History of the discovery of cell phones can not be separated from the development of radio. Early discovery of cell phones began in 1921 when the Detroit Police Department Michigan tried using a car phone in one direction. Then, in 1928 the Detroit Police Department began using one-way radio communication on all regular patrol car with a frequency of 2 MHz. on subsequent developments, radio evolved into a two-way communication with''''frequency modulated (FM).
In 1940, Galvin Manufactory Corporation (now Motorola) to develop a portable Handle SCR536-talkie, which means a communication tool on the battlefield during World War II. This period is the next generation mobile phone 0 or 0-G, where cell phones were introduced.
After removing the SCR536, later in the year 1943 Galvin Manufactory Corporation issued a return partable first FM two-way radio that is named SCR300 backpack model for U.S. army This tool weighs about 35 pounds and can work effectively within the operating range of 10 to 20 miles.
System-G 0 cell phones still use a VHF radio system for connecting a phone directly to PSTN landline. The weakness of this system is the problem of congestion on the network which then led to attempts to change this system.
Generation 0 ends with the discovery of the modern concept by engineers from Bell Labs in 1947. They invented the concept of using hexagonal phone as a basic cell phone. However, this new concept was developed in the 1960s.