A telephone is (from the Greek τ λε far and φωνή voice) a device for transmitting and receiving sound over a distance via electrical signals. In general, a telephone is any mechanism that is capable of transmitting sound over a long distance. The very first telephones were mechanical devices that relied on transmitting sound using air or other physical means, as opposed to electrical devices that relied on electromagnetic signals.
The invention of the telephone was a big breakthrough in the history of communications (since before that only steamship mail and telegraph were used). Now messages from one end of the world could reach the other in just a few minutes, rather than weeks and months. The first experiments in this area were carried out by the American physicist Page in 1837. Its design included a tuning fork, an electromagnet and galvanic elements. The telephone is an invention that changed people's lives.
Race's phone number. The very first telephone in the world capable of transmitting human speech and music was the Reis telephone. In 1860, Reis designed the first prototype telephone, capable of transmitting sound over distances of up to 100 meters. The device had a microphone of an original design, a power source (galvanic battery) and a speaker.
For deaf innovator Alexander Graham Bell, the year was a turning point for the young scientist, although he still had no idea about the possibility of creating a telephone. While teaching students, Bell constantly thought about improving articulation. Alexander remembered the book of the German physicist Helmholtz, where he read that it was possible to transmit a voice through an electric wire. Here it should be clarified that the German did not write anything like that, Bell simply had poor command of German language and misunderstood the physicist’s reasoning. Incredibly, it was the mistranslation of the book that became Bell's epiphany. Bell was obsessed with the idea of transforming sounds through a membrane into electric pulses. He brought his idea to life by inventing the first electric telephone.
Miracle device. In 1876, an industrial exhibition of world significance was launched. Bell's brainchild stood modestly at one of the exhibition stands, but no one was particularly interested in it. At the end of the presentation, the Brazilian Emperor Pedro II approached the telephone. He put the receiver to his ear and was surprised to hear Bell's voice from the other wing of the building. The device became the main sensational event of the exhibition. But there was no talk of using Bell’s invention on a large scale.
The battle for invention. Discussions on the topic “who invented the telephone” did not subside, so Bell had to fight for his brainchild. And it all happened because it turns out that on the day Bell submitted his application, the Bureau received another similar application from the inventor Elite Gray. The inventors, of course, had no idea about each other's existence. But Bell managed to fill out the documents and settle all the formalities several hours earlier than Gray, so he got the palm. Today it is difficult to answer unequivocally who was actually the first to invent the telephone - Bell or Gray.
A telephone with a rotating dial. The next stage in the history of the telephone was the appearance of a device with a rotating disk. It was invented by Kansas resident Almond Brown, and ten years later an automatic telephone exchange was built there. Later, in 1900, the first street telephone was installed in Connecticut, which you could call for a coin.
Development of telephony Telephony was developing at a rapid, unprecedented pace, Russia was actively moving towards all new technical trends from abroad, and telephone exchanges were opened in large Russian cities. By the beginning of the 20th century, a network of towers entangled a significant area of Russia in its European part.
The path to the future Ordinary telephone devices turned into mobile devices over many decades - the year the first radiotelephone network appeared with radio transmitters carrying signals from personal devices to the central station. In 1962, the first communications satellite flew into space, and after that the development of mobile connection, independent of wires and distance. Martin Cooper, having developed pocket radios for the police, realized that he could make a mobile phone. For a year he scrupulously carried out his developments with the consent of the management of Motorola. These developments by Cooper became the initial step towards the creation of modern mobile phones and cellular equipment in general. These developments by Cooper became the initial step towards the creation of modern mobile phones and cellular equipment in general. Conclusion. And finally. Bell's contemporary, Thomas Edison, initially said: “I... did not see anything special in the telephone at first, except perhaps a new kind of telegraph, through which you can transmit news from one station to another...” Now we can definitely say that it is very I was wrong!
Project History of the creation of cell phones and the cellular network
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MUNICIPALITY OF KRASNODAR
MUNICIPAL EDUCATIONAL INSTITUTION
MUNICIPAL FORMATION CITY OF KRASNODAR
GYMNASIUM No. 87
Individual
creative
History of Cell Phones and the Cellular Network
Students of class 7 "B"
Rutchina Marina
Project Manager:
IT-teacher
Serdyuk N.N.
Krasnodar city
Explanatory note
Target:
Relevance:
History of Cell Phones
History of cellular networks
Introduction
Main part of the project
Bibliography
Main part of the project
A cell phone is a telephone designed to operate on cellular networks. Uses a radio transceiver and traditional telephone communication to carry out telephone communication within the cellular network coverage area.
History of Cell Phones
History of the cellular network
One of the types of mobile radio communications, which is based on a cellular network. This network got its name “cellular” because the coverage area is divided into cells in the form of honeycombs. The networks partially overlap and form single network.
In many countries it has also developed cellular. But the network could not keep up with the rapidly growing needs, and a solution was found in the form of cellular communications, which made it possible to increase capacity by reusing frequencies in a mesh system.
The diagram shows that the most popular operator is MTS. 37% of people use it.
In second place is Beeline. It is used by 27% of the population.
In third place is Megafon. 25% of people use it.
11% of the population uses others mobile operators.
Comparison of modern cell phones
Cameraphone
Smartphone and communicator
Bibliography
Internet resources:
www.vikipedia.org
www.smartphone.ua
www.e-katalog.ru
View presentation content
“Project History of the creation of cell phones and the cellular network”
Cell phones and cellular network
Prepared by 7th grade student “B”
Municipal educational institution gymnasium No. 87
Rutchina Marina
Goal and tasks
Target: Explore the origins of cell phones and the cellular network.
- Review the history of cell phones
- Consider the history of the cellular network
- Consider modern cell phones
- Compare modern cell phones
Relevance
The relevance of this topic is beyond doubt, since basically when buying a new phone there is a choice, and in order to make the right one, the topic I have chosen will help you figure it out.
Cell phone is
A telephone designed to operate on cellular networks. Uses a radio transceiver and traditional telephone communication to carry out telephone communications within the cellular network coverage area.
The world's first cell phones
In 1957, Leonid Ivanovich Kupryanovich (USSR) created an experimental model of a mobile phone. It was called LK-1, weighing 3 kg. A base station was also built for this phone.
In subsequent samples of 1958, the weight of the mobile phone was reduced to 0.5 kg.
In 1961, L. I. Kupryanovich introduced a pocket telephone weighing only 70 grams, which fit in the palm of his hand.
In 1973, the first cell phone was released - the Motorola Dyna TAC.
The first call on it was made on April 3, 1973 by Martin Cooper, who called his competitors from AT&T.
This unit weighed 1.15 kg. The phone had no functions other than a call. You could talk on the phone for about an hour, but the phone took 10 hours to charge. A total of 5 prototypes were created.
Already in 1984, the Motorola DynaTAC 8000X went on sale. People liked the phone and its features so much that thousands of people queued up to buy the phone.
Cellular network
One of the types of mobile radio communications, which is based on a cellular network. This network got its name “cellular” because the coverage area is divided into cells in the form of honeycombs. The networks partially overlap and form a single network.
History of the cellular network
The first use of mobile telephone radio in the United States dates back to 1921: Detroit police used a one-way control room to transmit information from a central transmitter to vehicle-mounted receivers.
In 1933, the NYPD began using a two-way mobile telephone radio system.
In 1934, the US Federal Communications Commission allocated 4 channels for telephone radio communications, and by 1940, about 10 thousand police vehicles were already using telephone radio communications.
But the Russians also did not lag behind. So in the late 50s. of the last century in the USSR, the development of the Altai car radiotelephone system begins. In 1963, an experimental zone was launched in Moscow. At the end of the 70s. The Altai system operated successfully in 114 cities of the country. In the summer of 2011, the Altai system stopped operating.
Cellular communications have also developed in many countries. But the network could not keep up with the rapidly growing needs and a solution was found in the form of cellular communications, which made it possible to increase capacity by reusing frequencies in a system with a mesh structure.
Cameraphone
A camera phone is a type of phone that has a camera with a high-resolution matrix. Such phones have functions for processing photos and transmitting them to social media. networks.
Phones of this type became popular after they went on sale Sony Ericsson K and Sony Ericsson C in 2005. This device had a 2 -3.2 megapixel camera.
In 2009, Samsung released a phone that amazed the world because it had an 8 megapixel camera.
In 2012, Nokia 808 PureView with a 41 MP camera was introduced
It was officially announced in 2013 Samsung Galaxy S4 Zoom is a smartphone with a 16 MP camera with 10x optical zoom and a powerful flash.
Announced in February 2014 Sony Xperia The Z2 received a 20.7 megapixel camera with the world's first digital image stabilization system and Ultra HD video shooting.
Smartphone and communicator.
A smartphone is a mobile phone enhanced with the functionality of a pocket personal computer.
The communicator is almost no different from a smartphone, except that the communicator has a slide-out keyboard.
The first attempt to connect a telephone and a pocket computer appeared in the 90s of the last century. It was an IBM Simon phone. In addition to telephone functions, the device could receive faxes and allowed receiving email and had several games. There were no keys. All actions were performed through touch screen. But due to its size, the phone was not popular.
Comparison of cell phones
For comparison, I chose two phone models. Lenovo S 650 and Apple Iphone 6.
Lenovo S 650
communication standards
Apple Iphone 6
operating system
sensory
built-in memory
memory card slot
battery
material
not removable
0t 7000 to 12000r
CPU
from 43000 to 63000r
SIM card
- During the project work, it was found out when the first cell phones appeared. I also found out what they looked like and what they were like.
- While working on this topic, I learned what a cellular network is, when and where it originated and what it was.
- Looking at modern cell phones, I learned that progress does not stop, but moves forward, and every year we can see more and more interesting phones.
- Comparing two cell phones, I found out that the choice of phone depends on the purpose for which the phone is being purchased.
- I believe my project is of great significance for those who want to learn a little about cell phones. It can also help when choosing a phone.
- Next year I plan to supplement my project with new and interesting facts about cell phones, and compare another pair of phones.
Cellular communications Cellular communications have become a part of our lives. Today we cannot imagine ourselves without a mobile phone, either at home or at work. According to the New York company FastTrack Wireless, which researched the cellular communications market, in 2002. There are already a billion cellular subscribers in the world, which is 19% of the world's population. At the same time, their number continues to grow at a rapid pace. This means that today every fifth inhabitant of our planet is the owner of this little miracle. As for our country, in terms of the number of cell phones per capita, it ranks one of the first places among developed countries. Thus, according to the Statistical Office of the State of Israel, 78.8 percent of families had at least one mobile phone in 2002. And last year, two-thirds of Israeli teenagers used mobile phones. It would be something to be proud of if mobile phone owners were protected from the harmful effects of their harmful electromagnetic radiation (EMR).
A cell phone is... A cell (mobile) phone is a subscriber terminal operating in a cellular network. In fact, each cell phone is a specialized computer, which is focused primarily on providing (in the coverage area of a home or guest network) voice communication for subscribers, but also supports the exchange of text and multimedia messages, is equipped with a modem and a simplified interface. Modern mobile phones provide voice and data transmission in digital form.
Opinions...... Currently, there are 475 million mobile phone subscribers in the world, that is, 7.9% of the world's population. This data was provided by the Swiss Federal Department of Communications. According to the department, in 2000 the number of mobile phone users increased by 50%. At the end of 2000, Iceland ranked first in the number of mobile phones per capita. For the first time in the last few years, Finland lost the lead to Iceland. Mobile coverage in Iceland is now 75.8%, while in Finland it is 73.7%. This is data from EMC (World Cellular Database review). Norway, Sweden and Finland rank first in terms of mobile telephony density: from 59% to 67.8%.
The place of mobile communications in the global economy Communications are the most dynamically developing sector of the global economy. But mobile communications even in comparison with other areas of telecom they are developing at a faster pace. Devices of the first class are generators of electromagnetic fields, the nature and intensity of radiation of which corresponds to the natural electromagnetic background, which, as a rule, is suppressed in areas with high levels of man-made fields.
Mobile communications in Russia. There were no civilian mobile communication systems in the USSR. With some stretch, one can call the Altai mobile telephony system “civilian”, built on the basis of the MRT-1327 standard, which at the turn of the 1970s and 80s was created to provide communications to representatives of the party, state and economic leadership. "Altai" is successfully operated to this day. Of course, he cannot compete with cellular networks, but is used to solve some highly specialized problems: providing communications to mobile units of city emergency services, installing telephones in summer cafes, etc. There were no civilian mobile communication systems in the USSR. With some stretch, one can call the Altai mobile telephony system “civilian”, built on the basis of the MRT-1327 standard, which at the turn of the 1970s and 80s was created to provide communications to representatives of the party, state and economic leadership. "Altai" is successfully operated to this day. Of course, it cannot compete with cellular networks, but it is used to solve some highly specialized problems: providing communications to mobile units of city emergency services, installing telephones in summer cafes, etc.
Mobilization of regions. Development of mobile communications in Russia. Domestic telecom has shown excellent development dynamics over the past year. Mobile communications, being a large segment of the telecommunications market, also demonstrates active growth in all market indicators. And if in the center - Moscow and St. Petersburg - the era of the initial accumulation of cell phones among the population can be considered completed, then in the regions everything is just beginning. Three of the largest national cellular operators have already stepped into the province. Their strategic goal is huge Russia with many large industrial centers and small county towns
Security The problem of biological safety of cell phones in our country is very relevant. This is due to the fact that when the phone is turned on, it is a source of microwave radiation, even in standby mode. The direct source of radiation in a mobile phone is its whip antenna. All other radiation sources (the transmitter itself, receiver local oscillators, frequency synthesizer, etc.) are so low-power that they can be ignored.
Competition. In order to understand the trends in the development of mobile communications in the regions, we will try to imagine the picture of the domestic mobile market as a whole. According to the Modern Telecommunications company, the development of the Russian cellular communications market continues in the face of increasing competition. In order to understand the trends in the development of mobile communications in the regions, we will try to imagine the picture of the domestic mobile market as a whole. According to the Modern Telecommunications company, the development of the Russian cellular communications market continues in the face of increasing competition.
Microwave radiation directly heats the body (complete analogy with a microwave oven). Blood flow reduces heating, but, for example, the lens of the eye is not washed with blood and with significant heating it is destroyed and becomes cloudy. These changes are usually irreversible. This process accompanied by pain in the eyes and noise in the head.
Mobile phone radiation Professor Henry Ley of the University of Washington has established a link between microwave radiation and memory impairment in rats. The experiment involved two groups of rats, one of which was exposed to electromagnetic radiation at 2450 MHz for an hour. The rats then had to swim through a water maze and find their way to the shore. Rats that were exposed to microwave irradiation found their way much more slowly. This allowed Dr. Ley to conclude that in rats, as a result of irradiation, spatial memory is impaired and they lose orientation. Professor Henry Ley of the University of Washington has established a link between microwave radiation and memory impairment in rats. The experiment involved two groups of rats, one of which was exposed to electromagnetic radiation at 2450 MHz for an hour. The rats then had to swim through a water maze and find their way to the shore. Rats that were exposed to microwave irradiation found their way much more slowly. This allowed Dr. Ley to conclude that in rats, as a result of irradiation, spatial memory is impaired and they lose orientation. Scientists from the University of Bristol and the Bristol Royal Hospital under the leadership of Dr. Alan Preece conducted an experiment on humans. The subjects were volunteers. The participants in the experiment were asked to perform a certain set of intelligence tasks while being in different conditions: under the influence of microwave radiation from digital telephones, analog telephones, and without any influence. After 30 minutes of exposure to radiation, 36 subjects showed a significant reduction in reaction time during visual tests. Scientists from the University of Bristol and the Bristol Royal Hospital under the leadership of Dr. Alan Preece conducted an experiment on humans. The subjects were volunteers. The participants in the experiment were asked to perform a certain set of intelligence tasks while being in different conditions: under the influence of microwave radiation from digital telephones, analog telephones, and without any influence. After 30 minutes of exposure to radiation, 36 subjects showed a significant reduction in reaction time during visual tests.
Cell phones. Mobile phones can cause cancer. Mobile phones can cause cancer. For a long time, most scientists and scientific institutions have said that there are indications that mobile communications are harmful to health and it would be wise to use mobile communications devices with caution, especially limiting them to children. For a long time, most scientists and scientific institutions have said that there are indications that mobile communications are harmful to health and it would be wise to use mobile communications devices with caution, especially limiting them to children. Until now, scientific progress has proceeded at an offensively slow pace, reminiscent of a dash before the finish line in a turtle race. This applies primarily to those who are waiting for a verdict from scientists regarding the alleged harm to the health of a mobile phone: for example, whether it causes brain tumors. Until now, scientific progress has proceeded at an offensively slow pace, reminiscent of a dash before the finish line in a turtle race. This applies primarily to those who are waiting for a verdict from scientists regarding the alleged harm to the health of a mobile phone: for example, whether it causes brain tumors.
Effect on earthworms Research carried out in Scotland under the direction of Sir William Stewart gave very puzzling results. When earthworms were exposed to microwave radiation, a change in their protein structure was discovered. It felt like heatstroke - like worms had been lightly fried. Professor William Ross Edie from the University of California, who has been studying the effects of electromagnetic radiation for more than 20 years, came to the same conclusion: “Just as a microwave oven cooks meat, microwave radiation heats living tissue, which can lead to a wide variety of consequences. Research, conducted in Scotland under the direction of Sir William Stewart, gave very puzzling results. When earthworms were exposed to microwave radiation, a change in the structure of their protein was discovered. It was similar to heat stroke - as if the worms had been lightly fried. Professor William came to the same conclusion Ross Edie from the University of California, who has been studying the effects of electromagnetic radiation for more than 20 years: “Just as a microwave oven cooks meat, microwave radiation heats living tissue, which can lead to a wide variety of consequences.
Blood pressure and the telephone... German researchers from Freiburg have discovered another flaw in cell phones - during operation they increase a person's blood pressure. The research was carried out correctly. Ten volunteers per right side heads were recorded by cell phones operating in the 900 MHz band (GSM). The devices were positioned approximately the same as during the conversation. The phones were turned on in working mode without the subjects knowing about it. This made it possible to exclude subjective factors that could affect the pressure. Using special monitors, the patients' blood pressure was constantly measured.
Although many aspects of the health effects of mobile phones remain unclear, experts agree on one thing: talking on the phone while driving is dangerous. An analysis of 700 road traffic accidents in the UK found that talking on the phone quadruples the risk of getting into an accident. health There is no difference between a handset held in the driver's hand and a hands-free phone. But it is still necessary to have a phone in the car, since emergency calls from mobile phones in the event of an accident have saved many more lives than were lost due to talkative drivers.
Do not interfere with aircraft navigation equipment According to studies conducted by aircraft manufacturers Boeing and Airbus, there is no scientific basis for banning the use of mobile phones on aircraft. Representatives of the American and British civil aviation services came to the same conclusion. Research conducted by Boeing has shown that 20 mobile phones operating in the cabin of a Boeing 737 do not cause any interference. Airbus conducted similar studies. An analysis of aircraft crew reports did not reveal a single case of interference associated with the use of mobile phones. Despite this, not a single airline in the world allows the use cell phone on board their ships.
Experiments... Scientists fear that due to the widespread spread of mobile communications, humanity is facing a health crisis. Dr. George Carlo, former research director of the Cell Phone Safety Project, predicts that there could be more cases of brain and eye cancer each year between now and 2010 as a result of cell phone use. Currently, this figure remains at the level of thousands of cases per year. According to scientific research, cell phone radiation directly harms health: it has been proven that it leads to headaches, high blood pressure, brain tumors, cancer, Alzheimer's disease and other diseases. The photo shows the brain of a rat before and after exposure to rays.
Cell phone radiation damages genes Radio emissions similar to those emitted by cell phones can damage cells' DNA, a team of European scientists has reported. Extensive research has examined the effects of low-energy electromagnetic radiation similar to that emitted by conventional cell phones.
10 ways to save your brain and health from cell phone radiation. Limit your use of your mobile phone as much as possible, reduce the duration of the call. Limit your use of your mobile phone as much as possible, reduce the duration of the call. Children should only use a cell phone if absolutely necessary. Children should only use a cell phone if absolutely necessary. Use only wired headsets. Use only wired headsets. Do not carry mobile phones switched on in your pockets or on your belt. Do not carry mobile phones switched on in your pockets or on your belt. Raise the phone to your ear only when the person on the other end picks up the phone. Raise the phone to your ear only when the person on the other end picks up the phone. Do not use a cell phone in a car, elevator, or other enclosed metal space. Do not use a cell phone in a car, elevator, or other enclosed metal space. It is highly recommended not to use your phone when its charge indicator is one line. It is highly recommended not to use your phone when its charge indicator is one line. Buy mobile phones with the lowest SAR ratings. Buy mobile phones with the lowest SAR ratings. Use only scientifically approved, proven radiation protection products. Use only scientifically approved, proven radiation protection products. Use vitamin and mineral complexes that help reduce the body's reaction to the activity of electromagnetic waves. Use vitamin and mineral complexes that help reduce the body's reaction to the activity of electromagnetic waves.
As a result... Regular studies are currently being carried out, which should finally determine the extent of the negative impact of radiation wireless devices, in particular mobile phones, on human health. In parallel with medical research, Ericsson, Motorola and Nokia are developing a single standard permissible level radiation - specific absorption rates (SAR) - cell phone weight" of a person. According to the future specification, the maximum permissible amount of radiation will be determined, so to speak, "per kilogram of living things. health
“My phone rang...” I’m sure that none of us today can imagine life without communications. We forget our phone at home and rush back to get it; we can’t find it in our bag or briefcase and always get upset. Who brought into our lives a unique technique that helps connect people at a distance?
Lesson plan:
Is it possible to communicate without a phone?
Of course you can! People lived before, and they didn’t have any newfangled telephone models, but they transmitted information from each other far beyond the borders of their place of residence. The need for communication forced people to invent different ways, to “challenge” and tell the news to comrades located several kilometers away. How it was?
By that time, the first attempts had already been made to create a telegraph capable of transmitting signals over long distances using electricity. The fundamentals of electrical engineering were carried out by the scientists Galvani and Volt, and the Russians Schilling and Jacobi made their contribution, who invented transmission codes and an apparatus that converted signals into text.
A little later, in 1837, thanks to the American inventor Morse, an electric telegraph and a special code system of dots and dashes, widely known to everyone under the name “Morse code,” appeared.
But even this was not enough for the scientists of those centuries. They dreamed that it would be possible not only to receive dry text over wires, but also to speak over them!
This is interesting! Archaeologists discovered two pumpkins in the Peru region, connected by a rope and concluded that this structure is the thousand-year-old ancestor of the telephone. Indeed, it is very similar to two matchboxes connected by a thread, which we tried to “ring” in childhood.
Who invented it first?
The history of the appearance of the telephone is associated with Alexander Bell from America. But he was not the only one who was actively involved in the design idea of transmitting the human voice at a distance. Let's take a brief look through the pages of history and see how far the invention traveled in the first stages of its birth.
Italian Antonio Meucci
In 1860, Antonio Meucci, a native of Italy, showed the Americans a device that could transmit sound over a wire, but he filed a patent application only in 1871, and to all his questions about the fate of the documents, the company that took them answered that they were lost.
German Philipp Reis
In 1861, German physicist Philipp Reis introduced the public to an electrical apparatus capable of transmitting sound. By the way, from him came the name “telephone,” which we are accustomed to hearing today, which is translated from Greek as “sound from afar.”
Its transmitter was made in the form of a hollow box with holes: sound - in the front and covered with a membrane - on top. But the quality of sound transmission in Reis's phone was so low that it was impossible to make out anything, so his invention was not accepted by those around him.
Americans Gray and Bell
Only 15 years later, two American designers Gray and Bell, completely independently of each other, were able to discover how a metal membrane with the help of a magnet, like the eardrum of our ear, can transform sound and transmit it through an electrical signal.
Why did Bell get all the laurels of fame? It's simple! On February 14, 1876, he submitted his application to patent the invention he discovered - the “talking telegraph” - a couple of hours earlier than Gray did.
I can imagine how upset Gray was.
Bell presented the telephone at a technical exhibition in Philadelphia.
The new technology did not have a bell; the subscriber was called by the attached whistle, and the only handset both received and transmitted speech at the same time. The first telephones had to generate electricity themselves, so the telephone line only worked at a distance of up to 500 meters.
This is interesting! In 2002, the American Congress made a decision that turned the telephone world upside down: it recognized the Italian Meucci as the true inventor of the telephone.
Evolution of the phone
Since the first telephone was presented to the public, inventors and designers have put a lot of effort into making a modern means of communication out of a primitive device.
Thus, engineers were able to replace the whistle for calling a subscriber with an electric bell. In 1876, a switch was invented that could connect not only two, but several telephones with each other.
A year later, inventor Edison contributed to the development of the telephone - his induction coil increases the distance of sound transmission, and a carbon microphone, which improves the quality of communication, was used until the end of the 20th century. At the same time, in 1877, the first telephone exchange appeared in America, through which those wishing to call someone were connected to the desired number of the telephone operator through plugs.
Thanks to the contribution of the Russian inventor Golubitsky, centrally powered stations were able to serve tens of thousands of subscribers. Remarkably, the first phone conversation in Russia took place three years after the advent of the telephone, and in 1898 the first intercity line was built between Moscow and St. Petersburg.
This is interesting! The first telephones were not very convenient. It was difficult to hear through them, so they came up with special tubes of different sizes and shapes, into which you just had to stick your nose so that the subscriber could understand what the conversation was about. At first they were made separate: one - to speak into it, the second - to listen from it. Then they began to be connected with a handle, like a modern telephone receiver. Telephone sets were made from ivory, mahogany, and cast metal. The bell cups were chromed to a shine. But one thing remained unchanged: the body, the tube and the lever on which it was hung after the conversation.
By leaps and bounds towards modernity
The inventive world did not stop there. Having received a telephone at home, people wanted to use a modern means of communication on the street, in transport, and communicate on the way to work or home.
Such communication, not tied to the premises, was initially available only to special services - walkie-talkies under the nickname “walkie-talkie”, or “walk-talk”, became a tempting idea for ordinary users. Knowing the secrets of the device, the craftsmen tried to connect the devices to the line using such radio communication. So in the 80s, radiotelephones appeared that operated at a distance of up to 300 meters.
But the main advantage of recent years has undoubtedly been cellular communications, which operate on a signal moving from one station to another.
The modern “honeycomb” appeared in 1973 at Motorola. Their firstborn worked without recharging for no more than 20 minutes and was the size of a brick and weighed as much as 794 grams!
These are our modern “mobile phones” now, small and compact, capable of taking photographs, sending mail and messages, playing music and even thinking for their owner! They have become real helpers for children and their parents - you can always call and find out how they are doing!
This is interesting! Singapore resident En Yang can write SMS the fastest - he needs a little more than 40 seconds for a message of 160 characters to appear!
Interesting facts about mobile phones
There are 23 more in this video interesting facts about our telephone numbers. They can be added to your project, so look carefully.
Now you know everything about the appearance of the telephone. Make a report and tell your friends, they will be interested! And I say goodbye to you, but don’t forget to look into new projects and stay in touch!
Good luck in your studies!
Evgenia Klimkovich.
