A mobile or cellular telephone is a long-range, portable electronic device for mobile communication. In addition to the standard voice function of a telephone, current mobile phones can support many additional services such as SMS for text messaging, email, packet switching for access to the Internet, and MMS for sending and receiving photos and video. Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) (the exception are satellite phones).
Mobile phones are distinct from cordless telephones, which generally operate only within a limited range of a specific base station. Technically, the term mobile phone includes such devices as satellite phones and pre-cellular mobile phones such as those operating via MTS which do not have a cellular network, whereas the related term cell(ular) phone does not. In North America, the two terms are used nearly interchangeably, but the term cellular telephone is not used outside this region.
Contents[hide]
1 History
2 Manufacturers
3 Subscriptions
4 Culture and customs
4.1 Etiquette
4.2 Use in disaster response
4.3 Use by drivers
4.4 Applications
5 Power
6 Features
7 Forensics and evidence
8 Health impacts
9 Technology
10 Mobile communication studies
11 Terminology
11.1 Related non-mobile-phone systems
11.2 Terms in other countries
12 Gallery of notable cell phones
13 See also
14 Sources
15 External links
[edit] History
Main article: History of mobile phones
Mobile phones from various years, ranging from a large late 1980s-era phone to tiny 2000s phonesThe Mobile phone is one of the most used pieces of equipment today. The concept of using hexagonal cells for mobile phone base stations was invented in 1947 by Bell Labs engineers at AT&T and was further developed by Bell Labs during the 1960s. Radiophones have a long and varied history that stretches back to the Second World War when the military started to use radio telephony links and civil services in 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 1945, the 0G generation of mobile telephones were introduced. 0G mobile telephones, such as Mobile Telephone Service, were not officially categorized as mobile phones, since they did not support the automatic change of channel frequency in the middle of a call, when the user moved from one cell (base station coverage area) to another cell, a feature called"handover".
In 1970 Amos Joel of Bell Labs invented the"call handoff" feature, which allowed a mobile-phone user to travel through several cells during the same conversation. Martin Cooper of Motorola is widely considered to be the inventor of the first practical mobile phone for handheld use in a non-vehicle setting. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a handheld mobile phone on April 3, 1973. At the time he made his call, Cooper was working as Motorola's General Manager of its Communications Division.
Fully automatic cellular networks were first introduced in the early to mid-1980s (the 1G generation). The first fully automatic mobile phone system was the 1981 Nordic Mobile Telephone (NMT) system. Until the late 1980s, most mobile phones were too large to be carried in a jacket pocket, so they were usually permanently installed in vehicles as car phones. With the advance of miniaturization and smaller digital components, mobile phones got smaller and lighter.
[edit] Manufacturers
Nokia Corporation is currently the world's largest manufacturer of mobile telephones, with a global market share of approximately 36% in Q4 of 2006.[1] Other mobile phone manufacturers include Apple Inc., Audiovox (now UT Starcom), Benefon, BenQ-Siemens, High Tech Computer Corporation (HTC), Fujitsu, Kyocera, 3G, LG, Motorola, NEC, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research in Motion, Sagem, Samsung, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sony Ericsson, T&A Alcatel, and Toshiba. There are also specialist communication systems related to, but distinct from mobile phones, such as for exampleProfessional Mobile Radio.
[edit] Subscriptions
See also: List of mobile network operators of Europe
Several countries, including the UK, now have more mobile phones than people.[2] There will be over four hundred million cell phone users in China by 2008. Luxembourg has the highest mobile phone penetration rate in the world, at 164% in December 2005. In Hong Kong the penetration rate reached 117% of population in September 2004.[3] The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005.[4] Around 80% of world's population have mobile phone coverage as of 2006. This figure is expected to increase to 90% by the year 2010.[5]At present, Africa has the largest growth rate of cellular subscribers in the world.[6] African markets are expanding nearly twice as fast as Asian markets.[7] 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 on a monumental scale, not only in Africa but on other continents as well.
On a numerical basis, India is the biggest growth market adding about 6 million cell phones every month.[1]PDF (73.6 KiB) With 156.31 million cell phones, teledensity in the country is still low at 17.45% and country expects to reach 500 million subscribers by end of 2010.
All European nations and most Asian and African nations have adopted GSM. In other countries, such as the United States, Australia, India, Japan, and South Korea, legislation does not require any particular standard, and GSM coexists with other standards, such as CDMA and iDEN.
Some cellular systems are pay as you go, where top-ups can be purchased and added to a phone unit, in a wide variety of shops and even ATMs now, so there is no monthly bill. Many are"pay monthly", where a bill is issued every month for the amount of calls and text messages made.
[edit] Culture and customs
In fewer than twenty years, mobile phones have gone from being rare and expensive pieces of equipment used primarily by the business elite, 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. In the United States, 50% of children own mobile phones.[8] 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 address book 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 SMSs is growing. Many phones even offer Instant Messenger services to increase the simplicity and ease of texting on phones. Mobile 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.[9]
[edit] Etiquette
The use of a mobile phone is prohibited in some railroad company carriagesMobile phone etiquette has become an important issue with mobiles ringing at funerals, weddings, cinemas, and plays. Users often speak at increased volume which has led to places like book shops, libraries, movie theatres, doctors' offices, and houses of worship posting signs prohibiting the use of mobile phones, and in some places installing signal-jamming equipment to prevent usage (although in many countries, e.g., the United States, such equipment is currently illegal). Some new buildings such as auditoriums have installed wire mesh in the walls (turning the building into a Faraday cage) which prevents any signal getting through, but does not contravene the jamming laws.
Transportation providers, particularly those involving long-distance services, often offer a"quiet car" where phone use is prohibited, much like the designated non-smoking cars in the past. However many users tend to ignore this as it is rarely enforced, especially if the other cars are crowded and they have no choice but to go in the"quiet car". Mobile phone use on aircraft is also prohibited, because of concerns of possible interference with aircraft radio communications,[10] although the airline Emirates have announced plans to allow limited mobile phone usage on some flights. In April 2007 the Federal Communications Commission (FCC) officially grounded the idea of allowing passengers to use cell phones during a flight.[11] In a similar vein signs are put up in UK petrol stations prohibiting the use of mobile phones due to hypothetical safety issues. Most schools in the United States have prohibited mobile phones in the classroom due to the high amount of class disruptions that result from their use, and due to the possibility of photographing someone (without consent).
[edit] Use in disaster response
In Japan, mobile 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 no |
