A Mobile phone or Mobile (also called cellphone and handphone[1]) is an electronic device used for mobile telecommunications (mobile telephony, text messaging or data transmission) over a cellular network of specialized base stations known as cell sites. Mobile phones differ from cordless telephones, which only offer telephony service within a limited range, e.g. within a home or an office, through a fixed line and a base station owned by the subscriber and also from satellite phones and radio telephones. As opposed to a radio telephone, a cell phone offers full duplex communication, automatised calling to and paging from a public land mobile network (PLMN), and handoff (handover) during a phone call when the user moves from one cell (base station coverage area) to another. Most current cell phones connect to a cellular network consisting of switching points and base stations (cell sites) owned by a mobile network operator. In addition to the standard voice function, current mobile phones may support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, infrared, camera with video recorder and MMS for sending and receiving photos and video, MP3 player, radio and GPS.
The International Telecommunication Union estimated that mobile cellular subscriptions worldwide would reach approximately 4.6 billion by the end of 2009. Mobile phones have gained increased importance in the sector of Information and communication technologies for development in the 2000s and have effectively started to reach the bottom of the economic pyramid.[2]
History
In 1908, U.S. Patent 887,357 for a wireless telephone was issued to Nathan B. Stubblefield of Murray, Kentucky. He applied this patent to "cave radio" telephones and not directly to cellular telephony as the term is currently understood.[3] Cells for mobile phone base stations were invented in 1947 by Bell Labs engineers at AT&T and 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 mobile radio devices have been available since 1973. A patent for the first wireless phone as we know today was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969.
In 1945, the zero generation (0G) of mobile telephones was introduced.[citation needed] Like other technologies of the time, it involved a single, powerful base station covering a wide area, and each telephone would effectively monopolize a channel over that whole area while in use.
In 1960, the world’s first partly automatic car phone system Mobile System A (MTA)|MTA was launched in Sweden. With MTA, calls could be made and received in the car to/from the public telephone network, and the car phone could be paged. The phone number was dialed using a rotary dial. Calling from the car was fully automatic, while calling to it required an operator. The person who wanted to call a mobile phone had to know which base station the mobile phone was covered by. The system was developed by Sture Laurén and other engineers at Televerket network operator. Ericsson provided the switchboard while Svenska Radioaktiebolaget (SRA) owned by Ericsson and Marconi provided the telephones and base station equipment. MTA phones were consisted of vacuum tubes and relays, and had a weight of 40 kg. In 1962, a more modern version called Mobile System B (MTB) was launched which used transistors in order to enhance the telephone’s calling capacity and improve its operational reliability. In 1971 the MTD version was launched, opening for several different brands of equipment and gaining commercial success.[4][5]
The concepts of frequency reuse and handoff, as well as a number of other concepts that formed the basis of modern cell phone technology, were described in the 1970s; see for example Fluhr and Nussbaum,[6] Hachenburg et al.[7] , and U.S. Patent 4,152,647, issued May 1, 1979 to Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada and assigned by them to the United States Government.
Martin Cooper, a Motorola researcher and executive is considered to be the inventor of the first practical mobile phone for hand-held use in a non-vehicle setting. Cooper is the first inventor named on "Radio telephone system" filed on October 17, 1973 with the US Patent Office and later issued as US Patent 3,906,166;[8] other named contributors on the patent included Cooper's boss, John F. Mitchell, Motorola's chief of portable communication products, who successfully pushed Motorola to develop wireless communication products that would be small enough to use outside the home, office or automobile and participated in the design of the cellular phone.[9][10] Using a modern, if somewhat heavy portable handset, Cooper made the first call on a hand-held mobile phone on April 3, 1973 to a rival, Dr. Joel S. Engel of Bell Labs.[11]
Analog cellular telephony (1G)
The first commercial fully automated cellular network (the 1G generation) was launched in Japan by NTT in 1979. The initial launch network covered the full metropolitan area of Tokyo's over 20 million inhabitants with a cellular network of 23 base stations. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nation-wide 2G network.
The second launch of 1G networks was the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden in 1981.[12]. NMT was the first mobile phone network featuring international roaming. The Swedish electrical engineer Östen Mäkitalo started to work on this vision in 1966, and is considered as the father of the NMT system and some consider him also the father of the cellular phone.[13][14]
Several countries were among the early to launch 1G networks in the early 1980s including the UK, Mexico and Canada. The first 1G network launched in the USA was Chicago based Ameritech in 1983 using the famous first hand-held mobile phone Motorola DynaTAC. In 1984, Bell Labs developed modern commercial cellular technology (based, to a large extent, on the Gladden, Parelman Patent), which employed multiple, centrally controlled base stations (cell sites), each providing service to a small area (a cell). The cell sites would be set up such that cells partially overlapped. In a cellular system, a signal between a base station (cell site) and a terminal (phone) only need be strong enough to reach between the two, so the same channel can be used simultaneously for separate conversations in different cells.
The first NMT installations as well as the First AMPS installations were based on the Ericsson AXE digital exchange nodes.
Cellular systems required several leaps of technology, including handover, which allowed a conversation to continue as a mobile phone traveled from cell to cell. This system included variable transmission power in both the base stations and the telephones (controlled by the base stations), which allowed range and cell size to vary. As the system expanded and neared capacity, the ability to reduce transmission power allowed new cells to be added, resulting in more, smaller cells and thus more capacity. The evidence of this growth can still be seen in the many older, tall cell site towers with no antennae on the upper parts of their towers. These sites originally created large cells, and so had their antennae mounted atop high towers; the towers were designed so that as the system expanded—and cell sizes shrank—the antennae could be lowered on their original masts to reduce range.
Digital mobile communication (2G)
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.
The first data services appeared on mobile phones starting with person-to-person SMS text messaging in Finland in 1993. First trial payments using a mobile phone to pay for a Coca Cola vending machine were set in Finland in 1998. The first commercial payments were mobile parking trialled in Sweden but first commercially launched in Norway in 1999. The first commercial payment system to mimic banks and credit cards was launched in the Philippines in 1999 simultaneously by mobile operators Globe and Smart. The first content sold to mobile phones was the ringing tone, first launched in 1998 in Finland. The first full internet service on mobile phones was i-Mode introduced by NTT DoCoMo in Japan in 1999.
Wideband mobile communication (3G)
In 2001 the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard.[15]
The standard 2G CDMA networks became 3G compliant with the adoption of Revision A to EV-DO.
Revision A of EV-DO makes several additions to the protocol while keeping it completely backwards compatible with older versions of EV-DO.
These changes included the introduction of several new forward link data rates that increase the maximum burst rate from 2.45 Mbit/s to 3.1 Mbit/s. Also included were protocols that would decrease connection establishment time (called enhanced access channel MAC), the ability for more than one mobile to share the same time slot (multi-user packets) and the introduction of QoS flags. All these were put in place to allow for low latency, low bit rate communications such as VoIP.[16]
One of the newest 3G technologies to implemented is HSDPA.
High-Speed Downlink Packet Access or (HSDPA) is an enhanced 3G (third generation) mobile telephony communications protocol in the High-Speed Packet Access (HSPA) family, also coined 3.5G, 3G+ or turbo 3G, which allows networks based on Universal Mobile Telecommunications System (UMTS) to have higher data transfer speeds and capacity. Current HSDPA deployments support down-link speeds of 1.8, 3.6, 7.2 and 14.0 Mbit/s. Further speed increases are available with HSPA+, which provides speeds of up to 42 Mbit/s downlink and 84 Mbit/s with Release 9 of the 3GPP standards.[17]
[edit] Broadband Fourth generation (4G)
The next evolution that recently was released is the 4th generation, also known as Beyond 3G in the literature, with the aim to offer broadband wireless access with nominal data rates of 100 Mbit/s to fast moving devices, and 1 Gbit/s to stationary devices defined by the ITU-R[18] 4G systems may be based on the 3GPP LTE (Long Term Evolution) cellular standard, offering peak bit rates of 326.4 Mbit/s. It may perhaps also be based on WiMax or Flash-OFDM wireless metropolitan area network technologies that promise broadband wireless access with speeds that reaches 233 Mbit/s for mobile users. The radio interface in these systems is based on all-IP packet switching, MIMO diversity, multi-carrier modulation schemes, dynamic channel assignment (DCA) and channel-dependent scheduling. A 4G system should be a complete replacement for current network infrastructure and is expected to be able to provide a comprehensive and secure IP solution where voice, data, and streamed multimedia can be given to users on a "Anytime, Anywhere" basis, and at much higher data rates than previous generations. By 2011 it is expected that wireless companies will launch 4G Broadband networks.[18]
Uses
Mobile phones are used for a variety of purposes, including keeping in touch with family members, conducting business, and having access to a telephone in the event of an emergency. Some individuals keep multiple cell phones in some cases for legitimate reasons such as having one phone for business and another for personal use, though a second cell phone may also be used to covertly conduct an affair or illicit business transaction. Multiple mobile phones (or just multiple SIM cards to be swapped out or used together in a phone like the Samsung Duos series) are also commonly kept to take advantage of different calling plans' benefits. For example, one plan could come with cheap local calls, another would be for cheap long distance, and yet another for cheap international calls or cheap roaming (more universal in regions where pay-as-you-go plans without contracts or monthly fees are the norm). Child predators are able to take advantage of cell phones to secretly communicate with children without the knowledge of their parents or teachers, which has raised concerns.[19]
Organizations that aid victims of domestic violence offer a secret cell phone to potential victims. These devices are often old phones that are donated and refurbished to meet the victim's emergency needs. The victim can then have the phone handy when necessary and without the abuser knowing.[20]
Cell phone sharing is a phenomenon which exists around the world. It is very prevalent in urban India, as families and groups of friends often share one or more mobiles among their members. Two types of sharing which exist are conspicuous and stealthy sharing. An example of conspicuous sharing takes place when someone calls the friend of the person they are trying to reach in hopes of being able to talk to that individual, while an example of the latter type of sharing happens when a boy takes his father's cell phone without his knowledge. Phone sharing does not only take place because of its economic benefits, but it also often occurs due to familial customs and traditional gender roles.[21]
Another example of cell phone sharing occurs in Burkina Faso. There it is not uncommon for a village to only have access to one cell phone. This cell phone is typically owned by a person who is not natively from the village, such as a teacher or missionary. Although the cell phone is the sole property of one individual, it is the expectation that other members of the village are allowed to use the cell phone to make necessary calls. Although some may consider this a burden, it can actually be an opportunity to engage in reciprocal obligations. This type of cell phone sharing is an important for the small villages in Burkina Faso because it allows them to keep up with the expectations of the globalizing world.[22]
A study by Motorola found that one in ten cell phone subscribers have a second phone that often is kept secret from other family members. These phones are used to engage in activities including extramarital affairs or clandestine business dealings.[23]
The advent of widespread text messaging has resulted in the cell phone novel; the first literary genre to emerge from the cellular age via text messaging to a website that collects the novels as a whole.[24] Paul Levinson, in Information on the Move (2004), says "...nowadays, a writer can write just about as easily, anywhere, as a reader can read" and they are "not only personal but portable".
Handsets
There are several categories of mobile phones, from basic phones to feature phones such as musicphones and cameraphones. There are also smartphones, the first smartphone was the Nokia 9000 Communicator in 1996 which incorporated PDA functionality to the basic mobile phone at the time. As miniaturisation and increased processing power of microchips has enabled ever more features to be added to phones, the concept of the smartphone has evolved, and what was a high-end smartphone five years ago, is a standard phone today. Several phone series have been introduced to address a given market segment, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs; the SonyEricsson Walkman series of musicphones and Cybershot series of cameraphones; the Nokia Nseries of multimedia phones, the Palm Pre the HTC Dream and the Apple iPhone.
Features
Mobile phones often have features beyond sending text messages and making voice calls, including call registers, GPS navigation, music (MP3) and video (MP4) playback, RDS radio receiver, alarms, memo and document recording, personal organiser and personal digital assistant functions, ability to watch streaming video or download video for later viewing, video calling, built-in cameras (1.0+ Mpx) and camcorders (video recording), with autofocus and flash, ringtones, games, PTT, memory card reader (SD), USB (2.0), infrared, Bluetooth (2.0) and WiFi connectivity, instant messaging, Internet e-mail and browsing and serving 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. Some phones also include a touchscreen.
Nokia and the University of Cambridge are demonstrating a bendable cell phone called the Morph.[25]
- See also: Videophone, for UMTS-type mobile phones employing simultaneous video and audio
Software and applications
The most commonly used data application on mobile phones is SMS text messaging, with 74% of all mobile phone users as active users (over 2.4 billion out of 3.3 billion total subscribers at the end of 2007). SMS text messaging was worth over 100 billion dollars in annual revenues in 2007 and the worldwide average of messaging use is 2.6 SMS sent per day per person across the whole mobile phone subscriber base (source Informa 2007). The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.
The other non-SMS data services used by mobile phones were worth 31 Billion dollars in 2007, and were led by mobile music, downloadable logos and pictures, gaming, gambling, adult entertainment and advertising (source: Informa 2007). The first downloadable mobile content was sold to a mobile phone in Finland in 1998, when Radiolinja (now Elisa) introduced the downloadable ringing tone service. In 1999 Japanese mobile operator NTT DoCoMo introduced its mobile internet service, i-Mode, which today is the world's largest mobile internet service and roughly the same size as Google in annual revenues.
The first mobile news service, delivered via SMS, was launched in Finland in 2000. Mobile news services are expanding with many organisations 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![26] and small independent news companies such as Jasmine News in Sri Lanka.
Companies are starting to offer mobile services such as job search and career advice. Consumer applications are on the rise and include everything from information guides on local activities and events to mobile coupons and discount offers one can use to save money on purchases. Even tools for creating websites for mobile phones are increasingly becoming available.
Mobile payments were first trialled in Finland in 1998 when two Coca-Cola vending machines in Espoo were enabled to work with SMS payments. Eventually the idea spread and in 1999 the Philippines launched the first commercial mobile payments systems, on the mobile operators Globe and Smart. Today mobile payments ranging from mobile banking to mobile credit cards to mobile commerce are very widely used in Asia and Africa, and in selected European markets. For example in the Philippines it is not unusual to have one's entire paycheck paid to the mobile account. In Kenya the limit of money transfers from one mobile banking account to another is one million US dollars. In India paying utility bills with mobile gains a 5% discount. In Estonia mobile phones are the most popular method of paying for public parking. Power supply
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Mobile phones generally obtain power from batteries, which can be recharged from a USB port, from portable batteries, from mains power or a cigarette lighter socket in a car using an adapter (often called battery charger or wall wart) or from a solar panel or a dynamo (that can also use a USB port to plug the phone).
On 17 February 2009, the GSM Association announced[27] that they had agreed on a standard charger for mobile phones. The standard connector to be adopted by 17 manufacturers in the Open Mobile Terminal Platform including Nokia, Motorola and Samsung is to be the micro-USB connector (several media reports erroneously reported this as the mini-USB). The new chargers will be much more efficient than existing chargers. Having a standard charger for all phones, means that manufacturers will no longer have to supply a charger with every new phone.
Formerly, the most common form of mobile 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. Mobile phone manufacturers have been experimenting with alternative power sources, including solar cells.
The majority of energy lost in a mobile phone charger is in its no load condition, when the mobile phone is not connected but the charger has been left plugged in and using power. To combat this in November 2008 the top five mobile phone manufacturers Nokia, Samsung, LG Electronics, Sony Ericsson and Motorola set up a star rating system to rate the efficiency of their chargers in the no-load condition. Starting at zero stars for >0.5 W and going up to the top five star rating for <0.03>
A number of semiconductor companies offering flyback controllers, such as Power Integrations and CamSemi, now claim that the five star standard can be achieved with use of their product.
On 22 October 2009 the International Telecommunication Union (ITU) announced that it had embraced the Universal Charger Solution as its "energy-efficient one-charger-fits-all new mobile phone solution", and added: "Based on the Micro-USB interface, UCS chargers will also include a 4-star or higher efficiency rating — up to three times more energy-efficient than an unrated charger."[28]
[edit] SIM card
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In addition to the battery, GSM mobile phones require a small microchip, called a Subscriber Identity Module or SIM Card, to function. Approximately the size of a small postage stamp, the SIM Card is usually placed underneath the battery in the rear of the unit, and (when properly activated) stores the phone's configuration data, and information about the phone itself, such as which calling plan the subscriber is using. When the subscriber removes the SIM Card, it can be re-inserted into another phone that is configured to accept the SIM card[29] and used as normal.
Each SIM Card is activated by use of a unique numerical identifier; once activated, the identifier is locked down and the card is permanently locked in to the activating network. For this reason, most retailers refuse to accept the return of an activated SIM Card.
Those cell phones that do not use a SIM Card have the data programmed in to their memory. This data is accessed by using a special digit sequence to access the "NAM" as in "Name" or number programming menu. From here, one can add information such as a new number for your phone, new Service Provider numbers, new emergency numbers, change their Authentication Key or A-Key code, and update their Preferred Roaming List or PRL. However, to prevent someone from accidentally disabling their phone or removing it from the network, the Service Provider puts a lock on this data called a Master Subsidiary Lock or MSL.
The MSL also ensures that the Service Provider gets payment for the phone that was purchased or "leased". For example, the Motorola RAZR V9C costs upwards of CAD $500. You can get one for approximately $200, depending on the carrier. The difference is paid by the customer in the form of a monthly bill. If the carrier did not use a MSL, then they may lose the $300–$400 difference that is paid in the monthly bill, since some customers would cancel their service and take the phone to another carrier.
The MSL applies to the SIM only so once the contract has been completed the MSL still applies to the SIM. The phone however, is also initially locked by the manufacturer into the Service Providers MSL. This lock may be disabled so that the phone can use other Service Providers SIM cards. Most phones purchased outside the US are unlocked phones because there are numerous Service Providers in close proximity to one another or have overlapping coverage. The cost to unlock a phone varies but is usually very cheap and is sometimes provided by independent phone vendors.
Having an unlocked phone is extremely useful for travelers due to the high cost of using the MSL Service Providers access when outside the normal coverage areas. It can cost sometimes up to 10 times as much to use a locked phone overseas as in the normal service area, even with discounted rates. T-Mobile will provide a SIM unlock code to account holders in good standing after 90 days according to their FAQ.
For example, in Jamaica, an AT&T subscriber might pay in excess of US$1.65 per minute for discounted international service while a B-Mobile (Jamaican) customer would pay US$0.20 per minute for the same international service. Some Service Providers focus sales on international sales while others focus on regional sales. For example, the same B-Mobile customer might pay more for local calls but less for international calls than a subscriber to the Jamaican national phone C&W (Cable & Wireless) company. These rate differences are mainly due to currency variations because SIM purchases are made in the local currency. In the US, this type of service competition does not exist because some of the major Service Providers do not offer Pay-As-You-Go services. [Needs Pay-As-You-Go references, rumored T-Mobile, Verizon provide one, AT&T does not as of 12/2008]
[edit] Market
The world's largest individual mobile operator is China Mobile with over 500 million mobile phone subcribers. The world's largest mobile operator group by subscribers is UK based Vodafone. There are over 600 mobile operators and carriers in commercial production worldwide. Over 50 mobile operators have over 10 million subscribers each, and over 150 mobile operators have at least one million subscribers by the end of 2008 (source wireless intelligence).
In mobile phone handsets, in Q3/2008, Nokia was the world's largest manufacturer of mobile phones, with a global device market share of 39.4%, followed by Samsung (17.3%), Sony Ericsson (8.6%), Motorola (8.5%) and LG Electronics (7.7%). These manufacturers accounted for over 80% of all mobile phones sold at that time.[30]
Other manufacturers include Apple Inc., Audiovox (now UTStarcom), Benefon, BenQ-Siemens, CECT, HTC Corporation, Fujitsu, Kyocera, Mitsubishi Electric, NEC, Neonode, Panasonic, Palm, Matsushita, Pantech Wireless Inc., Philips, Qualcomm Inc., Research in Motion Ltd. (RIM), Sagem, Sanyo, Sharp, Siemens, Sendo, Sierra Wireless, SK Teletech, T&A Alcatel, Huawei, Trium, Toshiba[citation needed] and Vidalco. There are also specialist communication systems related to (but distinct from) mobile phones.
[edit] Media
The mobile phone became a mass media channel in 1998 when the first ringtones were sold to mobile phones by Radiolinja in Finland. Soon other media content appeared such as news, videogames, jokes, horoscopes, TV content and advertising. In 2006 the total value of mobile phone paid media content exceeded internet paid media content and was worth 31 Billion dollars (source Informa 2007). The value of music on phones was worth 9.3 Billion dollars in 2007 and gaming was worth over 5 billion dollars in 2007.[31]
The mobile phone is often called the Fourth Screen (if counting cinema, TV and PC screens as the first three) or Third Screen (counting only TV and PC screens).[weasel words] It is also called the Seventh of the Mass Media (with Print, Recordings, Cinema, Radio, TV and Internet the first six). Most early content for mobile tended to be copies of legacy media, such as the banner advertisement or the TV news highlight video clip. Recently unique content for mobile has been emerging, from the ringing tones and ringback tones in music to "mobisodes," video content that has been produced exclusively for mobile phones.
The advent of media on the mobile phone has also produced the opportunity to identify and track Alpha Users or Hubs, the most influential members of any social community. AMF Ventures measured in 2007 the relative accuracy of three mass media, and found that audience measures on mobile were nine times more accurate than on the internet and 90 times more accurate than on TV.[original research?]
Comparison to similar systems
- Car phone
- A type of telephone permanently mounted in a vehicle, these often have more powerful transmitters, an external antenna and loudspeaker for handsfree use. They usually connect to the same networks as regular mobile phones.
- Cordless telephone (portable phone)
- Cordless phones are telephones which use one or more radio handsets in place of a wired handset. The handsets connect wirelessly to a base station, which in turn connects to a conventional land line for calling. Unlike mobile phones, cordless phones use private base stations (belonging to the land-line subscriber), and which are not shared.
- 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, they may require the assistance of a human operator to set up a PSTN phone call.
- Satellite phone
- This type of phone communicates directly with an artificial satellite, which in turn relays calls to a base station or another satellite phone. A single satellite can provide coverage to a much greater area than terrestrial base stations. Since satellite phones are costly, their use is typically limited to people in remote areas where no mobile phone coverage exists, such as mountain climbers, mariners in the open sea, and news reporters at disaster sites.
- IP Phone
- This type of phone delivers calls over wireless internet networks using VoIP as opposed to traditional CDMA and GSM networks. Several vendors have developed standalone WiFi phones. Additionally, some cellular mobile phones include the ability to place VoIP calls over cellular high speed data networks and/or wireless internet.[32]
Privacy
Cell phones have numerous privacy issues associated with them, and are regularly used by governments to perform surveillance.
Law enforcement and intelligence services in the UK and the US possess technology to remotely activate the microphones in cell phones in order to listen to conversations that take place nearby the person who holds the phone.[33][34]
Mobile phones are also commonly used to collect location data. The geographical location of a mobile phone can be determined easily (whether it is being used or not), using a technique known multilateration to calculate the differences in time for a signal to travel from the cell phone to each of several cell towers near the owner of the phone.[35][36]Restriction on usage
Driving
Mobile phone use while driving is common but controversial. Being distracted while operating a motor vehicle has been shown to increase the risk of accident. Because of this, many governments have made the use of a mobile phone while driving illegal. Israel, Japan, Portugal and Singapore ban both hand-held and hands-free use of a mobile phone whilst many other countries –including the UK, France, and many US states– ban hand-held phone use only, allowing hands-free use.
Due to the increasing complexity of mobile phones –often more like mobile computers in their available uses– it has introduced additional difficulties for law enforcement officials in being able to tell one usage from another as drivers use their devices. This is more apparent in those countries who ban both hand-held and hands-free usage, rather those who have banned hand-held use only, as officials cannot easily tell which function of the mobile phone is being used simply by visually looking at the driver. This can mean that drivers may be stopped for using their device illegally on a phone call, when in fact they were not; instead using the device for a legal purpose such as the phones' incorporated controls for car stereo or satnav usage – either as part of the cars' own device or directly on the mobile phone itself.
Cases like these can often only be proved otherwise by a check of the mobile operators phone call records to see if a call was taking place during the journey concerned. Although in many countries the law enforcement official may have stopped the driver for a differing offence, for example, for lack of due care and attention in relation to their driving.
Schools
Some schools limit or restrict the use of mobile phones. Schools set restrictions on the use of mobile phones because of the use of cell phones for cheating on tests, harassing other people, causing threats to the schools security, distractions to the student and facilitating gossip and other social activity in school. Many mobile phones are banned in school locker room facilities, public restrooms and swimming pools.[citation needed]Production
Many mobile phones, along with other electronic products, have high quality capacitors in them, which contain tantalum. Typically, a mobile phone may have 40 milligrams of tantalum. One major source of tantalum is the coltan ore. Mines at Wodgina in the Pilbara region near Perth, Western Australia[37] are amongst many fully legal and identifiable sources of this raw material, although there have also been many reports that illegal mines in the Democratic Republic of Congo have been used to obtain the ore, operated by rebel groups to get money to fund their civil war and fuel further civil unrest against their own civilian population. Furthermore, lack of regulation has also meant that the Congolese military have also been implicated in being indirectly involved in mining operations. Both forces have gained via illegal exports through middlemen to companies from outside the country who often either turn a blind eye to its original source or do not adequately trace the source.[37][38]
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