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]
Contents
[hide]
* 1 History
o 1.1 Analog cellular telephony (1G)
o 1.2 Digital mobile communication (2G)
o 1.3 Wideband mobile communication (3G)
o 1.4 Broadband Fourth generation (4G)
* 2 Uses
* 3 Handsets
o 3.1 Features
o 3.2 Software and applications
o 3.3 Power supply
o 3.4 SIM card
o 3.5 Market
o 3.6 Media
* 4 Comparison to similar systems
* 5 Privacy
* 6 Restriction on usage
o 6.1 Driving
o 6.2 Schools
* 7 Production
* 8 See also
* 9 References
* 10 Further reading
* 11 External links
[edit] History
Main article: History of mobile phones
Analog Motorola DynaTAC 8000X Advanced Mobile Phone System mobile phone as of 1983
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]
[edit] Analog cellular telephony (1G)
Main article: 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]
Personal Handy-phone System mobiles and modems used in Japan around 1997–2003
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.
A 1991 GSM mobile phone
[edit] Digital mobile communication (2G)
Main articles: 2G, 2.5G, and 2.75G
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.
[edit] Wideband mobile communication (3G)
Main article: 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)
Main article: 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]
[edit] 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]
Darker colors indicate more cell phone users
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".
[edit] Handsets
A Nokia phone with box.
A printed circuit board inside a mobile phone
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.
[edit] Features
Main articles: Mobile phone features and Smartphone
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