What are cell sites?

A cell site, otherwise known as a mobile phone base station – often distinguished by tall masts – is a low power radio transmitter with an antenna to transmit radio waves to mobile phones.

Antennas have to be positioned high on masts because radio waves travel in straight lines and can be interrupted or deflected by buildings or terrain. It is the antenna that transmits radio frequencies: the masts supporting the antennas do not.

Macrocells, microcells, picocells and femtocells

A macrocell provides the largest area of coverage within a mobile network. Its antennas can be mounted on ground-based masts, rooftops or other structures and must be high enough to avoid obstruction. Macrocells provide radio coverage over varying distances, depending on the frequency used, the number of calls and the physical terrain. Typically they have a power output in tens of watts.

Macrocell examples are shown above.

Microcells provide additional coverage and capacity in areas where there are high numbers of users, urban and suburban areas, for example. The antennas for microcells are mounted at street level, are smaller than macrocell antennas and can often be disguised as building features so that they are less visually intrusive. Microcells provide radio coverage over distances – typically between 300m and 1000m – and have lower output powers than marocells, usually a few watts.

Microcell examples are shown above.

Picocells provide more localised coverage. These are generally found inside buildings where coverage is poor or where there is a dense population of users such as in airport terminals, train stations and shopping centres.

Femtocell base stations allow mobile phone users to make calls inside their homes via their Internet broadband connection. Femto-cells provide small area coverage solutions operating at low transmit powers

Find out more:

• What are radio waves?
• What is Specific Absorption Rate?
• Base stations – location and roll-out
• Network roll-out - best practice