Breakthrough for mobile telephony
With the invention of the telephone an age-old dream of being able to communicate over long distances came true. There were still limitations, however. Access to a telephone, wires and exchanges were required to make telecommunications possible.
This set the stage for the next dream - being able to communicate wherever you are without limitations. Although many people had this dream, it took some time for technology to catch up with the vision.
Guglielmo Marconi invented wireless telegraphy in the late 1800s, thus taking the first step. If sound would not be transmitted on a wire, it had to be carried by radio waves. In 1904, John Ambrose Fleming created the vacuum tube, which was then further enhanced by other researchers. By the mid-1910s, radio communication was a reality.
Commercial radio broadcasts began in the 1920s, but the development of radio communications remained a priority for the military. Communication using devices called walkie-talkies quickly became part of daily combat during World War II.
Things were also happening in the civilian sector, however, in 1946, AT&T received permission to build and operate the world's first mobile telephone service in St. Louis, Missouri. The system consisted of a base station with a transmitter with six channels. The telephones were mounted in cars and used large batteries hidden in the trunk. The system spread rapidly, and within a few years, it was used by about 1,000 subscribers in a total of 25 cities.
There were many disadvantages, however. The equipment was bulky, heavy and expensive. Transmission quality was uneven and often very poor. But the biggest problem was that there were not enough radio frequencies available to allow the system to be used by a large number of subscribers. It took many years before frequency allocation authorities were willing to grant frequencies for mobile telephony.
The problem was that the frequencies available for mobile telephony could not be used sufficiently effectively. To few users took up too much bandwidth. In 1947, however, AT&T introduced the cellular concept by which larger geographic areas were divided into cells, each with their own base station and channels. The available frequencies could be used in parallel in different cells without disturbing each other or infringing on other frequencies.
Mobile telephony could now in theory handle a large number of subscribers, but the technology was still lacking. Not until the development of transistors and microprocessors was the technology available for implementing the cellular concept.
There was also a political obstacle. In most countries, telephony had long been the domain of state-owned monopolies. This often guaranteed inexpensive and reliable telephone service, but interest for development and change was limited.
Even in countries where telephone services were operated by private companies, there was often a monopoly situation, and it was only when this was changed that mobile telephony could achieve a breakthrough.
In the US, the liberalization of the telecom industry reached its peak on January 1, 1984, when the Bell System was broken up. Bell, the gigantic company that had dominated the US telephone market for many years, was broken into seven operating companies. This in turn speeded the development of mobile telephony. The first licenses to operate mobile telephone systems were awarded in 1982, and the first system was taken into operation at the end of 1983.
Similar changes occurred in Europe. The Nordic countries and Great Britain were the first to start mobile telephone systems in the early 1980s, while other countries followed in the 1990s. However, the first country in the world with a functioning cellular system for mobile telephony was actually Saudi Arabia, which in 1981 took into operation a system delivered by Ericsson.
Author: Pontus Staunstrup
Guglielmo Marconi (1874-1937). In the beginning of the 1900s he invented wireless or radio telegraphy. The invention played an important part in the development of mobile telephony.
The first network diagram of the NMTsystems architecture.
The system MTA, the 1956 model.