The invention of mobile phones

In the 1970s, researchers at Bell Labs in the USA began to experiment 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 messages from mobile phones over radio frequencies. Any two adjacent cells would operate at different frequencies, so there was no danger of interference.

The stations would connect the radio signals with the main telecommunications network, and the phones would seamlessly switch frequencies as they moved between one cell and another.

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

Meanwhile, Martin Cooper, an engineer at the Motorola company 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.

Martin Cooper, the engineer from Motorola, developed the first hand-held phone that could connect over Bell’s AMPS. Motorola launched the DynaTAC in 1984. It weighed over a kilogram and was affectionately known as The Brick, but it quickly became a must-have accessory for wealthy financiers and entrepreneurs. The new mobile technology presented a problem in the USA, where the administration wanted to curb the dominance of AT&T, and in Britain, where Margaret Thatcher’s government wanted to move away from British Telecom’s state monopoly on telecommunications. The US approach offered contracts to two companies in every city, which resulted in a confusing mish-mash of incompatible networks. The British government took a different approach. In 1982 it licensed two companies, Cellnet and Vodafone, to operate the country’s first cellular phone networks.

British engineers developed expertise as ‘radio planners’, mapping the topography as well as the distances as they devised the optimal arrangement for the mobile phone network’s base stations. Too far apart and they would leave holes in the coverage; too close together and the signals would interfere with each other.

The first base stations, large and heavy pieces of kit, were installed in 1984. During a trial period engineers drove around the country making calls to patient volunteers to test the signal strength.

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

They each expected to win up to 20,000 subscribers within ten years. To their astonishment, three years later they had over half a million subscribers, and network coverage reached 90 per cent of the population.

A strong market for mobile technology drove the development of smaller and cheaper phones until there was one to suit every pocket.

It was teenagers—always cultural innovators—who developed extraordinary dexterity and (OMG!) a whole new language of abbreviations, initials and emoticons in the 1990s, as sending text messages became an integral part of their social interaction. 

No one would have been more surprised at this development than the companies who first invested in cellular mobile phone networks, thinking they might have a market among wealthy businesspeople keen to acquire the latest gadget.

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