Mobile Phone History

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.
In 1960, the world’s first partly automatic car phone system, Mobile System A (MTA), was launched in Sweden. MTA phones were composed of vacuum tubes and relays, and had a weight of 40 kg. In 1962, a more modern version called Mobile System B (MTB) was launched, which was a push-button telephone, and which used transistors 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.[5][6]
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. 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.[7]
The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nation-wide 1G network. In 1981, this was followed by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden.[8]. NMT was the first mobile phone network featuring international roaming. The first 1G network launched in the USA was Chicago based Ameritech in 1983 using the Motorola DynaTAC mobile phone. Several countries then followed in the early 1980s including the UK, Mexico and Canada. .
The first "modern" network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard which also marked the introduction of competition in mobile telecoms when Radiolinja challenged incumbent Telecom Finland (now part of TeliaSonera) who ran a 1G NMT network.
In 2001 the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard.[9]
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.

Mobile Phone

A mobile phone (also called mobile, cellular phone, cell phone or handphone) is an electronic device used for full duplex two-way radio telecommunications over a cellular network of base stations known as cell sites. Mobile phones differ from cordless telephones, which only offer telephone service within limited range through a single base station attached to a fixed land line, for example within a home or an office. Low-end mobile phones are often referred to as feature phones, whereas high-end mobile phones that offer more advanced computing ability are referred to as smartphones.

A mobile phone allows its user to make and receive telephone calls to and from the public telephone network which includes other mobiles and fixed line phones across the world. It does this by connecting to a cellular network owned by a mobile network operator. A key feature of the cellular network is that it enables seamless telephone calls even when the user is moving around wide areas via a process known as handoff or handover.

In addition to being a telephone, modern mobile phones also support many additional services, and accessories, such as SMS (or text) messages, email, Internet access, gaming, Bluetooth, infrared, camera, MMS messaging, MP3 player, radio and GPS.
The first hand held phone was demonstrated by Martin Cooper of Motorola in 1973, using a handset weighing in at two kilos. In the year 1990, 12.4 million people worldwide had cellular subscriptions. By the end of 2009, only 20 years later, the number of mobile cellular subscriptions worldwide reached approximately 4.6 billion, 300 times the 1990 number, penetrating the developing economies and reaching the bottom of the economic pyramid.

source : http://en.wikipedia.org/wiki/Mobile_phone

Electronic Television

In 1908, Alan Archibald Campbell-Swinton, fellow of the Royal Society (UK), published a letter in the scientific journal Nature in which he described how "distant electric vision" could be achieved by using a cathode ray tube (or "Braun" tube, after its inventor, Karl Braun) as both a transmitting and receiving device,[15][16] apparently the first iteration of the electronic television method that would dominate the field until recently. He expanded on his vision in a speech given in London in 1911 and reported in The Times[17] and the Journal of the Röntgen Society.[18] In a letter to Nature published in October 1926, Campbell-Swinton also announced the results of some "not very successful experiments" he had conducted with G. M. Minchin and J. C. M. Stanton. They had attempted to generate an electrical signal by projecting an image onto a selenium-coated metal plate that was simultaneously scanned by a cathode ray beam.[19][20] These experiments were conducted before March 1914, when Minchin died.[21] Although others had experimented with using a cathode ray tube as a receiver, the concept of using one as a transmitter was novel.[22] By the late 1920s, when electromechanical television was still being introduced, several inventors were already working separately on versions of all-electronic transmitting tubes, including Philo Farnsworth and Vladimir Zworykin in the United States, and Kálmán Tihanyi in Hungary.
On September 7, 1927, Farnsworth's Image Dissector camera tube transmitted its first image, a simple straight line, at his laboratory at 202 Green Street in San Francisco.[23][24] By September 3, 1928, Farnsworth had developed the system sufficiently to hold a demonstration for the press.[24] In 1929, the system was further improved by elimination of a motor generator, so that his television system now had no mechanical parts.[25] That year, Farnsworth transmitted the first live human images with his system, including a three and a half-inch image of his wife Elma ("Pem") with her eyes closed (possibly due to the bright lighting required).[26]
Meanwhile, Vladimir Zworykin was also experimenting with the cathode ray tube to create and show images. While working for Westinghouse Electric Corporation in 1923, he began to develop an electronic camera tube. But in a 1925 demonstration, the image was dim, had low contrast and poor definition, and was stationary.[27] Zworykin's imaging tube never got beyond the laboratory stage. But RCA, which had acquired the Westinghouse patent, asserted that the patent for Farnsworth's 1927 image dissector was written so broadly that it would exclude any other electronic imaging device. Thus RCA, on the basis of Zworykin's 1923 patent application, filed a patent interference suit against Farnsworth. The U.S. Patent Office examiner disagreed in a 1935 decision, finding priority of invention for Farnsworth against Zworykin. Farnsworth claimed that Zworykin's 1923 system would be unable to produce an electrical image of the type to challenge his patent. Zworykin received a patent in 1928 for a color transmission version of his 1923 patent application,[28] he also divided his original application in 1931.[29] Zworykin was unable or unwilling to introduce evidence of a working model of his tube that was based on his 1923 patent application. In September 1939, after losing an appeal in the courts and determined to go forward with the commercial manufacturing of television equipment, RCA agreed to pay Farnsworth US$1 million (the equivalent of $13.8 million in 2006) over a ten-year period, in addition to license payments, to use Farnsworth's patents.[30][31]


Drawing from Kálmán Tihanyi's 1926 patent application "Radioskop"
The problem of low sensitivity to light resulting in low electrical output from transmitting or "camera" tubes would be solved by Tihanyi beginning in 1924.[32] His solution was a camera tube that accumulated and stored electrical charges ("photoelectrons") within the tube throughout each scanning cycle. The device was first described in a patent application he filed in Hungary in March 1926 for a television system he dubbed "Radioskop".[33] After further refinements included in a 1928 patent application,[32] Tihanyi was awarded patents for the camera tube in both France and Great Britain in 1928, and applied for patents in the United States in June of the following year. Although his breakthrough would be incorporated into the design of RCA's "iconoscope" in 1931, the U.S. patent for Tihanyi's transmitting tube would not be granted until May 1939. The patent for his receiving tube had been granted the previous October. Both patents had been purchased by RCA prior to their approval.[34][35]
Development continued around the world. At the Berlin Radio Show in August 1931, Manfred von Ardenne gave a public demonstration of a television system using a CRT for both transmission and reception. However, Ardenne had not developed a camera tube, using the CRT instead as a flying-spot scanner to scan slides and film.[36] Philo Farnsworth gave the world's first public demonstration of an all-electronic television system, using a live camera, at the Franklin Institute of Philadelphia on August 25, 1934, and for ten days afterwards.[37][38]
In 1933 RCA introduced an improved camera tube that relied on Tihanyi's charge storage principle.[39] Dubbed the Iconoscope by Zworykin, the new tube had a light sensitivity of about 75,000 lux, and thus was claimed to be much more sensitive than Farnsworth's image dissector.[citation needed] However, Farnsworth had overcome his power problems with his Image Dissector through the invention of a completely unique "multipactor" device that he began work on in 1930, and demonstrated in 1931.[40][41] This small tube could amplify a signal reportedly to the 60th power or better[42] and showed great promise in all fields of electronics. A problem with the multipactor, unfortunately, was that it wore out at an unsatisfactory rate[43].
In Britain the EMI engineering team lead by Isaac Shoenberg applied in 1932 for a patent for a new device they dubbed "the Emitron",[44][45] which formed the heart of the cameras they designed for the BBC. On November 2, 1936, a 405-line broadcasting service employing the Emitron began at studios in Alexandra Palace, and transmitted from a specially-built mast atop one of the Victorian building's towers. It alternated for a short time with Baird's mechanical system in adjoining studios, but was more reliable and visibly superior. This was the world's first regular high-definition television service.[46]
The original american iconoscope was noisy, had a high ratio of interference to signal, and ultimately gave disappointing results, especially when compared to the high definition mechanical scanning systems then becoming available.[47][48] The EMI team under the supervision of Isaac Shoenberg analyzed how the iconoscope (or Emitron) produces an electronic signal and concluded that its real efficiency was only about 5% of the theoretical maximum.[49][50] They solved this problem by developing and patenting in 1934 two new camera tubes dubbed super-Emitron and CPS Emitron.[51][52][53] The super-Emitron was between ten and fifteen times more sensitive than the original Emitron and iconoscope tubes and, in some cases, this ratio was considerably greater.[49] It was used for an outside broadcasting by the BBC, for the first time, on Armistice Day 1937, when the general public could watch in a television set how the King lay a wreath at the Cenotaph.[54] This was the first time that anyone could broadcast a live street scene from cameras installed on the roof of neighbor buildings, because neither Farnsworth nor RCA could do the same before the 1939 New York World's Fair.
On the other hand, in 1934, Zworykin shared some patent rights with the German licensee company Telefunken.[55] The "image iconoscope" ("Superikonoskop" in Germany) was produced as a results of the collaboration. This tube is essentially identical to the super-Emitron.[citation needed] The production and commercialization of the super-Emitron and image iconoscope in Europe was not affected by the patent war between Zworykin and Farnsworth, because Dieckmann and Hell had priority in Germany for the invention of the image dissector, having submitted a patent application for their Lichtelektrische Bildzerlegerröhre für Fernseher (Photoelectric Image Dissector Tube for Television) in Germany in 1925,[56] two years before Farnsworth did the same in the United States.[57] The image iconoscope (Superikonoskop) became the industrial standard for public broadcasting in Europe from 1936 until 1960, when it was replaced by the vidicon and plumbicon tubes. Indeed it was the representative of the European tradition in electronic tubes competing against the American tradition represented by the image orthicon.[58][59] The German company Heimann produced the Superikonoskop for the 1936 Berlin Olympic Games,[60][61] later Heimann also produced and commercialized it from 1940 to 1955,[62] finally the Dutch company Philips produced and commercialized the image iconoscope and multicon from 1952 to 1958.[59][63]
American television broadcasting at the time consisted of a variety of markets in a wide range of sizes, each competing for programming and dominance with separate technology, until deals were made and standards agreed upon in 1941.[64] RCA, for example, used only Iconoscopes in the New York area, but Farnsworth Image Dissectors in Philadelphia and San Francisco.[65] In September 1939, RCA agreed to pay the Farnsworth Television and Radio Corporation royalties over the next ten years for access to Farnsworth's patents.[66] With this historic agreement in place, RCA integrated much of what was best about the Farnsworth Technology into their systems.[65]
In 1941, the United States implemented 525-line television.[67][68] The world's first 625-line television standard was designed in the Soviet Union in 1944, and became a national standard in 1946.[69] The first broadcast in 625-line standard occurred in 1948 in Moscow.[70] The concept of 625 lines per frame was subsequently implemented in the European CCIR standard.[71]

source : http://en.wikipedia.org/wiki/History_of_television

Electromechanical Television

The Nipkow disk. This schematic shows the circular paths traced by the holes, that may also be square for greater precision.
The beginnings of mechanical television can be traced back to the discovery of the photoconductivity of the element selenium by Willoughby Smith in 1873, the invention of a scanning disk by Paul Gottlieb Nipkow in 1884 and John Logie Baird's demonstration of televised moving images in 1926.
As 23-year-old German university student, Paul Nipkow proposed and patented the first electromechanical television system in 1884.[1] Although he never built a working model of the system, variations of Nipkow's spinning-disk "image rasterizer" for television became exceedingly common, and remained in use until 1939.[2] Constantin Perskyi had coined the word television in a paper read to the International Electricity Congress at the International World Fair in Paris on August 25, 1900. Perskyi's paper reviewed the existing electromechanical technologies, mentioning the work of Nipkow and others.[3] The photoconductivity of selenium and Nipkow's scanning disk were first joined for practical use in the electronic transmission of still pictures and photographs, and by the first decade of the 20th century halftone photographs, composed of equally spaced dots of varying size, were being transmitted by facsimile over telegraph and telephone lines as a newspaper service.[4]
However, it was not until 1907 that developments in amplification tube technology, by Lee DeForest and Arthur Korn among others, made the design practical.[4] The first demonstration of the instantaneous transmission of still silhouette images was by Georges Rignoux and A. Fournier in Paris in 1909, using a rotating mirror-drum as the scanner and a matrix of 64 selenium cells as the receiver.[5]
In 1911, Boris Rosing and his student Vladimir Zworykin created a television system that used a mechanical mirror-drum scanner to transmit, in Zworykin's words, "very crude images" over wires to the "Braun tube" (cathode ray tube or "CRT") in the receiver. Moving images were not possible because, in the scanner, "the sensitivity was not enough and the selenium cell was very laggy".[6]
On March 25, 1925, Scottish inventor John Logie Baird gave the first public demonstration of televised silhouette images in motion, at Selfridge's Department Store in London.[7] AT&T's Bell Telephone Laboratories transmitted halftone still images of transparencies in May 1925. On June 13 of that year, Charles Francis Jenkins transmitted the silhouette image of a toy windmill in motion, over a distance of five miles from a naval radio station in Maryland to his laboratory in Washington, using a lensed disk scanner with a 48-line resolution.[8][9]
However, if television is defined as the live transmission of moving images with continuous tonal variation, Baird first achieved this privately on October 2, 1925. But strictly speaking, Baird had not yet achieved moving images on October 2. His scanner worked at only five images per second, below the threshold required to give the illusion of motion, usually defined as at least 12 images per second. By January, he had improved the scan rate to 12.5 images per second. Then he gave the world's first demonstration of a working television system to members of the Royal Institution and a newspaper reporter on January 26, 1926 at his laboratory in London. Unlike later electronic systems with several hundred lines of resolution, Baird's vertically scanned image, using a scanning disk embedded with a double spiral of lenses, had only 30 lines, just enough to reproduce a recognizable human face.[citation needed]
In 1927, Baird transmitted a signal over 438 miles (705 km) of telephone line between London and Glasgow. In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal, between London and New York, and the first shore-to-ship transmission. He also demonstrated an electromechanical color, infrared (dubbed "Noctovision"), and stereoscopic television, using additional lenses, disks and filters. In parallel, Baird developed a video disk recording system dubbed "Phonovision"; a number of the Phonovision recordings, dating back to 1927, still exist.[10] In 1929, he became involved in the first experimental electromechanical television service in Germany. In November of the same year, Baird and Bernard Natan of Pathe established France's first television company, Télévision-Baird-Natan. In 1931, he made the first outdoor remote broadcast, of the Epsom Derby.[11] In 1932, he demonstrated ultra-short wave television. Baird's electromechanical system reached a peak of 240 lines of resolution on BBC television broadcasts in 1936 though the mechanical system did not scan the televised scene directly. Instead a 35 mm film was shot, rapidly developed and then scanned while the film was still wet. This intermediate film system was discontinued within three months in favor of a 405-line all-electronic system developed by Marconi-EMI.[12]
Herbert E. Ives and Frank Gray of Bell Telephone Laboratories gave a dramatic demonstration of mechanical television on April 7, 1927. The reflected-light television system included both small and large viewing screens. The small receiver had a two-inch-wide by 2.5-inch-high screen. The large receiver had a screen 24 inches wide by 30 inches high. Both sets were capable of reproducing reasonably accurate, monochromatic moving images. Along with the pictures, the sets also received synchronized sound. The system transmitted images over two paths: first, a wire link from Washington to New York City, then a radio link from Whippany, New Jersey. Comparing the two transmission methods, viewers noted no difference in quality. Subjects of the telecast included Secretary of Commerce Herbert Hoover. A flying-spot scanner beam illuminated these subjects. The scanner that produced the beam had a 50-aperture disk. The disc revolved at a rate of 18 frames per second, capturing one frame about every 56 milliseconds. (Today's systems typically transmit 30 or 60 frames per second, or one frame every 33.3 or 16.7 milliseconds respectively.) Television historian Albert Abramson underscored the significance of the Bell Labs demonstration: "It was in fact the best demonstration of a mechanical television system ever made to this time. It would be several years before any other system could even begin to compare with it in picture quality."[13]
Meanwhile in the Soviet Union, Léon Theremin had been developing a mirror drum-based television, starting with 16 lines resolution in 1925, then 32 lines and eventually 64 using interlacing in 1926, and as part of his thesis on May 7, 1926 he electrically transmitted and then projected near-simultaneous moving images on a five foot square screen.[9] By 1927 he achieved an image of 100 lines, a resolution that was not surpassed until 1931 by RCA, with 120 lines.[citation needed]
On December 25, 1926, Kenjiro Takayanagi demonstrated a television system with a 40-line resolution that employed a Nipkow disk scanner and CRT display at Hamamatsu Industrial High School in Japan. This protype is still on display at the Takayanagi Memorial Museum in Shizuoka University, Hamamatsu Campus. His research in creating a production model were halted by the US after Japan lost World War II.[14]
Mechanical scanning systems, though obsolete for the more familiar television systems, nevertheless survive in long wave infra red cameras because there is no suitable all-electronic pickup device

source : http://en.wikipedia.org/wiki/History_of_television