Cellular network

A cellular network or mobile network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station.

The most common example of a cellular network is a mobile phone (cell phone) network. A mobile phone is a portable telephone which receives or makes calls through a cell site (base station), or transmitting tower. Radio waves are used to transfer signals to and from the cell phone.

Modern mobile phone networks use cells because radio frequencies are a limited, shared resource. Cell-sites and handsets change frequency under computer control and use low power transmitters so that a limited number of radio frequencies can be simultaneously used by many callers with less interference.

There are a number of different digital cellular technologies, including:

• Global System for Mobile Communications (GSM);
• General Packet Radio Service (GPRS)
• Code Division Multiple Access (CDMA)
• Evolution-Data Optimized (EV-DO)
• Enhanced Data Rates for GSM Evolution (EDGE)
• 3GSM, Digital Enhanced Cordless Telecommunications (DECT)
• Digital AMPS (IS-136/TDMA)
• Integrated Digital Enhanced Network (iDEN).

A cellular network is used by the mobile phone operator to achieve both coverage and capacity for their subscribers. Large geographic areas are split into smaller cells to avoid line-of-sight signal loss and to support a large number of active phones in that area. All of the cell sites are connected to telephone exchanges (or switches), which in turn connect to the public telephone network.

Cellular operators provide the following services:

• Voice call;
• Autoresponder in a cellular communication (service);
• Roaming;
• ANI (Automatic Number Identification) and Caller Identity Restriction;
• Receive and send short text messages (SMS);
• Receiving and sending multimedia messages - images, music, videos (MMS-service);
• Mobile Banking (service);
• Access to the Internet;
• Video call and video conferencing.