mobile phones scientific and technical progress presentation

In the 1970s, researchers at Bell Labs in the USA began to _______ with the concept of a cellular phone network. The idea was to cover the country with a network of hexagonal cells, each of which would contain a base station.

These base stations would send and receive ________ from mobile phones over radio frequencies. Any two adjacent cells would operate at different frequencies, so there was no danger of interference.

Meanwhile, Martin Cooper, an engineer at the _____ _____ in the US, was developing something that came close to the Star Trek communicator that had fascinated him since he first saw it on TV.

By the end of the 1970s the Bell Labs Advance Mobile Phone System (AMPS) was up and running on a small scale.

as theThe stations would connect the radio signals with the main _______ network, and the phones would seamlessly switch frequencies y moved between one cell and another.

The British government took a different approach. In ____ it licensed two companies, Cellnet and Vodafone, to operate the country’s first cellular phone networks.

Vodafone launched its network on New Year’s Day, 1985, and Cellnet followed a few days later. 

The first base stations, large and heavy pieces of kit, were installed in _____. During a trial period engineers drove around the country making calls to patient volunteers to test the signal strength.