The image on the left shows a modern mobile phone tower. This is a latticework pylon designed mainly for use in the countryside where the tower's range and it's power output tends to be higher than for an equivalent tower in the city. Actually this tower services two network operators, with one operator handling the ring of transmitters just above the middle of the tower and the other provider having the transmitters at the top of the tower. Because the operators are separate they have their own separate equipment and this is why there are two huts at the base of the tower: one for each operator.

So that you can better see what's going on the image left shows a mobile telephon transmitter tower for only a single operator. At the top of the tower you can see that the radio frequency transmitters are arranged in pairs at the cardinal points of a triangle. This allows for 360° coverage within range of the tower with the minimum number of receivers and transmitters. Cabling within the tower's infrastructure connects the antennae to the radio-frequency generation and analysis equipment which, for security reasons, is secured within the building at the base of the tower.

In terms of a mobile phone network's infrastructure the tower is by far the most obvious and visible part of the entire network. Yet, all the interesting components of the network — what makes the network actually work is hidden away either in buildings or in covered boxes at the bases of these towers.

To contrast with the two country mobile phone towers shown above, the image on the left shows a typical inner-city mobile phone tower. As these are generally at lower power and cover a smaller range they are much smaller with far fewer antennae. They are also generally located on small tower paltforms housed at the top of tall buildings — this gives height for good coverage and obviates the need for a tall tower.

For these kinds of mobile phone transmitters the control functions are generally held within a small metal housing usually located either close to the base of the transmitter or on the roof in physical proximity but not ajacent to the transmitter.

Rather than being housed in huts or in secured boxes some cell phone tower installations are protected by wire fences and in these cases it's possible to have a better look at the equipment used, as shown on the left.

The box in the foreground holds the transformer that supplies power and the switching boxes that connect the tower to the landline system. The box on the left in the background actually houses the radio transmitters and receivers whose signals are relayed to the antennae at the top of the tower. It's possible to identify this component from the thick cables snaking out from it. These are the data cables that transmit the radio frequency signals to and from the tower. If you look closely at any tower you will also note that all components, form the tower itself to the tower's equipment are all heavily grounded. This is because of the risk of lightning strike to the tower itself which is often the tallest metal structure in the area.