Alexander Bell (some people say no, it is in the textbook, I think so for the moment, you have to read it yourself as to whether it is)
The development history of the telephone
In 1793, the French Chape brothers set up a 230-kilometer-long carriage line between Paris and Lille to transmit information via relay. This is a communication system consisting of 16 signal towers. The signal operator uses ropes and pulleys to manipulate the different angles of the bracket to express relevant information. At that time, France and Austria were at war, and it took only an hour for the signaling system to reach Paris with news of the victory over Condé-sur-Ais from the Austrian army. Later, Belgium, the Netherlands, Italy, Germany and Russia also established such communication systems. One of the two Chape brothers is said to have been the first to use the word "telegraph."
European research on long-distance sound transmission began in the 17th century. The famous British physicist and chemist Robert Hooke first proposed the idea of ??transmitting voice over long distances. In 1796, Hughes proposed a method of transmitting voice messages via microphone relay, and called this communication method Telephone, which is still in use today.
In 1832, the American doctor Jackson explained the principles of electromagnets to passengers on a mail ship sailing in the Atlantic Ocean. Among the passengers, the 41-year-old American painter Morse was deeply attracted. At that time, France's signal system could only communicate within a few miles of sight. Morse dreamed of using electric current to transmit electromagnetic signals and send messages thousands of miles away in an instant. From then on, Morse's life changed radically.
Morse was inspired by the fact that the current flowing in the wire will burst out sparks when the wire is suddenly cut off: if the current is cut off for a moment and sparks are emitted as a signal, the current is turned on without sparks. As another signal, the longer the current is on also acts as a signal. The combination of these three signals can represent all letters and numbers, and the text can be transmitted to distant places through the current in the wire. In 1837, Morse finally designed the famous Morse code, which uses different combinations of "dots", "dashes" and "spaces" to represent letters, numbers, punctuation and symbols. On May 24, 1844, in the meeting hall of the Federal Supreme Court in the Capitol Building in Washington, Morse personally operated the telegraph machine. With a series of "dot" and "dash" signals being sent, the telegraph reached Baltimore 64 kilometers away. Received the world's first telegram consisting of "beep" and "dah" sounds.
[Edit this paragraph] The invention of the telephone
The inventor of the telephone-Antonio Meucci
It has been a mess for several years. On page 75 of "History and Society" in the third year of junior high school, it is mentioned about "Technology and Culture in the 19th Century": "American Bell invented the telephone, which fundamentally changed the way human communication is done." Regarding the inventor of the telephone, the textbook was written Due to the relationship of time, the traditional view is still used to attribute the invention of the telephone to Bell. However, there is controversy in history about the real inventor of the telephone, which involves three related figures: Bell, Gray and Meucci. The following material provided to students is not meant to subvert our teaching materials, but I just hope that through in-depth exploration of this issue, everyone can have a more comprehensive and detailed understanding of it.
For most people, when the invention of the telephone is mentioned, Alexander Graham Bell will definitely come to mind. Bell conducted extensive research exploring the components of speech and analyzing the vibrations of sound on precision instruments. In the experimental instrument, the vibration on the diaphragm is transmitted to a glass piece coated black with carbon, and the vibration can be "seen". Next, Bell began to think about whether it was possible to convert sound vibrations into electronic vibrations. This allows sound to be passed through the wire. Over the years, Bell tried to invent several telegraph systems. Gradually, Bell came up with the idea of ??inventing a machine that could transmit several messages at the same time through a single line. He envisioned coordinating different frequencies through several armatures. On the transmitting side, these armatures interrupt the current at a certain frequency and send a series of pulses at a specific frequency. At the receiving end, only the armature matching the pulse frequency can be activated. During his experiments, Bell accidentally discovered that sound signals could be transmitted by transmitting electromagnetic waves along lines. After several experiments, the sound can be transmitted stably through the line, but it is still unclear.
Due to Bell's heavy teaching workload, his research did not progress for a long time. In 1876, on the eve of Bell's 30th birthday, the idea of ??transmitting sound through wires was unexpectedly patented. Bell rekindled his passion for research. On March 10, 1876, Bell's phone call heralded the arrival of a new era in human history.
But Bell was not the only person working on the invention of the telephone. A man named Elisha Gray once launched a legal battle with Bell over the telephone patent. Gray and Bell applied for patents on the same day, but because they were a little later than Bell in terms of specific time (only about 2 hours later), they ultimately lost the case.
In fact, regarding the invention of the telephone, we should also think of another unknown Italian, Antonio Meucci, who immigrated to the United States in 1845. Meucci was obsessed with the study of electrophysiology, and he inadvertently discovered that radio waves could transmit sound. From 1850 to 1862, Meucci produced several different forms of sound transmission instruments, called "telephones." Unfortunately, Meucci was too poor to protect his invention. At that time, applying for a patent required a filing fee of US$250, and the long-term research work had exhausted all his savings. Meucci's poor command of English also prevented him from understanding how to protect his invention. Then, fate dealt Meucci an even bigger blow. In 1870, Meucci became seriously ill and had to sell the telephone device he invented for a mere $6. In order to protect his invention, Meucci tried to obtain a document called a "Request to Protect an Invention." For this, he needs to pay a fee of US$10 per year, and needs to be updated every year. Three years later, Meucci was reduced to relying on social welfare benefits and could not afford the processing fees, so the application became invalid.
In 1874, Meucci sent several "long-distance transmission microphones" to the American Western Union Telegraph Company. Hoping to sell the invention to them. However, he didn't get an answer. When requesting the return of the original parts, he was told that the machines were missing! Two years later, Bell's invention was unveiled and he signed a huge contract with the Western Union Telegraph Company. Meucci sued, and the Supreme Court agreed to hear the case. However, Meucci died in 1889 and the lawsuit was dropped.
Until June 15, 2002, the U.S. Congress passed a bill recognizing Antonio Meucci as the inventor of the telephone. Today, there is a monument in Florence, Meucci’s birthplace, which reads, “Here lies the inventor of the telephone, Antonio Meucci.”
At present, Bell is generally recognized as the inventor of the telephone. He applied for a telephone patent at the U.S. Patent Office on February 14, 1876. In fact, just two hours after he filed his application, a man named E. Gray also applied for a telephone patent.
Before the two of them, many people in Europe were already carrying out ideas and research in this area. As early as 1854, the principle of the telephone had been conceived by the Frenchman Boussard, and six years later the German Reiss repeated this idea. The principle is: two thin metal sheets are connected with wires. When one side makes a sound, the metal sheet vibrates, turns into electricity, and is transmitted to the other side. But this is just an idea. The problem is the structure of the transmitter and receiver. How can the mechanical energy of sound be converted into electrical energy and transmitted.
Initially, Bell used electromagnetic switches to form an open and close pulse signal, but this method was obviously not feasible for such high frequencies as sound waves. The final success came from an accidental discovery. On June 2, 1875, during an experiment, he connected a metal piece to an electromagnetic switch. Unexpectedly, in this state, the sound magically turned into an electric current. According to the analysis principle, it turns out that the metal piece vibrates due to sound, which induces a current in the electromagnetic switch coil connected to it. It seems now that this principle is known to even a student who has studied junior high school physics, but at that time it was undoubtedly a very important discovery for Bell.
Gray's design principle is different from Bell's. It uses the resistance change of the liquid inside the microphone, while the receiver is exactly the same as Bell's. In 1877, Edison obtained a patent for the carbon microphone. At the same time, many people were making various improvements to the way the phone worked. The patent dispute was complicated and did not come to an end until 1892.
One reason for this situation was that the Western Union Telegraph Company, the largest in the United States at the time, bought the patent rights of Gray and Edison to compete with Bell's telephone company. The result of the long-running patent dispute was that the two parties reached an agreement. Western Union Telegraph Company fully recognized Bell's patent rights and would no longer be involved in the telephone industry. In exchange, it shared 20% of Bell Telephone Company's revenue within 17 years.
[Edit this paragraph] Development of telephone technology
In the decades after the invention of the telephone, a large number of patents were applied for regarding the management and technology of telephones. Strowger’s “ The "automatic dialing system" reduces various problems caused by manual wiring, the application of dry batteries reduces the size of the phone, and the application of loaded coils reduces signal loss in long-distance transmission. In 1906, Lee De invented the electronic test tube, and its loudspeaker function led the direction of telephone service. Later, Bell Telephone Laboratories made an electronic triode based on this. This research was of great significance. On January 25, 1915, the first interborough telephone line opened between New York and San Francisco. It used 2,500 tons of copper wire, 130,000 poles and countless loaded coils, and three vacuum tube amplifiers along the way to strengthen the signal. On July 1, 1948, scientists at Bell Labs invented the transistor. This is not only of great significance to the development of telephones, but also has a huge impact on all aspects of human life. In the following decades, a large number of new technologies emerged, such as the production of integrated circuits and the application of optical fibers, which all played a very important role in the development of communication systems.
[Edit this paragraph] Telephone in China
After the Opium War, while Western powers plundered land and wealth in China, they also brought modern postal and telecommunications to China. In 1900, China's first local telephone was launched in Nanjing; Shanghai and Nanjing Telegraph Offices opened local telephones, with only 16 telephones at that time. From 1904 to 1905, Russia set up radio stations in Yantai and Niuzhuang, China. China's ancient postal system and private communication institutions were gradually replaced by advanced postal services and telecommunications.
During the Republic of China, China's postal and telecommunications communications were still under the control of Western powers. Coupled with years of war, communication facilities are often damaged. During the Anti-Japanese War, the Japanese imperialists transformed and expanded the telecommunications network system out of war needs and the purpose of long-term domination of China. They took advantage of China's economic and technological backwardness and the corruption of the political system at that time to improve technology, equipment, maintenance, and management. and other aspects to control China’s communications industry.
Before 1949, China's telecommunications system developed slowly. By 1949, China's telephone penetration rate was only 0.05%, and there were only 260,000 telephone users.
After 1949, the Central People's Government quickly restored and developed communications. The Beijing Telegraph Building built in 1958 became an important milestone in the history of communications development in New China. Ten years after the "Cultural Revolution", postal and telecommunications suffered another blow. They have been losing money and business development has stagnated. By 1978, the national telephone penetration rate was only 0.38%, less than 1/10 of the world level. China, which accounts for 1/5 of the world's population, has less than 1% of the world's total number of telephones. Every 200 people have a telephone Less than one, 75 years behind the United States! The proportion of switch automation is low. Most counties and rural areas still use "shake handles". Long-distance transmission mainly relies on open wires and analog microwaves. Even in Beijing, 20% of long-distance calls cannot be answered every day, and 15% cannot be answered until an hour later. Pass. People who made calls at the Telegraph Building had to wait in line with their lunch.
In 1978, China had 3.59 million telephone lines, 2.14 million users, and a penetration rate of 0.38%.
After the reform and opening up, backward communication networks have become a bottleneck for economic development. Since the mid-1980s, the Chinese government has accelerated the construction of basic telecommunications facilities. By March 2003, the number of fixed phone users reached 225.626 million, and 221.491 million mobile phone users.
How many people at home and abroad have worked hard to deliver information faster and better. In the more than 100 years of telecommunications development, people have tried various communication methods: the original telegraph used something like " "Digital" means of expression to transmit information; later, telephones that transmitted information with analog signals appeared; with the advancement of technology, digital methods have once again received attention for their obvious superiority, digital program-controlled switches, digital mobile phones, optical fiber digital transmission... …The wheels of history are still moving forward.
[Edit this paragraph] A century of development history of the telephone
Since the invention of the telephone, there have been many changes from its working principle to its appearance design. Please follow us for a walk. This is the century-old development path of the telephone. Some of these phones are in the collections of antique phone collectors around the world.
In 1684, the famous British physicist and chemist Robert Hooke first proposed the principle of visual communication in a speech at the Royal Society. He suggested that when communicating, hang the letters of the text to be transmitted and the coded symbols representing various meanings on a high wooden frame, so that the other party can see and receive them. But this suggestion has never been realized.
On February 17, 1753, the idea of ??using electric current for communication was first proposed in a magazine called "The Scotsman", and the article was signed C.M.
In 1790, the outstanding French engineer Laud Chape and his brothers successfully developed a practical communication system based on the principles of visual communication proposed by Hooke. Messages were sent throughout France.
In 1793, the French Chape brothers set up a 230-kilometer-long carriage line between Paris and Lille to transmit information via relay. This is a communication system consisting of 16 signal towers. The signal operator uses ropes and pulleys to manipulate the different angles of the bracket to express relevant information.
On August 15, 1794, a visual communication method called "distant communication" was used for the first time between Lille and Paris, France.
In 1796, the Englishman Hughes proposed a method of transmitting voice via microphone relay and named it Telephone, a name that has been used to this day.
In 1832, Russian diplomat Schilling built a telegraph that used the deflection of the galvanometer pointer to receive information.
In 1835, the American Morse invented the telegraph machine that used electromagnetic principles for telegraph transmission.
In June 1837, the Englishman Cook obtained the first patent for the invention of the telegraph. The telegraph machine he made was first used on the railway.
From 1837 to 1838, Morse invented the method of "turning on" and "off" current to compile a code representing numbers and letters - Morse code.
In 1843, Morse built a telegraph line from Washington to Baltimore, with a total length of 64.4 kilometers.
On May 24, 1844, Morse sent the first telegram in human history to Baltimore from the Capitol Building: "What a miracle God has created!".
On August 28, 1850, the first submarine cable was built by brothers John and Jacob Brett between Cape Gris-Naze in France and Cape Leeseland in England. It was laid in the high seas, but it was interrupted after only a few telegrams were sent. It turned out that a fisherman hooked up a section of cable with a trawl net, cut off a section and happily showed off this rare "seaweed" specimen to others, saying in amazement that it was filled with gold.
On March 10, 1876, the British Scotsman Bell invented the telephone. "Mr. Watson, come and help me" became the first voice sent by humans through the telephone. At that time, Bell spilled acid from the microphone onto his leg.
1878, Handheld Telephone: This telephone was made in Germany in 1878 by Werner Siemens. Its earpiece and microphone are one, and they are used alternately when listening and speaking.
1879 Box Telephone: This telephone was equipped with a magnetic generator produced by the Viaduct Manufacturing Company and was made of mahogany. It also had a columnar receiver.
In 1879, a telegraph line was set up between Tianjin and Dagu Beitang Fort.
1880, Bell Telephone: This was the first telephone used in Europe. It replaced the telegraph and was more advanced than the magnetic engine telephone that had a handle.
Magnetic generator wall telephones, 1881 and 1882: The telephone on the left is called the American Bell type, manufactured in 1881 and used by the International Bell Telephone Company in Copenhagen. Manufactured by L.M. Ericsson. This phone was popular at the end of the last century.
On February 21, 1882, the Dango-Dabei Telegraph Company established a telephone exchange on the Bund in Shanghai.
1885, "Eiffel Tower" Magnetophone: This telephone was made in 1885 by L. M. Ericsson. At the time it was the first phone to be placed on a desktop. The microphone is mounted on a rotating arm, and a crank is used to connect to the switch.
1885, 1902, Magnetic Generator Wall Telephone: Made by Ferdinand E. Stensen in Copenhagen in 1885, it was the earliest telephone made by a Dane. This one was made by the Emil Mdlers Telephone Company in Hosen.
1885, wooden frame desk telephone: manufacturer and origin unknown.
1892, electric folding cabinet table phone: This kind of phone is mostly used in homes, hotels and phone booths.
1892, "Eiffel Tower" telephone with handset: This is a true classic telephone, made in 1892 by L. M. Ericsson. This phone spread all over the world, with nearly a million units produced.
1893, "Coffee Pot" Telephone: There are only a few examples of this phone in Denmark, and it is the most attractive and valuable for collectors.
In 1895, the Russian Popov and the Italian Marconi respectively invented the wireless telegraph.
On May 18, 1897, Marconi successfully conducted radio communications across the Bristol Channel.
1899, Digital Mechanical Wall Telephone: This digital mechanical telephone comes in both wall and table versions.
1900, Upright Desk Telephone: This round-belly desk telephone was made of nickel-plated bronze. There is a sturdy piece of bakelite underneath the hanging rod. It also has a peripheral earpiece to show off.
1900, Upright Tapered Desk Phone: This phone was nicknamed the "oil can" because of its shape.
1900, 20-wire split phone: This model is the so-called 20-wire split phone. For intercom use only, manufactured by L. M. Ericsson in Sweden.
In 1900, China's first local telephone was launched in Nanjing; the Shanghai and Nanjing Telegraph Bureau opened local telephones, with only 16 telephones at that time.
1901, Magnetic Generator Desk Telephone: This model was manufactured in Copenhagen in 1901 by Ferdinand E. Stensens Telefonfabrik. Pay attention to its earpiece, hanging separately on a hook. Perhaps it was because the quality of telephone access at that time was not high and sometimes one had to listen with two ears.
In 1901, Marconi achieved wireless communication across the Atlantic Ocean.
1902, Kellogg corner desk telephone: This corner desk phone was mostly used in homes, offices and phone booths. It was manufactured by the Hardwood Telephone Company of the United States. I bought it from a farmer in a small town in California.
1902, Public Battery Wall Telephone: This type of telephone does not require you to turn the handle, pick up the receiver and speak directly to the operator. It was purchased from an antique shop in San Francisco.
In 1903, the wireless telephone test was successful.
1904, “Spider” civilian band telephone: L. M. Ericsson’s first civilian band telephone.
1904, Magnetic Generator First Line Telephone: This telephone was manufactured in 1904 by L.M. Ericssom. This phone allows four users to share one phone line.
From 1904 to 1905, Russia set up radio stations from Yantai to Niuzhuang in China.
Chicago’s tree-style desk phone, 1905: This desk phone was known as the “Potty Bell” because of the bulge in the middle of the handle.
1905, Porch Intercom: This is a Connecticut Telecommunications Company 32-door porch intercom.
1905, 11-digit dialing desk phone: It uses an 11-digit dialing method.
On November 8, 1907, French inventor Edouard Belland demonstrated his development result-photo fax in the building of the French Photographic Association.
1907, "German model" radio band telephone: manufactured in Germany in 1907 by E.Zwuetysch & Co. The emergence of this telephone can solve the problem of long waiting time for calls to a certain extent.
1907, Magneto Generator Telephone: This telephone was manufactured in 1907 by L.M. Ericsson. Note: When answering a call, hang the handset on a separate hook. This was the unified standard for phone manufacturers at the time.
1908, CH-08 loudspeaker telephone: introduced by KTAS.
1910, Interphone: This was an upright tabletop interphone produced by the S.H. Couch Company for interoffice communications.
In 1912, office telephone: This telephone can have 17 extensions at the same time through the main unit. Each extension can make calls, and the extensions can also be connected to each other.
1912, CH-08 wall phone: This phone was produced in 1912 by the Danes in Copenhagen. It can automatically send and receive telegraphs.
1912, Magnetic Generator Telephone: A telegraph and fax telephone manufactured by L.M. Ericsson, often used in remote areas or small islands.
1914, Magnavox anti-noise desk phone: The unique design of this phone was that when you spoke into the microphone, the sound passed through a small hole in the top of the phone, causing the vibrating plate in the phone to vibrate. Noise is canceled when it enters the microphone. Its dual rotating earpieces help block unwanted noise.
1914, Magnavox anti-noise desk telephone Model B1: also has the function of canceling noise.
1914, Magnetic Generator Telephone: Made in HORWENS in 1914, it could be used for telegraph and fax.
1915, Veau desk telephone: unknown.
1915, home-made wall telephone: This phone was found on an abandoned farm in East Oregon. There are nearly 20 abandoned farms in the area with traces of telephones hanging on their walls.
In 1919, Palm and Belander invented the "crossbar connector." Ten years later, in 1929, the world's first large-scale cross-border telephone exchange was built in Sundsvall, Sweden.
In July 1920, China Post launched postal and telegraph services.
1920 Magneto Wall Telephone: This telephone, manufactured in 1904 and updated in 1920, featured a rotating red button that switched between answering and listening.
1927, D-08 semi-automatic telephone: the first dial-up telephone, its appearance will replace the manual calling system of the switchboard. The dialing device was installed in 1927 and it was first used in 1978.
1927, AC-powered ringing telephone: manufactured by Kristian Kirks Telefonfabrikker in Horsens, Denmark, still in use in the 1970s.
1929, automatic wall telephone: unknown.
In 1929, the world's first large-scale vertical and horizontal telephone exchange was built in Sundsvall, Sweden.
1930, D-30 semi-automatic gold-plated telephone: This telephone was manufactured by a Danish company in 1930. Its special feature is that the surface is gold-plated. At that time, most telephones were dark, and this telephone had a dialing device. .
1930, FL-30 automatic telephone: Made in Denmark in the 1930s, it used alphabetic dialing. This type of phone is about 48 years old.
1935, automatic telephone: This telephone was used to communicate with telecommunications switches in remote areas. Its design was influenced by the American telephone industry in the 1930s.
In 1937, the British Reeves proposed a method of transmitting voice information using all combinations of pulses (pulse code modulation).
1943, CB-43 telephone; this telephone was manufactured in Denmark by Kristian Kirks Telefonfabrikker. It was designed with two ring tones to distinguish calls from inside and outside the city.
In October 1945, the British A.C. Clark proposed the idea of ????stationary satellite communications.
In 1946, Eckert and Mauchly built the world's first electronic computer.
In 1947, Bell Labs in the United States proposed the concept of cellular communications, dividing the mobile phone service area into several cells, and setting up a base station in each cell to form a cellular mobile communication system.
In December 1950, the long-distance open-line international trunk line project in Northeast China was completed, and the cable carrier circuit from Beijing to Moscow was opened.
F-51 autodial telephone, 1951; this telephone was built by Kristian Kirks Telefonfabrikker after World War II.
1952, F-52 automatic dialing telephone: Made in 1952, it was made of ivory and later plastic materials instead of the black bakelite material of the past.
In July 1954, the U.S. Navy used the reflection of radio waves on the lunar surface to conduct a telephone transmission test between two places on the earth. In 1956, communications services were established between Washington and Hawaii.
In 1956, a telephone cable was laid on the Atlantic Ocean between the United Kingdom and Canada, making long-distance continental telephone communications a reality.
In 1956, the "Ericofon" automatic dialing telephone; this telephone was designed and manufactured by Swedish L.M. Ericsson and named Ericofon. It is made of new materials and is much lighter than a traditional phone receiver.
On October 4, 1957, the former Soviet Union successfully launched the first artificial satellite "Sputnik 1".
In August 1958, the first domestic 12-carrier telephone equipment was successfully developed at the Shanghai Post and Telecommunications Equipment Factory.
In January 1960, China’s first set of 1,000 vertical and horizontal automatic telephone exchanges was put into use at Shanghai Wusong Telephone Bureau.
In 1960, American physicist Maiman used powerful ordinary light to shine on artificial gems, creating a laser that was 10 million times stronger than sunlight.
In 1962, the United States successfully researched pulse code modulation equipment for multiplexed telephone communications.
In 1965, the first computer-controlled program-controlled telephone exchange was launched in the United States, marking the beginning of a new era of telephones.
In 1966, the British-Chinese Kao Kun proposed the idea of ??using glass fiber for long-distance laser communication.
1968, F-68 automatic dialing telephone: This telephone was the most common telephone in the 1970s. It was originally designed in the 1960s and was widely manufactured in Denmark.
In 1969, Beijing Long Distance Telecommunications Bureau successfully installed China's first fully automatic long-distance telephone equipment.
In 1969, the Advanced Research Projects Agency (ARPA) of the U.S. Department of Defense proposed a plan to develop the ARPA network. It was completed and put into operation in 1969, marking a new era in the development of computer communications.
In 1970, the world's first program-controlled digital switchboard was opened in Paris, France, which marked the full practicality of digital telephones and the arrival of a new era of digital communications.
1970, F-68 push-button dialing telephone: the first push-button telephone used in Denmark. This telephone used numeric buttons instead of the original dialing method.
In 1972, the Consultative Committee on International Telegraph and Telephone (CCITT) first proposed the concept of Integrated Services Digital Network-ISDN.
In 1974, the construction of the China-Japan submarine cable began. This was the first international submarine cable that China participated in the construction.
In 1975, the vertical and horizontal automatic telephone switching equipment developed and designed by China passed the national certification and began mass production.
1976, Model 76E/DK80 push-button dial telephone: originally manufactured in 1972 by Jutland Telephone Company.
In March 1976, the first large-capacity transmission system developed by China, the 1800-channel medium coaxial cable carrier system, was completed and put into production in Beijing, Shanghai, and Hangzhou, with a total length of 1,700 kilometers.
In 1978, China had 3.59 million telephone lines, 2.14 million users, and a penetration rate of 0.43%.
In 1979, F-79 push-button dialing charge telephone: This telephone is between ordinary telephones and public telephones. It is mainly used in service places, hotels and other similar places, and can prevent theft and make calls. .
1980, DA-80 push-button dial telephone: The design of this phone marked the true entry of electronic theory into the telephone industry.
In 1982, GSM was established in Europe with the task of formulating standards for pan-European mobile communication roaming.
In 1982, portable telegraph phone: This phone was manufactured by Ericsson Wireless Systems. At that time, it could only be used in countries such as Denmark, Finland, Norway, and Sweden. Its appearance opened the way for future GSM mobile phone systems. A new world.
In 1982, China's first batch of coin-operated public telephones appeared in bustling streets such as East and West Chang'an Street in Beijing, with 22 coin-operated public telephone booths.
In December 1982, China's first 10,000-door program-controlled local telephone switching system introduced from Japan was put into use at Fuzhou Telecommunications Bureau, establishing China's first introduced program-controlled telephone bureau.
In 1983, the AMPS cellular system was opened in Chicago, USA.
1983, DanMark 2 Button Phone: Manufactured in 1983, the DanMark 2 was the embodiment of state-of-the-art technology in the 1980s. It has many functions, such as phone number memory function, redial function, monitoring function, and 24 kinds of ringtones.
[Edit this paragraph] USB phone
It is a VoIP network phone that is small and beautiful in appearance, shaped like a mobile phone, and easy to carry. It uses a USB interface to connect to a computer and uses the computer to access the Internet to transmit voice. Professional and high performance, supports many softphones. Unique mobile phone-like appearance design, plug and play, connect to PC or notebook, simple and easy to use. You can use it to make or receive any Internet calls like an ordinary phone.