History of Mobile Phones

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History of mobile phones From Wikipedia, the free encyclopedia

The history of mobile phones records the development of interconnection between the public switched telephone systems to radio transceivers. From the earliest days of transmitting speech by radio, connection of the radio system to the telephone network had obvious benefits of eliminating the wires. Early systems used bulky, high power consuming equipment and supported only a few conversations at a time, with required manual set-up of the interconnection. Today cellular technology and microprocessor control systems allow automatic and pervasive use of mobile phones for voice and data.

The transmission of speech by radio has 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. Mobile telephones for automobiles became available from some telephone companies in the 1950s. Hand-held radio transceivers have been available since the Second World War. Mobile phone history is often divided into generations (first, second, third and so on) to mark significant step changes in capabilities as the technology improved over the years.Contents [hide] 1 Pioneers of radio telephony 1.1 Cellular concepts 2 Emergence of commercial mobile phone services 3 Handheld cell phone 4 First generation: Cellular networks 5 Second generation: Digital networks 6 Third generation: High speed IP data networks and mobile broadband 7 Fourth generation: All-IP networks 8 Satellite mobile 9 Patents 10 See also 11 Notes 12 References 13 External links

[edit] Pioneers of radio telephony

By 1930, telephone customers in the United States could place a call to a passenger on a liner in the Atlantic Ocean. Air time charges were quite high, at $7(1930)/minute (about $92.50/minute in 2011 dollars). [1] In areas with Marine VHF radio and a shore station, it is still possible to arrange a call from the public telephone network to a ship, still using manual call set-up and the services of a human marine radio operator.

However it was the 1940s onwards that saw the seeds of technological development which would eventually produce the mobile phone that we know today. Motorola developed a backpacked twoway radio, the Walkie-Talkie and a large hand-held two-way radio for the US military. This battery powered "Handie-Talkie" (HT) was about the size of a man's forearm.

In 1946 in St. Louis, the Mobile Telephone Service was introduced. Only three radio channels were available, and call set-up required manual operation by a mobile operator. [2] Although very popular and commercially successful, the service was limited by having only a few voice channels per district.

In 1964 Improved Mobile Telephone Service was introduced with additional channels and more automatic handling of calls to the public switched telephone network. Even the addition of radio channels in three bands was insufficient to meet demand for vehicle-mounted mobile radio systems.

In 1969, a patent for a wireless phone using an acoustic coupler for incoming calls was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969, but did not include dialing a number for outgoing calls.

Top of cellular telephone tower [edit] Cellular concepts See also: Cellular network

In December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in vehicles.[3] Philip T. Porter, also of Bell Labs, proposed that the cell towers be at the corners of the hexagons rather than the centers and have directional antennas that would transmit/receive in three directions (see picture at right) into three adjacent hexagon cells.[4] At this stage, the technology to implement these ideas did not exist, nor had the frequencies been allocated. Several years would pass before Richard H. Frenkiel and Joel S. Engel of Bell Labs developed the electronics to achieve this in the 1960s.

In all these early examples, a mobile phone had to stay within the coverage area serviced by one base station throughout the phone call, i.e. there was no continuity of service as the phones moved through several cell areas. 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. In 1970 Amos E. Joel, Jr., a Bell Labs engineer,[5] invented an automatic "call handoff" system to allow mobile phones to move through several cell areas during a single conversation without interruption.

In 1969 Amtrak equipped commuter trains along the 225-mile New York-Washington route with special pay phones that allowed passengers to place telephone calls while the train was moving. The system re-used six frequencies in the 450 MHZ band in nine sites, a precursor of the concept later applied in cellular telephones. [2]

In December 1971, AT&T submitted a proposal for cellular service to the Federal Communications Commission (FCC). After years of hearings, the FCC approved the proposal in 1982 for Advanced Mobile Phone System (AMPS) and allocated frequencies in the 824 894 MHz band.[6] Analog AMPS was eventually superseded by Digital AMPS in 1990.

A cellular telephone switching plan was described by Fluhr and Nussbaum in 1973,[7] and a cellular telephone data signaling system was described in 1977 by Hachenburg et al.[8] In 1979 a U.S. Patent 4,152,647 was issued to Charles A. Gladden and Martin H. Parelman, of Las Vegas for an emergency cellular system for rapid deployment in areas where there was no cellular service. [edit] Emergence of commercial mobile phone services

Alongside the early developments outlined above, a different technology was also growing in popularity. Two-way mobile radios (known as mobile rigs) were used in vehicles such as taxicabs, police cruisers, and ambulances, but were not mobile phones, because they were not connected to the telephone network.

The first fully automated mobile phone system for vehicles was launched in Sweden in 1960. Named MTA (Mobile Telephone system A), it allowed calls to be made and received in the car using a rotary dial. The car phone could also be paged. Calls from the car were direct dial, whereas incoming calls required an operator to determine which base station the phone was currently at. It was developed by Sture Laurén and other engineers at Televerket network operator. Ericsson provided the switchboard while Svenska Radioaktiebolaget (SRA) and Marconi provided the telephones and base station equipment. MTA phones consisted of vacuum tubes and relays, and weighed 40 kg. In 1962, an upgraded version called Mobile System B (MTB) was introduced. This was a push-button telephone, and used transistors and DTMF signaling to improve its operational reliability. In 1971 the MTD version was launched, opening for several different brands of equipment and gaining commercial success.[9][10] The network remained open until 1983 and still had 600 customers when it closed.

In 1958 development began on a similar system for motorists in the USSR.[11] The "Altay" national civil mobile phone service was based on Soviet MRT-1327 standard. The main developers of the Altay system were the Voronezh Science Research Institute of Communications (VNIIS) and the State Specialized Project Institute (GSPI). In 1963 the service started in Moscow, and by 1970 was deployed in 30 cities across the USSR. Versions of the Altay system are still in use today as a trunking system in some parts of Russia.

In 1959 a private telephone company located in Brewster, Kansas, USA, the S&T Telephone Company, (still in business today) with the use of Motorola Radio Telephone equipment and a private tower facility, offered to the public mobile telephone services in that local area of NW Kansas. This system was a direct dial up service through their local switchboard, and was installed in many private vehicles including grain combines, trucks, and automobiles. For some as yet unknown reason, the system, after being placed online and operated for a very brief time period, was shut down. The management of the company was immediately changed, and the fully operable system and related equipment was immediately dismantled in early 1960, not to be seen again.[citation needed]

In 1966, Bulgaria presented the pocket mobile automatic phone RAT-0,5 combined with a base station RATZ-10 (RATC-10) on Interorgtechnika-66 international exhibition. One base station, connected to one telephone wire line, could serve up to six customers.[citation needed]

One of the first successful public commercial mobile phone networks was the ARP network in Finland, launched in 1971. Posthumously, ARP is sometimes viewed as a zero generation (0G) cellular network, being slightly above previous proprietary and limited coverage networks.[citation needed]

[edit] Handheld cell phone

Dr. Martin Cooper of Motorola, made the first US analogue mobile phone call on a larger prototype model in 1973. This is a reenactment in 2007

Prior to 1973, cellular mobile phone technology was limited to phones installed in cars and other vehicles.[12]

On April 3, 1973, Martin Cooper, a Motorola researcher and executive, made the first analogue mobile phone call using a heavy prototype model. He called Dr. Joel S. Engel of Bell Labs.[13]

There was a long race between Motorola and Bell Labs to produce the first portable mobile phone. 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.[14] John F. Mitchell, Motorola's chief of portable communication products (and Cooper's boss) was also named on the patent. He successfully pushed Motorola to develop wireless communication products that would be small enough to use anywhere and participated in the design of the cellular phone.[15][16] [edit] First generation: Cellular networks Main article: 1G

The technological development that distinguished the First Generation of mobile phones from the previous generation was the use of multiple cell sites, and the ability to transfer calls from one site to the next as the user travelled between cells during a conversation. The first commercially 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 1G network.

Analog Motorola DynaTAC 8000X Advanced Mobile Phone System mobile phone as of 1983

The next 1G network to launch was the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden in 1981.[17] NMT was the first mobile phone network to feature international roaming. The Swedish electrical engineer Östen Mäkitalo started work on this vision in 1966, and is considered to be the father of the NMT system, and by some the father of the cellular phone itself, since he and two colleagues hold a patent from 1971 on a cellular system with handover and roaming.[18][19][20] The NMT installations were based on the Ericsson AXE digital exchange nodes.

Several other countries also launched 1G networks in the early 1980s including the UK, Mexico and Canada. A two year trial started in 1981 in Baltimore and Washington DC with 150 users and 300 Motorola DynaTAC pre-production phones. This took place on a seven tower cellular network that covered the area. The DC area trial turned into a commercial services in about 1983 with fixed cellular car phones also built by Motorola. They later added the 8000X to their Cellular offerings. A similar trial and commercial launch also took place in Chicago by Ameritech in 1983 using the famous first hand-held mobile phone Motorola DynaTAC.

AT&T's 1971 proposal for Advanced Mobile Phone System (AMPS) was approved by the FCC in 1982 and frequencies were allocated in the 824 894 MHz band.[6] Analog AMPS was superseded by Digital AMPS in 1990.

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 cell area. The sites were set up so that cells partially overlapped and different base stations operated using the same frequencies with little or no interference.

Vodafone made the UK's first mobile call at a few minutes past midnight on January 1 1985.[21]

The technology in these early networks was pushed to the limit to accommodate increasing usage. The base stations and the mobile phones utilized variable transmission power, 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. [edit]

Second generation: Digital networks Main articles: 2G, 2.5G, and 2.75G

Two 1991 GSM mobile phones with several AC adapters

In the 1990s, the 'second generation' (2G) mobile phone systems emerged, primarily using the GSM standard. These differed from the previous generation by using digital instead of analog transmission, and also fast out-of-band phone-to-network signaling. The rise in mobile phone usage as a result of 2G was explosive and this era also saw the advent of prepaid mobile phones

In 1991 the first GSM network (Radiolinja) launched in Finland. In general the frequencies used by 2G systems in Europe were higher than those in America, though with some overlap. For example, the 900 MHz frequency range was used for both 1G and 2G systems in Europe, so the 1G systems were rapidly closed down to make space for the 2G systems. In America the IS-54 standard was deployed in the same band as AMPS and displaced some of the existing analog channels.

Coinciding with the introduction of 2G systems was a trend away from the larger "brick" phones toward tiny 100 200g hand-held devices. This change was possible not only through technological improvements such as more advanced batteries and more energy-efficient electronics, but also because of the higher density of cell sites to accommodate increasing usage. The latter meant that the average distance transmission from phone to the base station shortened, leading to increased battery life whilst on the move.

Personal Handy-phone System mobiles and modems used in Japan around 1997 2003

The second generation introduced a new variant of communication called SMS or text messaging. It was initially available only on GSM networks but spread eventually on all digital networks. The first machine-generated SMS message was sent in the UK on 3 December 1992 followed in 1993 by the first person-to-person SMS sent in Finland. The advent of prepaid services in the late 1990s soon made SMS the communication method of choice amongst the young, a trend which spread across all ages.

2G also introduced the ability to access media content on mobile phones. In 1998 the first downloadable content sold to mobile phones was the ring tone, launched by Finland's Radiolinja

(now Elisa). Advertising on the mobile phone first appeared in Finland when a free daily SMS news headline service was launched in 2000, sponsored by advertising.

Mobile payments were trialled in 1998 in Finland and Sweden where a mobile phone was used to pay for a Coca Cola vending machine and car parking. Commercial launches followed in 1999 in Norway. 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 full internet service on mobile phones was introduced by NTT DoCoMo in Japan in 1999. [edit] Third generation: High speed IP data networks and mobile broadband Main article: 3G

As the use of 2G phones became more widespread and people began to utilize mobile phones in their daily lives, it became clear that demand for data services (such as access to the internet) was growing. Furthermore, experience from fixed broadband services showed there would also be an ever increasing demand for greater data speeds. The 2G technology was nowhere near up to the job, so the industry began to work on the next generation of technology known as 3G. The main technological difference that distinguishes 3G technology from 2G technology is the use of packet switching rather than circuit switching for data transmission.[22] In addition, the standardization process focused on requirements more than technology (2 Mbit/s maximum data rate indoors, 384 kbit/s outdoors, for example).

Inevitably this led to many competing standards with different contenders pushing their own technologies, and the vision of a single unified worldwide standard looked far from reality. The standard 2G CDMA networks became 3G compliant with the adoption of Revision A to EV-DO, which made several additions to the protocol whilst retaining backwards compatibility: 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. protocols that would decrease connection establishment time. the ability for more than one mobile to share the same time slot. the introduction of QoS flags.

All these were put in place to allow for low latency, low bit rate communications such as VoIP.[23]

The first pre-commercial trial network with 3G was launched by NTT DoCoMo in Japan in the Tokyo region in May 2001. NTT DoCoMo launched the first commercial 3G network on October 1, 2001, using the WCDMA technology. In 2002 the first 3G networks on the rival CDMA2000 1xEV-DO technology were launched by SK Telecom and KTF in South Korea, and Monet in the USA. Monet has since gone bankrupt. By the end of 2002, the second WCDMA network was launched in Japan by Vodafone KK (now Softbank). European launches of 3G were in Italy and the UK by the Three/Hutchison group, on WCDMA. 2003 saw a further 8 commercial launches of 3G, six more on WCDMA and two more on the EV-DO standard.

During the development of 3G systems, 2.5G systems such as CDMA2000 1x and GPRS were developed as extensions to existing 2G networks. These provide some of the features of 3G without fulfilling the promised high data rates or full range of multimedia services. CDMA2000-1X delivers theoretical maximum data speeds of up to 307 kbit/s. Just beyond these is the EDGE system which in theory covers the requirements for 3G system, but is so narrowly above these that any practical system would be sure to fall short.

The high connection speeds of 3G technology enabled a transformation in the industry: for the first time, media streaming of radio (and even television) content to 3G handsets became possible [1], with companies such as RealNetworks [2] and Disney [3] among the early pioneers in this type of offering.

In the mid 2000s an evolution of 3G technology begun to be implemented, namely High-Speed Downlink Packet Access (HSDPA). It 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.

By the end of 2007 there were 295 million subscribers on 3G networks worldwide, which reflected 9% of the total worldwide subscriber base. About two thirds of these were on the WCDMA standard and one third on the EV-DO standard. The 3G telecoms services generated over 120 Billion dollars of revenues during 2007 and at many markets the majority of new phones activated were 3G phones. In Japan and South Korea the market no longer supplies phones of the second generation.

Although mobile phones had long had the ability to access data networks such as the Internet, it was not until the widespread availability of good quality 3G coverage in the mid 2000s that specialized

devices appeared to access the mobile internet. The first such devices, known as "dongles", plugged directly into a computer through the USB port. Another new class of device appeared subsequently, the so-called "compact wireless router" such as the Novatel MiFi, which makes 3G internet connectivity available to multiple computers simultaneously over Wi-Fi, rather than just to a single computer via a USB plug-in.

Such devices became especially popular for use with laptop computers due to the added portability they bestow. Consequently, some computer manufacturers started to embed the mobile data function directly into the laptop so a dongle or MiFi wasn't needed. Instead, the SIM card could be inserted directly into the device itself to access the mobile data services. Such 3G-capable laptops became commonly known as "netbooks". Other types of data-aware devices followed in the netbook's footsteps. By the beginning of 2010, E-readers, such as the Amazon Kindle and the Nook from Barnes & Noble, had already become available with embedded wireless internet, and Apple Computer had announced plans for embedded wireless internet on its iPad tablet devices beginning that Fall. [edit] Fourth generation: All-IP networks Main article: 4G

By 2009, it had become clear that, at some point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications like streaming media.[24] Consequently, the industry began looking to data-optimized 4th-generation technologies, with the promise of speed improvements up to 10-fold over existing 3G technologies. The first two commercially available technologies billed as 4G were the WiMAX standard (offered in the U.S. by Sprint) and the LTE standard, first offered in Scandinavia by TeliaSonera.

One of the main ways in which 4G differed technologically from 3G was in its elimination of circuit switching, instead employing an all-IP network. Thus, 4G ushered in a treatment of voice calls just like any other type of streaming audio media, utilizing packet switching over internet, LAN or WAN networks via VoIP.[25] [edit] Satellite mobile Main article: Satellite phone

Earth-orbiting satellites can cover remote areas out of reach of wired networks or where construction of a cellular network is uneconomic. The Inmarsat satellite telephone system, originally

developed in 1979 for safety of life at sea, is now also useful for areas out of reach of landline, conventional cellular, or marine VHF radio stations. In 1998 the Iridium satellite system was set up, and although the initial operating company went bankrupt due to high initial expenses, the service is available today.

Mobile Phones
Mobile phone From Wikipedia, the free encyclopedia

"Cell Phone" redirects here. For the film, see Cell Phone (film). "Handphone" redirects here. For the film, see Handphone (film).

Motorola SLVR L7 mobile phone

A mobile phone (also known as a cellular phone, cell phone and a hand phone) is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator. The calls are to and from the public telephone network which includes other mobiles and fixed-line phones across the world. By contrast, a cordless telephone is used only within the short range of a single, private base station.

In addition to telephony, modern mobile phones also support a wide variety of other services such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, gaming and photography. Mobile phones that offer these and more general computing capabilities are referred to as smartphones.

The first hand-held mobile phone was demonstrated by Dr Martin Cooper of Motorola in 1973, using a handset weighing 2 1/2 lbs (about 1 kg).[1] In 1983, the DynaTAC 8000x was the first to be commercially available. In the twenty years from 1990 to 2010, worldwide mobile phone subscriptions grew from 12.4 million to over 4.6 billion, penetrating the developing economies and reaching the bottom of the economic pyramid.[2][3][4]Contents [hide] 1 History 2 Before cellular networks

2.1 Origins 2.2 Radio Common Carrier 2.3 Rural Radiotelephone Service 3 Features 3.1 Software and applications 3.2 Power supply 3.3 SIM card 3.4 Display 3.5 Central processing unit 4 Mobile phones in society 4.1 Market share 4.2 Media 5 Use of mobile phones 5.1 In general 5.2 Sharing 5.3 Whilst driving 5.4 In schools 5.5 Tracking and privacy 6 Health effects 7 Future evolution: Broadband Fourth generation (4G) 8 See also 9 References 10 Further reading 11 External links

History Main article: History of mobile phones

An evolution of mobile phones

Radiophones have a long and varied history going back to Reginald Fessenden's invention and shoreto-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s.

The first mobile telephone call made from a car occurred in St. Louis, Missouri, USA on June 17, 1946, using the Bell System's Mobile Telephone Service. The equipment weighed 80 pounds (36 kg), and the AT&T service, basically a massive party line, cost US$30 per month (equal to $337.33 today) plus 30 40 cents per local call, equal to $3.37 to $4.50 today.[5]

In 1956, the world s first partly automatic car phone system, Mobile System A (MTA), was launched in Sweden. MTA phones were composed 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 was a push-button telephone, and which used transistors to enhance the telephone s calling capacity and improve its operational reliability, thereby reducing the weight of the apparatus to 10 kg. In 1971, the MTD version was launched, opening for several different brands of equipment and gaining commercial success.[6][7]

Martin Cooper, a Motorola researcher and executive is considered to be the inventor of the first practical mobile phone for handheld use in a non-vehicle setting, after a long race against Bell Labs for the first portable mobile phone. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a handheld mobile phone on April 3, 1973 to his rival, Dr. Joel S. Engel of Bell Labs.[8]

The first commercially automated cellular network (the 1G) was launched in Japan by NTT in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nationwide 1G network. In 1981, this was followed by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden.[9] NMT was the first mobile phone network featuring international roaming. The first 1G network launched in the USA was Chicago-based Ameritech in 1983 using the Motorola DynaTAC mobile phone. Several countries then followed in the early-to-mid 1980s including the UK, Mexico and Canada.

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.

In 2001, the launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard.[10]

One of the newest 3G technologies to be implemented is High-Speed Downlink Packet Access (HSDPA). It 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. Before cellular networks

A mobile radio telephone.

Mobile radio telephone systems preceded modern cellular mobile telephony technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre cellular (or sometimes zero generation) systems. Technologies used in pre cellular systems included the Push to Talk (PTT or manual), Mobile Telephone System (MTS), Improved Mobile Telephone Service (IMTS), and Advanced Mobile Telephone System (AMTS) systems. These early mobile telephone systems can be distinguished from earlier closed radiotelephone systems in that they were available as a commercial service that was part of the public switched telephone network, with their own telephone numbers, rather than part of a closed network such as a police radio or taxi dispatch system.

These mobile telephones were usually mounted in cars or trucks, though briefcase models were also made. Typically, the transceiver (transmitter-receiver) was mounted in the vehicle trunk and attached to the "head" (dial, display, and handset) mounted near the driver seat.

They were sold through WCCs (Wireline Common Carriers, AKA telephone companies), RCCs (Radio Common Carriers), and two-way radio dealers. Origins

Early examples for this technology: Motorola in conjunction with the Bell System operated the first commercial mobile telephone service Mobile Telephone System (MTS) in the US in 1946, as a service of the wireline telephone company. The A-Netz launched 1952 in West Germany as the country's first public commercial mobile phone network. First automatic system was the Bell System's IMTS which became available in 1962, offering automatic dialing to and from the mobile. The Televerket opened its first manual mobile telephone system in Norway in 1966. Norway was later the first country in Europe to get an automatic mobile telephone system. The Autoradiopuhelin (ARP) launched in 1971 in Finland as the country's first public commercial mobile phone network. The B-Netz launched 1972 in West Germany as the country's second public commercial mobile phone network (but the first one that did not require human operators to connect calls). Radio Common Carrier

Parallel to Improved Mobile Telephone Service (IMTS) in the US until the rollout of cellular AMPS systems, a competing mobile telephone technology was called Radio Common Carrier or RCC. The service was provided from the 1960s until the 1980s when cellular AMPS systems made RCC equipment obsolete. These systems operated in a regulated environment in competition with the Bell System's MTS and IMTS. RCCs handled telephone calls and were operated by private companies and individuals. Some systems were designed to allow customers of adjacent RCCs to use their facilities but the universe of RCCs did not comply with any single interoperable technical standard (a capability called roaming in modern systems). For example, the phone of an Omaha, Nebraska based RCC service would not be likely to work in Phoenix, Arizona. At the end of RCC's existence, industry associations were working on a technical standard that would potentially have allowed roaming, and some mobile users had multiple decoders to enable operation with more than one of the common signaling formats (600/1500, 2805, and Reach). Manual operation was often a fallback for RCC roamers.

Roaming was not encouraged, in part, because there was no centralized industry billing database for RCCs. Signaling formats were not standardized. For example, some systems used two-tone sequential paging to alert a mobile or hand-held that a wired phone was trying to call them. Other systems used DTMF. Some used a system called Secode 2805 which transmitted an interrupted 2805 Hz tone (in a manner similar to IMTS signaling) to alert mobiles of an offered call. Some radio equipment used with RCC systems was half-duplex, push-to-talk equipment such as Motorola handhelds or RCA 700-series conventional two-way radios. Other vehicular equipment had telephone

handsets, rotary or pushbutton dials, and operated full duplex like a conventional wired telephone. A few users had full-duplex briefcase telephones (radically advanced for their day).

RCCs used paired UHF 454/459 MHz and VHF 152/158 MHz frequencies near those used by IMTS. Rural Radiotelephone Service

Using the same channel frequencies as IMTS, the US Federal Communications Commission authorized Rural Radiotelephone Service for fixed stations. Because RF channels were shared with IMTS, the service was licensed only in areas that were remote from large Bureau of the Census Metropolitan Statistical Areas (MSAs).[11]

Systems used UHF 454 MHz or 152 MHz radio channels to provide telephone service to extremely rural places where it would be too costly to extend cable plant. One such system was on a 454/459 MHz channel pair between the Death Valley telephone exchange and Stovepipe Wells, California. This specific system carried manual calls to the Traffic Service Position System (TSPS) center in Los Angeles. Stovepipe Wells callers went off-hook and were queried, "Number please," by a TSPS operator, who dialed the call. Dial service was introduced to Stovepipe Wells in the mid-1980s. The radio link has since been replaced by cable. The analog service has since been replaced by Basic Exchange Telephone Radio Service, a digital system using the same frequencies. Features Main articles: Mobile phone features and Smartphone

A printed circuit board inside a Nokia 3210

All mobile phones have a number of features in common, but manufacturers also try to differentiate their own products by implementing additional functions to make them more attractive to consumers. This has led to great innovation in mobile phone development over the past 20 years.

The common components found on all phones are: A battery, providing the power source for the phone functions. An input mechanism to allow the user to interact with the phone. The most common input mechanism is a keypad, but touch screens are also found in some high-end smartphones. Basic mobile phone services to allow users to make calls and send text messages.

All GSM phones use a SIM card to allow an account to be swapped among devices. Some CDMA devices also have a similar card called a R-UIM. Individual GSM, WCDMA, iDEN and some satellite phone devices are uniquely identified by an International Mobile Equipment Identity (IMEI) number.

Low-end mobile phones are often referred to as feature phones, and offer basic telephony, as well as functions such as playing music and taking photos, and sometimes simple applications based on generic managed platforms such as Java ME or BREW. Handsets with more advanced computing ability through the use of native software applications became known as smartphones. The first smartphone was the Nokia 9000 Communicator in 1996 which added PDA functionality to the basic mobile phone at the time. As miniaturization 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.

Other features that may be found on mobile phones include GPS navigation, music (MP3) and video (MP4) playback, RDS radio receiver, alarms, memo recording, personal digital assistant functions, ability to watch streaming video, video download, 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), dual line support, infrared, Bluetooth (2.0) and WiFi connectivity, instant messaging, Internet e-mail and browsing and serving as a wireless modem. Nokia and the University of Cambridge demonstrated a bendable cell phone called the Morph.[12] Some phones can make mobile payments via direct mobile billing schemes or through contactless payments if the phone and point of sale support Near Field Communication (NFC).[13] Some of the largest mobile phone manufacturers and network providers along with many retail merchants support, or plan to support, contactless payments through NFC-equipped mobile phones.[14][15][16]

Some phones have an electromechanical transducer on the back which changes the electrical voice signal into mechanical vibrations. The vibrations flow through the cheek bones or forehead allowing the user to hear the conversation. This is useful in the noisy situations or if the user is hard of hearing. [17] Software and applications

A Toshiba TG01 phone with touchscreen feature See also: Mobile Industry Processor Interface

The most commonly used data application on mobile phones is SMS text messaging. The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first personto-person SMS from phone to phone was sent in Finland in 1993.

Other non-SMS data services used on mobile phones include mobile music, downloadable logos and pictures, gaming, gambling, adult entertainment and advertising. The first downloadable mobile content was sold to a mobile phone in Finland in 1998, when Radiolinja (now Elisa) introduced the downloadable ringtone 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.

The first mobile news service, delivered via SMS, was launched in Finland in 2000. 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 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. Power supply

Mobile phone charging service in Uganda

Mobile phones generally obtain power from rechargeable batteries. There are a variety of ways used to charge cell phones, including USB, portable batteries, mains power (using an AC adapter), cigarette lighters (using an adapter), or a dynamo. In 2009, the first wireless charger was released for consumer use.[18]

Various initiatives, such as the EU Common External Power Supply have been announced to standardize the interface to the charger, and to promote energy efficiency of mains-operated

chargers. A star rating system is promoted by some manufacturers, where the most efficient chargers consume less than 0.03 watts and obtain a five-star rating.

The world's five largest handset makers introduced a new rating system in November 2008 to help consumers more easily identify the most energy-efficient chargers

[19]

Battery

A popular early mobile phone battery was the nickel metal-hydride (NiMH) type, due to its relatively small size and low weight. Lithium ion batteries are also used, as they are lighter and do not have the Voltage depression due to long-term over-charging that nickel metal-hydride batteries do. Many mobile phone manufacturers use lithium polymer batteries as opposed to the older Lithium-Ion, the main advantages being even lower weight and the possibility to make the battery a shape other than strict cuboid.[20] Mobile phone manufacturers have been experimenting with alternative power sources, including solar cells.[21] SIM card This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2009)

Main articles: Subscriber Identity Module and Removable User Identity Module

Typical mobile phone SIM card

GSM mobile phones require a small microchip called a Subscriber Identity Module or SIM Card, to function. The SIM card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. The SIM securely stores the service-subscriber key (IMSI) used to identify a subscriber on mobile telephony devices (such as mobile phones and computers). The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device.

A SIM card contains its unique serial number, internationally unique number of the mobile user (IMSI), security authentication and ciphering information, temporary information related to the local

network, a list of the services the user has access to and two passwords (PIN for usual use and PUK for unlocking).

SIM cards are available in three standard sizes. The first is the size of a credit card (85.60 mm × 53.98 mm x 0.76 mm, defined by ISO/IEC 7810 as ID-1). The newer, most popular miniature version has the same thickness but a length of 25 mm and a width of 15 mm (ISO/IEC 7810 ID-000), and has one of its corners truncated (chamfered) to prevent misinsertion. The newest incarnation known as the 3FF or micro-SIM has dimensions of 15 mm × 12 mm. Most cards of the two smaller sizes are supplied as a full-sized card with the smaller card held in place by a few plastic links; it can easily be broken off to be used in a device that uses the smaller SIM.

The first SIM card was made in 1991 by Munich smart card maker Giesecke & Devrient for the Finnish wireless network operator Radiolinja. Giesecke & Devrient sold the first 300 SIM cards to Elisa (ex. Radiolinja).

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 there, information can be added, including a new number for the phone, new Service Provider numbers, new emergency numbers, new Authentication Key or A-Key code, and a Preferred Roaming List or PRL. However, to prevent the phone being accidentally disabled or removed from the network, the Service Provider typically locks this data with a Master Subsidiary Lock (MSL). The MSL also locks the device to a particular carrier when it is sold as a loss leader.

The MSL applies only to the SIM, so once the contract has expired, the MSL still applies to the SIM. The phone, however, is also initially locked by the manufacturer into the Service Provider's MSL. This lock may be disabled so that the phone can use other Service Providers' SIM cards. Most phones purchased outside the U.S. are unlocked phones because there are numerous Service Providers that are close 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.

A similar module called a Removable User Identity Module or RUIM card is present in some CDMA networks, notably in China and Indonesia.

Multi-card hybrid phones

A hybrid mobile phone can take more than one SIM card, even of different types. The SIM and RUIM cards can be mixed together, and some phones also support three or four SIMs.[22][23]

From 2010 onwards they became popular in India and Indonesia and other emerging markets,[24] attributed to the desire to obtain the lowest on-net calling rate. In Q3 2011, Nokia shipped 18 million of its low cost dual SIM phone range in an attempt to make up lost ground in the higher end smartphone market.[25] Display

Mobile phones have a display device, some of which are also touch screens. The screen size varies greatly by model and is usually specified either as width and height in pixels or the diagonal measured in inches.

Some mobiles have more than one display, for example the Kyocera Echo, an Android smartphone with a dual 3.5 inch screen. The screens can also be combined into a single 4.7 inch tablet style computer.[26] Central processing unit

Mobile phones have central processing units (CPUs), similar to those in computers, but optimised to operate in low power environments.

Mobile CPU performance depends not only on the clock rate (generally given in multiples of hertz)[27] but also the memory hierarchy also greatly affects overall performance. Because of these problems, the performance of mobile phone CPUs is often more appropriately given by scores derived from various standardized tests to measure the real effective performance in commonly used applications. Mobile phones in society Main article: Mobile telephony Market share

See also: List of best-selling mobile phonesQuantity Market Shares by Gartner (New Sales) BRAND Percent

Nokia 2009 Nokia 2010 Samsung 2009 Samsung 2010 LG Electronics 2009 LG Electronics 2010

36.4% 28.9% 19.5% 17.6% 10.1% 7.1% 2.8% 3.0%

Research In Motion 2009 Research In Motion 2010 Apple 2009 Apple 2010 Others-1 2009 Others-1 2010 Others-2 2009 Others-2 2010 2.1% 2.9% 12.6% 9.8% 16.5% 30.6%

Note: Others-1 consist of Sony Ericsson, Motorola, ZTE, HTC and Huawei.(2009-2010)

Mobile phone subscribers per 100 inhabitants 1997 2007

Global mobile phone subscribers per country from 1980-2009. The growth in users has been exponential since they were first made available.

The world's largest individual mobile operator by subscribers is China Mobile with over 500 million mobile phone subscribers.[28] 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 2009 (source wireless intelligence). In February 2010, there were 4.6 billion mobile phone subscribers, a number that is estimated to grow.[4]

Prior to 2010, Nokia was the market leader. However, during that year competition emerged in the Asia Pacific region with brands such as Micromax, Nexian, and i-Mobile and chipped away at Nokia's

market share. Android powered smartphones also gained momentum across the region at the expense of Nokia. In India, their market share also dropped significantly to around 31 percent from 56 percent in the same period. Their share was displaced by Chinese and Indian vendors of low-end mobile phones.[29]

In 2010 worldwide sales were 1.6 billion units, an increase of 31.8 percent from 2009. The top five manufacturers by market share were Nokia followed by Samsung, LG Electronics, ZTE and Apple. The last three replaced RIM, Sony Ericsson and Motorola who were previously among the top five list.[30][31] Outside the top five a significant market share increase from 16.5 percent to 30.6 percent was achieved by many smaller and new brands.

In Q1 2011, Apple surpassed Nokia as the world's biggest handset vendor by revenue, as Nokia's market share dropped to 29 percent in Q1 2011, the lowest level since the late 1990s. In June 2011, Nokia announced lower expectations for sales and margin due to global competition in both lowand-high end markets.[32]

By Q2 2011, worldwide sales grew 16.5 percent to 428.7 million units. Top 5 market share by vendorSource Others References Gartner Q2/2011 IDC Q2/2011 Date Nokia SAMSUNG LG Apple ZTE

22.8% 16.3% 5.7% 24.2% 19.2% 6.8%

4.6% 5.6%

3.0% 4.5%

47.6% [33] 39.7% [34]

Source: Gartner & IDC, Q2-2011 Note: Vendor shipments are branded shipments and exclude OEM sales for all vendors

Other manufacturers outside the top five are Research In Motion Ltd. (RIM), HTC Corporation, Motorola, Huawei, Sony Ericsson. Smaller players include Audiovox (now UTStarcom), BenQSiemens, CECT, Fujitsu, Kyocera, Mitsubishi Electric, NEC, Panasonic, Palm, Pantech Wireless Inc., Philips, Qualcomm Inc., Sagem, Sanyo, Sharp, Sierra Wireless, Just5, SK Teletech, T&A Alcatel, Trium, Toshiba, and Vidalco. Media

In 1998, one of the first examples of selling media content through the mobile phone was the sale of ringtones by Radiolinja in Finland. Soon afterwards, other media content appeared such as news,

videogames, jokes, horoscopes, TV content and advertising. 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.

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.[35]

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?]

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). Use of mobile phones In general

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 people carry more than one cell phone for different purposes, such as for business and personal use. Multiple SIM cards may also be used to take advantage of the benefits of different calling plans a particular plan might provide cheaper local calls, long-distance calls, international calls, or roaming. 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 may be used to engage in activities including extramarital affairs or clandestine business dealings.[36] The mobile phone has also been used in a variety of diverse contexts in society, for example: Organizations that aid victims of domestic violence may offer a cell phone to potential victims without the abuser's knowledge. These devices are often old phones that are donated and refurbished to meet the victim's emergency needs.[37] 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.[38] 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."

Mobile telephony also facilitates activism and public journalism being explored by Reuters and Yahoo![39] and small independent news companies such as Jasmine News in Sri Lanka. Mobile phones help lift poor out of poverty. The United Nations has reported that mobile phones spreading faster than any other information technology can improve the livelihood of the poorest people in developing countries. The economic benefits of mobile phones go well beyond access to information where a landline or Internet is not yet available in rural areas, mostly in Least Developed Countries. Mobile phones have spawned a wealth of micro-enterprises, offering work to people with little education and few resources, such as selling airtime on the streets and repairing or refurbishing handsets.[40] In Mali and some African countries, villagers sometimes had to go from village to village all day, covering up to 20 villages, to let friends and relatives know about a wedding, a birth or a death, but such travel is no longer necessary if the villages are within the coverage area of a mobile phone network. Like in many African countries, the coverage is better than that of landline networks, and most people own a mobile phone. However, small villages have no electricity, leaving mobile phone owners to have to recharge their phone batteries using a solar panel or motorcycle battery.[41] The TV industry has recently started using mobile phones to drive live TV viewing through mobile apps, advertising, social tv, and mobile TV.[42] 86% of Americans use their mobile phone while watching TV. In March 2011, a pilot project experimenting with branchless banking was launched by the International Finance Corporation, a member of the World Bank, and Bank Harapan Bali, a subsidiary of Bank Mandiri the biggest bank in Indonesia and one of the cellular operators in Bali. Its aim is to increase the amount of bank customers. In Indonesia, only 60 million people have a bank account even though banks have existed for more than a hundred years, whereas 114 million people have become users of mobile phones in only two decades. Branchless banking has been successful in Kenya, South Africa and Philippines.[43] Sharing

In some parts of the world, mobile phone sharing is common. It is prevalent in urban India, as families and groups of friends often share one or more mobiles among their members. There are obvious economic benefits, but often familial customs and traditional gender roles play a part.[44] For example, in Burkina Faso, it is not uncommon for a village to have access to only one mobile phone. The phone is typically owned by a person who is not natively from the village, such as a teacher or missionary, but it is expected that other members of the village are allowed to use the cell phone to make necessary calls.[45] Whilst driving Main article: Mobile phones and driving safety

Texting in stop-and-go traffic in New York City

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 jurisdictions prohibit the use of mobile phones while driving. Egypt, Israel, Japan, Portugal and Singapore ban both handheld and hands-free use of a mobile phone; others including the UK, France, and many U.S. states ban handheld phone use only, allowing hands-free use.

Due to the increasing complexity of mobile phones, they are often more like mobile computers in their available uses. This has introduced additional difficulties for law enforcement officials in distinguishing one usage from another as drivers use their devices. This is more apparent in those countries which ban both handheld and hands-free usage, rather those who have banned handheld use only, as officials cannot easily tell which function of the mobile phone is being used simply by looking at the driver. This can lead to drivers being stopped for using their device illegally on a phone call when, in fact, they were using the device for a legal purpose such as the phone's incorporated controls for car stereo or satnav.

A recently published study has reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety.[46] In 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, harassment and bullying, causing threats to the schools security, distractions to the students, and facilitating gossip and other social activity in school. Many mobile phones are banned in school locker room facilities, public restrooms and swimming pools due to the built-in cameras that most phones now feature. Tracking and privacy See also: Mobile phone tracking

Mobile phones are also commonly used to collect location data. While the phone is turned on, 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.[47][48]

The movements of a mobile phone user can be tracked by their service provider and, if desired, by law enforcement agencies and their government. Both the SIM card and the handset can be tracked.[49]

China has proposed using this technology to track commuting patterns of Beijing city residents.[50] In the UK and US, law enforcement and intelligence services use mobiles to perform surveillance. They possess technology to activate the microphones in cell phones remotely in order to listen to conversations that take place near to the person who holds the phone.[51][52] Health effects Main article: Mobile phone radiation and health Further information: Mobile phones on aircraft

On 31st May 2011, the World Health Organization confirmed that mobile phone use may represent a long-term health risk[53][54], classifying mobile phone radiation as a "carcinogenic hazard" and "possibly carcinogenic to humans" after a team of scientists reviewed peer-review studies on cell phone safety.[55] One study of past cell phone use cited in the report showed a "40% increased risk for gliomas (brain cancer) in the highest category of heavy users (reported average: 30 minutes per day over a 10-year period)."[56] This is a reversal from their prior position that cancer was unlikely to be caused by cellular phones or their base stations and that reviews had found no convincing evidence for other health effects.[54][57] Certain countries, including France, have warned against the use of cell phones especially by minors due to health risk uncertainties.[58]

The effect mobile phone radiation has on human health is the subject of recent interest and study, as a result of the enormous increase in mobile phone usage throughout the world (as of June 2009, there were more than 4.3 billion users worldwide[59]). Mobile phones use electromagnetic radiation in the microwave range, which some believe may be harmful to human health. A large body of research exists, both epidemiological and experimental, in non-human animals and in humans, of which the majority shows no definite causative relationship between exposure to mobile phones and harmful biological effects in humans. This is often paraphrased simply as the balance of evidence showing no harm to humans from mobile phones, although a significant number of individual studies do suggest such a relationship, or are inconclusive. Other digital wireless systems, such as data communication networks, produce similar radiation.

At least some recent studies have found an association between cell phone use and certain kinds of brain and salivary gland tumors. Lennart Hardell and other authors of a 2009 meta-analysis of 11 studies from peer-reviewed journals concluded that cell phone usage for at least ten years approximately doubles the risk of being diagnosed with a brain tumor on the same ('ipsilateral') side of the head as that preferred for cell phone use. [60]

In addition, a mobile phone can spread infectious diseases by its frequent contact with hands. One study came to the result that pathogenic bacteria are present on approximately 40% of mobile phones belonging to patients in a hospital, and on approximately 20% of mobile phones belonging to hospital staff.[61] Future evolution: Broadband Fourth generation (4G) Main articles: 4G and 5G

The recently released 4th generation, also known as Beyond 3G, aims to provide 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[62]

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.

In March 2011, KT from South Korea announced that they has expanded its high-speed wireless broadband network by 4G WiBro cover 85 percent of the population. It is the largest broadband network covered in the world, followed by Japan and US with 70 percent and 36 percent respectively.[63]

In early 2011, 4G mobile phones were released by Motorola, HTC and Samsung.[64]

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