Digital Cell Phone from NokiaMillions of people in the United States and around the world use cell phones. They are amazing gadgets – with a mobile phone you can talk to anyone on the planet from anywhere! Nowadays, cell phones provide an incredible array of features, and new ones are being added at a dizzying rate. Depending on your phone model, you can: Store contact information Create task or to-do lists Track appointments and set reminders Use the built-in calculator for simple calculations Send or receive emails Get information (news, entertainment, quotes) stock) from the InternetPlay simple gamesIntegrate other devices such as PDAs, MP3 players and GPS receiversBut have you ever wondered how a cell phone works? What makes it different from a normal phone? What do all those confusing terms like PCS, GSM, CDMA and TDMA mean? In this article we will discuss the technology behind cell phones so you can see how amazing they really are. If you're thinking about buying a cell phone, be sure to check out How Buying a Cell Phone Works to learn everything you should know before making a purchase. Let's start with the basics: Essentially, a cell phone is a radio. One of the coolest things about a cell phone is that it's actually a radio: an extremely sophisticated radio, but still a radio. The telephone was invented by Alexander Graham Bell in 1876, and wireless communication has its roots in Nikolai Tesla's invention of the radio in 1880 (formally introduced in 1894 by a young Italian named Guglielmo Marconi). It was only natural that these two great technologies would eventually be combined! In the dark ages before cell phones, people who really needed mobile communication capabilities installed radio telephones in their cars. In the radiotelephone system there was one central antenna tower per city, and perhaps 25 channels were available on that tower. This central antenna meant that your car phone needed a powerful transmitter, large enough to transmit for 40 or 50 miles (about 70 km). It also meant that not many people could use radio telephones - there simply weren't enough channels. The genius of the cellular system is the division of a city into small cells. This allows for widespread reuse of frequencies in a city, so that millions of people can use cell phones at the same time.