(Redirected from Mobile telephony)
Several mobile phones of the "candy bar" variety (non-folding)
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
Main articles: History of mobile phones
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.
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".
In 1970,
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.
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.
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.
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, such as
Professional Mobile Radio.
Subscriptions
This Railfone found on some
Amtrak trains uses cellular technology.
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. 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. 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. 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.
Etiquette
The use of a mobile phone is prohibited in some train company carriages
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 even though this has been proven to be completely untrue. 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. 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. In this way they would not attempt to find connection to the ground base stations as the planes take off and land. 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.
Emirates have announced plans to allow limited mobile phone usage on some flights.
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. 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. In the event of an emergency,
disaster response crews can locate trapped or injured people using the signals from their mobile phones or the small detonator of flare in the battery of every cellphone; an interactive menu accessible through the phone's
Internet browser notifies the company if the user is safe or in distress. 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
One phone in each hand
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. It is generally agreed that using a hand-held mobile phone while driving is a distraction that brings 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 the main safety problem.
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.
Applications
Mobile news services are expanding with many organizations providing "on-demand" news services by SMS. Some also provide "instant" news pushed out by SMS. Mobile telephony also facilitates
activism and public journalism being explored by
Reuters and
Yahoo[16] and small independent news companies such as
Jasmine News in Sri Lanka. Also companies like
Monster[17] are starting to offer mobile services such as job search and career advice.
The total value of mobile data services exceeds the value of paid services on the internet, and was worth 31 billion dollars in 2006 (source Informa). The largest categories of mobile services are music, picture downloads, videogaming, adult entertainment, gambling, video/TV.
Power
Mobile phones generally obtain power from
batteries which can be recharged from
mains power, a
USB port or a cigarette lighter socket in a
car. Formerly, the most common form of cell phone batteries were
nickel metal-hydride, as they have a low size and weight.
Lithium-Ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using
lithium-Polymer batteries as opposed to the older
Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Cell phone manufacturers have been experimenting with alternate power sources.
Features
Main articles: Mobile phone features
There are significant questions as to who first invented the camera phone, as numerous other people received patents filed in the early 1990s for the device, including David M. Britz of AT&T Research in March of 1994 and
Phillipe Kahn, who claims to have first invented it in 1997. The
camera phone now holds 85% of the mobile phone market. Mobile phones often have features beyond sending text messages and making voice calls, including Internet browsing, music (
MP3) playback, memo recording, personal organizer functions,
e-mail, instant messaging, built-in cameras and camcorders,
ringtones, games, radio,
Push-to-Talk (PTT),
infrared and
Bluetooth connectivity, call registers, ability to watch streaming video or download video for later viewing, video calling and serve as a
wireless modem for a PC, and soon will also serve as a console of sorts to online games and other high quality games (e.g. Final Fantasy Agito).
When cellular telecoms services were launched, phones and calls were very expensive and early mobile operators (carriers) decided to charge for all air time consumed by the mobile phone user. This resulted in the concept of charging callers for outbound calls and also for receiving calls. As mobile phone call charges diminished and phone adoption rates skyrocketed, more modern operators decided not to charge for incoming calls. Thus some markets have "Receiving Party Pays" models, in which both outbound and received calls are charged, and other markets have "Calling Party Pays" models, by which only making calls produces costs, and receiving calls is free. An exception to this is international roaming, by which also receiving calls is normally also charged.
The European market adopted a "Calling Party Pays" model throughout the GSM environment and soon various other GSM markets also started to emulate this model. As Receiving Party Pays systems have the undesired effect of phone owners keeping their phones turned off to avoid receiving unwanted calls, the total voice usage rates (and profits) in Calling Party Pays countries outperform those in Receiving Party Pays countries. Consequently, most countries previously with Receiving Party Pays models have either abandoned them or employed alternative marketing methods, such as massive voice call buckets, to avoid the problem of phone users keeping phones turned off.
In most countries today, including European nations,
Kazakhstan,
Romania,
Turkey,
New Zealand,
Korea,
Japan,
Pakistan,
Australia,
Bulgaria,
Brazil,
Chile,
Colombia,
India,
18 Maldives,
Peru,
South Africa,
Israel,
Lebanon and
Jordan the person receiving a mobile phone call pays nothing. However, in
Hong Kong,
Canada, and the
United States, one can be charged per minute. In the United States, a few carriers are beginning to offer unlimited received phone calls. For the
Chinese mainland, it was reported that both of its two operators will adopt the caller-pays approach as early as January 2007.
[18]
Forensics and evidence
Law enforcement globally rely heavily upon mobile telephone evidence, to the extent that in the EU the "communications of every mobile telephone user are recorded"
[11]. The concerns over
terrorism and terrorist use of technology prompted an inquiry by the
British House of Commons Home Affairs Select Committee into the use of evidence from mobile telephone devices, prompting leading mobile telephone forensic specialists to identify forensic techniques available in this area.
[20] NIST have published guidelines and procedures for the preservation, acquisition, examination, analysis, and reporting of digital information present on cell phones can be found under the NIST Publication SP800-101.
[21]
An example of criminal investigations using mobile phones is the initial location and ultimate identification of the terrorists of the
2004 Madrid train bombings. In the attacks, mobile phones had been used to detonate the bombs. However, one of the bombs failed to detonate, and the
SIM card in the corresponding mobile phone gave the first serious lead about the terrorists to investigators. By tracking the whereabouts of the SIM card and correlating other mobile phones that had been registered in those areas, police were able to locate the terrorists.
Human health impacts
Main articles: Mobile phone radiation and health
Since the introduction of mobile phones, concerns have been raised about the potential health impacts from regular use.
[22] As mobile phone penetrations grew past fixed landline penetration levels in 1998 in Finland and from 1999 in Sweden, Denmark and Norway, the Scandinavian health authorities have run continuous long term studies of effects of mobile phone radiation effects to humans, and in particular children. Numerous studies have reported and most studies consistently report no significant relationship between mobile phone use and health. Studies from the Institute of Cancer Research, National Cancer Institute and researchers at the Danish Institute of Cancer Epidemiology in Copenhagen for example showed any link between mobile phone use and cancer.
[23][24] The Danish study only covered analog mobile phone usage up through 1995, and subjects who started mobile phone usage after 1995 were counted as non-users in the study.
[25] The health concerns have grown as mobile phone penetration rates throughout Europe reached 80%–90% levels earlier in this decade and prolonged exposure studies have been carried out in almost all European countries again most reporting no effect, and the most alarming studies only reporting a possible effect. However, a study by the
International Agency for Research on Cancer of 4,500 users found a statistically significant link between tumor frequency and mobile phone use.
[26]
Environmental impacts
The typical hysteria around mobile phones and mobile networks is seen in the widely reported and immediately totally discredited claim that mobile phone masts are associated with the "
Colony Collapse Disorder" (CCD) which has reduced bee hive numbers by up to 75% in many areas, especially near cities in the US. The Independent newspaper cited a scientific study claiming it provided evidence for the theory that mobile phone masts are a major cause in the collapse of bee populations, with controlled experiments demonstrating a rapid and catastrophic effect on individual hives near masts.
[27]
Mobile phones were in fact not covered in the study, and the original researchers have since emphatically disavowed any connection between their research, mobile phones, and CCD, specifically indicating that the Independent article had misinterpreted their results and created "a horror story".
[28][29][30]
It should be pointed out that if this CCD would be caused by mobile phones, then beekeepers in countries with advanced use of mobile phones such as those in Scandinavia, Italy, Portugal, Austria etc should have seen these effects years earlier than the USA. But this finding was uniformly and globally dismissed by all from the telecoms industry to animal safety experts and even beekeepers worldwide. While the initial claim of damage to bees was widely reported, the corrections to the story were almost non-existent in the media.
Technology
Mobile phone tower
Mobile phones and the network they operate under vary significantly from provider to provider, and country to country. 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 not more than 5 to 8 miles (approximately 8 to 13 kilometers) away. When the mobile 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 "
handoff" to various cell sites during calls, or while waiting (idle) between calls it will
reselect 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. Many of these sites are camouflaged to blend with existing environments, particularly in scenic areas.
The dialogue between the handset and the cell site is a stream of digital data that includes digitized audio (except for the first generation analog networks). The technology that achieves this depends on the system which the
mobile phone operator has adopted. The technologies are grouped by generation. The first generation systems started in 1979 with Japan, are all analog and include AMPS and NMT. Second generation systems started in 1991 in Finland are all digital and include GSM, CDMA and TDMA. Third generation networks are still being deployed, started with Japan in 2001, are all digital and offer high speed data access in addition to voice services and include WCDMA known also as UMTS, and CDMA2000 EV-DO. China will launch a third 3G technlogy on the TD-SCDMA standard. Each network operator has a unique
radio frequency band.
Books about mobile communication
Since 2002, many books have been written on the social impact of mobile phones:
★ Agar, Jon, ''Constant Touch: A Global History of the Mobile Phone'', 2004 ISBN 1840465417
★ Ahonen, Tomi, ''m-Profits: Making Money with 3G Services'', 2002, ISBN 0-470-84775-1
★ Ahonen, Kasper and Melkko, ''3G Marketing'' 2004, ISBN 0-470-85100-7
★ Glotz, Peter & Bertsch, Stefan, eds. ''Thumb Culture: The Meaning of Mobile Phones for Society'', 2005
★ Katz, James E. & Aakhus, Mark, eds. ''Perpetual Contact: Mobile Communication, Private Talk, Public Performance'', 2002
★ Kavoori, Anandam & Arceneaux, Noah, eds. ''The Cell Phone Reader: Essays in Social Transformation'', 2006
★
Levinson, Paul, ''Cellphone: The Story of the World's Most Mobile Medium, and How It Has Transformed Everything!'', 2004 ISBN 1-4039-6041-0
★
Ling, Rich, ''The Mobile Connection: the Cell Phone's Impact on Society'', 2004 ISBN 1558609369
★ Ling, Rich and Pedersen, Per, eds. ''Mobile Communications: Re-negotiation of the Social Sphere'', 2005 ISBN 1852339314
★ Nyíri, Kristóf, ed. ''Mobile Communication: Essays on Cognition and Community'', 2003
★ Nyíri, Kristóf, ed. ''Mobile Learning: Essays on Philosophy, Psychology and Education'', 2003
★ Nyíri, Kristóf, ed. ''Mobile Democracy: Essays on Society, Self and Politics'', 2003
★ Nyíri, Kristóf, ed. ''A Sense of Place: The Global and the Local in Mobile Communication'', 2005
★ Nyíri, Kristóf, ed. '' Mobile Understanding: The Epistemology of Ubiquitous Communication'', 2006
★
Plant, Dr. Sadie,
''on the mobile – the effects of mobile telephones on social and individual life'', 2001
★
Rheingold, Howard, ''Smart Mobs: The Next Social Revolution'', 2002 ISBN 0738208612
Terminology
Related non-mobile-phone systems
;
Cordless telephone (portable phone) : Cordless phones are standard telephones with radio handsets. Unlike mobile phones, cordless phones use private base stations that are not shared between subscribers. The base station is connected to a land-line. Increasingly, with
wireless local loop technologies, namely
DECT, the distinction is blurred.
;
Professional Mobile Radio : Advanced professional mobile radio systems can be very similar to mobile phone systems. Notably, the
IDEN standard has been used as both a private
trunked radio system as well as the technology for several large public providers. Similar attempts have even been made to use
TETRA, the European digital PMR standard, to implement public mobile networks.
; Radio phone : This is a term which covers radios which could connect into the telephone network. These phones may not be mobile; for example, they may require a
mains power supply. Also, they may require the assistance of a human operator to set up a
PSTN phone call.
Terms in various countries
See also
References
1. Special History Issue, , , , speleonics 15,
2. BBC interview with Martin Cooper
3. Nokia − Quarterly information, 2007
4. CIA World Factbook - UK
5. 500 mln cell phone accounts in China
6. Telecom milestones, Office of the Telecommunications Authority, Hong Kong.
7. Total mobile subscribers top 1.8 billion
8. Up to 90 percent of globe to have mobile coverage
9. Mobile growth fastest in Africa
10. Phone revolution makes Africa upwardly mobile
11.
12. Cell Phones for Kids Under 15: a Responsible Question
13. Rise in executions for mobile use
14. FCC says 'no' to cell phones on planes. Yahoo News, April 3, 2007.
15. Exams ban for mobile phone users
16. You Witness News
17. Monster Mobile
18. Amy Gu, "Mainland mobile services to be cheaper", ''South China Morning Post'', December 18, 2006, Page A1.
19.
20. Supplementary memorandum submitted by Gregory Smith
21. , Recommendations of the National Institute of Standards and Technology, May 2007.
22. Cellular Phones and Cancer
23. Cell Phones Don't Cause Brain Tumors, Study Says
24. No Risk of Cancer using Cell Phone
25. Study Finds No Link Between Cellphones and Cancer Katherine Hobson
26. Europe cell phone study focuses on tumors
27. Are mobile phones wiping out our bees?
28.
Wireless: Case of the disappearing bees creates a buzz about cellphones
29.
Researchers: Often-cited study doesn't relate to bee colony collapse
30.
Cellphone researchers claim data misinterpreted
External links
★
Mobile phone at the
Open Directory Project
★
The British Library – finding information on the mobile phone industry
★
Basics understanding of the working of Mobile phones
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