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. At present, the frequency resources are obviously insufficient, and the number of mobile phone users is 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".
Extended data
Development history
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 early 1960s, 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"? . 1959, Altai system with excellent performance won the gold medal of Brussels World Expo? .
1973, a man stood on the street of new york, took out a wireless phone the size of a brick and started talking.
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.