The first mobile phone invented is rooted in the history and technology of the hand held radio. Two way radios, or mobile rigs, were widely used by taxis and emergency services prior to the invention of the first mobile or cellular phones. Two way radios allowed communication among vehicles and stations within a defined group, but they were not really the first mobile phones. Mobile rigs did not use the telephone network and users could not dial out to standard telephone numbers.
The first mobile phone call was made by a truck driver as an experiment in the summer of 1946 from a phone weighing close to 80 pounds. The experiment was considered a success but mobile telecommunication technology was far from commonplace.
By 1948, wireless telephone service was available in almost 100 cities. Users numbered about 5,000 with 30,000 calls being made weekly. The service was considered very expensive at about fifteen dollars a month with an additional 30 to 40 cent charge per call.
Limited mobile phone service was available, providing for about three calls to take place at one time in any service area. The first users would wait and listen for a line to open up as others users finished their calls.
The first hand held mobile phone call was made by Martin Cooper, who led the team that developed the first hand held phones. Cooper made his phone call on April 3, 1973 on a prototype Dyna-Tac phone that weighed about 2.5 lb (1.1 kg). The call
Mobile telecomunication service capabilities improved in 1982 when the Federal Communications Commission (FCC) approved the establishment of a mobile telephone system and allocated a limited number of analog frequencies to be used by the network.
At this time, mobile phones were not cellular. Signals were conducted by large transmission towers and conversations were tied to a single tower’s transmission area. This meant a user could not leave the designated transmission area during a conversation. The number of transmission towers was limited, each requiring significant frequency space.
In the early to mid eighties, mobile phones were commonly called car phones as they were permanently mounted in automobiles. These phones were followed by bag phones that used a portable phone housed in a bag with plugs adapted to receive power from a car’s cigarette lighter.
A significant breakthrough in mobile phone technology came when the mobile system became cellular. The introduction of cellphones allowed users to move in and out of tower frequency areas while on a call. This freedom of movement made the device much more useful than the first mobile phone.
Cellular technology was invented by Joel Engel and Richard Frenkiel, two researchers for AT&T Labs, in 1983. They introduced the cellular concept of replacing large broadcast towers, with smaller low powered towers.
Each of these smaller towers would cover an area, or cell, of only a few miles. The technology allowed calls to be passed from cell to cell. Although each tower covered a relatively small radius, by passing calls from tower to tower, the system was capable of covering large areas. By this time, the FCC had allocated more frequencies to the system. Each cell tower required less frequency space but more towers were needed. Mobile callers could now move about freely while on their phones.