The history of the mobile phone is a remarkable chapter in the pursuit of excellence by the human being. Since its inception, a lot of research has been done in just a span of about half a century. The man does not stop reinventing and innovating these phones to make life easier and adapted to the lifestyle and individual needs. It has become the most powerful device after computers.

In the case of the USA, the mobile account can be broken down into three different important points. First is the feature from its early days as a car phone that led to the compact phones we know today. Second is the technology used to adopt radio frequency to send voice signals. The third is the pace of development, from a car phone to being analog and its current digital greatness.

Let us take a look at the history of the mobile phone in the aspect of its features.
During the 1940s, cell phones were car phones used by police, ambulance services, and trucks. This continued until 1973 when Motorola designed a system that did not need to be installed in automobiles. Several years later, they became smaller and more compact.

Technology and the pace of mobile development in the history of mobile phones in the US go hand in hand with these instances. When AT&T, through Bell Labs, proposed to the Federal Communications Commission (FCC) that a mobile phone system be established by placing six cellular or base stations in an area with a less powerful central transmitter to ensure continuous communication between users , the commission hesitated. . What they did was assign a limited frequency to be used as a solution to said proposal. Apart from the limited frequency, the technology with which it would be operated was not available at the time. It was only acted after 37 years giving 800 MHz. to be implemented by the telephone companies. The interested parties themselves caused the delay.

Meanwhile, mobile phone companies continued to improve the technology. AMPS or Advanced Mobile Phone System was invented in the 1980s. This system brought analog technology into play, equated to a radio transmitter. The drawback of this technology is that it does not allow multiple users at the same time. The signal is also weak and static when the user moves from one place to another.

Analog was later replaced by digital technology in the 1990s. Digital makes stronger and clearer signals possible. You can also handle multiple users.

Mobile technology is divided into three different types, CDMA, TDMA and SMS. These make Internet browsing and international calls possible. The United States of America has yet to come up with more innovations, but it has already made a significant and impressive contribution to the development of mobile phones.

Today, it is still reinventing itself to cope with man’s ever-changing standard of living. Little by little they are specializing to meet the special needs of people.

MONITORING TECHNOLOGY GROUP INC
… or “telephone”, is connected via radio frequencies to transmitting and receiving base stations that connect the user to a conventional telephone network…
www.survtech.org/home/cellphoneforensics.php