Mobile phone coverage is distributed by networks consisting of multiple contiguous cells, each of which is served by a separate transmitter with fixed locations, called base station. Rent land for a cell tower makes it easier to set up a base station.
Each cell covers a certain area and all the cells together provide radio coverage of a much wider geographical area. This makes it possible to operate simultaneously a plurality of mobile transceivers (e.g., mobile phones, pagers, among others), irrespective of whether they are stationary or moving from one cell to another.
Before the introduction of mobile phone networks there were mobile radiotelephone systems – for example, in cars. The radio telephone system, however, had only one central antenna tower in every city and a limited number (perhaps 25) of channels for use by each tower.
This means that a phone in a car needed a powerful transmitter so that it can link on a radio distance of 40 or 50 miles.