Modern means of communication. Telephone network The telephone network is the most common type of operational communication.

Description of the presentation on individual slides:

1 slide

Description of the slide:

2 slide

Description of the slide:

What is communication and means of communication? Communication is the most important link in the country's economic system, a way for people to communicate, to satisfy their production, spiritual, cultural and social needs. Communication means - hardware and software devices used for the formation, reception, processing, storage, transmission, delivery of telecommunication messages or mail, as well as other hardware and software used in the provision of communication services or the operation of communication networks.

3 slide

Description of the slide:

Communication types. Wireless Wireless communication is the transmission of information over a distance without the use of electrical conductors or "wires". Wired Wired communication - communication in which messages are transmitted over wires by means of electrical signals; type of telecommunication

4 slide

Description of the slide:

The main directions of development of means of communication. Radio communication Telephone communication Television communication Cellular communication Internet Space communication Phototelegraph (Fax) Videotelephone communication Telegraph communication

5 slide

Description of the slide:

Stages of development of means of communication. Creation of an optical telegraph. Optical telegraph - a device for transmitting information over long distances using light signals. Invented by the Frenchman Claude Chappe.

6 slide

Description of the slide:

The first electric telegraph was created in 1837 by English inventors William Cook and Charles Whitson.

7 slide

Description of the slide:

Morse code. Samuel Finley Breeze Morse is an American inventor and artist. The most famous inventions are the electromagnetic writing telegraph and the Morse code. He developed signs for each letter of dots and dashes.

8 slide

Description of the slide:

The invention of radio. Scheme and appearance of the radio receiver A.S. Popov made by himself The relay worked, the bell turned on, and the coherer received a “light shake”, the adhesion between the metal filings weakened, and they were ready to receive the next signal At first, radio communication was established at a distance of 250 m. working on his invention, Popov soon achieved a communication range of more than 600 m. Then, at the maneuvers of the Black Sea Fleet in 1899. the scientist established radio communication at a distance of over 20 km, and in 1901. The radio communication range was already 150 km. The new design of the transmitter played an important role in this.

9 slide

Description of the slide:

Satellite connection. Satellites are unmanned space vehicles that fly in orbit around the Earth. They can transmit telephone conversations and television signals anywhere in the world. They also transmit weather and navigation information. In 1957, the USSR launched Sputnik 1, the world's first artificial Earth satellite.

10 slide

Description of the slide:

Fiber-optic communication lines Fiber-optic communication lines (FOCL) are currently considered the most advanced physical medium for information transmission. Data transmission in optical fiber is based on the effect of total internal reflection. Thus, the optical signal transmitted by the laser on one side is received on the other, much more distant side. To date, a huge number of trunk fiber-optic rings, intracity and even intra-office, have been built and are being built. And this number will continue to grow.

11 slide

Description of the slide:

Laser communication system. A rather curious solution for high-quality and fast network communication was developed by the German company Laser2000. The two presented models look like the most ordinary video cameras and are designed for communication between offices, inside offices and along corridors. Simply put, instead of laying an optical cable, you just need to install inventions from Laser2000. However, in fact, these are not video cameras, but two transmitters that communicate with each other by means of laser radiation. Recall that a laser, unlike ordinary light, such as lamp light, is characterized by monochromaticity and coherence, that is, laser beams always have the same wavelength and scatter little.

Introduction The way the world works is that any technical invention of the human mind that expands our capabilities and creates additional comfort for us inevitably contains negative aspects that may pose a potential danger to the user. Modern means of personal communication are no exception in this regard. Yes, they have expanded our freedom immeasurably by "untethering" us from the telephone set on the desktop and giving us the opportunity to contact the necessary correspondent at any time and in any place.

Telephone Cellular mobile phones are in fact a complex miniature radio transceiver. Each cellular phone is assigned its own Electronic Serial Number (ESN), which is encoded on the phone's microchip when it is manufactured and communicated by the device manufacturers to service providers.

A mobile cell phone has a large and sometimes unlimited range, which is provided by the cellular structure of communication zones. The entire territory served by a cellular communication system is divided into separate communication zones adjacent to each other, or cells. Telephone traffic in each such zone is controlled by a base station capable of receiving and transmitting signals on a large number of radio frequencies. A mobile cell phone has a large and sometimes unlimited range, which is provided by the cellular structure of communication zones. The entire territory served by a cellular communication system is divided into separate communication zones adjacent to each other, or cells. Telephone traffic in each such zone is controlled by a base station capable of receiving and transmitting signals on a large number of radio frequencies.

Pagers Pagers are mobile radios with letter, numeric, or mixed message logging, operating primarily in the 100-400 MHz band. The paging system receives a message from a telephone subscriber, encodes it into the desired format and transmits it to the pager of the called subscriber.

Fixed wireless radiotelephone A fixed wireless radiotelephone combines a conventional wired telephone, represented by the device itself, connected to the telephone network, and a radio transceiver in the form of a handset that provides two-way signal exchange with the base device. Depending on the type of radiotelephone, the communication range between the handset and the device, taking into account the presence of interference and reflective surfaces, is on average up to 50 meters.

Radio and television stations Widespread sources of electromagnetic field (EMF) in populated areas at present are radio transmission centers (RTTC), emitting ultrashort waves of very high (VHF) and ultra-high (UHF) ranges into the environment.

Television station Television transmitters. Television transmitters are located, as a rule, in cities. Transmitting antennas are usually located at a height above 110 m. From the point of view of assessing the impact on health, field levels at a distance of several tens of meters to several kilometers are of interest. Typical electric field strengths can reach 15 V/m at a distance of 1 km from a 1 MW transmitter.

Conclusion It is impossible to see electromagnetic radiation, but not everyone can imagine it, and therefore a normal person is almost not afraid of it. Meanwhile, if we sum up the influence of electromagnetic radiation from all devices on the planet, then the level of the natural geomagnetic field of the Earth will be exceeded millions of times. The scale of electromagnetic pollution of the human environment has become so significant that the World Health Organization has included this problem among the most urgent for mankind, and many scientists attribute it to potent environmental factors with catastrophic consequences for all living things.

The work can be used for lessons and reports on the subject "Technology"

This section contains the best reports and presentations on technology and mechanical engineering.

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, abbreviated from electronic mail) - a method of transmitting information in computer networks, is widely used on the Internet.

The main feature of e-mail: information is not sent directly to the recipient, but through an intermediate link - an electronic mailbox, which is a place on the server where the message is stored until the recipient requests it.

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 of a cellular network. Currently, cellular communications are the most common of all types of mobile communications, therefore, a cell phone is usually called a mobile phone, although mobile phones, in addition to cellular phones, also include radio telephones, satellite phones and trunking communication devices. Cellular communication penetration in Russia was 87%, and in Moscow and St. Petersburg it has already reached the 100% mark.

Slide 17

The number of Russians who have mobile phones at their disposal has grown 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 a 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%).

View all slides

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