History of Mobile Phones
History of mobile phones:
Before the devices that are now referred to as a mobile phone existed, there were some precursors. The development of mobile telephony began in 1918 with tests of wireless telephony on military trains between Berlin and Zossen. In 1924, public trials started with telephone connection on trains between Berlin and Hamburg. In 1925, the company Zugtelephonie A. G. was founded to supply train telephony equipment[1] and in 1926 telephone service in trains of the Deutsche Reichsbahn and the German mail service on the route between Hamburg and Berlin was approved and offered to 1st class travelers.
In 1926 the artist Karl Arnold created a visionary cartoon about the use of mobile phones in the street, in the picture „wireless telephony", published in the German satirical magazine Simplicissimus.
The portrayal of a utopia of mobile phone in literature dates back to the year 1931. It is found in Erich Kästner's children's book The 35th of May, or Conrad's Ride to the South Seas:
“ A gentleman who rode along the sidewalk in front of them, suddenly stepped off the conveyor belt, pulled a phone from his coat pocket, spoke a number into it and shouted: "Gertrude, listen, I'll be an hour late for lunch because I want to go to the laboratory. Goodbye, sweetheart!" Then he put his pocket phone away again, stepped back on the conveyor belt, started reading a book... ”
—Erich Kästner
The Second World War made 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 the inauguration of mobile service on 17 June 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.
In the USSR, Leonid Kupriyanovich, engineer from Moscow, in 1957-1961 developed and presented a number of experimental models of handheld mobile phone. The weight of a latest model, presented in 1961, was only 70 g and it freely took place on a palm. However in the USSR the decision at first to develop the system of automobile "Altai" phone was made ("Nauka i zhizn" magazine, 8, 1957 and 10, 1958, "Technika-molodezhi" magazine, 2, 1959, "Za rulem" magazine, 12, 1957, "Yuny technik" magazine, 7, 1957, 2, 1958 and 9, 1996, "Orlovskaya pravda" newspaper, 12, 1961).
In 1965, Bulgarian company "Radioelektronika" presented on Inforga-65 interrnational exhibition in Moscow the mobile automatic phone combined with a base station. Solutions of this phone based on the system, developed by Leonid Kupriyanovich. One base station, connected to one telephone wire line, could serve up to 15 customer. ("Nauka i zhizn" magazine, 8, 1965).
The advances in mobile telephony can be traced in successive generations from the early "0G" services like MTS and its 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.
Motorola was the first company to produce a handheld mobile phone. On 3 April 1973 Martin Cooper, a Motorola engineer and executive, made the first mobile telephone call from handheld subscriber equipment in front of reporters, placing a call to Dr. Joel S. Engel of Bell Labs. The prototype handheld phone used by Dr. Martin Cooper weighed 1.1 kg and measured 23 cm long, 13 cm deep and 4.45 cm wide. The prototype offered a talk time of just 30 minutes and took 10 hours to re-charge. Cooper has stated his vision for the handheld device was inspired by Captain James T. Kirk using his Communicator on the television show Star Trek.
John F. Mitchell, Motorola's chief of portable communication products and Martin 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.
Contents :
1.1 MTS
1.2 IMTS
1.3 Radio Common Carrier
1.4 Other services
1.5 European mobile radio networks
1.6 Cellular concepts
2 Emergence of automated services
3 Handheld mobile phone
4 Analog cellular networks – 1G
5 Digital cellular networks – 2G
6 Mobile broadband data – 3G
7 Native IP networks – 4G
8 Satellite mobile
9 See also
10 References
11 Further reading
12 External links
Early services – 0G
MTS:
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. Mobile Telephone Service was expensive, costing 15 USD per month, plus 0.30 to 0.40 USD per local call, equivalent to about 176 USD per month and 3.50 to 4.75 per call in 2012 USD.
IMTS:
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.
Radio Common Carrier:
A mobile radio telephone:
Radio Common Carrier or RCC was a service introduced in the 1960s 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:
European mobile radio networks:
This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2012)
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 OLT which was manually controlled.
Cellular concepts and Cellular network:
A multi-directional, cellular network antenna array
In December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in vehicles. At this stage, the technology to implement these ideas did not exist, nor had the frequencies been allocated. Two decades would pass before Richard H. Frenkiel, Joel S. Engel and Philip T. Porter of Bell Labs expanded the early proposals into a much more detailed system plan. It was Porter who first proposed that the cell towers use the now-familiar directional antennas to reduce interference and increase channel reuse (see picture at right) Porter also invented the dial-then-send method used by all cell phones to reduce wasted channel time.
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 late 1960s, in papers by Frenkiel and Porter. In 1970 Amos E. Joel, Jr., a Bell Labs engineer, invented a "three-sided trunk circuit" to aid in the "call handoff" process from one cell to another. His patent contained an early description of the Bell Labs cellular concept, but as switching systems became faster, such a circuit became unnecessary and was never implemented in a system.
Emergence of automated services:
The first fully automated mobile phone system for vehicles was launched in Sweden in 1956. 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. 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.[22] 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.
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 ("Radio" magazine, 2, 1967; "Hovosti dnya" newsreel, 37, 1966).
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.
Handheld mobile phone:
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.
Analog cellular networks – 1G:
The first analog cellular system widely deployed in North America was the Advanced Mobile Phone System (AMPS). It was commercially introduced in the Americas in 1978, Israel in 1986, and Australia in 1987.
AMPS was a pioneering technology that helped drive mass market usage of cellular technology, but it had several serious issues by modern standards. It was unencrypted and easily vulnerable to eavesdropping via a scanner; it was susceptible to cell phone "cloning;" and it used a Frequency-division multiple access (FDMA) scheme and required significant amounts of wireless spectrum to support. Many of the iconic early commercial cell phones such as the Motorola DynaTAC Analog AMPS were eventually superseded by Digital AMPS (D-AMPS) in 1990, and AMPS service was shut down by most North American carriers by 2008.
Digital cellular networks – 2G:
In the 1990s, the 'second generation' 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.
In 1993, IBM Simon was introduced. This was possibly the world's first smartphone. It was a mobile phone, pager, fax machine, and PDA all rolled into one. It included a calendar, address book, clock, calculator, notepad, email, and a touchscreen with a QWERTY keyboard. The IBM Simon had a stylus you used to tap the touch screen with. It featured predictive typing that would guess the next characters as you tapped. It had apps, or at least a way to deliver more features by plugging a PCMCIA 1.8 MB memory card into the phone.
Coinciding with the introduction of 2G systems was a trend away from the larger "brick" phones toward tiny 100 – 200 gram hand-held devices. This change was possible not only through technological improvements such as more advanced batteries and more energy-efficient electronics, but also because of the higher density of cell sites to accommodate increasing usage. The latter meant that the average distance transmission from phone to the base station shortened, leading to increased battery life whilst on the move.
Personal Handy-phone System mobiles and modems used in Japan around 1997–2003
The second generation introduced a new variant of communication called SMS or text messaging. It was initially available only on GSM networks but spread eventually on all digital networks. The first machine-generated SMS message was sent in the UK on 3 December 1992 followed in 1993 by the first person-to-person SMS sent in Finland. The advent of prepaid services in the late 1990s soon made SMS the communication method of choice amongst the young, a trend which spread across all ages.
2G also introduced the ability to access media content on mobile phones. In 1998 the first downloadable content sold to mobile phones was the ring tone, launched by Finland's Radiolinja (now Elisa). Advertising on the mobile phone first appeared in Finland when a free daily SMS news headline service was launched in 2000, sponsored by advertising.
Mobile payments were 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 (such as access to browse 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. 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 while retaining backwards compatibility:
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
Ability for more than one mobile to share the same time slot
Introduction of QoS flags
All these were put in place to allow for low latency, low bit rate communications such as VoIP.
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, with companies such as Real Networks and Disney among the early pioneers in this type of offering.
In the mid-2000s (decade), an evolution of 3G technology began 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.
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:
+v1.20.01.jpg "to see more, click here.")
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. 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.
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.
.jpg)
.jpg)
.jpg)
.jpg)
0 comments: