A mobile network consists of a network of base stations that cover a limited area (cell) and route communications as radio waves to and from the user terminals.
Mobile communications follow the general principle telephony: Connect two remote users via the computer network of an operator responsible for managing the service. However, unlike the fixed telephone, the mobile network no copper pair or fiber optic, and radio transmissions are the final link. The mobile phone user communicates through the air with an antenna, which in turn communicates with the central operator. This routes the communication to the share in the fixed network or via other antennas.
For communication to be effective, the mobile user must be within range of an antenna. It is limited in scope and covers a small area around called “cell” (hence the other name of “red cell” or “cellular network” often used to designate mobile networks). To cover the most territory and ensure that users can always call, operators deploy thousands of cells, each equipped with base stations, ensuring that no gaps between them so that the location of users will never miss.
cell urban, rural cells
The size of the cells depends on many factors such as the type of antenna used, the terrain (plains, mountains, valleys, etc.), the installation location (rural, urban, etc.), population density, etc.. The cell size is also limited by the scope of the mobile phone to be able to establish the return link. In addition, a base station has a limited transmission capacity and can simultaneously only handle a certain number of calls. Therefore, in urban areas with high population density and a significant number of communications, the cells tend to be numerous and small (hundreds or even only a few dozen meters away). In rural areas with lower population density, the cell size is much larger, sometimes up to several kilometers, but rarely more than ten kilometers. It is important to emphasize that the decrease in power of the signal emitted by the antennas leads to a reduction of coverage cells. Conversely, increasing the number of cells improves transmission voice traffic or network data, but requires that the number of base stations is increased.