How do you make a mobile phone how it was made where it was made?

Answer 1

In the US the Bell System had done some experimentation with mobile phones mounted in car trunks before WW2 and implemented the first mobile phone exchange in June 1946 in St. Louis, Missouri. By 1950 most major cities and about 4000 miles of highway were connected to mobile exchanges, and more than 7500 cars, trucks, and other vehicles had been equipped with leased mobile phones. All mobile calls were handled via operators on switchboards (even in major cities where all standard landline calls were already handled by fully automated dial exchanges). However these mobile phones were not like modern cellular phones and due to limited radio bandwidth assignment by the FCC the initial systems saturated at about 3 active calls per exchange, although by the 1960s these systems had been improved and could support more than 25 active calls per exchange before saturating. In some situations with this early system it could take as long as half an hour after a mobile phone customer indicated they wished to make a call before they were connected to an operator.

In December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in vehicles however they recognized that the vacuum tube and relay technology of the phone system of the time could not handle all of the demands of such a cellular mobile phone system. In 1969 with the newly available miniaturized solid state electronics technology A. T. & T. began serious work on a vehicle trunk mounted cellular mobile phone and contacted the FCC about licensing of radio bandwidth assignments for this new cellular mobile phone system that would replace the older system. In 1971 Martin Cooper, a Motorola researcher and executive began working on a handheld portable cellular mobile phone and on April 3, 1973 he made the first call using it. For several years however cellular mobile phone calls still frequently had to be made through an operator (see the "Cannon" detective series of 1971-1976 where he had a Motorola car cellular mobile phone), but eventually direct customer dialed automated calling became universal.