The history of mobile phones charts the development of devices which connect wirelessly to the public switched telephone network. The transmission of speech by radio has a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links. Hand-held radio transceivers have been available since the 1940s. Mobile telephones for automobiles became available from some telephone companies in the 1940s. Early devices were bulky and consumed high power and the network supported only a few simultaneous conversations. Modern cellular networks allow automatic and pervasive use of mobile phones for voice and data communications.
In the United States, engineers from Bell Labs began work on a system to allow mobile users to place and receive telephone calls from automobiles, leading to inaguation of mobile service on June 17, 1946 in St. Louis, Missouri. Shortly after, AT&T offered Mobile Telephone Service. A wide range of mostly incompatible mobile telephone services offered limited coverage area and only a few available channels in urban areas. The introduction of cellular technology, which allowed re-use of frequencies many times in small adjacent areas covered by relatively low powered transmitters, made widespread adoption of mobile telephones economically feasible.
The advances in mobile telephony can be traced in successive generations from the early "0G" services like MTS and it's successor Improved Mobile Telephone Service, to first generation (1G) analog cellular network, second generation (2G) digital cellular networks, third generation (3G) broadband data services to the current state of the art, fourth generation (4G) native-IP networks.
Pioneers of mobile telephony
By 1930, telephone customers in the United States could be connected by radio to a passenger on an ocean liner in the Atlantic Ocean. The service was expensive, costing $7 per minute, equivalent to about $92.50/minute in 2011 dollars.[1]
The first mobile telephone call was placed in St. Louis, Missouri on June 17, 1946 from a telephone set installed in an automobile. This first mobile telephone call was the end result of more than 10 years of work by Bell Labs scientists Alton Dickieson, D. Mitchell and H.I. Romnes.[2]
Early services - 0G
MTS
In 1947 AT&T commercialized Mobile Telephone Service. From its start in St. Louis in 1946, AT&T then introduced Mobile Telephone Service to 100 towns and highway corridors by 1948. Mobile Telephone Service was a rarity with only 5,000 customers placing about 30,000 calls each week. Calls were set up manually by an operator and the user had to depress a button on the handset to talk and release the button to listen. The call subscriber equipment weighed about 80 pounds.[2]
Subscriber growth and revenue generation were hampered by the constraints of the technology. Because only three radio channels were available, only three customers in any given city could make mobile telephone calls at one time.[3] Mobile Telephone Service was expensive, costing US$15 per month, plus $.30 to $.40 per local call, equivalent to about $176 per month and $3.50 to $4.75 per call in 2012 dollars.[2]
IMTS
AT&T introduced the first major improvement to mobile telephony in 1965, giving the improved service the obvious name of Improved Mobile Telephone Service. IMTS used additional radio channels, allowing more simultaneous calls in a given geographic area, introduced customer dialing, eliminating manual call set by an operator, and reduced the size and weight of the subscriber equipment.[2]
Despite the capacity improvement offered by IMTS, demand outstripped capacity. In agreement with state regulatory agencies, AT&T limited the service to just 40,000 customers system wide. In New York, NY, for example, 2,000 customers shared just 12 radio channels and typically had to wait 30 minutes to place a call.[2]
Radio Common Carrier
Radio Common Carrier or RCC was a service introduced in the 1960's by independent telephone companies to compete against AT&T's IMTS. RCC systems used paired UHF 454/459 MHz and VHF 152/158 MHz frequencies near those used by IMTS. RCC based services were provided until the 1980s when cellular AMPS systems made RCC equipment obsolete.
Some RCC systems were designed to allow customers of adjacent carriers to use their facilities, but equipment used by RCCs did not allow the equivalent of modern "roaming" because technical standards were not uniform. For example, the phone of an Omaha, Nebraska–based RCC service would not be likely to work in Phoenix, Arizona. Roaming was not encouraged, in part, because there was no centralized industry billing database for RCCs. Signaling formats were not standardized. For example, some systems used two-tone sequential paging to alert a mobile of an incoming call. Other systems used DTMF. Some used Secode 2805, which transmitted an interrupted 2805 Hz tone (similar to IMTS signaling) to alert mobiles of an offered call. Some radio equipment used with RCC systems was half-duplex, push-to-talk LOMO equipment such as Motorola hand-helds or RCA 700-series conventional two-way radios. Other vehicular equipment had telephone handsets, rotary or pushbutton dials, and operated full duplex like a conventional wired telephone. A few users had full-duplex briefcase telephones (radically advanced for their day).
At the end of RCC's existence, industry associations were working on a technical standard that would have allowed roaming, and some mobile users had multiple decoders to enable operation with more than one of the common signaling formats (600/1500, 2805, and Reach). Manual operation was often a fallback for RCC roamers.
Other services
In 1969 Penn Central Railroad equipped commuter trains along the 225-mile New York-Washington route with special pay phones that allowed passengers to place telephone calls while the train was moving. The system re-used six frequencies in the 450 MHZ band in nine sites.[3]
European mobile radio networks
In Europe, several mutually incompatible mobile radio services were developed. West Germany had a network called A-Netz launched in 1952 as the country's first public commercial mobile phone network. In 1972 this was displaced by B-Netz which connected calls automatically. In 1966 Norway had a system called Televerket which was manually controlled.
Cellular concepts
In December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in vehicles.[4] 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 on three different frequencies.[5] At this stage, the technology to implement these ideas did not exist, nor had the frequencies been allocated. Several years would pass before Richard H. Frenkiel and Joel S. Engel of Bell Labs developed the electronics to achieve this in the 1960s.
In all these early examples, a mobile phone had to stay within the coverage area serviced by one base station throughout the phone call, i.e. there was no continuity of service as the phones moved through several cell areas. The concepts of frequency reuse and handoff, as well as a number of other concepts that formed the basis of modern cell phone technology, were described in the 1970s. In 1970 Amos E. Joel, Jr., a Bell Labs engineer,[6] invented an automatic "call handoff" system to allow mobile phones to move through several cell areas during a single conversation without interruption.
A cellular telephone switching plan was described by Fluhr and Nussbaum in 1973,[7] and a cellular telephone data signaling system was described in 1977 by Hachenburg et al.[8]
Emergence of automated services
The first fully automated mobile phone system for vehicles was launched in Sweden in 1960. Named MTA (Mobile Telephone system A), it allowed calls to be made and received in the car using a rotary dial. The car phone could also be paged. Calls from the car were direct dial, whereas incoming calls required an operator to determine which base station the phone was currently at. It was developed by Sture Laurén and other engineers at Televerket network operator. Ericsson provided the switchboard while Svenska Radioaktiebolaget (SRA) and Marconi provided the telephones and base station equipment. MTA phones consisted of vacuum tubes and relays, and weighed 40 kg. In 1962, an upgraded version called Mobile System B (MTB) was introduced. This was a push-button telephone, and used transistors and DTMF signaling to improve its operational reliability. In 1971 the MTD version was launched, opening for several different brands of equipment and gaining commercial success.[9][10] The network remained open until 1983 and still had 600 customers when it closed.
In 1958 development began on a similar system for motorists in the USSR.[11] The "Altay" national civil mobile phone service was based on Soviet MRT-1327 standard. The main developers of the Altay system were the Voronezh Science Research Institute of Communications (VNIIS) and the State Specialized Project Institute (GSPI). In 1963 the service started in Moscow, and by 1970 was deployed in 30 cities across the USSR. Versions of the Altay system are still in use today as a trunking system in some parts of Russia.
In 1959 a private telephone company located in Brewster, Kansas, USA, the S&T Telephone Company, (still in business today) with the use of Motorola Radio Telephone equipment and a private tower facility, offered to the public mobile telephone services in that local area of NW Kansas. This system was a direct dial up service through their local switchboard, and was installed in many private vehicles including grain combines, trucks, and automobiles. For some as yet unknown reason, the system, after being placed online and operated for a very brief time period, was shut down. The management of the company was immediately changed, and the fully operable system and related equipment was immediately dismantled in early 1960, not to be seen again.[citation needed]
In 1966, Bulgaria presented the pocket mobile automatic phone RAT-0,5 combined with a base station RATZ-10 (RATC-10) on Interorgtechnika-66 international exhibition. One base station, connected to one telephone wire line, could serve up to six customers.[citation needed]
One of the first successful public commercial mobile phone networks was the ARP network in Finland, launched in 1971. Posthumously, ARP is sometimes viewed as a zero generation (0G) cellular network, being slightly above previous proprietary and limited coverage networks.[citation needed]
Handheld mobile phone
Prior to 1973, mobile telephony was limited to phones installed in cars and other vehicles.[6] Motorola and Bell Labs raced to be the first to produce a handheld mobile phone. That race ended on April 3, 1973 when Martin Cooper, a Motorola researcher and executive, made the first mobile telephone call from handheld subscriber equipment, placing a call to Dr. Joel S. Engel of Bell Labs.[12][13] The prototype handheld phone used by Dr. Cooper weighed 2.5 pounds and measured 9 long, 5 inches deep and 1.75 inches wide. The prototype offered a talk time of just 30 minutes and took 10 hours to re-charge.[14]
John F. Mitchell, Motorola's chief of portable communication products and Cooper's boss in 1973, played a key role in advancing the development of handheld mobile telephone equipment. Mitchell successfully pushed Motorola to develop wireless communication products that would be small enough to use anywhere and participated in the design of the cellular phone.[15][16]
Analog cellular networks - 1G
The technological development that distinguished the First Generation of mobile phones from the previous generation was the use of multiple cell sites, and the ability to transfer calls from one site to the next as the user travelled between cells during a conversation. The first cellular network in the world was built in 1977 in Chicago and turned on in 1978. By the end of 1978 it had over 1300 customers. In 1979 a cellular network (the 1G generation) was launched in Japan by NTT. 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 next 1G network to launch was the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden in 1981.[17] NMT was the first mobile phone network to feature international roaming. The Swedish electrical engineer Östen Mäkitalo started work on this vision in 1966, and is considered to be the father of the NMT system, and by some the father of the cellular phone itself, since he and two colleagues hold a patent from 1971 on a cellular system with handover and roaming.[18][19][20] The NMT installations were based on the Ericsson AXE digital exchange nodes.
Several other countries also launched 1G networks in the early 1980s including the UK, Mexico and Canada. A two year trial started in 1981 in Baltimore and Washington DC with 150 users and 300 Motorola DynaTAC pre-production phones. This took place on a seven tower cellular network that covered the area. The DC area trial turned into a commercial services in about 1983 with fixed cellular car phones also built by Motorola. They later added the 8000X to their Cellular offerings. A similar trial and commercial launch also took place in Chicago by Ameritech in 1983 using the famous first hand-held mobile phone Motorola DynaTAC.
In 1984, Bell Labs developed modern commercial cellular technology (based, to a large extent, on the Gladden, Parelman Patent), which employed multiple, centrally controlled base stations (cell sites), each providing service to a small cell area. The sites were set up so that cells partially overlapped and different base stations operated using the same frequencies with little or no interference.
Vodafone made the UK's first mobile call at a few minutes past midnight on 1 January 1985.[21]
The technology in these early networks was pushed to the limit to accommodate increasing usage. The base stations and the mobile phones utilized variable transmission power, which allowed range and cell size to vary. As the system expanded and neared capacity, the ability to reduce transmission power allowed new cells to be added, resulting in more, smaller cells and thus more capacity. The evidence of this growth can still be seen in the many older, tall cell site towers with no antennae on the upper parts of their towers. These sites originally created large cells, and so had their antennae mounted atop high towers; the towers were designed so that as the system expanded—and cell sizes shrank—the antennae could be lowered on their original masts to reduce range.
Advanced Mobile Phone System
In December 1971, AT&T submitted a proposal for cellular service to the United States Federal Communications Commission (FCC). In 1977 AT&T built the first cellular network in Chicago and had 1300 customers on the system by the end of 1978.[22] After more than a decade of hearings, the FCC approved a version of AT&T's 1971 proposal in 1982, allocating frequencies in the 824–894 MHz band for a new cellular network technology called Advanced Mobile Phone System (AMPS).[23] Analog AMPS was eventually superseded by Digital AMPS (D-AMPS) in 1990.
Digital cellular networks - 2G
In the 1990s, the 'second generation' (2G) mobile phone systems emerged. Two systems competed for supremacy in the global market: the european developed GSM standard and the U.S. developed CDMA standard. These differed from the previous generation by using digital instead of analog transmission, and also fast out-of-band phone-to-network signaling. The rise in mobile phone usage as a result of 2G was explosive and this era also saw the advent of prepaid mobile phones
In 1991 the first GSM network (Radiolinja) launched in Finland. In general the frequencies used by 2G systems in Europe were higher than those in America, though with some overlap. For example, the 900 MHz frequency range was used for both 1G and 2G systems in Europe, so the 1G systems were rapidly closed down to make space for the 2G systems. In America the IS-54 standard was deployed in the same band as AMPS and displaced some of the existing analog channels.
Coinciding with the introduction of 2G systems was a trend away from the larger "brick" phones toward tiny 100–200g hand-held devices. This change was possible not only through technological improvements such as more advanced batteries and more energy-efficient electronics, but also because of the higher density of cell sites to accommodate increasing usage. The latter meant that the average distance transmission from phone to the base station shortened, leading to increased battery life whilst on the move.
The second generation introduced a new variant of communication called SMS or text messaging. It was initially available only on GSM networks but spread eventually on all digital networks. The first machine-generated SMS message was sent in the UK on 3 December 1992 followed in 1993 by the first person-to-person SMS sent in Finland. The advent of prepaid services in the late 1990s soon made SMS the communication method of choice amongst the young, a trend which spread across all ages.
2G also introduced the ability to access media content on mobile phones. In 1998 the first downloadable content sold to mobile phones was the ring tone, launched by Finland's Radiolinja (now Elisa). Advertising on the mobile phone first appeared in Finland when a free daily SMS news headline service was launched in 2000, sponsored by advertising.
Mobile payments were trialed in 1998 in Finland and Sweden where a mobile phone was used to pay for a Coca Cola vending machine and car parking. Commercial launches followed in 1999 in Norway. The first commercial payment system to mimic banks and credit cards was launched in the Philippines in 1999 simultaneously by mobile operators Globe and Smart.
The first full internet service on mobile phones was introduced by NTT DoCoMo in Japan in 1999.
Mobile broadband data - 3G
As the use of 2G phones became more widespread and people began to utilize mobile phones in their daily lives, it became clear that demand for data services (such as access to the internet) was growing. Furthermore, experience from fixed broadband services showed there would also be an ever increasing demand for greater data speeds. The 2G technology was nowhere near up to the job, so the industry began to work on the next generation of technology known as 3G. The main technological difference that distinguishes 3G technology from 2G technology is the use of packet switching rather than circuit switching for data transmission.[24] In addition, the standardization process focused on requirements more than technology (2 Mbit/s maximum data rate indoors, 384 kbit/s outdoors, for example).
Inevitably this led to many competing standards with different contenders pushing their own technologies, and the vision of a single unified worldwide standard looked far from reality. The standard 2G CDMA networks became 3G compliant with the adoption of Revision A to EV-DO, which made several additions to the protocol whilst retaining backwards compatibility:
- the introduction of several new forward link data rates that increase the maximum burst rate from 2.45 Mbit/s to 3.1 Mbit/s.
- protocols that would decrease connection establishment time.
- the ability for more than one mobile to share the same time slot.
- the introduction of QoS flags.
All these were put in place to allow for low latency, low bit rate communications such as VoIP.[25]
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 1 October 2001, using the WCDMA technology. In 2002 the first 3G networks on the rival CDMA2000 1xEV-DO technology were launched by SK Telecom and KTF in South Korea, and Monet in the USA. Monet has since gone bankrupt. By the end of 2002, the second WCDMA network was launched in Japan by Vodafone KK (now Softbank). European launches of 3G were in Italy and the UK by the Three/Hutchison group, on WCDMA. 2003 saw a further 8 commercial launches of 3G, six more on WCDMA and two more on the EV-DO standard.
During the development of 3G systems, 2.5G systems such as CDMA2000 1x and GPRS were developed as extensions to existing 2G networks. These provide some of the features of 3G without fulfilling the promised high data rates or full range of multimedia services. CDMA2000-1X delivers theoretical maximum data speeds of up to 307 kbit/s. Just beyond these is the EDGE system which in theory covers the requirements for 3G system, but is so narrowly above these that any practical system would be sure to fall short.
The high connection speeds of 3G technology enabled a transformation in the industry: for the first time, media streaming of radio (and even television) content to 3G handsets became possible [1], with companies such as RealNetworks [2] and Disney [3] among the early pioneers in this type of offering.
In the mid 2000s (decade), an evolution of 3G technology begun to be implemented, namely High-Speed Downlink Packet Access (HSDPA). It is an enhanced 3G (third generation) mobile telephony communications protocol in the High-Speed Packet Access (HSPA) family, also coined 3.5G, 3G+ or turbo 3G, which allows networks based on Universal Mobile Telecommunications System (UMTS) to have higher data transfer speeds and capacity. Current HSDPA deployments support down-link speeds of 1.8, 3.6, 7.2 and 14.0 Mbit/s. Further speed increases are available with HSPA+, which provides speeds of up to 42 Mbit/s downlink and 84 Mbit/s with Release 9 of the 3GPP standards.
By the end of 2007, there were 295 million subscribers on 3G networks worldwide, which reflected 9% of the total worldwide subscriber base. About two thirds of these were on the WCDMA standard and one third on the EV-DO standard. The 3G telecoms services generated over 120 Billion dollars of revenues during 2007 and at many markets the majority of new phones activated were 3G phones. In Japan and South Korea the market no longer supplies phones of the second generation.
Although mobile phones had long had the ability to access data networks such as the Internet, it was not until the widespread availability of good quality 3G coverage in the mid-2000s (decade) that specialized devices appeared to access the mobile internet. The first such devices, known as "dongles", plugged directly into a computer through the USB port. Another new class of device appeared subsequently, the so-called "compact wireless router" such as the Novatel MiFi, which makes 3G internet connectivity available to multiple computers simultaneously over Wi-Fi, rather than just to a single computer via a USB plug-in.
Such devices became especially popular for use with laptop computers due to the added portability they bestow. Consequently, some computer manufacturers started to embed the mobile data function directly into the laptop so a dongle or MiFi wasn't needed. Instead, the SIM card could be inserted directly into the device itself to access the mobile data services. Such 3G-capable laptops became commonly known as "netbooks". Other types of data-aware devices followed in the netbook's footsteps. By the beginning of 2010, E-readers, such as the Amazon Kindle and the Nook from Barnes & Noble, had already become available with embedded wireless internet, and Apple Computer had announced plans for embedded wireless internet on its iPad tablet devices beginning that Fall.
Native IP networks - 4G
By 2009, it had become clear that, at some point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications like streaming media.[26] Consequently, the industry began looking to data-optimized 4th-generation technologies, with the promise of speed improvements up to 10-fold over existing 3G technologies. The first two commercially available technologies billed as 4G were the WiMAX standard (offered in the U.S. by Sprint) and the LTE standard, first offered in Scandinavia by TeliaSonera.
One of the main ways in which 4G differed technologically from 3G was in its elimination of circuit switching, instead employing an all-IP network. Thus, 4G ushered in a treatment of voice calls just like any other type of streaming audio media, utilizing packet switching over internet, LAN or WAN networks via VoIP.[27]
Satellite mobile
Earth-orbiting satellites can cover remote areas out of reach of wired networks or where construction of a cellular network is uneconomic. The Inmarsat satellite telephone system, originally developed in 1979 for safety of life at sea, is now also useful for areas out of reach of landline, conventional cellular, or marine VHF radio stations. In 1998 the Iridium satellite system was set up, and although the initial operating company went bankrupt due to high initial expenses, the service is available today.
See also
- Autopatch
- Joel S. Engel
- Richard H. Frenkiel
- B-Netz
- C-Netz
- MTD (mobile network)
- OLT (mobile network)
- History of the prepaid mobile phone
- Cellular network
- Personal Communications Service PCS
References
- ^ Ship to Shore Telephone Service Opened, Popular Science, March 1930 page 34
- ^ a b c d e "1946: First Mobile Telephone Call". corp.att.com. AT&T Intellectual Property. 2011. http://www.corp.att.com/attlabs/reputation/timeline/46mobile.html. Retrieved 2012-04-24.
- ^ a b Gordon A. Gow, Richard K. Smith Mobile and wireless communications: an introduction, McGraw-Hill International, 2006 ISBN 0335217613 page 23
- ^ 1947 memo by Douglas H. Ring proposing hexagonal cells
- ^ article by Tom Farley "Cellular Telephone Basics"
- ^ a b 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)
- ^ "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)
- ^ Mingtao Shi, Technology base of mobile cellular operators in Germany and China, page 55
- ^ Facts about the Mobile. A Journey through Time
- ^ The first Russian mobile phone
- ^ Shiels, Maggie (21 April 2003). "BBC interview with Martin Cooper". BBC News. http://news.bbc.co.uk/1/hi/uk/2963619.stm.
- ^ Cooper, et al., "Radio Telephone System", US Patent number 3,906,166; Filing date: 17 October 1973; Issue date: September 1975; Assignee Motorola
- ^ "Martin Cooper-The Inventer of the Cell Phone". http://www.cellular.co.za/cellphone_inventor.htm. Retrieved 23 March 2012.
- ^ "Motorola Executive Helped spur Cellphone Revolution, Oversaw Ill-fated Iridium Project". The Wall Street Journal, 20–21 June 2009, p. A10.
- ^ "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 29 July 2009.
- ^ "Swedish National Museum of Science and Technology". Tekniskamuseet.se. http://www.tekniskamuseet.se/mobilen/engelska/1980_90.shtml. Retrieved 29 July 2009.
- ^ Swedish Patent N:o 357481 Mobile radio system, 1971.
- ^ Mobile and technology: The Basics of Mobile Phones
- ^ The cell phone 50 years – facts and numbers
- ^ Vodafone
- ^ http://techchannel.att.com/play-video.cfm/2011/6/13/AT&T-Archives-AMPS:-coming-of-age
- ^ AT&T article
- ^ Privateline.com: 3G and Cellular radio Information
- ^ 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.
- ^ Fahd Ahmad Saeed. "Capacity Limit Problem in 3G Networks". Purdue School of Engineering. http://www.ece.iupui.edu/~dskim/Classes/ECE695MWN/2006-saeed-Capacity_Limit_Problem_in_3G_Networks.ppt. Retrieved 23 April 2010.
- ^ "VoIP Support in Nokia Devices". http://www.forum.nokia.com/Technology_Topics/Mobile_Technologies/VoIP/Nokia_VoIP_Framework/VoIP_support_in_Nokia_devices.xhtml. Retrieved 16 August 2009.[dead link]
Further reading
- Farley, Tom (2007). "The Cell-Phone Revolution". American heritage of invention & technology (New York: American Heritage) 22 (3): 8–19. ISSN 8756-7296. OCLC 108126426. BL Shelfmark 0817.734000.
External links
- The history of cellular telephones in the US
- Cell Phone Basics
- Mobile Phone Museum from Europe
- Mobile Phone Technology Old Patents
- Mobile Phone Museum from Ireland
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