CELLULAR

Car telephone - and hence mobile telephone - was already in progress when Cellular began in approximately 1983.  Cellular then became the modern means for car telephones - and now portable telephones to transmit wirelessly for both voice and data applications.

Cellular had a few large changes from the early car telephone systems.  The first major change had the biggest impact.  Instead of operating at 150 MHz and 450 MHz as did the early car telephone systems - competing for space with television - the new cellular system was to be at a higher frequency, 800 and 900MHz - which at the time was open frequency and was not much in use.  Therefore cellular now had the possibility to allow many customers (subscribers) to use their mobile phone service at the same time.

The second large change, was the means of transmitting.  Early car telephone systems would use a powerful base station in the central area of the city that was expected to transmit all over the city.  Even with the help of electronic repeaters, this system did not allow many customers to use their mobile phones at the same time.  Cellular systems instead, installed land line systems all over a city, usually a few miles apart or less.  These base station sites then became known as cell-sites and from the air looking down on the city, it would seem that the whole system was cellular - or honey-combed in appearance - with small central cell sites at equal distances all over the city.  A big advantage of using cell-sites and a cellular approach was that unlike the previous centralized base station, the transmitters were now lower power.  Cell sites a distance from each other could even reuse the same frequencies - allowing for even more customers or cellular subscribers to use their cell phones at the same time.

All of the above reasons made cellular a much larger application that allowed many, many more customers using mobile phones than the early car telephone systems.  Regardless of some marketing claims, all current and projected mobile telephone systems (including PCS) are cellular in nature in the manner in which their base stations and cell sites are deployed.