Cell phone usage is proliferating at a rapid rate and phones are getting more and more sophisticated. A quarter of U.S. households have only a cell phone and cannot be reached by a land-line telephone.
A cell phone, also called a mobile phone,is an electronic device used primarily for making phone calls over a cellular network of towers and stations. Cell phones are different from cordless phones, which offer service only in a limited range within a home or office property.
In addition to making phone calls over a voice network, current phones may support many additional services such as SMS (text) messaging, email, Internet access, gaming, Bluetooth, infrared, camera with video recorder and MMS for sending and receiving videos and photos, MP3 players, radios, and GPS navigation systems. The International Telecom Union estimates there are 4.6 billion cellular subscriptions worldwide.
Once viewed as an electronic gadget only for the wealthy, now almost everyone has a cell phone as indicated by the ITU's estimate number of subscriptions. Some popular models of current cell phones include the Apple iPhone, Google Nexus One, and the RIM Blackberry.