This is an accepted version of this page
98-417: A mobile network operator (MNO), also known as a mobile network provider , mobile network carrier , mobile telco , wireless service provider , wireless carrier , wireless operator , wireless telco , or cellular company , is a telecommunications provider of services that sells, delivers and maintains mobile telephony services to an end user. A key defining characteristic of a mobile network operator
196-412: A thermionic tube or thermionic valve uses thermionic emission of electrons from a heated cathode for a number of fundamental electronic functions such as signal amplification and current rectification . The simplest vacuum tube, the diode invented in 1904 by John Ambrose Fleming , contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through
294-411: A radio broadcasting station , the station's large power amplifier is the transmitter and the broadcasting antenna is the interface between the power amplifier and the free space channel. The free space channel is the transmission medium and the receiver's antenna is the interface between the free space channel and the receiver. Next, the radio receiver is the destination of the radio signal, where it
392-411: A better price for their goods. In Côte d'Ivoire , coffee growers share mobile phones to follow hourly variations in coffee prices and sell at the best price. On the macroeconomic scale, Lars-Hendrik Röller and Leonard Waverman suggested a causal link between good telecommunication infrastructure and economic growth. Few dispute the existence of a correlation although some argue it is wrong to view
490-422: A broadcast medium. In his laboratory on 2 October 1925, Baird successfully transmitted the first television picture with a greyscale image: the head of a ventriloquist's dummy nicknamed " Stooky Bill " in a 32-line vertically scanned image, at five pictures per second. Baird went downstairs and fetched an office worker, 20-year-old William Edward Taynton, to see what a human face would look like, and Taynton became
588-438: A caveat for it in 1876. Gray abandoned his caveat and because he did not contest Bell's priority, the examiner approved Bell's patent on March 3, 1876. Gray had filed his caveat for the variable resistance telephone, but Bell was the first to document the idea and test it in a telephone.[88] Antonio Meucci invented a device that allowed the electrical transmission of voice over a line nearly 30 years before in 1849, but his device
686-441: A connection between two or more users. For both types of networks, repeaters may be necessary to amplify or recreate the signal when it is being transmitted over long distances. This is to combat attenuation that can render the signal indistinguishable from the noise. Another advantage of digital systems over analogue is that their output is easier to store in memory, i.e., two voltage states (high and low) are easier to store than
784-495: A continuous range of states. Telecommunication has a significant social, cultural and economic impact on modern society. In 2008, estimates placed the telecommunication industry 's revenue at US$ 4.7 trillion or just under three per cent of the gross world product (official exchange rate). Several following sections discuss the impact of telecommunication on society. On the microeconomic scale, companies have used telecommunications to help build global business empires. This
882-401: A definition of 500 lines. On 16 August 1944, he gave the world's first demonstration of a practical fully electronic colour television display. His 600-line colour system used triple interlacing , using six scans to build each picture. Similar concepts were common through the 1940s and 50s, differing primarily in the way they re-combined the colours generated by the three guns. One of them,
980-516: A glass razor, which was rust-resistant, but shattered. Inspired by pneumatic tyres he attempted to make pneumatic shoes, but his prototype contained semi-inflated balloons, which burst (years later this same idea was successfully adopted for Dr. Martens boots). He also invented a thermal undersock (the Baird undersock), which was moderately successful. Baird suffered from cold feet, and after a number of trials, he found that an extra layer of cotton inside
1078-406: A higher-frequency signal (known as the " carrier wave ") before transmission. There are several different modulation schemes available to achieve this [two of the most basic being amplitude modulation (AM) and frequency modulation (FM)]. An example of this process is a disc jockey's voice being impressed into a 96 MHz carrier wave using frequency modulation (the voice would then be received on
SECTION 10
#17327731359951176-450: A key advantage of digital signals over analogue signals. However, digital systems fail catastrophically when noise exceeds the system's ability to autocorrect. On the other hand, analogue systems fail gracefully: as noise increases, the signal becomes progressively more degraded but still usable. Also, digital transmission of continuous data unavoidably adds quantization noise to the output. This can be reduced, but not eliminated, only at
1274-525: A lunatic who's down there. He says he's got a machine for seeing by wireless! Watch him—he may have a razor on him." In these attempts to develop a working television system, Baird experimented using the Nipkow disk . Paul Gottlieb Nipkow had invented this scanning system in 1884. Television historian Albert Abramson calls Nipkow's patent "the master television patent". Nipkow's work is important because Baird, followed by many others, chose to develop it into
1372-438: A mobile network operator may also sell access to network services at wholesale rates to mobile virtual network operators (MVNO). Telecommunications Telecommunication , often used in its plural form or abbreviated as telecom , is the transmission of information with an immediacy comparable to face-to-face communication. As such, slow communications technologies like postal mail and pneumatic tubes are excluded from
1470-838: A new international frequency list and used in conformity with the Radio Regulation". According to the ITU's Radio Regulations adopted in Atlantic City, all frequencies referenced in the International Frequency Registration Board , examined by the board and registered on the International Frequency List "shall have the right to international protection from harmful interference". From a global perspective, there have been political debates and legislation regarding
1568-496: A patent for a device that formed images from reflected radio waves, a device remarkably similar to radar, and that he was in correspondence with the British government at the time. The radar contribution is in dispute. According to some experts, Baird's "Noctovision" is not radar. Unlike radar (except continuous wave radar ), Noctovision is incapable of determining the distance to the scanned subject. Noctovision also cannot determine
1666-437: A person's age, interests, sexual preference and relationship status. In this way, these sites can play important role in everything from organising social engagements to courtship . Prior to social networking sites, technologies like short message service (SMS) and the telephone also had a significant impact on social interactions. In 2000, market research group Ipsos MORI reported that 81% of 15- to 24-year-old SMS users in
1764-430: A phosphor plate. The phosphor was patterned so the electrons from the guns only fell on one side of the patterning or the other. Using cyan and magenta phosphors, a reasonable limited-colour image could be obtained. He also demonstrated the same system using monochrome signals to produce a 3D image (called "stereoscopic" at the time). In 1941, he patented and demonstrated this system of three-dimensional television at
1862-549: A prominent place in television's history. In 2006, Baird was named as one of the 10 greatest Scottish scientists in history, having been listed in the National Library of Scotland 's 'Scottish Science Hall of Fame'. In 2015 he was inducted into the Scottish Engineering Hall of Fame . In 2017, IEEE unveiled a bronze street plaque at 22 Frith Street ( Bar Italia ), London, dedicated to Baird and
1960-491: A radio as the channel "96 FM"). In addition, modulation has the advantage that it may use frequency division multiplexing (FDM). A telecommunications network is a collection of transmitters, receivers, and communications channels that send messages to one another. Some digital communications networks contain one or more routers that work together to transmit information to the correct user. An analogue communications network consists of one or more switches that establish
2058-475: A service that operated for a year until the gap in the telegraph link was closed. In the Middle Ages, chains of beacons were commonly used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance. One notable instance of their use
SECTION 20
#17327731359952156-411: A telephone network, the caller is connected to the person to whom they wish to talk by switches at various telephone exchanges . The switches form an electrical connection between the two users and the setting of these switches is determined electronically when the caller dials the number. Once the connection is made, the caller's voice is transformed to an electrical signal using a small microphone in
2254-412: A version of the electrical telegraph that he unsuccessfully demonstrated on September 2, 1837. His code was an important advance over Wheatstone's signaling method. The first transatlantic telegraph cable was successfully completed on July 27, 1866, allowing transatlantic telecommunication for the first time. The conventional telephone was patented by Alexander Bell in 1876. Elisha Gray also filed
2352-581: Is adapted from the French, because its written use was recorded in 1904 by the French engineer and novelist Édouard Estaunié . Communication was first used as an English word in the late 14th century. It comes from Old French comunicacion (14c., Modern French communication), from Latin communicationem (nominative communication), noun of action from past participle stem of communicare, "to share, divide out; communicate, impart, inform; join, unite, participate in," literally, "to make common", from communis". At
2450-671: Is called point-to-point communication because it occurs between a transmitter and a receiver. Telecommunication through radio broadcasts is called broadcast communication because it occurs between a powerful transmitter and numerous low-power but sensitive radio receivers. Telecommunications in which multiple transmitters and multiple receivers have been designed to cooperate and share the same physical channel are called multiplex systems . The sharing of physical channels using multiplexing often results in significant cost reduction. Multiplexed systems are laid out in telecommunication networks and multiplexed signals are switched at nodes through to
2548-451: Is called (in the jargon of the field) " quadrature amplitude modulation " (QAM) that are used in high-capacity digital radio communication systems. Modulation can also be used to transmit the information of low-frequency analogue signals at higher frequencies. This is helpful because low-frequency analogue signals cannot be effectively transmitted over free space. Hence the information from a low-frequency analogue signal must be impressed into
2646-434: Is commonly called "keying" —a term derived from the older use of Morse Code in telecommunications—and several keying techniques exist (these include phase-shift keying , frequency-shift keying , and amplitude-shift keying ). The " Bluetooth " system, for example, uses phase-shift keying to exchange information between various devices. In addition, there are combinations of phase-shift keying and amplitude-shift keying which
2744-794: Is converted from electricity to sound. Telecommunication systems are occasionally "duplex" (two-way systems) with a single box of electronics working as both the transmitter and a receiver, or a transceiver (e.g., a mobile phone ). The transmission electronics and the receiver electronics within a transceiver are quite independent of one another. This can be explained by the fact that radio transmitters contain power amplifiers that operate with electrical powers measured in watts or kilowatts, but radio receivers deal with radio powers measured in microwatts or nanowatts . Hence, transceivers have to be carefully designed and built to isolate their high-power circuitry and their low-power circuitry from each other to avoid interference. Telecommunication over fixed lines
2842-481: Is degraded by undesirable noise . Commonly, the noise in a communication system can be expressed as adding or subtracting from the desirable signal via a random process . This form of noise is called additive noise , with the understanding that the noise can be negative or positive at different instances. Unless the additive noise disturbance exceeds a certain threshold, the information contained in digital signals will remain intact. Their resistance to noise represents
2940-609: Is self-evident in the case of online retailer Amazon.com but, according to academic Edward Lenert, even the conventional retailer Walmart has benefited from better telecommunication infrastructure compared to its competitors. In cities throughout the world, home owners use their telephones to order and arrange a variety of home services ranging from pizza deliveries to electricians. Even relatively poor communities have been noted to use telecommunication to their advantage. In Bangladesh 's Narsingdi District , isolated villagers use cellular phones to speak directly to wholesalers and arrange
3038-448: Is separated from its adjacent stations by 200 kHz, and the difference between 200 kHz and 180 kHz (20 kHz) is an engineering allowance for the imperfections in the communication system. In the example above, the "free space channel" has been divided into communications channels according to frequencies , and each channel is assigned a separate frequency bandwidth in which to broadcast radio waves. This system of dividing
Mobile network operator - Misplaced Pages Continue
3136-459: Is that it must own or control access to a radio spectrum license from a regulatory or government entity, and also that it must own or control the elements of the cellular network infrastructure necessary to provide services to subscribers over the licensed radio spectrum . In addition the operator would also contain other elements like the back haul infrastructure and provisioning computer systems. A mobile network operator typically also has
3234-449: Is the informational equivalent of two newspaper pages per person per day in 1986, and six entire newspapers per person per day by 2007. Given this growth, telecommunications play an increasingly important role in the world economy and the global telecommunications industry was about a $ 4.7 trillion sector in 2012. The service revenue of the global telecommunications industry was estimated to be $ 1.5 trillion in 2010, corresponding to 2.4% of
3332-723: The Geer tube , was similar to Baird's concept, but used small pyramids with the phosphors deposited on their outside faces, instead of Baird's 3D patterning on a flat surface. In 1943, the Hankey Committee was appointed to oversee the resumption of television broadcasts after the war. Baird persuaded them to make plans to adopt his proposed 1000-line Telechrome electronic colour system as the new post-war broadcast standard. The picture resolution on this system would have been comparable to today's HDTV ( High Definition Television). The Hankey Committee's plan lost all momentum partly due to
3430-721: The Nipkow disk by Paul Nipkow and thus became known as the mechanical television . It formed the basis of experimental broadcasts done by the British Broadcasting Corporation beginning on 30 September 1929. However, for most of the 20th century, televisions depended on the cathode ray tube invented by Karl Ferdinand Braun . The first version of such a television to show promise was produced by Philo Farnsworth and demonstrated to his family on 7 September 1927. After World War II, interrupted experiments resumed and television became an important home entertainment broadcast medium. The type of device known as
3528-440: The spark gap transmitter for radio or mechanical computers for computing, it was the invention of the thermionic vacuum tube that made these technologies widespread and practical, leading to the creation of electronics . In the 1940s, the invention of semiconductor devices made it possible to produce solid-state devices, which are smaller, cheaper, and more efficient, reliable, and durable than thermionic tubes. Starting in
3626-705: The 1932 Plenipotentiary Telegraph Conference and the International Radiotelegraph Conference in Madrid, the two organizations merged to form the International Telecommunication Union (ITU). They defined telecommunication as "any telegraphic or telephonic communication of signs, signals, writing, facsimiles and sounds of any kind, by wire, wireless or other systems or processes of electric signaling or visual signaling (semaphores)." The definition
3724-497: The 1970s. In the 1960s, Paul Baran and, independently, Donald Davies started to investigate packet switching , a technology that sends a message in portions to its destination asynchronously without passing it through a centralized mainframe . A four-node network emerged on 5 December 1969, constituting the beginnings of the ARPANET , which by 1981 had grown to 213 nodes . ARPANET eventually merged with other networks to form
3822-628: The 30-line Baird system, and from 1932 to 1935 the BBC also produced the programmes in their own studio, first at Broadcasting House and then later at 16 Portland Place. In addition, from 1933 Baird and the Baird Company were producing and broadcasting a small number of television programmes independent of the BBC from Baird's studios and transmitter at the Crystal Palace in south London. On 2 November 1936, from Alexandra Palace located on
3920-552: The BBC ceased broadcasts with the Baird system in February 1937, due in part to a disastrous fire in the Baird facilities at Crystal Palace. It was becoming apparent to the BBC that the Baird system would ultimately fail due in large part to the lack of mobility of the Baird system's cameras, with their developer tanks, hoses, and cables. Commercially Baird's contemporaries, such as George William Walton and William Stephenson , were ultimately more successful as their patents underpinned
4018-514: The Case cell. He accomplished this by improving the signal conditioning from the cell, through temperature optimisation (cooling) and his own custom-designed video amplifier. Baird gave the first public demonstration of moving silhouette images by television at Selfridges department store in London in a three-week series of demonstrations beginning on 25 March 1925. On 26 January 1926, Baird gave
Mobile network operator - Misplaced Pages Continue
4116-552: The Farnsworth tubes instead to scan cinefilm, in which capacity they proved serviceable though prone to drop-outs and other problems. Farnsworth himself came to London to the Baird Crystal Palace laboratories in 1936 but was unable to fully solve the problem; the fire that burned Crystal Palace to the ground later that year further hampered the Baird company's ability to compete. Baird made many contributions to
4214-466: The ITU was able to compile an index that measures the overall ability of citizens to access and use information and communication technologies. Using this measure, Sweden, Denmark and Iceland received the highest ranking while the African countries Niger , Burkina Faso and Mali received the lowest. Telecommunication has played a significant role in social relationships. Nevertheless, devices like
4312-744: The Internet. While Internet development was a focus of the Internet Engineering Task Force (IETF) who published a series of Request for Comments documents, other networking advancements occurred in industrial laboratories , such as the local area network (LAN) developments of Ethernet (1983), Token Ring (1984) and Star network topology. The effective capacity to exchange information worldwide through two-way telecommunication networks grew from 281 petabytes (PB) of optimally compressed information in 1986 to 471 PB in 1993 to 2.2 exabytes (EB) in 2000 to 65 EB in 2007. This
4410-506: The United Kingdom had used the service to coordinate social arrangements and 42% to flirt. In cultural terms, telecommunication has increased the public's ability to access music and film. With television, people can watch films they have not seen before in their own home without having to travel to the video store or cinema. With radio and the Internet, people can listen to music they have not heard before without having to travel to
4508-797: The United States was spent on media that depend upon telecommunication. Many countries have enacted legislation which conforms to the International Telecommunication Regulations established by the International Telecommunication Union (ITU), which is the "leading UN agency for information and communication technology issues". In 1947, at the Atlantic City Conference, the ITU decided to "afford international protection to all frequencies registered in
4606-418: The caller's handset . This electrical signal is then sent through the network to the user at the other end where it is transformed back into sound by a small speaker in that person's handset. John Logie Baird John Logie Baird FRSE ( / ˈ l oʊ ɡ i b ɛər d / ; 13 August 1888 – 14 June 1946) was a Scottish inventor, electrical engineer, and innovator who demonstrated
4704-542: The challenges of postwar reconstruction. The monochrome 405-line standard remained in place until 1985 in some areas, and the 625-line system was introduced in 1964 and ( PAL ) colour in 1967. A demonstration of large screen three-dimensional television by the BBC was reported in March 2008, over 60 years after Baird's demonstration. Some of Baird's early inventions were not fully successful. In his twenties he tried to create diamonds by heating graphite . Later Baird invented
4802-578: The coordinates of the subject in three-dimensional space. From December 1944, Logie Baird lived at 1 Station Road, Bexhill-on-Sea , East Sussex, he later died there on 14 June 1946 after suffering a stroke in February. The house was demolished in 2007 and the site is now occupied by apartments named Baird Court. Logie Baird is buried beside his parents in Helensburgh Cemetery , Argyll, Scotland. Australian television's Logie Awards were named in honour of John Logie Baird's contribution to
4900-437: The correct destination terminal receiver. Communications can be encoded as analogue or digital signals , which may in turn be carried by analogue or digital communication systems. Analogue signals vary continuously with respect to the information, while digital signals encode information as a set of discrete values (e.g., a set of ones and zeroes). During propagation and reception, information contained in analogue signals
4998-500: The definition. Many transmission media have been used for telecommunications throughout history, from smoke signals , beacons , semaphore telegraphs , signal flags , and optical heliographs to wires and empty space made to carry electromagnetic signals. These paths of transmission may be divided into communication channels for multiplexing , allowing for a single medium to transmit several concurrent communication sessions . Several methods of long-distance communication before
SECTION 50
#17327731359955096-519: The development of optical fibre. The Internet , a technology independent of any given medium, has provided global access to services for individual users and further reduced location and time limitations on communications. Telecommunication is a compound noun of the Greek prefix tele- (τῆλε), meaning distant , far off , or afar , and the Latin verb communicare , meaning to share . Its modern use
5194-537: The device—from the cathode to the anode. Adding one or more control grids within the tube enables the current between the cathode and anode to be controlled by the voltage on the grid or grids. These devices became a key component of electronic circuits for the first half of the 20th century and were crucial to the development of radio, television, radar, sound recording and reproduction , long-distance telephone networks, and analogue and early digital computers . While some applications had used earlier technologies such as
5292-542: The early television system used by Scophony Limited who operated in Britain up to WWII and then in the US. "Of all the electro-mechanical television techniques invented and developed by the mid 1930s, the technology known as Scophony had no rival in terms of technical performance." In 1948 Scophony acquired John Logie Baird Ltd. Baird's television systems were replaced by the first fully electronic television system developed by
5390-422: The electrical telegraph, the last commercial line was abandoned in 1880. On July 25, 1837, the first commercial electrical telegraph was demonstrated by English inventor Sir William Fothergill Cooke and English scientist Sir Charles Wheatstone . Both inventors viewed their device as "an improvement to the [existing] electromagnetic telegraph" and not as a new device. Samuel Morse independently developed
5488-403: The expense of increasing the channel bandwidth requirement. The term "channel" has two different meanings. In one meaning, a channel is the physical medium that carries a signal between the transmitter and the receiver. Examples of this include the atmosphere for sound communications, glass optical fibres for some kinds of optical communications , coaxial cables for communications by way of
5586-454: The field of electronic television after mechanical systems became obsolete. In 1939, he showed a system known today as hybrid colour using a cathode-ray tube in front of which revolved a disc fitted with colour filters, a method taken up by CBS and RCA in the United States. As early as 1940, Baird had started work on a fully electronic system he called the " Telechrome ". Early Telechrome devices used two electron guns aimed at either side of
5684-458: The first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi , who won the 1909 Nobel Prize in Physics . Other early pioneers in electrical and electronic telecommunications include co-inventors of the telegraph Charles Wheatstone and Samuel Morse , numerous inventors and developers of
5782-584: The first person to be televised in a full tonal range. In June 1924, Baird had bought from Cyril Frank Elwell a thallium sulphide (Thalofide) cell, developed by Theodore Case in the USA. The Thalofide cell was part of the important new technology of 'talking pictures'. Baird's pioneering implementation of this cell allowed Baird to become the first person to produce a live, moving, greyscale television image from reflected light . Baird achieved this, where other inventors had failed, by applying two unique methods to
5880-611: The first public demonstration of true television images for members of the Royal Institution and a reporter from The Times in his laboratory at 22 Frith Street in the Soho district of London, where Bar Italia is now located. Baird initially used a scan rate of 5 pictures per second, improving this to 12.5 pictures per second c.1927. It was the first demonstration of a television system that could scan and display live moving images with tonal graduation. He demonstrated
5978-628: The first transatlantic television transmission, from London to Hartsdale , New York, and in 1929 the first television programmes officially transmitted by the BBC . In November 1929, Baird and Bernard Natan established France's first television company, Télévision-Baird-Natan. Broadcast on the BBC on 14 July 1930, The Man with the Flower in His Mouth was the first drama shown on UK television. The BBC transmitted Baird's first live outside broadcast with
SECTION 60
#17327731359956076-410: The high ground of the north London ridge, the BBC began alternating Baird 240-line transmissions with EMI 's electronic scanning system, which had recently been improved to 405-lines after a merger with Marconi . The Baird system at the time involved an intermediate film process, where footage was shot on cinefilm, which was rapidly developed and scanned. The trial was due to last for 6 months but
6174-431: The importance of social conversations and staying connected to family and friends. Since then the role that telecommunications has played in social relations has become increasingly important. In recent years, the popularity of social networking sites has increased dramatically. These sites allow users to communicate with each other as well as post photographs, events and profiles for others to see. The profiles can list
6272-703: The invention of television. In 2021, the Royal Mint unveiled a John Logie Baird 50p coin commemorating the 75th anniversary of his death. Baird was born on 13 August 1888 in Helensburgh , Dunbartonshire, and was the youngest of four children of the Reverend John Baird, the Church of Scotland 's minister for the local St Bride's Church, and Jessie Morrison Inglis, the orphaned niece of the wealthy Inglis family of shipbuilders from Glasgow . He
6370-670: The invention of the television. Baird became the only deceased subject of This Is Your Life when he was honoured by Eamonn Andrews at the BBC Television Theatre in 1957. In 2014, the Society of Motion Picture and Television Engineers (SMPTE) inducted Logie Baird into The Honor Roll, which "posthumously recognizes individuals who were not awarded Honorary Membership during their lifetimes but whose contributions would have been sufficient to warrant such an honor". In 2023, John MacKay portrayed John Logie Baird in both
6468-552: The management of telecommunication and broadcasting. The history of broadcasting discusses some debates in relation to balancing conventional communication such as printing and telecommunication such as radio broadcasting. The onset of World War II brought on the first explosion of international broadcasting propaganda. Countries, their governments, insurgents, terrorists, and militiamen have all used telecommunication and broadcasting techniques to promote propaganda. Patriotic propaganda for political movements and colonization started
6566-567: The medium into channels according to frequency is called " frequency-division multiplexing ". Another term for the same concept is " wavelength-division multiplexing ", which is more commonly used in optical communications when multiple transmitters share the same physical medium. Another way of dividing a communications medium into channels is to allocate each sender a recurring segment of time (a "time slot", for example, 20 milliseconds out of each second), and to allow each sender to send messages only within its own time slot. This method of dividing
6664-414: The medium into communication channels is called " time-division multiplexing " ( TDM ), and is used in optical fibre communication. Some radio communication systems use TDM within an allocated FDM channel. Hence, these systems use a hybrid of TDM and FDM. The shaping of a signal to convey information is known as modulation . Modulation can be used to represent a digital message as an analogue waveform. This
6762-693: The mid-1930s. In 1936, the BBC broadcast propaganda to the Arab World to partly counter similar broadcasts from Italy, which also had colonial interests in North Africa. Modern political debates in telecommunication include the reclassification of broadband Internet service as a telecommunications service (also called net neutrality ), regulation of phone spam , and expanding affordable broadband access. According to data collected by Gartner and Ars Technica sales of main consumer's telecommunication equipment worldwide in millions of units was: In
6860-596: The mid-1960s, thermionic tubes were replaced with the transistor . Thermionic tubes still have some applications for certain high-frequency amplifiers. On 11 September 1940, George Stibitz transmitted problems for his Complex Number Calculator in New York using a teletype and received the computed results back at Dartmouth College in New Hampshire . This configuration of a centralized computer ( mainframe ) with remote dumb terminals remained popular well into
6958-429: The modern era used sounds like coded drumbeats , the blowing of horns , and whistles . Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the telegraph , telephone , television , and radio . Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In
7056-452: The music store. Telecommunication has also transformed the way people receive their news. A 2006 survey (right table) of slightly more than 3,000 Americans by the non-profit Pew Internet and American Life Project in the United States the majority specified television or radio over newspapers. Telecommunication has had an equally significant impact on advertising. TNS Media Intelligence reported that in 2007, 58% of advertising expenditure in
7154-402: The necessary provisioning, billing, and customer care computer systems, and the marketing, customer care, and engineering organizations needed to sell, deliver, and bill for services. However, a mobile network operator can outsource any of these systems or functions and still be considered a mobile network operator. In addition to obtaining revenue by offering retail services under its own brand,
7252-400: The neighbourhood of 94.5 MHz (megahertz) while another radio station can simultaneously broadcast radio waves at frequencies in the neighbourhood of 96.1 MHz. Each radio station would transmit radio waves over a frequency bandwidth of about 180 kHz (kilohertz), centred at frequencies such as the above, which are called the "carrier frequencies" . Each station in this example
7350-628: The newly formed company EMI- Marconi under Sir Isaac Shoenberg , who headed a research group that developed an advanced camera tube (the Emitron) and a relatively efficient hard-vacuum cathode-ray tube for the television receiver. Philo T. Farnsworth 's electronic "Image Dissector" camera was available to Baird's company via a patent-sharing agreement. However, the Image Dissector camera was found to be lacking in light sensitivity, requiring excessive levels of illumination. The Baird company used
7448-472: The original Phonovision discs have been preserved. Baird's other developments were in fibre-optics , radio direction finding, infrared night viewing and radar . There is discussion about his exact contribution to the development of radar, for his wartime defence projects have never been officially acknowledged by the UK government . According to Malcolm Baird, his son, what is known is that in 1926 Baird filed
7546-515: The presence or absence of an atmosphere between the two. Radio waves travel through a perfect vacuum just as easily as they travel through air, fog, clouds, or any other kind of gas. The other meaning of the term "channel" in telecommunications is seen in the phrase communications channel , which is a subdivision of a transmission medium so that it can be used to send multiple streams of information simultaneously. For example, one radio station can broadcast radio waves into free space at frequencies in
7644-709: The relationship as causal. Because of the economic benefits of good telecommunication infrastructure, there is increasing worry about the inequitable access to telecommunication services amongst various countries of the world—this is known as the digital divide . A 2003 survey by the International Telecommunication Union (ITU) revealed that roughly a third of countries have fewer than one mobile subscription for every 20 people and one-third of countries have fewer than one land-line telephone subscription for every 20 people. In terms of Internet access, roughly half of all countries have fewer than one out of 20 people with Internet access. From this information, as well as educational data,
7742-405: The sock provided warmth. Between 1926 and 1928, he attempted to develop an early video recording device, which he dubbed Phonovision . The system consisted of a large Nipkow scanning disk attached by a mechanical linkage to a record-cutting lathe . The result was a disc that could record a 30-line video signal. Technical difficulties with the system prevented its further development, but some of
7840-556: The south coast of England. He later rented a workshop in the Queen's Arcade in the town. Baird built what was to become the world's first working television set using items that included an old hatbox and a pair of scissors, some darning needles, a few bicycle light lenses, a used tea chest, and sealing wax and glue that he purchased. In February 1924, he demonstrated to the Radio Times that a semi-mechanical analogue television system
7938-516: The telephone including Antonio Meucci , Philipp Reis , Elisha Gray and Alexander Graham Bell , inventors of radio Edwin Armstrong and Lee de Forest , as well as inventors of television like Vladimir K. Zworykin , John Logie Baird and Philo Farnsworth . Since the 1960s, the proliferation of digital technologies has meant that voice communications have gradually been supplemented by data. The physical limitations of metallic media prompted
8036-412: The telephone system were originally advertised with an emphasis on the practical dimensions of the device (such as the ability to conduct business or order home services) as opposed to the social dimensions. It was not until the late 1920s and 1930s that the social dimensions of the device became a prominent theme in telephone advertisements. New promotions started appealing to consumers' emotions, stressing
8134-513: The televising of The Derby in 1931. He demonstrated a theatre television system, with a screen two feet by five feet (60 cm by 150 cm), in 1930 at the London Coliseum , Berlin, Paris, and Stockholm . By 1939 he had improved his theatre projection to televise a boxing match on a screen 15 ft (4.6 m) by 12 ft (3.7 m). From 1929 to 1935, the BBC transmitters were used to broadcast television programmes using
8232-631: The then-newly discovered phenomenon of radio waves , demonstrating, by 1901, that they could be transmitted across the Atlantic Ocean. This was the start of wireless telegraphy by radio. On 17 December 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, Canada , became the world's first radio message to cross the Atlantic from North America. In 1904, a commercial service
8330-490: The voltages and electric currents in them, and free space for communications using visible light , infrared waves, ultraviolet light , and radio waves . Coaxial cable types are classified by RG type or "radio guide", terminology derived from World War II. The various RG designations are used to classify the specific signal transmission applications. This last channel is called the "free space channel". The sending of radio waves from one place to another has nothing to do with
8428-439: The wartime purposes of aircraft and land communication, radio navigation, and radar. Development of stereo FM broadcasting of radio began in the 1930s in the United States and the 1940s in the United Kingdom, displacing AM as the dominant commercial standard in the 1970s. On March 25, 1925, John Logie Baird demonstrated the transmission of moving pictures at the London department store Selfridges . Baird's device relied upon
8526-524: The world's first colour transmission on 3 July 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with a filter of a different primary colour; and three light sources at the receiving end, with a commutator to alternate their illumination. That same year he also demonstrated stereoscopic television. In 1927, Baird transmitted a long-distance television signal over 438 miles (705 km) of telephone line between London and Glasgow ; Baird transmitted
8624-573: The world's first live working television system on 26 January 1926. He went on to invent the first publicly demonstrated colour television system and the first viable purely electronic colour television picture tube. In 1928 the Baird Television Development Company achieved the first transatlantic television transmission. Baird's early technological successes and his role in the practical introduction of broadcast television for home entertainment have earned him
8722-655: The world's first long-distance television pictures to the Central Hotel at Glasgow Central Station. This transmission was Baird's response to a 225-mile, long-distance telecast between stations of AT&T Bell Labs. The Bell stations were in New York and Washington, DC. The earlier telecast took place in April 1927, a month before Baird's demonstration. Baird set up the Baird Television Development Company Ltd , which in 1928 made
8820-418: The world's gross domestic product (GDP). Modern telecommunication is founded on a series of key concepts that experienced progressive development and refinement in a period of well over a century: Telecommunication technologies may primarily be divided into wired and wireless methods. Overall, a basic telecommunication system consists of three main parts that are always present in some form or another: In
8918-490: Was during the Spanish Armada , when a beacon chain relayed a signal from Plymouth to London . In 1792, Claude Chappe , a French engineer, built the first fixed visual telegraphy system (or semaphore line ) between Lille and Paris. However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres (six to nineteen miles). As a result of competition from
9016-668: Was educated at Larchfield Academy (now part of Lomond School ) in Helensburgh; the Glasgow and West of Scotland Technical College ; and the University of Glasgow . While at college, Baird undertook a series of engineering apprentice jobs as part of his course. The conditions in industrial Glasgow at the time helped form his socialist convictions but also contributed to his ill health. He became an agnostic, though this did not strain his relationship with his father. His degree course
9114-407: Was established to transmit nightly news summaries to subscribing ships, which incorporated them into their onboard newspapers. World War I accelerated the development of radio for military communications . After the war, commercial radio AM broadcasting began in the 1920s and became an important mass medium for entertainment and news. World War II again accelerated the development of radio for
9212-629: Was interrupted by the First World War and he never returned to graduate. At the beginning of 1915 he volunteered for service in the British Army but was classified as unfit for active duty. Unable to go to the front, he took a job with the Clyde Valley Electrical Power Company, which was engaged in munitions work. In early 1923, and in poor health, Baird moved to 21 Linton Crescent, Hastings , on
9310-471: Was later reconfirmed, according to Article 1.3 of the ITU Radio Regulations , which defined it as "Any transmission , emission or reception of signs, signals, writings, images and sounds or intelligence of any nature by wire , radio, optical, or other electromagnetic systems". Homing pigeons have been used throughout history by different cultures. Pigeon post had Persian roots and
9408-676: Was later used by the Romans to aid their military. Frontinus claimed Julius Caesar used pigeons as messengers in his conquest of Gaul . The Greeks also conveyed the names of the victors at the Olympic Games to various cities using homing pigeons. In the early 19th century, the Dutch government used the system in Java and Sumatra . And in 1849, Paul Julius Reuter started a pigeon service to fly stock prices between Aachen and Brussels ,
9506-486: Was of little practical value because it relied on the electrophonic effect requiring users to place the receiver in their mouths to "hear". The first commercial telephone services were set up by the Bell Telephone Company in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London. In 1894, Italian inventor Guglielmo Marconi began developing a wireless communication using
9604-552: Was possible by transmitting moving silhouette images. In July of the same year, he received a 1000-volt electric shock but survived with only a burnt hand but, as a result, his landlord, Mr Tree, asked him to vacate the premises. Soon after arriving in London, looking for publicity, Baird visited the Daily Express newspaper to promote his invention. The news editor was terrified and he was quoted by one of his staff as saying: "For God's sake, go down to reception and get rid of
#994005