CELL PHONE

Computer Engineering electronics Engineering Civil Engineering

A mobile phone allows its user to make and receive telephone calls to and from the public telephone network which includes other mobiles and fixed line phones across the world. It does this by connecting to a cellular network owned by a mobile network operator. A key feature of the cellular network is that it enables seamless telephone calls even when the user is moving around wide areas via a process known as handoff or handover. Modern mobile phones also support many additional services, and accessories, such as SMS (or text) messages, email, Internet access, gaming, Bluetooth, infrared, camera, MMS messaging, MP3 player, radio and GPS. Low-end mobile phones are often referred to as feature phones, whereas high-end mobile phones that offer more advanced computing ability are referred to as smart-phones. The first handheld cellular phone was demonstrated by Martin Cooper of Motorola in 1973, using a handset weighing in at two kilos. By the end of 2009, only 20 years later, the number of mobile cellular subscriptions worldwide reached approximately 4.6 billion, 370 times the 1990 number, penetrating the developing economies and reaching the bottom of the economic pyramid. The first mobile telephone call made from a car occurred in St. Louis, Missouri, USA on June 17, 1946, but the system was impractical from what is considered a portable handset today In 1960, the world loading..