Mobile Phones

A mobile phone.

A mobile phone or cell phone is an electronic telecommunications device. Most current mobile phones connect to the network using a wireless radio wave transmission technology (the exception are satellite phones). These mobile phones communicate via a cellular network of base stations (cell sites), which is in turn linked to the conventional telephone network and were first introduced in the early to mid 1980s (the 1G generation). Prior mobile phones operating without a cellular network (the so-called 0G generation), such as Mobile Telephone Service, date back to 1946. Until the mid to late 1980s, most mobile phones were sufficiently large that they were often permanently installed in vehicles as car phones. With the advance of miniaturization, currently the vast majority of mobile phones are handheld.

In addition to the standard voice function of a telephone, a mobile phone can support many additional services such as SMS for text messaging, packet switching for access to the Internet, and MMS for sending and receiving photos and video.

Some of the world's largest mobile phone manufacturers include Alcatel, Audiovox, Fujitsu, Kyocera, LG, Motorola, NEC, Nokia, Panasonic (Matsushita Electric), Philips, Sagem, Samsung, Sanyo, Sharp, BenQ-Siemens, SK Teletech, Sony Ericsson, and Toshiba.

Worldwide Deployment

Radio phones have a long and varied history that stretches back to the 1950s, with hand-held cellular radio devices being available since 1983. Due to their low establishment costs and rapid deployment, mobile phone networks have since spread rapidly throughout the world, outstripping the growth of fixed telephony.

In most of Europe, wealthier parts of Asia, Africa, the Caribbean, Latin America, Australia, Canada, and the United States, mobile phones are now widely used, with the majority of the adult, teenage, and even child population owning one. At present India and China have the largest growth rates of cellular subscribers in the world. The availability of Prepaid or pay as you go services, where the subscriber does not have to commit to a long term contract, has helped fuel this growth.

The mobile phone has become ubiquitous because of the interoperability of mobile phones across different networks and countries. This is due to the equipment manufacturers working to meet one of a few standards, particularly the GSM standard which was designed for Europe-wide interoperability. All European nations and most Asian and African nations adopted it as their sole standard. In other countries, such as the United States, Japan, and South Korea, legislation does not require any particular standard, and GSM coexists with other standards, such as CDMA and iDen

Mobile Phone Culture

In less than twenty years, mobile phones have gone from being rare and expensive pieces of equipment used by businesses to a pervasive low-cost personal item. In many countries, mobile phones now outnumber land-line telephones, with most adults and many children now owning mobile phones. It is not uncommon for young adults to simply own a mobile phone instead of a land-line for their residence. In some developing countries, where there is little existing fixed-line infrastructure, the mobile phone has become widespread.

With high levels of mobile telephone penetration, a mobile culture has evolved, where the phone becomes a key social tool, and people rely on their mobile phone addressbook to keep in touch with their friends. Many people keep in touch using SMS, and a whole culture of "texting" has developed from this. The commercial market in SMS's is growing. Many phones even offer Instant Messenger services to increase the simplicity and ease of texting on phones. Cellular phones in Japan, offering Internet capabilities such as NTT DoCoMo's i-mode, offer text messaging via standard e-mail.

The mobile phone itself has also become a totemic and fashion object, with users decorating, customizing, and accessorizing their mobile phones to reflect their personality. This has emerged as its own industry. The sale of commercial ringtones exceeded $2.5 billion in 2004.

Mobile phone etiquette has become an important issue with mobiles ringing at funerals, weddings, movies, and plays. Users often speak at increased volume which has led to places like bookshops, libraries, movie theatres, doctor's offices, and houses of worship posting signs prohibiting the use of mobile phones, and sometimes even installing illegal jamming equipment to prevent them. Many rail companies, particularly those providing long-distance services, offer a "quiet car" where phone use is prohibited, much like the designated non-smoking cars in the past. Mobile phone use on aircraft is also prohibited, but because of concerns of possible interference with aircraft radio communications.

Cameraphones and videophones that can capture video and take photographs are increasingly being used to cover breaking news. Many important news stories been reported on by cameraphone users on news sites like NowPublic and photosharing sites like Flickr.

In Japan, cellular phone companies provide immediate notification of earthquakes and other natural disasters to their customers free of charge. In the event of an emergency, disaster response crews can locate trapped or injured people using the signals from their mobile phones; an interactive menu accessible through the phone's Internet browser notifies the company if the user is safe or in distress.

Mobile phone features

Mobile phones often have features beyond sending text messages and make voice calls—including Internet browsing, music (MP3) playback, personal organizers, e-mail, built-in cameras and camcorders, ringtones, games, radio, Push-to-Talk (PTT), infrared and bluetooth connectivity, call registers, and ability to watch streaming video or download video for later viewing.

Technology

Mobile phones and the network they operate under vary significantly from provider to provider, and even from nation to nation. However, all of them communicate through electromagnetic radio waves with a cell site/base station, the antennas of which are usually mounted on a tower, pole, or building.

The phones have a low-power transceiver that transmits voice and data to the nearest cell sites, usually .5 to 10 miles away. When the cellular phone or data device is turned on, it registers with the mobile telephone exchange, or switch, with its unique identifiers, and will then be alerted by the mobile switch when there is an incoming telephone call. The handset constantly listens for the strongest signal being received from the surrounding base stations. As the user moves around the network, the mobile device will "hand off" to new cell sites.

Cell sites have relatively low-power (often only one or two Watts) radio transmitters which broadcast their presence and relay communications between the mobile handsets and the switch. The switch in turn connects the call to another subscriber of the same wireless service provider or to the public telephone network, which includes the networks of other wireless carriers.

Future prospects

There is a great deal of active research and development into mobile phone technology that is currently underway. Some of the improvements that are being worked on are: