86-489: Cable & Wireless plc was a British telecommunications company. In the mid-1980s, it became the first company in the UK to offer an alternative telephone service to British Telecom (via subsidiary Mercury Communications ). The company later offered cable TV to its customers, but it sold its cable assets to NTL in 2000. It remained a significant player in the UK telecoms market and in certain overseas markets, especially in
172-412: 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
258-411: 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
344-411: 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
430-438: 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
516-441: 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
602-658: A considerable contribution to the Allied war effort, supplying, for instance, the wireless equipment with which the North African campaign was conducted in 1942, and sending staff, in army uniforms marked with Telcon flashes, into several campaigns, starting in Italy in 1943. Following the Labour Party 's victory in the 1945 general election, the government announced its intention to nationalise Cable and Wireless, which
688-495: 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
774-406: 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
860-450: 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
946-838: 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
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#17327803739341032-437: 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
1118-491: 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
1204-625: A reverse takeover in terms of senior management, with John Pluthero appointed from Energis to head the UK business and Francesco Caio departing by April 2006. Cable & Wireless cancelled its American depositary receipts programme in December 2005, voluntarily delisting from the New York Stock Exchange . In February 2007, Cable & Wireless sold the Web Technology Group , which focused on internet systems for
1290-475: 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
1376-953: A strategy to sell global IP services to corporations. Cable & Wireless purchased Japanese company IDC (International Digital Communications), naming it Cable & Wireless IDC Inc. In July 1999, NTL purchased the consumer assets of Cable & Wireless for nearly £8.2 billion, integrating the telephone, internet and television operations of Cable & Wireless into its own ever-expanding operation. This in-part lead to an aggressive strategy where, during 1999 and 2000, Cable and Wireless purchased 12 ISPs and other companies across mainland Europe (Austria, France, Germany, The Netherlands, Belgium, Italy, Spain, and Switzerland) and Sweden and Ireland to create, with its UK business, Cable and Wireless Europe. In December 2000, Cable and Wireless purchased Hyperlink-Interactive . In 2001, Cable and Wireless sold its 52.5 percent stake in Cable and Wireless Optus , which
1462-411: 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
1548-412: 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
1634-581: 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
1720-671: 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
1806-451: 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
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#17327803739341892-434: 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
1978-794: 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
2064-481: 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
2150-543: Is now the largest communications carrier in that country. In 1998, MCI Communications and WorldCom merged to create MCI WorldCom , the company's existing US subsidiary Cable and Wireless USA, Inc. purchased the MCI tier 1 backbone in the U.S. : prior to 1998, Cable & Wireless USA had merely operated a long-distance telephone business and a small internet service. In 1999, Cable & Wireless began building global IP and IP MPLS (multiprotocol label switching) networks with
2236-609: 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
2322-448: 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
2408-449: 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
2494-576: The British Empire into one operating company, initially known as the Imperial and International Communications Ltd , and from 1934 as Cable and Wireless Limited . The firm formed subsidiary corporations in various countries, such as the Indian Radio and Cable Communications Company in 1932, designed to oversee India's external communications with other countries. World War II revived
2580-773: 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
2666-717: The States of Guernsey . Later in 2002, Cable & Wireless announced its withdrawal from the US corporate market, with operations being sold to Primus Telecom . In March 2004, SAVVIS Communications Corporation purchased Cable and Wireless America for US$ 155 million via the Chapter 11 creditor protection process, assuming liabilities of around US$ 12.5 million and assets including the former MCI IP backbone AS3561. Cable & Wireless acquired Energis for £674 million in August 2005, resulting in
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2752-440: 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
2838-457: The 'cable war' of 1914–1918. In 1939, German-owned cables across the Atlantic were cut once again, and, in 1940, Italian cables to South America and Spain were cut in retaliation for Italian action against two of the five British cables linking Gibraltar and Malta. Electra House , the company's head office and central cable station, was damaged by German bombing in 1941. However, the company made
2924-705: 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
3010-497: 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
3096-634: The Anglo-Mediterranean cable (linking Malta to Alexandria using a cable manufactured by one of Pender's companies) to Britain and India, respectively. The London to Bombay telegraph line was completed in 1870, and in 1872 the three companies were merged with the Marseilles, Algiers and Malta Telegraph Company to form the Eastern Telegraph Company , with Pender as chairman. The Eastern Telegraph Company expanded
3182-548: The British government as a prize of war, to be operated by the General Post Office. In 1920, the government decided to keep this cable, despite U.S. protests, and to purchase a second line, the two together being renamed Imperial Cable . With increasing competition from companies using radio communications, such as Marconi's Wireless Telegraph Company , it was decided in 1928 to merge the communications methods of
3268-466: 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
3354-744: 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
3440-668: The Pacific Cable and the cable across the Indian Ocean, by attacking island stations in each ocean. However, the most spectacular event of the first "cable war" came in 1917, when, following the United States' entry into the war, the German cable that had been cut three years before was lifted out of its position between New York and Emden, Germany, moved to a new position between Nova Scotia and Cornwall, and taken over by
3526-519: The UK government, and in March sold its cabling business Allnet . In October 2008, Cable & Wireless completed the purchase of Thus plc , which was rebranded as "Thus, a Cable & Wireless business". In November 2009, the Cable and Wireless plc board announced its intention to separate the Cable & Wireless Communications Group and the Cable & Wireless Worldwide Group, reflecting its belief that
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3612-506: 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
3698-734: 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
3784-617: The businesses had reached a position where they would deliver increased value to shareholders as separately listed companies. On 26 March 2010, Cable & Wireless Communications demerged as the former CWI Group business (Cable & Wireless International) from Cable and Wireless plc and was listed as a public company on the London Stock Exchange. Cable & Wireless plc became Cable & Wireless Worldwide. On 23 April 2012, Vodafone announced an agreement to acquire Cable & Wireless Worldwide for £1.04 billion. The purchase
3870-582: The cable length from 8,860 miles on its founding to 22,400 miles just 15 years later. The company steadily took over a number of companies founded to connect the West Indies and South America , among them the Eastern Extension Australasia and China Telegraph Company , leading to a name change to The Eastern and Associated Telegraph Companies in 1902. Throughout World War I , all cable services out of Britain were controlled by
3956-896: 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. Indian Radio and Cable Communications Company Former corporation based in India [REDACTED] This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed. Find sources: "Indian Radio and Cable Communications Company" – news · newspapers · books · scholar · JSTOR ( May 2023 ) ( Learn how and when to remove this message ) The Indian Radio and Cable Communications Company
4042-437: 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
4128-500: 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
4214-519: 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
4300-537: 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
4386-422: 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
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#17327803739344472-403: 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
4558-458: 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
4644-505: The first long-distance switches to utilize least-cost routing, follow-on account codes and PINs. In 1997, Mercury was merged with three cable operators in the UK ( Vidéotron , Nynex , and Bell Cablemedia), and renamed Cable & Wireless Communications. Later that year, Cable & Wireless bought 49% of the Panamanian state-run INTEL (Instituto Nacional de TELecomunicaciones, National Telecommunications Institute) for US$ 652 million: it
4730-931: The former British colonies of the Caribbean , where it was formerly the monopoly incumbent. It was also the main supplier of communication in the British South Atlantic, including Saint Helena and the Falkland Islands . It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index . The company split in March 2010, with its international division demerging to form Cable & Wireless Communications , acquired by Liberty Global in 2015, and since spun-off in 2018 from Liberty Global to Liberty Latin America, while
4816-729: The government. The Eastern Telegraph group profited enormously from the diversion of business to India and East Asia, away from the German-owned overland routes and from the general use of telegrams in preference to letters, which were delayed by lack of civilian shipping. For the first time, cables became targets of warfare in themselves. Eastern Telegraph, the British Royal Navy , and the General Post Office collaborated on cutting all cable links between Germany and North America. The Germans temporarily disabled both
4902-431: 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
4988-552: 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
5074-567: 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
5160-414: 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
5246-742: 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
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#17327803739345332-596: 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
5418-429: 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
5504-452: 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
5590-464: The nationalised industries, and Cable and Wireless was an early candidate because of its history as a private company. The plan to privatise was announced in 1980. The government sold the first half of its share in Cable & Wireless in November 1981. In February 1982, the government granted a licence for a UK telecommunications network, Mercury Communications Ltd , as a rival to British Telecom . It
5676-400: 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
5762-515: 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
5848-709: 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,
5934-586: The remainder of the Cable & Wireless business became Cable & Wireless Worldwide and was acquired by Vodafone in 2012. Cable and Wireless traces its history back to a number of British telegraph companies founded in the 1860s, and cites Sir John Pender as the founder. In 1869, Pender founded the Falmouth, Malta, Gibraltar Telegraph Company and the British Indian Submarine Telegraph Company , which connected
6020-516: 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
6106-412: 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
6192-575: 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
6278-490: 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
6364-492: 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
6450-418: 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
6536-841: Was a subsidiary corporation formed by Imperial and International Communications, Ltd. and the India Radio Telegraph Company in 1932. Its purpose was to operate India's external communications to other countries. The Indian government took over the assets of the company in 1947, placing them into the Ministry of Communications as the Overseas Communications Service. References [ edit ] ^ Robert Boyce, "The Origins of Cable and Wireless Limited, 1918-1939," in Bernard Finn and Daqing Yang, eds., Communications Under
6622-747: Was a company named TDX Systems. In 1986, the US long distance industry was deregulated, and many new companies launched into the equal access market. TDX Systems, based in Falls Church, Virginia , was one of these, with a footprint between Washington, DC and New York. TDX carried data (analog modem up to digital DS3), and built its own telephone switches at its engineering facility in Chantilly, VA. TDX voice switches, called "SSTs" (satellite switching terminal) were centrally controlled nationwide by Perkin-Elmer mainframes in Falls Church, and were some of
6708-477: Was carried out in 1947. While the company would remain in being as a government-owned company, continuing to own assets and operating telecommunication services outside the UK, all assets in the UK were integrated with those of the General Post Office , which operated the UK's domestic telecommunications monopoly. In 1979, the Conservative Party government led by Margaret Thatcher began privatising
6794-413: Was completed on 30 July 2012, and Cable & Wireless was fully integrated into Vodafone on 1 April 2013. Telecommunication 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
6880-490: 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
6966-465: Was established as a subsidiary of Cable & Wireless. Seeing an opportunity to enter the growing US telecom market afforded by new, optical fiber technology (The US Communications Act of 1934 prohibited ownership of radio facilities by foreign owned companies), Cable & Wireless acquired 9xDS3s from MCI along the Amtrak right of way and began selling transmission services. Among its early customers
7052-407: 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
7138-471: 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
7224-676: 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 ,
7310-486: 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
7396-584: Was the second-largest telecom company in Australia, to SingTel . The deal was said to be the second largest corporate deal in Australian history. In November 2001, Cable and Wireless acquired the bankrupt co-location provider Exodus Communications for US$ 800 million, and Exodus' operations were then merged with the previously acquired Digital Island and renamed Cable and Wireless America. In May 2002, Cable and Wireless purchased Guernsey Telecoms from
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