Mobile Phone

HistoryThe mobile phone or mobile, also called a cellular phone, or cell phone is a long-range, portable electronic device used for mobile communication that uses a network of specialized base stations known as cell sites. 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 is satellite phones).
There is one U.S. patent, Patent Number 887357 for a wireless telephone, issued 1908 to Nathan B. Stubblefield of Murray, Kentucky. He applied this to "cave radio" telephones and not directly to cellular telephony as the term is currently understood.[1] However, the introduction of cells for mobile phone base stations, invented in 1947 by Bell Labs engineers at AT&T, was further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been available since 1973. 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.[citation needed]
In 1945, the zero generation (0G) of mobile telephones was 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 during calls, which allows the user to move from one cell (the base station coverage area) to another cell, a feature called "handover".[citation needed]
In 1984, Bell Labs invented such a "call handoff" feature, which allowed mobile-phone users to travel through several cells during the same conversation. 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, Motorola manager Martin Cooper made the first call on a handheld mobile phone on April 3, 1973.[2]
The first commercial cellular network was launched in Japan by NTT in 1979. Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation) with the Nordic Mobile Telephone (NMT) system in 1981. This was followed by a boom in mobile telephone usage, particularly in Northern Europe.[citation needed]
The first "modern" network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard which also marked the introduction of competition in mobile telecoms when Radiolinja challenged incumbent Telecom Finland (now part of TeliaSonera) who ran a 1G NMT network. A decade later, the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard.[citation needed][3] Until the early 1990s, most mobile phones were too large to be carried in a jacket pocket, so they were typically installed in vehicles as car phones. With the miniaturization of digital components, mobile phones have become increasingly portable over the years.
Today, video and TV services are driving forward third generation (3G) deployment. And in the future, low cost, high speed data will drive forward the fourth generation (4G) as short-range communication emerges. Service and application ubiquity, with a high degree of personalization and synchronization between various user appliances,will be another driver. At the same time, it is probable that the radio access network will evolve from a centralized architecture to a distributed one.
ManufacturersNokia Corporation is currently the world's largest manufacturer of mobile telephones, with a global device market share of approximately 36% in Q1 of 2007.[4] Other mobile phone manufacturers include Apple Inc., Audiovox (now UT Starcom), Benefon, BenQ-Siemens, High Tech Computer Corporation (HTC), Fujitsu, Kyocera, LG Mobile, Mitsubishi, Motorola, NEC, Neonode, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Samsung, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sonim Technologies, Sony Ericsson, T&A Alcatel, and Toshiba. There are also specialist communication systems related to (but distinct from) mobile phones.
The mobile phone manufacturers can be grouped into two. The top five are available in practically all countries and comprise about 75% of all phones sold. A second tier of small manufacturers exists with phones mostly sold only in specific regions or for niche markets. The top five in order of market share are Nokia, Samsung, Motorola, SonyEricsson and LG.
Several countries, including the UK, now have more mobile phones than people.[5] There are over five hundred million active mobile phone accounts in China, as of 2007.[6] Luxembourg has the highest mobile phone penetration rate in the world, at 164% in December 2001. In Hong Kong the penetration rate reached 139.8% of the population in July 2007.[7] The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005.[8] The subscriber count reached 2.7 billion by end of 2006 according to Informa[citation needed], and 3.3 billion by November, 2007[9], thus reaching an equivalent of over half the planet's population. Around 80% of the world's population enjoys mobile phone coverage as of 2006. This figure is expected to increase to 90% by the year 2010.[10]
At present, Africa has the largest growth rate of cellular subscribers in the world,[11] its markets expanding nearly twice as fast as Asian markets.[12] The availability of prepaid or 'pay-as-you-go' services, where the subscriber is not committed to a long term contract, has helped fuel this growth in Africa as well as in other continents.
On a numerical basis, India is the largest growth market, adding about 6 million cell phones every month.[13] With 256.55 million cell phones, market penetration in the country is still low at 22.52%. India expects to reach 500 million subscribers by end of 2010.
There are three major technical standards for the current generation of mobile phones and networks, and two major standards for the next generation 3G phones and networks. All European, African and many Asian countries have adopted a single system, GSM, which is the only technology available on all continents and in most countries and covers over 74% of all subscribers on mobile networks. In many countries, such as the United States, Australia, Brazil, India, Japan, and South Korea GSM co-exists with other internationally adopted standards such as CDMA and TDMA, as well as national standards such as iDEN in the USA and PDC in Japan. Over the past five years several dozen mobile operators (carriers) have abandoned networks on TDMA and CDMA technologies, switching over to GSM.
With third generation (3G) networks, which are also known as IMT-2000 networks, about three out of four networks are on the W-CDMA (also known as UMTS) standard, usually seen as the natural evolution path for GSM and TDMA networks. One in four 3G networks is on the CDMA2000 1x EV-DO technology. Some analysts count a previous stage in CDMA evolution, CDMA2000 1x RTT, as a 3G technology whereas most standardization experts count only CDMA2000 1x EV-DO as a true 3G technology. Because of this difference in interpreting what is 3G, there is a wide variety in subscriber counts. As of June 2007, on the narrow definition there are 200 million subscribers on 3G networks. By using the more broad definition, the total subscriber count of 3G phone users is 475 million.
While some systems of payment are 'pay-as-you-go' where conversation time is purchased and added to a phone unit via an Internet account or in shops or ATMs, other systems are more traditional ones where bills are paid by regular intervals. Pay as you go (also known as "pre-pay") accounts were invented simultaneously in Portugal and Italy and today form more than half of all mobile phone subscriptions. USA, Canada, Japan and Finland are among the rare countries left where most phones are still contract-based.
Culture and customsIn less than twenty years, the mobile telephone has gone from being rare, expensive equipment of the business elite to a pervasive, low-cost personal item. In many countries, mobile telephones outnumber land-line telephones; in the U.S., 50 percent of children have mobile telephones.[14] In many young adults' households it has supplanted the land-line telephone. The mobile phone is banned in some countries, such as North Korea.[15]
Given the high levels of societal mobile telephone service penetration, it is a key means for people to communicate with each other. The SMS feature spawned the "texting" sub-culture.[citation needed] In December 1993, the first person-to-person SMS text message was transmitted in Finland. Currently, texting is the most widely-used data service; 1.8 billion users generated $80 billion of revenue in 2006 (source ITU).
Many telephones offer Instant Messenger services for simple, easy texting. Mobile phones have Internet service (e.g. NTT DoCoMo's i-mode), offering text messaging via e-mail in Japan, South Korea, China, and India. In Europe, 30–40 per cent of internet access is via mobile telephone. Most mobile internet access is much different from computer access, featuring alerts, weather data, e-mail, search engines, instant messages, and game and music downloading; most mobile internet access is hurried and short.
The mobile telephone can be a fashion totem custom-decorated to reflect the owner's personality.[16] This aspect of the mobile telephony business is, in itself, an industry, e.g. ringtone sales exceeded $5 billion in 2006EtiquetteMobile telephone use in etiquette is an important matter of social discourtesy, phones ringing during funerals, weddings, in toilets, cinemas, and plays. Users often speak loudly, leading to book shops, libraries, bathrooms, cinemas, doctors' offices, and houses of worship prohibiting their uses, and, in some places, the installation of signal-jamming equipment to prevent their use (though in many countries, including the U.S., such equipment is currently illegal). Some new buildings, such as auditoriums, have installed wire mesh in the walls (making it a Faraday cage), which prevents signal penetration without violating signal jamming laws.
Trains, particularly those involving long-distance services, often offer a "quiet car" where phone use is prohibited, much like the designated non-smoking car 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 and many airlines claim in their in-plane announcements that this prohibition is due to possible interference with aircraft radio communications. Shut-off mobile phones do not interfere with aircraft avionics. The concern about cell phones is partially based on the crash of Crossair Flight 498.
As of 2007, several airlines are experimenting with base station and antenna systems installed to the airplane, allowing low power, short-range connection of any phones aboard to remain connected to the aircraft's base station.[18] Thus, they would not attempt connection to the ground base stations as during take off and landing.[citation needed] Simultaneously, airlines may offer phone services to their traveling passengers either as full voice and data services, or initially only as SMS text messaging and similar services. Qantas, the Australian airline, is the first airline to run a test airplane in this configuration in the Autumn of 2007.[citation needed] Emirates has announced plans to allow limited mobile phone usage on some flights.[citation needed]
In any case, there are inconsistencies between practices allowed by different airlines and even on the same airline in different countries. For example, Northwest Airlines may allow the use of mobile phones immediately after landing on a domestic flight within the US, whereas they may state "not until the doors are open" on an international flight arriving in the Netherlands. In April 2007 the US Federal Communications Commission officially grounded the idea of allowing passengers to use phones during a flight.[19]
In a similar vein, signs are put up in many countries, such as Canada, The U.K. and the U.S., petrol stations prohibiting the use of mobile phones, due to possible safety issues.[citation needed] Most schools in the United States have prohibited mobile phones in the classroom, due to the large number of class disruptions that result from their use, the potential for cheating via text messaging, and the possibility of photographing someone without consent.[citation needed] In the UK, possession of a mobile phone in an examination can result in immediate disqualification from that subject or from all that student's subjects.[20]
A working group, made up of Finnish telephone companies, public transport operators and communications authorities, have launched a campaign to remind mobile phone users of courtesy, especially when using mass transit – what to talk about on the phone, and how to. In particular, the campaign wants to impact loud mobile phone usage as well as calls regarding sensitive matters.[21]
Many US cities with subway transit systems underground are studying or have implemented cell phone reception in their underground tunnels for their riders. Boston, Massachusetts has investigated such usage in their tunnels, although there is a question of usage etiquette and also how to fairly award contracts to carriers.[22]
The issue of mobile communication and etiquette has also become an issue of academic interest. The rapid adoption of the device has resulted in the intrusion of telephony into situations where this was previously not known. This has exposed the implicit rules of courtesy and opened them to reevaluation. Use by driversMobile-phone use while driving is common but controversial. While few jurisdictions have banned motorists from using mobile phones while driving outright, some have banned or restricted drivers from using hand-held mobile phones while exempting phones operated in a hands-free fashion. Using a hand-held mobile phone while driving is an impediment to vehicle operation that can increase the risk of road traffic accidents. However, some studies have found