A cellular network is a radio network made up of a number of radio
cells (or just cells) each served by a fixed transmitter,
known as a
cell site or base station. These cells are used to cover different areas in
order to provide radio coverage over a wider area than the area of one cell.
Cellular networks are inherently asymmetric with a set of fixed main
transceivers each serving a cell and a set of distributed (generally, but not always,
mobile) transceivers which provide services to the network''s users.
Cellular networks offer a number of advantages over alternative solutions:
increased capacityreduced power usagebetter coverage
A good (and simple) example of a cellular system is an old taxi driver''s
radio system where the taxi company will have several
transmitters based around
a city each operated by an individual operator.
The primary requirement for a network to succeed as a cellular network is
for it to have developed a standardized method for each distributed station to
distinguish the signal emanating from its own transmitter from the signals
received from other transmitters. Presently, there are two standardized
solutions to this issue: · frequency division multiple access (FDMA) and; · code
division multiple access (CDMA).