Introduction to the development history of mobile phones

If we go back, we will find that the concept of mobile phone appeared as early as 1940s.

At that time, Bell Laboratories, the largest communication company in the United States, began trial production.

1940, Bell Laboratories manufactured the first so-called mobile phone.

But because of its large size, researchers can only put it on the shelf in the laboratory, and people will gradually forget it.

1973 in April, marty cooper, an engineer and technician of the famous American Motorola Company, invented the world's first civil mobile phone.

When Cooper made the world's first mobile phone, he could use any electromagnetic frequency band.

The first generation of analog mobile phones is actually to distinguish different mobile phones of different users by different frequencies.

The second generation mobile phone -GSM system distinguishes users with a very small time difference.

Today, the frequency resources are obviously insufficient, and the number of mobile phone users is also growing rapidly in geometric series.

As a result, the updated CDMA technology, using different codes to distinguish different computers, came into being.

The mobile phone using this technology not only has better call quality and confidentiality, but also can reduce radiation, which is called "green mobile phone".

Development history

183 1 year, Faraday discovered the phenomenon of electromagnetic induction in England. Maxwell further expounded the research results of Faraday and others with mathematical formulas, and extended the theory of electromagnetic induction to space.

More than 60 years later, Hertz confirmed the existence of electromagnetic waves in experiments.

The discovery of electromagnetic waves has become the turning point from "wired communication" to "radio communication" and the origin of the whole mobile communication.

As a scientist said, "Mobile phones were born on the shoulders of telegrams and telephones. Wireless communication is impossible without the efforts of predecessors.

65438+May 24th 0844.

Morse's telegram sent the first telegram from Washington to Baltimore in human history. "What a miracle God has created!" "

1On June 2, 875, Bell accidentally spilled sulfuric acid on his leg while doing the experiment.

He was in pain and shouted to his colleagues in the other room, "Come and help me!" " This sentence was transmitted to Hotell who answered the phone in another room through the telephone in the experiment, which became the first sentence transmitted by human beings by telephone.

1902, an American named "Nathan Stubblefield" made the first wireless telephone equipment in his country house in Murray, Kentucky. This kind of wireless mobile communication telephone is the earliest exploration and research on "mobile phone" technology.

1940, Bell Laboratories made mobile phones.

1946, it was the first time in the world to make a call from a moving car in St. Louis with a mobile phone.

1957, Leonid, an outstanding engineer in the Soviet Union.

Kupriyan Norwich invented лк- 1 mobile phone.

In 1958, he further improved his mobile phone.

The weight of the equipment is reduced from 3 kg to 500 g (including the battery weight), and the shape is simplified to the size of two cigarette cases, so that you can make a phone call anywhere in the city and connect any fixed telephone.

By the mid-1960s, the mobile phones in Norich, Kupriyan had been able to work effectively within 200 kilometers.

From 65438 to 0958, the Soviet Union began to develop the world's first fully automatic mobile phone communication system "Altai" (алтай).

1959, Altai system with excellent performance won the gold medal in Brussels World Expo.

1973, a man stood on the street in new york, pulled out a wireless phone about the size of two bricks and started talking.

Marty cooper (marty cooper)

This man is marty cooper, the inventor of mobile phone.

At that time, he was an engineer at Motorola.

This was the first mobile phone in the world at that time.

1975, the Federal Communications Commission (FCC) of the United States determined the spectrum of land mobile phone communication and large-capacity cellular mobile phone.

It is ready for the commercial application of mobile phones.

From 65438 to 0979, Japan opened the world's first cellular mobile phone network.

1982, GSM (mobile communication task force) was established in Europe.

1985, the first commercial mobile phone was born.

It puts the power supply and antenna in an example and weighs 3 kilograms.

The modern mobile phone was born in 1987.

Its weight is still about 750 grams, which is like a big brick compared with today's mobile phone with only 60 grams.

Since then, the "slimming" of mobile phones has become more and more rapid.

199 1 year, and the weight of the mobile phone is about 250g.

1in the autumn of 996, a mobile phone with a volume of 100 cubic centimeter and a weight of 100 gram appeared.

Since then, it has been further miniaturized and lightweight, and 1999 has been lighter than 60 grams.

Development details

At present, the so-called third generation mobile phone (3G) is the most widely used in the world, which is mainly based on the GSM system in Europe and the CDMA system in the United States. They are all digital systems, which can not only carry out voice communication, but also send and receive short messages and wireless application protocols.

In Chinese mainland and Taiwan Province Province, GSM is the most popular, CDMA mobile phones are also very popular, and the whole industry is migrating to the fourth generation mobile phones (4G).

In addition to typical telephone functions, some mobile phones also include PDA, game machine, MP3, camera, photography, recording, GPS, Internet access and other functions, and there is a trend to develop mobile phone functions to PDA.

The microphone and earphone of the telephone and the corresponding microphone and receiver are all installed on one handle.

Formerly known as mobile phones, handheld devices, mobile phones and faxes, they are portable telephone terminals that can move in a large range.

According to industry analysts, although the basic protection functions of mobile phone security products are relatively complete, there are still shortcomings in anti-harassment, privacy protection and data protection, and there is still a large market space in the future. QQ mobile phone housekeeper, security housekeeper, NetQin and other security vendors have announced their entry into the field of cloud security. 20 13 will be a crucial year for the accelerated landing of mobile cloud security, and major security vendors will continue to increase their investment in mobile cloud security solutions.

1G

The first generation mobile phone (1G) refers to analog mobile phones, which appeared in China, Hongkong, the United States and other film and television works in 1980s and 1990s.

The first person who invented the mobile phone was Dr. Cooper from America.

Due to the limitation of battery capacity and the development of analog modulation technology, such as huge antenna and integrated circuit, this mobile phone has a square appearance and can only be moved, but not portable.

Many people call this kind of mobile phone "brick" or "Black King Kong".

There are many formats of this kind of mobile phone, such as NMT, AMPS, TACS, etc., but frequency division multiplexing can only be used for voice communication, with unstable reception effect, insufficient confidentiality and insufficient wireless bandwidth.

This kind of mobile phone is similar to a simple radio duplex station. The call is locked on a certain frequency, and you can use FM radio to eavesdrop on the call.

2G

The second generation mobile phone (2G) is also the most common mobile phone.

Usually, these mobile phones use very mature standards such as GSM or CDMA, with stable call quality and appropriate standby time.

In the second generation, in order to meet the needs of data communication, some intermediate standards are also supported on mobile phones, such as GPRS supporting MMS service, WAP service for Internet service, and various Java programs.

2.5G

Some mobile phone manufacturers refer to some of their mobile phones as 2.5G mobile phones, which are characterized by GPRS function.

2.75 grams

Some mobile phone manufacturers also refer to some of their own mobile phones as 2.75G mobile phones, which are characterized by faster EDGE function than GPRS.

third generation

3G, the abbreviation of the third generation in English, refers to the third generation mobile communication technology.

Compared with the first generation analog mobile phone (1G) and the second generation digital mobile phone (2G), the third generation mobile phone generally refers to a new generation mobile communication system which combines wireless communication with multimedia communication such as the Internet.

It can handle images, music, video streams and other media forms, and provide a variety of information services including web browsing, teleconference, e-commerce and so on.

That is to say, in indoor, outdoor and driving environments, it can support at least 2Mbps (megabits per second), 384kbps (kilobits per second) and 144kbps respectively.

ITU defines 3G mobile phone as IMT-2000 (International Mobile Phone 2000) standard, and European telecom giants call it "UMTS" universal mobile telecommunication system.

There are three international standards for 3G mobile phones: WCDMA in Europe, CDMA2000 in the United States and TD-SCDMA proposed by scientists in China.

"3G communication" is about to become people's mantra. The so-called 3G, in fact, its full name is 3G, which means the third generation digital communication in Chinese.

1995, the first generation of digital mobile phones, can only make voice calls; The second generation digital mobile phones from 1996 to 1997 have added the function of receiving data, such as accepting emails or web pages; The main difference between the third generation and the first two generations is that the speed of transmitting sound and data has increased.

Compared with the first generation of analog mobile phones (1G) and the second generation of 2G digital mobile phones, 3G communication has many names. ITU defines it as "IMT-2000" (International Mobile Phone 2000) standard, and European telecom giants call it "UMTS" universal mobile telecommunications system.

According to the standard, when the mobile terminal moves at vehicle speed, its data transmission rate is 144kbps, the outdoor stationary or walking speed is 384kbps, and the indoor speed is 2Mbps.

However, these requirements do not mean that the available rate of users can reach 2Mbps, because the indoor rate will also depend on the detailed frequency planning in the building and the close cooperation between organizations and operators.

3.5 g /3.75 g

3.5G adopts HSDPA, HSDPA+, HSDPA 2+ and HSUDA.

Users can enjoy a download rate of 7.2M to 42m..

While providing high-speed data services, security has also been improved, and 3.5G mobile phones focus on security and data communication.

On the one hand, it strengthens the protection of personal privacy, on the other hand, it strengthens the research and development of data services and introduces more multimedia functions. The mobile phone has stronger computing power, which is no longer just a personal call and text information terminal, but more functional choices.

Mobile office and strong demand for communication will accelerate the integration of mobile phones and personal computers, and mobile phones will gradually have the functions of personal computers, which has been fully reflected in the mobile phone market in China.

the 4th generation mobile communication technology

4G is the abbreviation of the fourth generation mobile communication and its technology, which can transmit high-quality video images and technical products, and the image transmission quality is equivalent to that of HDTV.

Mobile phones that have been developing.

The most widely used mobile phones in the world are GSM and CDMA.

In Chinese mainland and Taiwan Province Province, GSM is the most popular, and CDMA and PHS mobile phones are also very popular. These are the so-called second generation mobile phones (2G). They are all in digital format. Besides voice communication, they can also send and receive short messages (SMS), multimedia messages (technology) and wireless application protocol (WAP).

Generally, the appearance of a mobile phone should include at least one LCD screen and a set of buttons (some touch-screen phones reduce buttons).

In addition to the typical telephone functions, some mobile phones also include PDA, game machine, MP3, camera, recording, photographing, positioning and other functions, and there is a tendency to develop into handheld computers with mobile phone functions.