History of Mobile Phones

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History of mobile phones
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• • • • • • • • • • •

1 Pioneers of radio telephony 2 Emergence of commercial mobile phone services 3 First generation: Cellular networks 4 Second generation: Digital networks 5 Third generation: High speed IP data networks 6 Growth of mobile broadband and the emergence of 4G 7 Patents 8 See also 9 Notes 10 References 11 External links

[edit] Pioneers of radio telephony
of Murray, Kentucky. He applied this patent to "cave radio" telephones and not directly to cellular telephony as the term is currently understood.[1] In 1910 Lars Magnus Ericsson installed a telephone in his car, although this was not a radio telephone. While travelling across the country, he would stop at a place where telephone lines were accessible and using a pair of long electric wires he could connect to the national telephone network.[2] In Europe, radio telephony was first used on the first-class passenger trains between Berlin and Hamburg in 1926. At the same time, radio telephony was introduced on passenger airplanes for air traffic security. Later radio telephony was introduced on a large scale in German tanks during the Second World War. After the war German police in the British zone of occupation first used disused tank telephony equipment to run the first radio patrol cars.[citation needed] In all of these cases the service was confined to specialists that were trained to use the equipment. In the early 1950s ships on the Rhine were among the first to use radio telephony with an untrained end customer as a user. Two-way 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 normally connected to the telephone network. Users could not dial phone numbers from their vehicles. A large community of mobile radio users, known as the mobileers, popularized the technology that would eventually give way to the mobile phone. Originally, mobile two-way radios were permanently installed in vehicles, but later versions such as the so-

called transportables or "bag phones" were equipped with a cigarette lighter plug so that they could also be carried, and thus could be used as either mobile or as portable two-way radios. During the early 1940s, Motorola developed a backpacked two-way radio, the Walkie-Talkie and later developed 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 soviet engineers G. Shapiro and I. Zaharchenko successfully tested their version of a radio mobile phone mounted inside a car. The device could connect to local telephone network with a range of up to 20 kilometers.

Top of cellular telephone tower 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] The technology did not exist then and the frequencies had not yet been allocated. Cellular technology was undeveloped until the 1960s, when Richard H. Frenkiel and Joel S. Engel of Bell Labs developed the electronics. In 1957 young Soviet radio engineer Leonid Kupriyanovich from Moscow created the portable mobile phone, named after himself as LK-1 or "radiophone".[5] This true mobile phone consisted of a relatively small-sized handset equipped with an antenna and rotary dial, and communicated with a base station. Kupriyanovich's "radiophone" had 3 kilogram of total weight, could operate up to 20 or 30 kilometers, and had 20 or 30 hours of battery lifespan. LK-1 and its layout was depicted in popular Soviet magazines as Nauka i zhizn, 8, 1957, p. 49, Yuniy technik, 7, 1957, p. 43–44. Engineer Kupriyanovich patented his mobile phone in the same year 1957 (author's certificate (USSR Patent) # 115494, 1.11.1957). The base station of LK-1 (called ATR, or Automated Telephone Radiostation) could connect to local telephone network and serve several customers.

In 1958, Kupriyanovich resized his "radiophone" to "pocket" version. The weight of improved "light" handset was about 500 grams. In 1967, each mobile phone had to stay within the cell area serviced by one base station throughout the phone call. This did not provide continuity of automatic telephone service to mobile phones moving through several cell areas. 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. 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., another Bell Labs engineer,[6] invented an automatic "call handoff" system to allow mobile phones to move through several cell areas during a single conversation without loss of conversation. Also Fluhr and Nussbaum,[7] Hachenburg et al. [8] , 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.

[edit] Emergence of commercial mobile phone services

Mobile car phone, 1964 During the 1950s the experiments of the pioneers started to appear as usable services across society, both commercially and culturally. In the 1954 movie Sabrina, the businessman Linus Larrabee (played by Humphrey Bogart) makes a call from the phone in the back of his limousine. In 1956, the first fully automatic mobile phone system, called MTA (Mobile Telephone system A), was developed by Ericsson and commercially released in Sweden. This was the first system that did not require any kind of manual control in base stations, but had the disadvantage of a phone weight of 40 kg (90 lb). MTB, an upgraded version with transistors, weighing 9 kg (20 lb), was introduced in 1965 and used DTMF signaling. It had 150 customers in the beginning and 600 when it shut down in 1983. The first person to have a mobile phone in the United Kingdom was reputedly Prince Philip, who had a system fitted into the trunk of his Aston Martin in 1957. The Prince

could make phone calls to the Queen while driving, which was thought to be quite amazing at the time. The Duke of Gloucester heard about the mobile phone and tried to obtain one, but the Post Office denied his request. They were prepared to indulge the husband of Her Majesty, but nobody else, as the system used an entire dedicated radio frequency.

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 In 1958 the USSR also began to deploy the "Altay" national civil mobile phone service specially for motorists.[9] The newly-developed mobile telephone system 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 this service started in Moscow, and in 1970 the Altay service already was deployed in 30 cities of the USSR. The last upgraded versions of the Altay system are still in use in some places of Russia as a trunking system. 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. 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 was a push-button telephone, and 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.[10][11] 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.

Portable cellphone, 1970s 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.[12] Analog AMPS was superseded by Digital AMPS in 1990. 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. The origin of the modern cell phone can be traced back to the year 1973 when Motorola invented the first cellular portable telephone to be commercialised, known as Motorola DynaTAC 8000X. Martin Cooper, a Motorola researcher and executive is considered to be the inventor of this mobile phone for use in a non-vehicle setting. There was a long race between Motorola and Bell Labs to produce the first such 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;[13] 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.[14][15] Using a modern, if somewhat heavy portable handset, Cooper made the first cellular phone call on a handheld mobile phone on April 3, 1973 to his rival, Dr. Joel S. Engel of Bell Labs.[16]. Vodafone made the UK's first mobile call at a few minutes past midnight on 1 January 1985.[17]

[edit] First generation: Cellular networks
Main article: 1G

Man using cell phone, 1973 The main technological development that distinguished the First Generation 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 second launch of 1G networks was the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden in 1981.[18]. 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.[19][20] Several countries were among the earliest 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.

[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 2G phone systems differed from the previous generation in their use of digital transmission instead of analog transmission, and also by the introduction of advanced and fast 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) opened 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 "brickle" phones toward tiny 100–200g hand-held devices, which soon became the norm. This change was possible through technological improvements such as more advanced batteries and more energy-efficient electronics, but also was largely related to the higher density of cellular sites caused by increasing usage levels. This decreased the demand for high transmission powers to reach distant towers for customers to be satisfied.

Personal Handy-phone System mobiles and modems used in Japan around 1997–2003 The second generation introduced a new variant to communication, as SMS text messaging became possible, initially on GSM networks and eventually on all digital networks. The first machine-generated SMS message was sent in the UK in 1991. The first person-to-person SMS text message was sent in Finland in 1993. Soon SMS became the communication method of preference for the youth. Today in many advanced markets the general public prefers sending text messages to placing voice calls. 2G also introduced the ability to access media content on mobile phones, when Radiolinja (now Elisa) in Finland introduced the downloadable ring tone as paid content. Finland was also the first country where advertising appeared on the mobile phone when a free daily news headline service on SMS text messaging was launched in 2000, sponsored by advertising. 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 introduced by NTT DoCoMo in Japan in 1999.

[edit] Third generation: High speed IP data networks
Main article: 3G As the use of 2G phones became more widespread and people began to utilise mobile phones in their daily lives, it became clear that demand for data services (such as access to the internet) was growing. Furthermore, if the experience from fixed broadband services was anything to go by, there would also be a demand for ever 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[21]. 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. 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.[22] 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. 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. Earlier in the decade there were doubts about whether 3G might happen, and also whether 3G might become a commercial success. By the end of 2007 it had become clear that 3G was a reality and was clearly on the path to become a profitable venture. 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 [2], with companies such as RealNetworks [3] and Disney [4] among the early pioneers in this type of offering.

In the mid 2000s an evolution of 3G technology begun to be implemented, namely HighSpeed 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.

[edit] Growth of mobile broadband and the emergence of 4G
Main article: 4G 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 specialised 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 netbooks' 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. These types of devices marked the need to consider to evolve towards the fourth generation of the technology. 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[23]. Consequently, the industry began looking to data-optimized 4thgeneration 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.[24]

[edit] Patents
• • • •



• •



• •

U.S. Patent 3,663,762: Cellular Mobile Communication System — Amos Edward Joel (Bell Labs), filed December 21, 1970, issued May 16, 1972 U.S. Patent 3,906,166: Radio Telephone System (Dyna-Tac) — Martin Cooper et al. (Motorola), filed October 17, 1973, issued September 16, 1975 U.S. Patent 4,144,411: Cellular Radiotelephone System for Different Cell Sizes — Richard H. Frenkiel (Bell Labs), filed September 22, 1976, issued March 13, 1979 U.S. Patent 4,399,555: Cellular Mobile Radiotelephone System — Verne MacDonald, Philip Porter, Rae Young, (Bell Labs) filed April 28, 1980, issued August 16, 1983 U.S. Patent 5,129,098: Radio telephone using received signal strength in controlling transmission power — Andrew McGirr, Barry Cassidy (Novatel), filed September 24, 1990, issued July 7, 1992 U.S. Patent 5,265,158: Construction of a stand alone portable telephone unit — Jouko Tattari (Nokia), filed May 11, 1992, issued November 23, 1993 U.S. Patent 5,722,067: Security cellular telecommunications system — Douglas Fougnies et al. (Freedom Wireless), filed December 1994, issued February 24, 1998 U.S. Patent 5,826,185: Cellular phone system wherein the air time use is predetermined — Andrew Wise et al. (Banana Communications), filed November 1994, issued October 20, 1998 U.S. Patent 5,841,856: Hands-free telephone set — Yoshiyuki Ide (NEC), filed May 21, 1997, issued November 24, 1998 U.S. Patent 7,324,480: Mobile communication apparatus and method including base station and mobile station having multi-antenna: Per-User Unitary Rate Control (PU2RC) — James S. Kim, Kwangbok Lee, Kiho Kim and Changsoon Park, filed July 10, 2003, issued January 29, 2008

[edit] See also
• • • •

Mobile phone History of the prepaid mobile phone Cellular network Personal Communications Service PCS

[edit] Notes
1. ^ "Special History Issue" (PDF). Speleonics 15 IV (3). October 1990. 2. ^ Agar, Jon (2003). Constant Touch: a brief history of the mobile phone. Icon. pp. 8–9.
ISBN 9781840464191. http://wgbush.com/splncs/splncs15.pdf.

3. 4. 5. 6. 7.

^ see external link for the 1947 memo ^ article by Tom Farley "Cellular Telephone Basics" ^ History of mobile telephones in the USSR (in Russian) ^ See Amos Joel patent 3,663,762. ^ "Switching Plan for a Cellular Mobile Telephone System:, Z. Fluhr and E. Nussbaum, IEEE Transactions on Communications volume 21, #11 p. 1281 (1973) 8. ^ "Data signaling functions for a cellular mobile telephone system", V. Hachenburg, B. Holm and J. Smith, IEEE Trans Vehicular Technology, volume 26, #1 p. 82 (1977) 9. ^ The first Russian mobile phone 10. ^ Mingtao Shi, Technology base of mobile cellular operators in Germany and China, page 55 11. ^ Facts about the Mobile. A Journey through Time 12. ^ AT&T article 13. ^ Cooper, et al., "Radio Telephone System", US Patent number 3,906,166; Filing date: Oct 17, 1973; Issue date: September 1975; Assignee Motorola 14. ^ "Motorola Executive Helped spur Cellphone Revolution, Oversaw Ill-fated Iridium Project". The Wall Street Journal, June 20–21, 2009, p. A10. 15. ^ "John F. Mitchell, 1928-2009: Was president of Motorola from 1980 to '95, Chicago Tribune, June 17, 2009, retrieved June 17, 2009". Chicagotribune.com. http://www.chicagotribune.com/news/chi-hed-jmitchell-17-jun17,0,955426.story. Retrieved 2009-07-29. 16. ^ Shiels, Maggie. "BBC interview with Martin Cooper". http://news.bbc.co.uk/1/hi/uk/2963619.stm. 17. ^ [1] 18. ^ "Swedish National Museum of Science and Technology". Tekniskamuseet.se. http://www.tekniskamuseet.se/mobilen/engelska/1980_90.shtml. Retrieved 2009-07-29. 19. ^ Mobile and technology: The Basics of Mobile Phones 20. ^ The cell phone 50 years - facts and numbers 21. ^ Privateline.com: 3G and Cellular radio Information 22. ^ Gopal, Thawatt (11–15 March 2007). "EVDO Rev. A Control Channel Bandwidth Analysis for Paging". IEEE Wireless Communications and Networking Conference. IEEE. pp. 3262–7. doi:10.1109/WCNC.2007.601. 23. ^ Fahd Ahmad Saeed. "Capacity Limit Problem in 3G Networks". Purdue School of Engineering. http://www.ece.iupui.edu/~dskim/Classes/ECE695MWN/2006-saeedCapacity_Limit_Problem_in_3G_Networks.ppt. Retrieved April 23, 2010. 24. ^ "VoIP Support in Nokia Devices". http://www.forum.nokia.com/Technology_Topics/Mobile_Technologies/VoIP/Nokia_Vo IP_Framework/VoIP_support_in_Nokia_devices.xhtml. Retrieved 2009-08-16.

[edit] References


Farley, Tom (2007). "The Cell-Phone Revolution". American heritage of invention & technology (New York: American Heritage) 22 (3): 8–19. BL Shelfmark 0817.734000. ISSN 8756-7296. OCLC 108126426. http://www.americanheritage.com/events/articles/web/20070110-cell-phone-attmobile-phone-motorola-federal-communications-commission-cdma-tdmagsm.shtml. Retrieved 2008-04-21.

[edit] External links
• • • • • • • •

• • •

1947 memo by Douglas H. Ring proposing hexagonal cells The history of cellular telephones in the US Mobile Phone Museum from Europe Mobile Forum Mobile Phone Forum Cell Phone Basics Cellular Convergence: Evolution, Revolution and Speculation Thoughts about next generation phones: end-user applications matter, open systems, phones based on GNU/Linux, phones serving as desktop computers. Original draft designs of phones The history of mobile telephones in the USSR - in Russian Mobile Phone Technology Old Patents Mobile Phone Museum from Ireland

v•d•e

Mobile phones
General History · GSM · Features · OS · Services

Network operators · Standard comparison · Frequencies · Mobile VoIP · SIM · WAP · XHT Networking Mobile phone signal Generations: 0G · 1G · 2G · 3G · 4G Devices Manufacturers · Camera phone · Smartphones

The introduction of hexagonal cells for mobile phone base stations, invented in 1947 by Bell Labs engineers at AT&T, was further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been available since 1983. Due to their low establishment costs and rapid deployment, mobile phone networks have since spread rapidly throughout the world, outstripping the growth of fixed telephony. In 1945, the 0G generation of mobile telephones were introduced. 0G mobile telephones, such as Mobile Telephone Service, were not officially categorized as mobile phones, since they did not support the automatic change of channel frequency in the middle of a call, when the user moved from one cell (base station coverage area) to another cell, a feature called "handover". In 1970 Amos Joel of Bell Labs invented the "call handoff" feature, which allowed a mobile-phone user to travel through several cells during the same conversation. Martin Cooper of Motorola is widely considered to be the inventor of the first practical mobile phone for handheld use in a non-vehicle setting. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a handheld mobile phone on April 3, 1973. At the time he made his call, Cooper was working as Motorola's General Manager of its Communications Division. Fully automatic cellular networks were first introduced in the early to mid1980s (the 1G generation). The first fully automatic mobile phone system was the 1981 Nordic Mobile Telephone (NMT) system. Until the early 1990s, most mobile phones were too large to be carried in a jacket pocket, so they were usually permanently installed in vehicles as car phones. With the advance of miniaturization and smaller digital components, mobile phones got smaller and lighter.

Manufacturers

Nokia Corporation is currently the world's largest manufacturer of telephones, with a global market share of approximately 36% in Q 2007.Other mobile phone manufacturers include Audiovox (now U Starcom), Benefon, BenQ-Siemens, High Tech Computer Corporat Fujitsu, Kyocera, 3G, LG Mobile, Motorola, NEC, Panasonic (Matsu Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Sam Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sony Ericss Alcatel,Toshiba, Verizon, and soon to be Apple Inc.. There are also communication systems related to (but distinct from) mobile phon Professional Mobile Radio. Technology

Mobile phones and the network they operate under vary significan provider to provider, and nation to nation. However, all of them co through electromagnetic radio waves with a cell site base station, antennas of which are usually mounted on a tower, pole or buildin

The phones have a low-power transceiver that transmits voice and the nearest cell sites, usually not more than 5 to 8 miles (approxi 13 kilometers) away. When the mobile phone or data device is tur registers with the mobile telephone exchange, or switch, with its u identifiers, and will then be alerted by the mobile switch when the incoming telephone call. The handset constantly listens for the str signal being received from the surrounding base stations. As the u around the network, the mobile device will "handoff" to various ce during calls, or while waiting (idle) between calls it will reselect ce

Cell sites have relatively low-power (often only one or two watts) transmitters which broadcast their presence and relay communica between the mobile handsets and the switch. The switch in turn c call to another subscriber of the same wireless service provider or public telephone network, which includes the networks of other w carriers. Many of these sites are camouflaged to blend with existin environments, particularly in high-scenery areas.

The dialogue between the handset and the cell site is a stream of that includes digitized audio (except for the first generation analog networks). The technology that achieves this depends on the syst the mobile phone operator has adopted. Some technologies includ analog, and D-AMPS, CDMA2000, GSM, GPRS, EV-DO, and UMTS communications. Each network operator has a unique radio freque

3G Technology
Here is a simple introduction to some aspects of 3G radio transmission technologies (RTTs). You will find the subjects covered in this section useful if you later consider the more detailed discussions in the sections on 3G Standards and 3G Spectrum.

Simplex vs. Duplex
When people use walkie-talkie radios to communicate, only one person can talk at a time (the person doing the talking has to press a button). This is because walkie-talkie radios only use one communication frequency - a form of communication known as simplex:

Simplex: Using a walkie-talkie you have to push a button to talk one-way.

Of course, this is not how mobile phones work. Mobile phones allow simultaneous twoway transfer of data - a situation known as duplex (if more than two data streams can be transmitted, it is called multiplex):

Duplex: Allows simultaneous two-way data transfers.

The communication channel from the base station to the mobile device is called the downlink, and the communication from the mobile device back to the base station is called the uplink. How can duplex communication be achieved? Well, there are two possible methods which we will now consider: TDD and FDD.

TDD vs. FDD
Wireless duplexing has been traditionally implemented by dedicating two separate frequency bands: one band for the uplink and one band for the downlink (this arrangement of frequency bands is called paired spectrum). This technique is called Frequency Division Duplex, or FDD. The two bands are separated by a "guard band" which provides isolation of the two signals:

FDD: Uses paired spectrum - one frequency band for the uplink, one frequency band for the downlink.

Duplex communications can also be achieved in time rather than by frequency. In this approach, the uplink and the downlink operate on the same frequency, but they are switched very rapidly: one moment the channel is sending the uplink signal, the next moment the channel is sending the downlink signal. Because this switching is performed very rapidly, it does appear that one channel is acting as both an uplink and a downlink at the same time. This is called Time Division Duplex, or TDD. TDD requires a guard time instead of a guard band between transmit and receive streams.

Symmetric Transmission vs. Asymmetric Transmission

Data transmission is symmetric if the data in the downlink and the data in the uplink is transmitted at the same data rate. This will probably be the case for voice transmission the same amount of data is sent both ways. However, for internet connections or broadcast data (e.g., streaming video), it is likely that more data will be sent from the server to the mobile device (the downlink).

FDD transmission is not so well suited for asymmetric applications as it uses equal frequency bands for the uplink and the downlink (a waste of valuable spectrum). On the other hand, TDD does not have this fixed structure, and its flexible bandwidth allocation is well-suited to asymmetric applications, e.g., the internet (see this PDF file for more details). For example, TDD can be configured to provide 384kbps for the downlink (the direction of the major data transfer), and 64kbps for the uplink (where the traffic largely comprises requests for information and acknowledgements). See this PDF file for more details.

Macro Cells, Micro Cells, and Pico Cells
The 3G network might be divided up in hierarchical fashion:

• • •

Macro cell - the area of largest coverage, e.g., an entire city. Micro cell - the area of intermediate coverage, e.g., a city centre. Pico cell - the area of smallest coverage, e.g., a "hot spot" in a hotel or airport.

Why is there this sub-division of regions? It is because smaller regions (shorter ranges) allow higher user density and faster transmission rates. This is why they are called "hot spots". TDD mode does not allow long range transmission (the delays incurred would cause interference between the uplink and the downlink). For this reason, TDD mode can only be used in environments where the propagation delay is small (pico cells). As was explained in the previous section on symmetric transmission vs. asymmetric transmission, TDD mode is highly efficient for transmission of internet data in pico cells.

TDMA vs. CDMA
We have considered how a mobile phone can send and receive calls at the same time (via an uplink and a downlink). Now we will examine how many users can be multiplexed into the same channel (i.e., share the channel) without getting interference from other users, a capability called multiple access. For 3G technology, there are basically two competing technologies to achieve multiple access: TDMA and CDMA. TDMA is Time Division Multiple Access. It works by dividing a single radio frequency into many small time slots. Each caller is assigned a specific time slot for transmission. Again, because of the rapid switching, each caller has the impression of having exclusive use of the channel. CDMA is Code Division Multiple Access. CDMA works by giving each user a unique code. The signals from all the users can then be spread over a wide frequency band. The transmitting frequency for any one user is not fixed but is allowed to vary within the limits of the band. The receiver has knowledge of the sender's unique code, and is therefore able to extract the correct signal no matter what the frequency. This technique of spreading a signal over a wide frequency band is known as spread spectrum. The advantage of spread spectrum is that it is resistant to interference - if a source of interference blocks one frequency, the signal can still get through on another frequency. Spread spectrum signals are therefore difficult to jam, and it is not surprising that this technology was developed for military uses.

Finally, let's consider another robust technology originally developed by the military which is finding application with 3G: packet switching.

Circuit Switching vs. Packet Switching
Traditional connections for voice communications require a physical path connecting the users at the two ends of the line, and that path stays open until the conversation ends. This method of connecting a transmitter and receiver by giving them exclusive access to a direct connection is called circuit switching. Most modern networking technology is radically different from this traditional model because it uses packet data. Packet data is information which is: 1. 2. 3. 4. 5. chopped into pieces (packets), given a destination address, mixed with other data from other sources, transmitted over a line with all the other data, reconstituted at the other end.

Packet-switched networks chop the telephone conversation into discrete "packets" of data like pieces in a jigsaw puzzle, and those pieces are reassembled to recreate the original conversation. Packet data was originally developed as the technology behind the Internet.

A data packet.

The major part of a packet's contents is reserved for the data to be transmitted. This part is called the payload. In general, the data to be transmitted is arbitrarily chopped-up into payloads of the same size. At the start of the packet is a smaller area called a header. The header is vital because the header contains the address of the packet's intended recipient. This means that packets from many different phone users can be mixed into the same transmission channel, and correctly sorted at the other end. There is no longer a need for a constant, exclusive, direct channel between the sender and the receiver.

Packet data is added to the channel only when there is something to send, and the user is only charged for the amount of data sent. For example, when reading a small article, the user will only pay for what's been sent or received. However, both the sender and the receiver get the impression of a communications channel which is "always on". On the downside, packets can only be added to the channel where there is an empty slot in the channel, leading to the fact that a guaranteed speed cannot be given. The resultant delays pose a problem for voice transmission over packet networks, and is the reason why internet pages can be slow to load.

References
1. 2. 3. 4. 5. 6.
An Introduction to Third Generation Mobile Comms How Cell Phones Work ITU: All About 3G Technology CDMA Technology TDMA Technology FOMA Technology

Cellular network
From Wikipedia, the free encyclopedia

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Top of a cellular radio tower A cellular network is a radio network made up of a number of cells, each served by at least one fixed-location transceiver known as a cell site or base station. When joined together these cells provide radio coverage over a wide geographic area. This enables a

large number of portable transceivers (mobile phones, pagers, etc) to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the transceivers are moving through more than one cell during transmission. Cellular networks offer a number of advantages over alternative solutions:
• • • •

increased capacity reduced power usage larger coverage area reduced interference from other signals

An example of a simple non-telephone cellular system is an old taxi driver's radio system where the taxi company has several transmitters based around a city that can communicate directly with each taxi.

Contents
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• • • • • • •

• •

1 The concept 2 Cell signal encoding 3 Frequency reuse 4 Directional antennas 5 Broadcast messages and paging 6 Movement from cell to cell and handover 7 Example of a cellular network: the mobile phone network o 7.1 Structure of the mobile phone cellular network o 7.2 Cellular handover in mobile phone networks o 7.3 Cellular frequency choice in mobile phone networks o 7.4 Coverage comparison of different frequencies 8 See also 9 References

[edit] The concept
Example of frequency reuse factor or pattern 1/4 In a cellular radio system, a land area to be supplied with radio service is divided into regular shaped cells, which can be hexagonal, square, circular or some other irregular shapes, although hexagonal cells are conventional. Each of these cells is assigned multiple frequencies (f1 - f6) which have corresponding radio base stations. The group of

frequencies can be reused in other cells, provided that the same frequencies are not reused in adjacent neighboring cells as that would cause co-channel interference. The increased capacity in a cellular network, compared with a network with a single transmitter, comes from the fact that the same radio frequency can be reused in a different area for a completely different transmission. If there is a single plain transmitter, only one transmission can be used on any given frequency. Unfortunately, there is inevitably some level of interference from the signal from the other cells which use the same frequency. This means that, in a standard FDMA system, there must be at least a one cell gap between cells which reuse the same frequency. In the simple case of the taxi company, each radio had a manually operated channel selector knob to tune to different frequencies. As the drivers moved around, they would change from channel to channel. The drivers know which frequency covers approximately what area. When they do not receive a signal from the transmitter, they will try other channels until they find one that works. The taxi drivers only speak one at a time, when invited by the base station operator (in a sense TDMA).

[edit] Cell signal encoding
To distinguish signals from several different transmitters, frequency division multiple access (FDMA) and code division multiple access (CDMA) were developed. With FDMA, the transmitting and receiving frequencies used in each cell are different from the frequencies used in each neighbouring cell. In a simple taxi system, the taxi driver manually tuned to a frequency of a chosen cell to obtain a strong signal and to avoid interference from signals from other cells. The principle of CDMA is more complex, but achieves the same result; the distributed transceivers can select one cell and listen to it. Other available methods of multiplexing such as polarization division multiple access (PDMA) and time division multiple access (TDMA) cannot be used to separate signals from one cell to the next since the effects of both vary with position and this would make signal separation practically impossible. Time division multiple access, however, is used in combination with either FDMA or CDMA in a number of systems to give multiple channels within the coverage area of a single cell.

[edit] Frequency reuse
The key characteristic of a cellular network is the ability to re-use frequencies to increase both coverage and capacity. As described above, adjacent cells must utilise different frequencies, however there is no problem with two cells sufficiently far apart operating on the same frequency. The elements that determine frequency reuse are the reuse distance and the reuse factor.

The reuse distance, D is calculated as where R is the cell radius and N is the number of cells per cluster. Cells may vary in radius in the ranges (1 km to 30 km). The boundaries of the cells can also overlap between adjacent cells and large cells can be divided into smaller cells [1] The frequency reuse factor is the rate at which the same frequency can be used in the network. It is 1/K (or K according to some books) where K is the number of cells which cannot use the same frequencies for transmission. Common values for the frequency reuse factor are 1/3, 1/4, 1/7, 1/9 and 1/12 (or 3, 4, 7, 9 and 12 depending on notation). In case of N sector antennas on the same base station site, each with different direction, the base station site can serve N different sectors. N is typically 3. A reuse pattern of N/K denotes a further division in frequency among N sector antennas per site. Some current and historical reuse patterns are 3/7 (North American AMPS), 6/4 (Motorola NAMPS), and 3/4 (GSM). If the total available bandwidth is B, each cell can only utilize a number of frequency channels corresponding to a bandwidth of B/K, and each sector can use a bandwidth of B/NK. Code division multiple access-based systems use a wider frequency band to achieve the same rate of transmission as FDMA, but this is compensated for by the ability to use a frequency reuse factor of 1, for example using a reuse pattern of 1/1. In other words, adjacent base station sites use the same frequencies, and the different base stations and users are separated by codes rather than frequencies. While N is shown as 1 in this example, that does not mean the CDMA cell has only one sector, but rather that the entire cell bandwidth is also available to each sector individually. Depending on the size of the city, a taxi system may not have any frequency-reuse in its own city, but certainly in other nearby cities, the same frequency can be used. In a big city, on the other hand, frequency-reuse could certainly be in use.

[edit] Directional antennas

Cellular telephone frequency reuse pattern. See U.S. Patent 4,144,411 Although the original 2-way-radio cell towers were at the centers of the cells and were omni-directional, a cellular map can be redrawn with the cellular telephone towers located at the corners of the hexagons where three cells converge.[2] Each tower has three sets of directional antennas aimed in three different directions and receiving/transmitting into three different cells at different frequencies. This provides a minimum of three channels for each cell. The numbers in the illustration are channel numbers, which repeat every 3 cells. Large cells can be subdivided into smaller cells for high volume areas.[3]

[edit] Broadcast messages and paging
Practically every cellular system has some kind of broadcast mechanism. This can be used directly for distributing information to multiple mobiles, commonly, for example in mobile telephony systems, the most important use of broadcast information is to set up channels for one to one communication between the mobile transceiver and the base station. This is called paging. The details of the process of paging vary somewhat from network to network, but normally we know a limited number of cells where the phone is located (this group of

cells is called a Location Area in the GSM or UMTS system, or Routing Area if a data packet session is involved). Paging takes place by sending the broadcast message to all of those cells. Paging messages can be used for information transfer. This happens in pagers, in CDMA systems for sending SMS messages, and in the UMTS system where it allows for low downlink latency in packet-based connections.

[edit] Movement from cell to cell and handover
In a primitive taxi system, when the taxi moved away from a first tower and closer to a second tower, the taxi driver manually switched from one frequency to another as needed. If a communication was interrupted due to a loss of a signal, the taxi driver asked the base station operator to repeat the message on a different frequency. In a cellular system, as the distributed mobile transceivers move from cell to cell during an ongoing continuous communication, switching from one cell frequency to a different cell frequency is done electronically without interruption and without a base station operator or manual switching. This is called the handover or handoff. Typically, a new channel is automatically selected for the mobile unit on the new base station which will serve it. The mobile unit then automatically switches from the current channel to the new channel and communication continues. The exact details of the mobile system's move from one base station to the other varies considerably from system to system (see the example below for how a mobile phone network manages handover).

[edit] Example of a cellular network: the mobile phone network
GSM network architecture The most common example of a cellular network is a mobile phone (cell phone) network. A mobile phone is a portable telephone which receives or makes calls through a cell site (base station), or transmitting tower. Radio waves are used to transfer signals to and from the cell phone. Modern mobile phone networks use cells because radio frequencies are a limited, shared resource. Cell-sites and handsets change frequency under computer control and use low power transmitters so that a limited number of radio frequencies can be simultaneously used by many callers with less interference. A cellular network is used by the mobile phone operator to achieve both coverage and capacity for their subscribers. Large geographic areas are split into smaller cells to avoid line-of-sight signal loss and to support a large number of active phones in that area. All of

the cell sites are connected to telephone exchanges (or switches) , which in turn connect to the public telephone network. In cities, each cell site may have a range of up to approximately ½ mile, while in rural areas, the range could be as much as 5 miles. It is possible that in clear open areas, a user may receive signals from a cell site 25 miles away. Since almost all mobile phones use cellular technology, including GSM, CDMA, and AMPS (analog), the term "cell phone" is in some regions, notably the US, used interchangeably with "mobile phone". However, satellite phones are mobile phones that do not communicate directly with a ground-based cellular tower, but may do so indirectly by way of a satellite. There are a number of different digital cellular technologies, including: Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Evolution-Data Optimized (EV-DO), Enhanced Data Rates for GSM Evolution (EDGE), 3GSM, Digital Enhanced Cordless Telecommunications (DECT), Digital AMPS (IS-136/TDMA), and Integrated Digital Enhanced Network (iDEN).

[edit] Structure of the mobile phone cellular network
Main article: GSM

Structure of a 2G cellular network A simple view of the cellular mobile-radio network consists of the following:
• • • •

A network of Radio base stations forming the Base station subsystem. The core circuit switched network for handling voice calls and text A packet switched network for handling mobile data The Public switched telephone network to connect subscribers to the wider telephony network

This network is the foundation of the GSM system network. There are many functions that are performed by this network in order to make sure customers get the desired service including mobility management, registration, call set up, and handover.

Any phone connects to the network via an RBS in the corresponding cell which in turn connects to the MSC. The MSC allows the onward connection to the PSTN. The link from a phone to the RBS is called an uplink while the other way is termed downlink. Radio channels effectively use the transmission medium through the use of the following multiplexing schemes: frequency division multiplex (FDM), time division multiplex (TDM), code division multiplex (CDM), and space division multiplex (SDM). Corresponding to these multiplexing schemes are the following access techniques: frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), and space division multiple access (SDMA).[4]

[edit] Cellular handover in mobile phone networks
Main article: Handoff As the phone user moves from one cell area to another cell whilst a call is in progress, the mobile station will search for a new channel to attach to in order not to drop the call. Once a new channel is found, the network will command the mobile unit to switch to the new channel and at the same time switch the call onto the new channel. With CDMA, multiple CDMA handsets share a specific radio channel. The signals are separated by using a pseudonoise code (PN code) specific to each phone. As the user moves from one cell to another, the handset sets up radio links with multiple cell sites (or sectors of the same site) simultaneously. This is known as "soft handoff" because, unlike with traditional cellular technology, there is no one defined point where the phone switches to the new cell. In IS-95 inter-frequency handovers and older analog systems such as NMT it will typically be impossible to test the target channel directly while communicating. In this case other techniques have to be used such as pilot beacons in IS-95. This means that there is almost always a brief break in the communication while searching for the new channel followed by the risk of an unexpected return to the old channel. If there is no ongoing communication or the communication can be interrupted, it is possible for the mobile unit to spontaneously move from one cell to another and then notify the base station with the strongest signal.

[edit] Cellular frequency choice in mobile phone networks
Main article: GSM frequency bands The effect of frequency on cell coverage means that different frequencies serve better for different uses. Low frequencies, such as 450 MHz NMT, serve very well for countryside coverage. GSM 900 (900 MHz) is a suitable solution for light urban coverage. GSM 1800 (1.8 GHz) starts to be limited by structural walls. UMTS, at 2.1 GHz is quite similar in coverage to GSM 1800.

Higher frequencies are a disadvantage when it comes to coverage, but it is a decided advantage when it comes to capacity. Pico cells, covering e.g. one floor of a building, become possible, and the same frequency can be used for cells which are practically neighbours. Cell service area may also vary due to interference from transmitting systems, both within and around that cell. This is true especially in CDMA based systems. The receiver requires a certain signal-to-noise ratio. As the receiver moves away from the transmitter, the power transmitted is reduced. As the interference (noise) rises above the received power from the transmitter, and the power of the transmitter cannot be increased any more, the signal becomes corrupted and eventually unusable. In CDMA-based systems, the effect of interference from other mobile transmitters in the same cell on coverage area is very marked and has a special name, cell breathing. One can see examples of cell coverage by studying some of the coverage maps provided by real operators on their web sites. In certain cases they may mark the site of the transmitter, in others it can be calculated by working out the point of strongest coverage.

[edit] Coverage comparison of different frequencies
Following table shows the dependency of frequency on coverage area of one cell of a CDMA2000 network:[5] Frequency (MHz) Cell radius (km) Cell area (km2) Relative Cell Count 450 48.9 7521 1 950 26.9 2269 3.3 1800 14.0 618 12.2 2100 12.0 449 16.2

[edit] See also
• • • • •

Cellular traffic Base Station Subsystem GSM radio network Cell on wheels Cell site Cellular frequencies o GSM frequency bands
o

• •

• •

UMTS frequency bands

• •

Cellular repeater Code Division Multiple Access (CDMA) Mobile phone Multiple-input multiple-output communications (MIMO) Professional Mobile Radio (PMR) Radio resource



• •

Spectral efficiency comparison table OpenBTS Cellular router

management (RRM)


Signal strength

[edit] References
1. ^ J. E. Flood. Telecommunicattions Networks. Institution of Electrical Engineers, 2. ^ Cell towers at corners of hexagon cells 3. ^ U.S. Patent 4,144,411 -- Cellular Radiotelephone System for Different Cell Sizes -Richard H. Frenkiel (Bell Labs), filed Sep 22, 1976, issued March 13, 1979 London, UK, 1997. chapter 12.

4. ^ Bernhard H. Walke. Mobile Radio Networks: Networking, protocols and traffic
performance. John Wiley and Sons, LTD West Sussex England, 2002. Chapter 2. 5. ^ http://www.itu.int/ITU-D/imt-2000/Meetings/Slovenia/Presentations/Day %203/3.3.1_Chandler.pdf page 17


P. Key, D. Smith. Teletraffic Engineering in a competitive world. Elsevier Science B.V., Amsterdam Netherlands, 1999. Chapter 1 (Plenary) and 3 (mobile). [hide]

v•d•e

Mobile telephony standards
0G (radio MTS · MTA · MTB · MTC · IMTS · MTD · AMTS · OLT · telephones) Autoradiopuhelin AMPS familyAMPS · TACS · ETACS 1G OtherNMT · Hicap · Mobitex · DataTAC GSM/3GPP GSM · CSD family 2G 3GPP2 familyCdmaOne (IS-95) AMPS familyD-AMPS (IS-54 and IS-136) OtherCDPD · iDEN · PDC · PHS GSM/3GPP HSCSD · GPRS · EDGE/EGPRS family 2G transitional (2.5G, 2.75G) 3GPP2 familyCDMA2000 1xRTT (IS-2000) OtherWiDEN

3G (IMT-2000)

UMTS (UTRAN) · WCDMA-FDD · 3GPP familyWCDMA-TDD · UTRA-TDD LCR (TDSCDMA) 3GPP2 familyCDMA2000 1xEV-DO (IS-856) 3GPP familyHSDPA · HSUPA · HSPA+ · LTE (E-UTRA)

3G transitional (3.5G, 3.9G)

3GPP2 familyEV-DO Rev. A · EV-DO Rev. B Mobile WiMAX (IEEE 802.16e-2005) · Other Flash-OFDM · IEEE 802.20 3GPP familyLTE Advanced

4G (IMT-Advanced) WiMAX familyIEEE 802.16m History · Cellular network theory · List of standards · Comparison of standards · Channel access methods · Spectral efficiency comparison table · Cellular frequencies · GSM frequency bands · UMTS frequency bands · Mobile broadband

Related articles

A mobile phone or mobile (also called cellphone and handphone[1]) is an electronic device used for mobile telecommunications (mobile telephone, 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 telephone service within 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, automates 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
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• •

• • • • •

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 o 2.1 Multiple phones o 2.2 Sharing 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 share o 3.6 Media 4 Privacy 5 Restriction on usage o 5.1 Use while driving o 5.2 Schools 6 Comparison to similar systems 7 See also 8 References 9 Further reading 10 External links

History

Mobile car phone, 1964

Portable cellphone, 1970s

Man using cell phone, 1973 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 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 was a push-button telephone, and 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, after a long race against Bell Labs for 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;[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 his rival, Dr. Joel S. Engel of Bell Labs.[11]

Analog cellular telephony (1G)
Main article: 1G

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. 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 earliest 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

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 introduced by NTT DoCoMo in Japan in 1999.

Wideband mobile communication (3G)

An early 3G handset 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 (multiuser 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 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. 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.

Broadband Fourth generation (4G)
Main article: 4G 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[17] 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 allIP 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. Sprint in the US has claimed its WiMax network to be "4G network" which most cellular telecoms standardization experts dispute repeatedly around the world. Sprint's 4G is seen as a marketing gimmick as WiMax itself is part of the 3G air interface. The officially accepted, ITU ratified standards-based 4G networks are not expected to be commercially launcnhed until 2011.

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. 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.[18] Child predators have taken advantage of cell phones to secretly communicate with children without the knowledge of their parents or teachers.[19] 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.[20] 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".

Multiple phones
Individuals may have multiple cell phones for separate purposes, such as for business and personal use. Multiple phones (or multiple SIM cards) may 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.[21]

Sharing
Cell phone sharing is a phenomenon which exists around the world. It is 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; stealthy sharing occurs when an individual uses another's cell phone without their

knowledge. Phone sharing does not only take place because of its economic benefits, but also often due to familial customs and traditional gender roles.[22] 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.[23]

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.

Features
Main articles: Mobile phone features and Smartphone

Mobile phones often have features extending 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.[24] See also: Videophone, for UMTS-type mobile phones employing simultaneous video and audio

Software and applications

A phone with touchscreen feature. Mobile phone subscribers per 100 inhabitants 1997–2007 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![25] 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 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, wireless charging became a reality, and the first wireless charger was released for consumer use.
[26]

Standardization of Micro-USB connector for charging Starting from 2010, many mobile phone manufacturers have agreed to use the MicroUSB connector for charging their phones.[27] The mobile phone manufacturers who have agreed to this standard include:
• • • • • • •

Apple LG Motorola Nokia Research In Motion Samsung Sony Ericsson

On 17 February 2009, the GSM Association announced[28] 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. In addition, on 22 October 2009 the International Telecommunication Union (ITU) announced that it had embraced micro-USB as the Universal Charger Solution 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."[29]

Charger efficiency

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 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 W (30 mW) no load power. 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. Battery 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 and Coca Cola.[30]

SIM card
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Main article: Subscriber Identity Module

Typical mobile phone SIM card 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[31] 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 the 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. Depending on the carrier, such a phone may be available for as little as $200. The difference is paid by the customer in the form of a monthly bill. If the carrier did not use an 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-YouGo references, rumored T-Mobile, Verizon provide one, AT&T does not as of 12/2008]

Market share
The world's largest individual mobile operator is China Mobile with over 500 million mobile phone subscribers. 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 2009 (source wireless intelligence). LG Sony Motorola Others References Electronics Ericsson 11.0% 4.9% 4.7% 20.6%
[32]

Source

Date

Nokia Samsung

IDC

Q3/2009 37.8% 21.0%

Gartne Q4/2009 36.4% 19.5% r

10.1%

4.8%

4.5%

24.7%

[33]

In mobile phone handsets, in Q3/2009, Nokia was the world's largest manufacturer of mobile phones, with a global device market share of 37.8%, followed by Samsung (21.0%), LG Electronics (11.0%), Sony Ericsson (4.9%) and Motorola (4.7%). These manufacturers accounted for over 80% of all mobile phones sold at that time.[34] Other manufacturers include Apple Inc., Audiovox (now UTStarcom), Benefon, BenQSiemens, 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 and Vidalco. There are also specialist communication systems related to (but distinct from) mobile phones.

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.[35] 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?]

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.[36][37]

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.[38][39]

Restriction on usage
Main article: Mobile phones on aircraft This section does not cite any references or sources.
Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2010)

There exists a growing body within the scientific community which believes mobile phone use represents a long-term health risk, particularly to young children. Certain countries, including France, restrict the use and sale of cell phones to minors for this reason. The telecommunications insdustry rejects such claims, claming there is no proof of long-term adverse health effects. Groups of scientists, however, such as the U.S. based group "Bioinitiative (see www.bioinitiative.org) argue that because mobile phone use is recently-introduced technology, long-term 'proof' has been impossible - and use should be restricted, or monitored closely, while the technology is still new. The very first generation of cell-phone users, for example, are only now entering middle-age. Studies in Europe, for example, are only now emerging which link long-term cell phone use to brain tumours. Other studies link cell-phone use to child-diabetes, concentration difficulty, and sleep disorders.

Use while driving
Main article: Mobile phones and driving safety 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 hand-held and hands-free use of a mobile phone whilst many other countries –including the UK, France, and many US states– ban handheld 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, 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. A recently published study has reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety.[40]

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 hands free 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), 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, or 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 or receives calls over internet, LAN or WAN networks using VoIP as opposed to traditional CDMA and GSM networks. In business, the majority of these IP Phones tend to be connected via wired Ethernet, however wireless varieties do exist. 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.
[41]

See also Best Answer - Chosen by Voters
Ok ok - here are the definitions: A mobile phone is the type of cellular phone that is installed in a motor vehicle. There are three main types of cellular phones mobile, transportable, and portable. A mobile unit is attached to the vehicle, draws its power from the vehicles battery and has an external antenna. A satellite phone or satphone is a mobile phone that communicates directly with orbiting satellites. Depending on the architecture of a particular system, coverage may include the entire planet, or only specific
Cellular: A type of wireless communication that is most familiar to mobile phones users. It's called 'cellular' because the system uses many base stations to divide a service area into multiple 'cells'. Cellular calls are transferred from base station to base station as a user travels from cell to cell. - definition from the Wireless Advisor Glossary. The basic concept of cellular phones began in 1947, when researchers looked at crude mobile (car) phones and realized that by using small cells (range of service area) with frequency reuse they could increase the traffic capacity of mobile phones substantially. However at that time, the technology to do so was nonexistent. Anything to do with broadcasting and sending a radio or television message out over the airwaves comes under Federal Communications Commission (FCC) regulation. A cell phone is a type of two-way radio. In 1947, AT&T proposed that the FCC allocate a large number of radio-spectrum frequencies so that widespread mobile telephone service would become feasible and AT&T would have a incentive to research the new technology. We can partially blame the FCC for the gap between the initial concept of cellular service and its availability to the public. The FCC decided to limit the amount of frequencies available in 1947, the limits made only twenty-three phone conversations possible simultaneously in the same service area - not a market

incentive for research. Sponsored Links

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The FCC reconsidered its position in 1968, stating "if the technology to build a better mobile service works, we will increase the frequencies allocation, freeing the airwaves for more mobile phones." AT&T and Bell Labs proposed a cellular system to the FCC of many small, low-powered, broadcast towers, each covering a 'cell' a few miles in radius and collectively covering a larger area. Each tower would use only a few of the total frequencies allocated to the system. As the phones traveled across the area, calls would be passed from tower to tower. Individual Inventors & Mobile Phone Patents Dr. Martin Cooper for Motorola. US03906166 09/16/1975 Radio telephone system Inventors: Martin Cooper, Richard W. Dronsuth, ; Albert J. Mikulski, Charles N. Lynk Jr., James J. Mikulski, John F. Mitchell, Roy A. Richardson, John H. Sangster Dr Martin Cooper, a former general manager for the systems division at Motorola, is considered the inventor of the first modern portable handset. Cooper made the first call on a portable cell phone in April 1973. He made the call to his rival, Joel Engel, Bell Labs head of research. Bell Laboratories introduced the idea of cellular communications in 1947 with the police car technology. However, Motorola was the first to incorporate the technology into portable device that was designed for outside of a automobile use. Cooper and his co-inventors are listed above. By 1977, AT&T and Bell Labs had constructed a prototype cellular system. A year later, public trials of the new system were started in Chicago with over 2000 trial customers. In 1979, in a separate venture, the first commercial cellular telephone system began operation in Tokyo. In 1981, Motorola and American Radio telephone started a second U.S. cellular radio-telephone system test in the Washington/Baltimore area. By 1982, the slow-moving FCC finally authorized commercial cellular service for the USA. A year later, the first American commercial analog cellular service or AMPS (Advanced Mobile Phone Service) was made available in Chicago by Ameritech. Despite the incredible demand, it took cellular phone service 37 years to become

commercially available in the United States. Consumer demand quickly outstripped the 1982 system standards. By 1987, cellular telephone subscribers exceeded one million and the airways were crowded. Three ways of improving services existed: • one - increase frequencies allocation • two - split existing cells • three - improve the technology

The FCC did not want to handout any more bandwidth, and building/splitting cells would have been expensive and would have added bulk to the network. To stimulate the growth of new technology, the FCC declared in 1987 that cellular licensees could employ alternative cellular technologies in the 800 MHz band. The cellular industry began to research new transmission technology as an alternative. Editor's Note: African American Inventor Henry Sampson did not invent the cell phone. Sampson is a brilliant and accomplished inventor who invented a GammaElectrical Cell and not a phone cell. Sampson's patent (US 3,591,860) can be viewed online or in person at the United States Patent and Trademark Office. Continue with>>> Selling The Cell Phone - Wireless Cellular Technology
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