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Thursday, September 13, 2007

Mobile phone

Mobile phone:

A mobile telephone or cellular telephone (commonly "mobile phone" or "cell phone") is a long-range, portable electronic device used 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 is satellite phones).

History:

There is one U.S. Patent Number 887357 for a wireless telephone, issued 1908 to Nathan B. Stubblefield of Murray, Kentucky. He applied this to "cave radio" phones and not directly to cellular telephony as we know it today.[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 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.[citation needed]
BORING 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] 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 handy over the years.[citation needed]

Manufacturers:

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, Motorola, Samsung, SonyEricsson and LG.
Nokia Corporation is currently the world's largest manufacturer of mobile telephones, with a global device market share of approximately 36% in Q1 of 2007.[3] 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,Toshiba, and Verizon. There are also specialist communication systems related to (but distinct from) mobile phones, date=August 2007}

Subscriptions:

Several countries, including the UK, now have more mobile phones than people.[4] There are over five hundred million active mobile phone accounts in China, as of 2007.[5] Luxembourg has the highest mobile phone penetration rate in the world, at 164% in December 2001. In Hong Kong the penetration rate reached 117% of the population in September 2004.[6] The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005.[7] The subscriber count reached 2.7 billion by end of 2006 according to Informa.[citation needed] 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.[8]
At present, Africa has the largest growth rate of cellular subscribers in the world,[9] its markets expanding nearly twice as fast as Asian markets.[10] 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 to a monumental scale 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.
[11] With 156.31 million cell phones, market penetration in the country is still low at 17.45% 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 countries and African countries 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. None have switched away from GSM.
With third generation (3G) networks which are also known as IMT-2000 networks, about three out of four networks are on WCDMA (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.[citation needed] 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 customs:

In less 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 using mobile phones. In the United States, 50% of children are using mobile phones.[12] In many young adults' households the mobile phone has supplanted land-line telephones. In some areas in developing countries with scarce fixed-line infrastructure, the mobile phone has introduced telephony as such. It has given poor people in isolated communities access to services such as medical and legal advice. However, the mobile phone is also banned in some countries like North Korea.[13]
With high levels of mobile telephone penetration, mobile culture has evolved where the phone is a key social tool with people relying on their mobile phone address book to keep in touch with friends, not least by SMS, and a whole culture of "texting" has developed from this.[citation needed] Since the first person-to-person SMS text message was sent in Finland in December 1993, today "texting" has become the most widely used data service on the planet, with 1.8 billion people as active users of SMS texting and the service generated 80 billion dollars of service revenues in 2006 (source ITU). Many phones 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. In several countries internet access from mobile phones has become used by more internet users than access from PCs. Japan was first, followed by South Korea, China and India. In Europe several countries have proportions of 30%–40% of all internet users now accessing via mobile phones. Most mobile internet access is significantly different from PC based internet access, with services such as alerts, weather information, e-mail, search, IM and downloads of games and music favored over classic "web browsing". Most mobile internet use is of short duration and in a hurry.
The mobile phone itself has also become a
fashion object of totemic value, 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 5 billion in 2006 according to Informa.[citation needed].

Etiquette:

Mobile phone etiquette has become an important issue with phones ringing at funerals, weddings,toilets,cinemas, and plays. Users often speak at increased volume which has led to places like book shops, libraries, bathrooms, movie theaters, 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 including 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.
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.[citation needed] There is no interference from mobile phones that remain turned to aircraft avionics, as the airline safety staff well know as a typical airliner has dozens of phones that were forgotten to be turned off, on every flight. The real nuisance of phones that are on while planes take off and land, is that they disrupt the mobile phone networks on the ground.[citation needed] With busy airports landing jumbo jets every few minutes, the ground based mobile phone networks would experience continuous peaks in brief traffic overloads as hundreds of passenger phones would attempt to connect to the ground base stations.
As customers want to be connected on planes, now several airlines are experimenting with tiny base stations and antenna systems installed into the cabin of the airplane, allowing low power short range connection of any phones onboard to maintain a connection to the base station in the plane.[
citation needed] In this way they would not attempt to find connection to the ground base stations as the planes take off and land.[citation needed] At the same time the airlines could offer phone services to their travelling passengers either as full voice and data servies, 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 have 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.[14]
In a similar vein signs are put up in UK petrol stations prohibiting the use of mobile phones due to possible safety issues. 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 their subjects.[15].

Use in disaster response:

The Finnish government decided in 2005 that the fastest way to warn citizens of disasters was the mobile phone network. In Japan, mobile phone companies provide immediate notification of earthquakes and other natural disasters to their customers free of charge.[citation needed] 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.[citation needed] In Finland rescue services suggest hikers carry mobile phones in case of emergency even when deep in the forests beyond cellular coverage, as the radio signal of a cellphone attempting to connect to a base station can be detected by overflying rescue aircraft with special detection gear. Also, users in the United States can sign up through their provider for free text messages when an Amber Alert goes out for a missing person in their area.

Use by drivers:

Mobile-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 similarly elevated accident rates among drivers using hands-free phones, suggesting that the distraction of a telephone conversation itself is a significant safety problem.[citation needed]
Use of handheld mobile phones by drivers is illegal in many European countries and a number of Asian and South American countries and Australia. Use of hands-free mobiles is permitted, although the Australian states of
New South Wales and Victoria have banned hands free for learner and first year provisional/probationary licence holders. In Greece the use of mobile phone and hands free has been banned, while the use of bluetooth technology is permitted. However some countries like Japan ban mobile phone use while driving completely. Similar laws exist in six U.S. states with legislation proposed in 40 other states. The United States Department of Defense has outlawed the use of all mobile phones while driving on any DOD installation, unless a hands-free device is used. In Israel, it is common practice to pull over to the side of the road where possible to answer a mobile phone. In Croatia law prohibits usage of mobile phones while crossing the road as a pedestrian.