The huge part of the populated area of Russia is covered with base stations. In the fields they look like red and white towers and in the city they are hidden on the roofs of houses. Each station receives a signal from a cellphone at the distance up to 35 km and communicates with a cellphone via engineering channels and voice canals.
A base station represents a couple of iron boxes locked inside a well-conditioned room.
An antenna of a base station has some sectors. The vertical one communicates with mobile phones, the round one connects the base station with a controller.
Each sector can support up to 72 calls at the same time. Each base station can support up to 432 calls. Cellular operators prefer to use more base stations to get better quality connection.
A box with 3D equipment looks like this:
A base station may work in three diapasons:
900MHz – long-distance signal;
1800MHz – shorter-distance signal;
2100MHz – 3G net.
An ordinary cellphone may send a signal at the distance 70km.
From the base station the signal is sent to the controller looking like this: