The first mobile phone concept evolved from the two way radio systems that started back in the 1940's. The first radio telephone probably began in 1946 when AT&T started using the push to talk feature in conjunction with a manual operator. AT&T and Southwestern Bell began MTS the first mobile telephone service in St Louis MO.
This evolved into the 1970s when the FCC allocated new frequencies just for land mobile communications. They were known as IMTS, for improved mobile telephone service, and were actually radios connected to land lines. These were hard wired in the car with the push to talk feature and only one person speaking at the same time, they also used licensed towers and others could actually listen in over their scanners. But this was still radio technology.
In 1973 Mr Martin Cooper stood on a Manhattan street corner and placed a call to his competition at Bell Labs acknowledging to them that he had actually made the first call from a true mobile phone, one you could carry anywhere. Even though it weighed about 30 ounces and was shaped like a brick, it was truly mobile.
With Mr Coopers invention the technology emerged into the idea of cell technology. This technology used antennas emitting signal in a hexagonal direction hence calling it a cell. You may notice on cell towers that there are usually two or three antennas pointing in one direction. These antennas point the signal in an area (cell) and other towers point their signals into neighboring areas (cells). These cells even though they overlap at times, are pointed in directions that meet at the edges of each cell, giving full coverage in most cases.
Frequency reuse then came into play where one cell works on the previous cell frequency, and the calls can be handed off when one goes from one cell into another. This concept gives us uninterrupted cell service. You can start talking while on the road and even cover several states without loosing coverage. Now the cell coverage is so advanced that the companies can offer internet through the cell system.
From the first true mobile phone in 1973, to the palm sized phone, and even that which has evolved into a hand held computer on which you can surf the web and talk at the same time. The first mobile phone invention was a race to be first, now the race is to be the biggest, the competition is still on.
