A mobile phone is a device used to make and receive calls over a radio frequency carrier (Electromagnetic waves) while the user is moving within a telephone service area.
Mobile phones use a cellular network architecture therefore they are also called cellular phones or cell phones.
Mobile phone is primarily designed for Voice communication only. New generation mobile phones support many applications such as SMS, Internet, GPS and etc.
When a mobile phone start a call / communication, mobile phone antennas transmit electromagnetic signals to radio towers and receive signals back simultaneously.
Mobile phone network use cellular networks. In a cellular network, the mobile towers are installed over portions of land. Each portion around a mobile tower called a cell. These cells are circular but on paper ther are hexagonal in shape.
Mobile Tower / BTS
A BTS ” Base transiver station” (usually placed in the center of a cell) make a cell and handles the mobile phones in that via radio link. BTS basic functions is to Connects mobile devices having SIM card of its network.
BSC “Base station controller” manages one or more BTS. It connects BTS to the MSC “Mobile switching center”.BSC handles inter-cell handover. It controls the power of BTS.
Mobile phone providers do not allow a phone to receive and transmit calls without identification and authentication. This process is done by a small microchips called “SIM Subscriber Identity Modules.SIM cards are common in mobile phones but some network do not use removable cards, they embed the security information permanently in memory.
MSC “mobile switching center is the center point to connect BSCs. It connects to the PSTN and MSC of other mobile pone network. Communication between two cell phones or between a cell phone and a landline telephone, travel through the MSC.