A phone mast, more commonly referred to as a cell phone mast, cell tower or cell site, is essentially an elevated large and powerful radio transmitter and receiver coupled with the computing technology of digital signal processors. A mobile phone itself is basically a weak radio transmitter and receiver. A geographical area containing a phone mast, or multiple phone masts, is referred to as a cell. When a call, message or other data is sent from a mobile phone, a signal is transmitted out and picked up by the nearest cell tower in range, which then encodes the signal and transmits the signal, sometimes across a series of cells, until it reaches its relevant destination.
The structure of a cell phone mast usually consists of a tower, which a tall building might serve as, with at least one base station, along with multiple receivers, transmitters and digital signal processors. Antennas are mounted atop the tower or other tall structure occupied by a cell phone base station site, because elevation is important when transmitting a signal over long distances. Some cities have ordinances requiring that every cell phone mast must blend in with its surroundings, so a phone mast often is made to look like a tall tree, flagpole, work of art or other commonly seen structure.
When a cell phone mast receives a signal, part of the information encoded from that signal includes the dialed phone number, which acts as a unique address so that the information can then be transmitted to the desired recipient. Additionally, a mobile phone will always send out identifier signals in frequent intervals. Identifier signals are picked up by the nearest cell tower, which confirms the location of the receiver, or mobile phone, to which the transmitted signal needs to be delivered. A base transceiver station, also known as a cell phone base station or, more simply, just a base station, manages the traffic of signals between multiple phone operators and might also host several types of air interface technologies, which can vary by cell phone service provider and the type of data being transmitted. To avoid interference or an encumbering amount of data, a cell phone mast will often operate using more than one cell phone base station site.