Who invented SMS?

1one day in April, 973, a man stood on the street of new york, took out a wireless phone about the size of two bricks and made a call, which attracted passers-by to stop and stare. This man is marty cooper, the inventor of mobile phone. At that time, Cooper was an engineer of the famous Motorola company in the United States.

The world's first mobile phone was called to an opponent who worked in Bell Laboratories. The other party was also developing a mobile phone at that time, but it has not been successful. Cooper later recalled: "I called him and said,' Joe, I'm talking to you on my mobile phone.' I heard the voice of "gnashing my teeth" on the other end of the phone-although he has always been quite polite. "

By April this year, the mobile phone has been born for 3 1 year. This product of the competition of scientific and technological personnel in those days has blossomed everywhere now, which has brought great convenience to our modern life.

Marty cooper is 74 years old. After working in Motorola for 29 years, he founded his own communication technology research company in Silicon Valley. He is currently the chairman and CEO of this company. Marty cooper's idea at that time was to let the media know that wireless communication, especially small mobile phones, was very valuable. In addition, he also hopes to arouse the interest of the Federal Communications Commission and support the competition between Motorola and AT&T (AT&T is also a big communication company in the United States).

In fact, going back, we will find that the concept of mobile phone appeared as early as 1940s. At that time, the trial production was started by Bell Laboratories, the largest communication company in the United States. 1946, 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.

It was not until the late 1960s that AT&T and Motorola became interested in this technology. At that time, AT&T rented a large mobile wireless phone, which customers could put on a big truck. At&T's vision is to develop a mobile phone with the power of 10W in the future, and communicate with it by using the radio equipment on the truck. Cooper thinks this kind of mobile phone is too big and heavy to move and carry. Therefore, Motorola applied to the Federal Communications Commission for the requirement that the power of mobile communication equipment can only be 1 watt, and the maximum power cannot exceed 3 watts. In fact, the maximum radio power of most mobile phones today is only 500 MW.

From 1973 to 1985, the first modern mobile phone was born. It puts the power supply and antenna in a box, weighing 3 kilograms, which is very heavy and inconvenient. Users must carry it like a backpack, so it is called a "shoulder phone".

Similar-looking mobile phones were born in 1987. Compared with the "shoulder phone", it is much lighter and easier to carry. Nevertheless, it still weighs about 750 grams, which is like a big brick compared with the mobile phone that weighs only 60 grams today.

Since then, the development 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. In other words, a mobile phone is not much heavier than an egg.

Modern mobile phones have become more and more like a multi-functional Swiss army knife, except for their smaller mass and volume. In addition to the most basic calling functions, the new mobile phone can also be used to send and receive emails and text messages, surf the Internet, play games, take photos and even watch movies! This was unexpected by the original mobile phone inventor.

In terms of communication technology, modern mobile phones have also made remarkable progress. Cooper can use any electromagnetic frequency band when he makes the first call with his mobile phone. 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, a new CDMA technology that distinguishes different mobile phones with different codes 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".