracts, telephone exchanges and lines built at the expense of private companies, after 20 years of operation, became state property. By the beginning of the 20th century, there were 77 state and 11 private telephone exchanges in Russia. Telephone charges in the public sector were half those in the private sector. In total, in 1913, 300 thousand telephone sets were installed in Russian cities.

slide 6

Features of telephone communication

The main indicator of the development of the public telecommunication services market is telephone density (TP), that is, the number of telephones per 100 inhabitants, which is directly correlated with GDP per capita. According to official statistics, at the end of the 90s, the telephone fleet in Russia consisted of more than 31 million devices, that is, there were 21 telephones per 100 Russians, while the same number of residents of the United States and Western European countries - from 60 to 70 telephones . In Russia, at the beginning of the third millennium, 54 thousand settlements were not provided with telephones, there were 6 million people on the waiting list and about 50 million potential telephone owners. Tariffs for local telephone communication for the population were lower than the actual cost

Slide 7

radio and television communications

At the end of the 19th century, radio communication appeared - the wireless transmission of electrical signals over long distances using radio waves (electromagnetic waves with a frequency in the range of 105-1012 Hz). Later, powerful transmitters and sensitive receivers appeared, their sizes decreased, and their parameters improved. Significant achievements in the development of means of communication were the inventions of the phototelegraph and television communications. Video signals are transmitted with the help of these means of communication. For television communication, two transmitters are already needed: one for sound, the other for video signals. The next step in the improvement of television communications was the invention of color television.

Slide 8

Telegraph communication

The first telegraph line appeared in Russia in 1835. It connected St. Petersburg with Kronstadt and was intended for the needs of the military department. Four years later, the construction of the second line was completed, which connected the northern capital with Warsaw. Since the mid-1950s, where the railways were being built, the German company Siemens has been laying a telegraph equipped with new electromagnetic technology. By the beginning of the 20th century, the length of state telegraph lines amounted to 127 thousand miles. By that time, underwater telegraph cables had been laid connecting Russia with Denmark and Sweden. Russian telegraph lines were connected to telegraph lines in China and Japan. If in 1897 14 million internal telegrams were sent, then in 1912 more than 36 million were already sent.

Slide 9

Telegram - a message sent by telegraph, one of the first types of communication using electrical transmission of information. Telegrams are transmitted, as a rule, by wire, using Morse code. Telegrams are printed on paper tape, which is then pasted onto a piece of paper for ease of reading. Telegraph (from the Greek tele - "far" + grapho - "I write") - in the modern sense - a means for transmitting a signal over wires or other telecommunication channels. Electrical new connection

Slide 10

slide 11

Satellite connection

Satellite communication is one of the types of radio communication based on the use of artificial earth satellites as repeaters. Satellite communication is carried out between earth stations, which can be both stationary and mobile. Network subscribers in the regions will receive the following services via satellite communication channel: fax, telephone, Internet, radio and TV programs.

slide 12

Digital communication is a field of technology related to the transmission of digital data over a distance.

slide 13

Telex communication

By 1930, the design of a start-stop telegraph apparatus equipped with a telephone-type disk dialer (teletype) was created. This type of telegraph apparatus, among other things, made it possible to personalize the subscribers of the telegraph network and to quickly connect them.

Slide 14

E-mail (eng. E-mail or email, abbr. from electronic mail) - a method of transmitting information to computer networks, widely used on the Internet.

Main Feature Email: information is sent to the recipient not directly, but through an intermediate link - electronic Mailbox, which is the location on the server where the message is stored until requested by the recipient.

slide 15

Cellular communication is one of the types of mobile radio communication, which is based on a cellular network.

Cellular phone - a mobile communication device that uses a combination of radio transmission and traditional telephone switching to carry out telephone communications in an area (coverage area) consisting of "cells" surrounding base stations cellular network. Currently, cellular communication is the most widespread of all types. mobile communications, which is why it is usually called a mobile phone cellular telephone, although radiotelephones are also mobile phones in addition to cellular phones, satellite phones and trunking communication devices. Penetration cellular communication in Russia it was 87%, and in Moscow and St. Petersburg it has already reached the milestone of 100%.

Slide 17

The number of Russians who have at their disposal Cell phones, rose from 40% in mid-2005 to 52% this year. More than half of Russians, 55%, already use telephone communications at home (there have been one percent increase over the year). According to sociologists, the number of Russians who have a computer at home is also growing - now 20% of respondents have it (15% a year ago). As the study showed, now 19% of Russians (against 17% a year ago) use personal computer daily or several times a week at home, at work and in other places, 5% - about once a week (3%), never use a computer - 73% (last year - 76%).

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