A MOBILE PHONE also known as cellular phone or hand phone is an electronic tool used for mobile telecommunications over a cellular system of particular base stations known as “Cell sites”. Cell phones are change from cordless phones, which just offer telephone service within restricted range; for example, in a home or an office, through a fixed line and a base station owned by the subscriber and also from satellite handset and broadcasting phone.
Because opposed to a broadcasting phone, a mobile phone present complete duplex communication, automates calling to and paging from a public land mobile network (PLMN), and handoff during a call when the user moves from one cell (base station coverage area) to a different position. Nearly all current mobiles connect to a cellular system consisting of switching points and base stations (cell sites) owned by a mobile system operator. Additionally to the standard voice function, current cell phones can support many additional services, and accessories, such as SMS for Text messaging, E-mail, Pad for access to the Internet, Gaming, Bluetooth, Information list, Camera with video recorder and MMS for sending and receiving photos and video, MP3 player, Radio and GPS. The idea of a handheld phone was Martin Cooper's brainchild, and with the help of his Motorola team, the first handset was born in 1973 weighing in at two kilos.
The International Telecommunication Union estimated that mobile cellular subscriptions worldwide would come to approximately 4.6 billion by the end of 2009. Cell phones have gained increased importance in the sector of Information and communication technologies for development in the 2000s and have effectively started to reach the bottom of the economic pyramid.
