91-724: Sema Group plc was an Anglo-French IT services company. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index . It was acquired by Schlumberger in 2001. The Company was founded in 1988 by the merger of the British CAP Group and the French company, Sema-Metra SA. In 1991 Sema and British Aerospace established the BAeSEMA naval systems joint venture to produce naval systems: it
182-514: A ringer or a visual indicator, to announce an incoming telephone call. Telephone calls are initiated most commonly with a keypad or dial, affixed to the telephone, to enter a telephone number , which is the address of the call recipient's telephone in the telecommunications system, but other methods existed in the early history of the telephone. The first telephones were directly connected to each other from one customer's office or residence to another customer's location. Being impractical beyond just
273-408: A speaking tube . In the U.S., a somewhat dated slang term refers to the telephone as "the horn," as in "I couldn't get him on the horn," or "I'll be off the horn in a moment." Early telephones were technically diverse. Some used a water microphone , some had a metal diaphragm that induced current in an electromagnet wound around a permanent magnet, and some were dynamic – their diaphragm vibrated
364-618: A business context, the Information Technology Association of America has defined information technology as "the study, design, development, application, implementation, support, or management of computer-based information systems". The responsibilities of those working in the field include network administration, software development and installation, and the planning and management of an organization's technology life cycle, by which hardware and software are maintained, upgraded, and replaced. Information services
455-497: A coil of wire in the field of a permanent magnet or the coil vibrated the diaphragm. The sound-powered dynamic variants survived in small numbers through the 20th century in military and maritime applications, where its ability to create its own electrical power was crucial. Most, however, used the Edison/Berliner carbon transmitter , which was much louder than the other kinds, even though it required an induction coil which
546-422: A common battery exchange had a magneto hand-cranked generator to produce a high voltage alternating signal to ring the bells of other telephones on the line and to alert the operator. Some local farming communities that were not connected to the main networks set up barbed wire telephone lines that exploited the existing system of field fences to transmit the signal. In the 1890s a new smaller style of telephone
637-542: A complete computing machine. During the Second World War , Colossus developed the first electronic digital computer to decrypt German messages. Although it was programmable , it was not general-purpose, being designed to perform only a single task. It also lacked the ability to store its program in memory; programming was carried out using plugs and switches to alter the internal wiring. The first recognizably modern electronic digital stored-program computer
728-475: A component of their 305 RAMAC computer system. Most digital data today is still stored magnetically on hard disks, or optically on media such as CD-ROMs . Until 2002 most information was stored on analog devices , but that year digital storage capacity exceeded analog for the first time. As of 2007 , almost 94% of the data stored worldwide was held digitally: 52% on hard disks, 28% on optical devices, and 11% on digital magnetic tape. It has been estimated that
819-485: A few customers, these systems were quickly replaced by manually operated centrally located switchboards . These exchanges were soon connected together, eventually forming an automated, worldwide public switched telephone network . For greater mobility, various radio systems were developed in the mid-20th century for transmission between mobile stations on ships and in automobiles. Hand-held mobile phones were introduced for personal service starting in 1973. In later decades,
910-486: A home and a shop. Users who wanted the ability to speak to several different locations would need to obtain and set up three or four pairs of telephones. Western Union , already using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco , and Bell was not slow in appreciating the potential. Signalling began in an appropriately primitive manner. The user alerted
1001-570: A limited group of IT users, and an IT project usually refers to the commissioning and implementation of an IT system. IT systems play a vital role in facilitating efficient data management, enhancing communication networks, and supporting organizational processes across various industries. Successful IT projects require meticulous planning, seamless integration, and ongoing maintenance to ensure optimal functionality and alignment with organizational objectives. Although humans have been storing, retrieving, manipulating, and communicating information since
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#17327974626911092-450: A more efficient manner are usually seen as "just the cost of doing business." IT departments are allocated funds by senior leadership and must attempt to achieve the desired deliverables while staying within that budget. Government and the private sector might have different funding mechanisms, but the principles are more-or-less the same. This is an often overlooked reason for the rapid interest in automation and Artificial Intelligence , but
1183-586: A new industry comprising many VoIP companies that offer services to consumers and businesses . The reported global VoIP market in October 2021 was $ 85.2 billion with a projection of $ 102.5 billion by 2026. IP telephony uses high-bandwidth Internet connections and specialized customer premises equipment to transmit telephone calls via the Internet, or any modern private data network. The customer equipment may be an analog telephone adapter (ATA) which translates
1274-400: A numeric keypad for dialing, and a display for caller ID . In addition, answering machine function may be built in. The cordless handset contains a rechargeable battery , which the base station recharges when the handset rests in its cradle. Muilt-handset systems generally also have additional charging stands. A cordless telephone typically requires a constant electricity supply to power
1365-417: A particular letter; possible delays in message delivery (up to several days); limits on the size of one message and on the total size of messages in the mailbox (personal for users). A software and hardware complex with a web interface that provides the ability to search for information on the Internet. A search engine usually means a site that hosts the interface (front-end) of the system. The software part of
1456-591: A satellite phone is that it can be used in such regions where local terrestrial communication infrastructures, such as landline and cellular networks, are not available. Satellite phones are popular on expeditions into remote locations, hunting, fishing, maritime sector, humanitarian missions, business trips, and mining in hard-to-reach areas, where there is no reliable cellular service. Satellite telephones rarely get disrupted by natural disasters on Earth or human actions such as war, so they have proven to be dependable communication tools in emergency situations, when
1547-405: A search engine is a search engine (search engine) — a set of programs that provides the functionality of a search engine and is usually a trade secret of the search engine developer company. Most search engines look for information on World Wide Web sites, but there are also systems that can look for files on FTP servers, items in online stores, and information on Usenet newsgroups. Improving search
1638-431: A separate enclosure, called the subscriber set. The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line one to ten times for each digit, and the hook switch (in the center of the circuit diagram) disconnected the line and the transmitter battery while the handset was on the cradle. In the 1930s, telephone sets were developed that combined the bell and induction coil with
1729-464: A technology now obsolete. Electronic data storage, which is used in modern computers, dates from World War II, when a form of delay-line memory was developed to remove the clutter from radar signals, the first practical application of which was the mercury delay line. The first random-access digital storage device was the Williams tube , which was based on a standard cathode ray tube . However,
1820-514: A wired interface, such as USB or Lightning connectors. Smartphones, being able to run apps , have vastly expanded functionality compared to previous mobile phones. Having internet access and built in cameras, smartphones have made video calling readily accessible via IP connections. Smartphones also have access to a large number of web services and web apps, giving them functionality similar to traditional computers, although smartphones are often limited by their relatively small screen size and
1911-465: Is a set of related fields that encompass computer systems, software , programming languages , and data and information processing, and storage. IT forms part of information and communications technology (ICT). An information technology system ( IT system ) is generally an information system , a communications system , or, more specifically speaking, a computer system — including all hardware , software , and peripheral equipment — operated by
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#17327974626912002-487: Is a term somewhat loosely applied to a variety of IT-related services offered by commercial companies, as well as data brokers . The field of information ethics was established by mathematician Norbert Wiener in the 1940s. Some of the ethical issues associated with the use of information technology include: Research suggests that IT projects in business and public administration can easily become significant in scale. Work conducted by McKinsey in collaboration with
2093-433: Is also worth noting that from a business perspective, Information technology departments are a " cost center " the majority of the time. A cost center is a department or staff which incurs expenses, or "costs", within a company rather than generating profits or revenue streams. Modern businesses rely heavily on technology for their day-to-day operations, so the expenses delegated to cover technology that facilitates business in
2184-566: Is commonly held in relational databases to take advantage of their "robust implementation verified by years of both theoretical and practical effort." As an evolution of the Standard Generalized Markup Language (SGML), XML's text-based structure offers the advantage of being both machine- and human-readable . Data transmission has three aspects: transmission, propagation, and reception. It can be broadly categorized as broadcasting , in which information
2275-489: Is derived from the Greek : τῆλε , tēle , "far" and φωνή, phōnē , "voice", together meaning "distant voice". Credit for the invention of the electric telephone is frequently disputed. As with other influential inventions such as radio , television , the light bulb , and the computer , several inventors pioneered experimental work on voice transmission over a wire and improved on each other's ideas. New controversies over
2366-428: Is limited, usually to within the same building or within a short distance from the base station. Base stations include a radio transceiver which enables full-duplex, outgoing and incoming signals and speech with the handsets. The base station often includes a microphone, audio amplifier , and a loudspeaker to enable hands-free speakerphone conversations, without needing to use a handset. The base station may also have
2457-507: Is one of the priorities of the modern Internet (see the Deep Web article about the main problems in the work of search engines). Companies in the information technology field are often discussed as a group as the "tech sector" or the "tech industry." These titles can be misleading at times and should not be mistaken for "tech companies;" which are generally large scale, for-profit corporations that sell consumer technology and software. It
2548-424: Is still widely deployed more than 50 years later. IMS stores data hierarchically , but in the 1970s Ted Codd proposed an alternative relational storage model based on set theory and predicate logic and the familiar concepts of tables, rows, and columns. In 1981, the first commercially available relational database management system (RDBMS) was released by Oracle . All DMS consist of components, they allow
2639-417: Is transmitted unidirectionally downstream, or telecommunications , with bidirectional upstream and downstream channels. XML has been increasingly employed as a means of data interchange since the early 2000s, particularly for machine-oriented interactions such as those involved in web-oriented protocols such as SOAP , describing "data-in-transit rather than... data-at-rest". Hilbert and Lopez identify
2730-663: The Earth instead of terrestrial cell sites , as cellphones do. Therefore, they can work in most geographic locations on the Earth's surface, as long as open sky and the line-of-sight between the phone and the satellite is provided. Depending on the architecture of a particular system, coverage may include the entire Earth or only specific regions. Satellite phones provide similar functionality to terrestrial mobile telephones; voice calling , text messaging , and low-bandwidth Internet access are supported through most systems. The advantage of
2821-612: The Internet , giving rise to the field of Internet Protocol (IP) telephony, also known as voice over Internet Protocol (VoIP). VoIP has proven to be a disruptive technology that is rapidly replacing traditional telephone network infrastructure. By January 2005, up to 10% of telephone subscribers in Japan and South Korea had switched to this digital telephone service. A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing." The technology has spawned
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2912-399: The Internet , which was equivalent to 51 million households. Along with the Internet, new types of technology were also being introduced across the globe, which has improved efficiency and made things easier across the globe. Along with technology revolutionizing society, millions of processes could be done in seconds. Innovations in communication were also crucial as people began to rely on
3003-567: The University of Oxford suggested that half of all large-scale IT projects (those with initial cost estimates of $ 15 million or more) often failed to maintain costs within their initial budgets or to complete on time. Telephones A telephone , colloquially referred to as a phone , is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound , typically and most efficiently
3094-402: The human voice , into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from Ancient Greek : τῆλε , romanized : tēle , lit. 'far' and φωνή ( phōnē , voice ), together meaning distant voice . In 1876, Alexander Graham Bell
3185-432: The 16th century, and it was not until 1645 that the first mechanical calculator capable of performing the four basic arithmetical operations was developed. Electronic computers , using either relays or valves , began to appear in the early 1940s. The electromechanical Zuse Z3 , completed in 1941, was the world's first programmable computer, and by modern standards one of the first machines that could be considered
3276-658: The 1990s, mobile phones have gained other features which are not directly related to their primary function as telephones. These include text messaging, calendars, alarm clocks, personal schedulers, cameras, music players, games and later, internet access and smartphone functionality. Nearly all mobile phones have the ability to send text messages to other users via the SMS (Short Message Service) protocol. The multimedia messaging service (MMS) protocol enables users to send and receive multimedia content, such as photos, audio files and video files. As their functionality has increased over
3367-524: The IT Services division of Olivetti , adding another important market to its geography. In 2000, Sema acquired LHS for €5.1 billion to access its US telecoms software and services businesses: some analysts blamed the LHS acquisition for a profits warning in 2000 and a 45% fall in its stock market valuation. In 2001, Sema Group plc was acquired by Schlumberger and was renamed SchlumbergerSema . In 2004
3458-410: The Internet alone while e-commerce a decade later resulted in $ 289 billion in sales. And as computers are rapidly becoming more sophisticated by the day, they are becoming more used as people are becoming more reliant on them during the twenty-first century. Early electronic computers such as Colossus made use of punched tape , a long strip of paper on which data was represented by a series of holes,
3549-417: The ability to transfer both plain text and formatted, as well as arbitrary files; independence of servers (in the general case, they address each other directly); sufficiently high reliability of message delivery; ease of use by humans and programs. Disadvantages of e-mail: the presence of such a phenomenon as spam (massive advertising and viral mailings); the theoretical impossibility of guaranteed delivery of
3640-493: The advent of smartphones, mobile phone manufacturers have also included consumer electronics companies, such as Apple , Samsung and Xiaomi . As of 2022, most mobile phones are smartphones, being a combination of a mobile phone and a personal computing device in the same unit. Most smartphones are primarily operated using a graphical user interface and a touch screen. Many phones have a secondary voice user interface, such as Siri on Apple iPhones , which can operate many of
3731-451: The analog cellular system evolved into digital networks with greater capability and lower cost. Convergence in communication services has provided a broad spectrum of capabilities in cell phones, including mobile computing, giving rise to the smartphone , the dominant type of telephone in the world today. Before the development of the electric telephone, the term telephone was applied to other inventions, and not all early researchers of
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3822-527: The appearance of the term in 1990 contained within documents for the International Organization for Standardization (ISO). Innovations in technology have already revolutionized the world by the twenty-first century as people were able to access different online services. This has changed the workforce drastically as thirty percent of U.S. workers were already in careers in this profession. 136.9 million people were personally connected to
3913-567: The application of statistical and mathematical methods to decision-making , and the simulation of higher-order thinking through computer programs. The term is commonly used as a synonym for computers and computer networks , but it also encompasses other information distribution technologies such as television and telephones . Several products or services within an economy are associated with information technology, including computer hardware , software , electronics, semiconductors, internet , telecom equipment , and e-commerce . Based on
4004-401: The assistance of a telephone operator. What turned out to be the most popular and longest-lasting physical style of telephone was introduced in the early 20th century, including Bell's 202-type desk set. A carbon granule transmitter and electromagnetic receiver were united in a single molded plastic handle, which when not in use was secured in a cradle in the base unit. The circuit diagram of
4095-526: The base station and charger units by means of a DC transformer which plugs into a wall AC power outlet. A mobile phone or cellphone or hand phone is a handheld telephone which connects via radio transmissions to a cellular telephone network . The cellular network consists of a network of ground based transmitter/receiver stations with antennas – which are usually located on towers or on buildings – and infrastructure connecting to land-based telephone lines. Analog cellular networks first appeared in 1979, with
4186-404: The bell, induction coil, battery and magneto were in a separate bell box or " ringer box ". In phones connected to common battery exchanges, the ringer box was installed under a desk, or other out-of-the-way place, since it did not need a battery or magneto. Cradle designs were also used at this time, having a handle with the receiver and transmitter attached, now called a handset , separate from
4277-654: The bulk of the company was sold on to Atos Origin . The messaging unit was merged with Taral Networks and spun off as Airwide Solutions . The Smart Card and Terminal Department (formerly part of Schlumberger Test & Transactions) became Axalto , which later merged with Gemplus International to form Gemalto . Sema was registered in the United Kingdom but headquartered in Paris. Sema originally stood for Société d'Économétrie et de Mathématiques Appliquées. Information technology Information technology ( IT )
4368-409: The capacity, quality, and cost of the network. Integrated Services Digital Network (ISDN) was launched in the 1980's, providing businesses and consumers with access to digital telephony services such as data, voice, video , and fax services. The development of digital data communications methods made it possible to digitize voice and transmit it as real-time data across computer networks and
4459-464: The computer to communicate through telephone lines and cable. The introduction of the email was considered revolutionary as "companies in one part of the world could communicate by e-mail with suppliers and buyers in another part of the world..." Not only personally, computers and technology have also revolutionized the marketing industry, resulting in more buyers of their products. During the year of 2002, Americans exceeded $ 28 billion in goods just over
4550-419: The constant pressure to do more with less is opening the door for automation to take control of at least some minor operations in large companies. Many companies now have IT departments for managing the computers , networks, and other technical areas of their businesses. Companies have also sought to integrate IT with business outcomes and decision-making through a BizOps or business operations department. In
4641-470: The cradle base that housed the magneto crank and other parts. They were larger than the "candlestick" and more popular. Disadvantages of single-wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long-distance telephones, four-wire circuits . Users at the beginning of the 20th century did not place long-distance calls from their own telephones but made an appointment and were connected with
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#17327974626914732-431: The data they store to be accessed simultaneously by many users while maintaining its integrity. All databases are common in one point that the structure of the data they contain is defined and stored separately from the data itself, in a database schema . In recent years, the extensible markup language (XML) has become a popular format for data representation. Although XML data can be stored in normal file systems , it
4823-532: The desk set, obviating a separate ringer box. The rotary dial becoming commonplace in the 1930s in many areas enabled customer-dialed service, but some magneto systems remained even into the 1960s. After World War II, the telephone networks saw rapid expansion and more efficient telephone sets, such as the model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices. A breakthrough new technology
4914-420: The device's functions, as well as enabling users to use spoken commands to interact with the internet. Typically alphanumeric text input is accomplished via an on-screen virtual keyboard, although some smartphones have a small physical keyboard. Smartphones offer the ability to access internet data through the cellular network and via wi-fi, and usually allow direct connectivity to other devices via Bluetooth or
5005-402: The earliest Strowger switch automatic exchanges had seven wires, one for the knife switch , one for each telegraph key , one for the bell, one for the push-button and two for speaking. Large wall telephones in the early 20th century usually incorporated the bell, and separate bell boxes for desk phones dwindled away in the middle of the century. Rural and other telephones that were not on
5096-504: The earliest writing systems were developed, the term information technology in its modern sense first appeared in a 1958 article published in the Harvard Business Review ; authors Harold J. Leavitt and Thomas L. Whisler commented that "the new technology does not yet have a single established name. We shall call it information technology (IT)." Their definition consists of three categories: techniques for processing,
5187-457: The electrical device used the term. Perhaps the earliest use of the word for a communications system was the telephon created by Gottfried Huth in 1796. Huth proposed an alternative to the optical telegraph of Claude Chappe in which the operators in the signaling towers would shout to each other by means of what he called "speaking tubes", but would now be called giant megaphones . A communication device for sailing vessels, called telephone ,
5278-566: The emergence of information and communications technology (ICT). By the year of 1984, according to the National Westminster Bank Quarterly Review , the term information technology had been redefined as "The development of cable television was made possible by the convergence of telecommunications and computing technology (…generally known in Britain as information technology)." We then begin to see
5369-404: The exponential pace of technological change (a kind of Moore's law ): machines' application-specific capacity to compute information per capita roughly doubled every 14 months between 1986 and 2007; the per capita capacity of the world's general-purpose computers doubled every 18 months during the same two decades; the global telecommunication capacity per capita doubled every 34 months;
5460-455: The field of data mining — "the process of discovering interesting patterns and knowledge from large amounts of data" — emerged in the late 1980s. The technology and services it provides for sending and receiving electronic messages (called "letters" or "electronic letters") over a distributed (including global) computer network. In terms of the composition of elements and the principle of operation, electronic mail practically repeats
5551-524: The first digital cellular networks appearing in the early 1990s. Mobile phones require a SIM card to be inserted into the phone. The SIM card is a small PVC card containing a small integrated circuit which stores the user's international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers to the cellular network. Mobile phones generally incorporate an LCD or OLED display, with some types, such as smartphones, having touch screens. Since
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#17327974626915642-455: The first planar silicon dioxide transistors by Frosch and Derick in 1957, the MOSFET demonstration by a Bell Labs team. the planar process by Jean Hoerni in 1959, and the microprocessor invented by Ted Hoff , Federico Faggin , Masatoshi Shima , and Stanley Mazor at Intel in 1971. These important inventions led to the development of the personal computer (PC) in the 1970s, and
5733-443: The first transistorized computer developed at the University of Manchester and operational by November 1953, consumed only 150 watts in its final version. Several other breakthroughs in semiconductor technology include the integrated circuit (IC) invented by Jack Kilby at Texas Instruments and Robert Noyce at Fairchild Semiconductor in 1959, silicon dioxide surface passivation by Carl Frosch and Lincoln Derick in 1955,
5824-488: The information stored in it and delay-line memory was volatile in the fact that it had to be continuously refreshed, and thus was lost once power was removed. The earliest form of non-volatile computer storage was the magnetic drum , invented in 1932 and used in the Ferranti Mark 1 , the world's first commercially available general-purpose electronic computer. IBM introduced the first hard disk drive in 1956, as
5915-538: The introduction of computer science-related courses in K-12 education . Ideas of computer science were first mentioned before the 1950s under the Massachusetts Institute of Technology (MIT) and Harvard University , where they had discussed and began thinking of computer circuits and numerical calculations. As time went on, the field of information technology and computer science became more complex and
6006-531: The issue still arise from time to time. Charles Bourseul , Antonio Meucci , Johann Philipp Reis , Alexander Graham Bell , and Elisha Gray , amongst others, have all been credited with the invention of the telephone. Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. Before Bell's patent,
6097-412: The model 202 shows the direct connection of the transmitter to the line, while the receiver was inductively coupled. In local battery configurations, when the local loop was too long to provide sufficient current from the exchange, the transmitter was powered by a local battery and inductively coupled, while the receiver was included in the local loop. The coupling transformer and the ringer were mounted in
6188-471: The other end, or the exchange operator , by whistling into the transmitter. Exchange operation soon resulted in telephones being equipped with a bell in a ringer box , first operated over a second wire, and later over the same wire, but with a condenser ( capacitor ) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone " on hook "). Telephones connected to
6279-426: The service location to the emergency services when an emergency telephone number is called. A cordless telephone or portable telephone consists of a base station unit and one or more portable cordless handsets . The base station connects to a telephone line, or provides service by voice over IP (VOIP). The handset communicates with the base station via radio frequency signals. A handset's operational range
6370-453: The signals of a conventional analog telephone; an IP Phone , a dedicated standalone device; or a computer softphone application, utilizing the microphone and headset devices of a personal computer or smartphone. While traditional analog telephones are typically powered from the central office through the telephone line, digital telephones require a local power supply. Internet-based digital service also requires special provisions to provide
6461-510: The size of their keyboards. Typically, smartphones feature such tools as cameras, media players, web browsers, email clients, interactive maps, satellite navigation and a variety of sensors, such as a compass , accelerometers and GPS receivers . In addition to voice calls, smartphone users commonly communicate using a wide variety of messaging formats, including SMS, MMS, email, and various proprietary messaging services, such as iMessage and various social media platforms. In 2002, only 10% of
6552-503: The storage and processing technologies employed, it is possible to distinguish four distinct phases of IT development: pre-mechanical (3000 BC — 1450 AD), mechanical (1450 — 1840), electromechanical (1840 — 1940), and electronic (1940 to present). Information technology is a branch of computer science , defined as the study of procedures, structures, and the processing of various types of data. As this field continues to evolve globally, its priority and importance have grown, leading to
6643-417: The system of regular (paper) mail, borrowing both terms (mail, letter, envelope, attachment, box, delivery, and others) and characteristic features — ease of use, message transmission delays, sufficient reliability and at the same time no guarantee of delivery. The advantages of e-mail are: easily perceived and remembered by a person addresses of the form user_name@domain_name (for example, somebody@example.com);
6734-458: The telephone transmitted sound in a way that was similar to the telegraph. This method used vibrations and circuits to send electrical pulses, but was missing key features. Bell found that this method produced a sound through intermittent currents, but in order for the telephone to work a fluctuating current reproduced sounds the best. The fluctuating currents became the basis for the working telephone, creating Bell's patent. That first patent by Bell
6825-438: The user alternately listening and speaking (or rather, shouting) into the same hole. Sometimes the instruments were operated in pairs at each end, making conversation more convenient but also more expensive. At first, the benefits of a telephone exchange were not exploited. Instead, telephones were leased in pairs to a subscriber , who had to arrange for a telegraph contractor to construct a line between them, for example, between
6916-522: The voice at a distant location. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The transmitter converts the sound waves to electrical signals which are sent through the telecommunications system to the receiving telephone, which converts the signals into audible sound in the receiver or sometimes a loudspeaker . Telephones permit transmission in both directions simultaneously. Most telephones also contain an alerting feature, such as
7007-456: The world's population used mobile phones and by 2005 that percentage had risen to 46%. By the end of 2009, there were a total of nearly 6 billion mobile and fixed-line telephone subscribers worldwide. This included 1.26 billion fixed-line subscribers and 4.6 billion mobile subscribers. A satellite telephone, or satphone, is a type of mobile phone that connects to other phones or the telephone network by radio link through satellites orbiting
7098-405: The world's storage capacity per capita required roughly 40 months to double (every 3 years); and per capita broadcast information has doubled every 12.3 years. Massive amounts of data are stored worldwide every day, but unless it can be analyzed and presented effectively it essentially resides in what have been called data tombs: "data archives that are seldom visited". To address that issue,
7189-403: The worldwide capacity to store information on electronic devices grew from less than 3 exabytes in 1986 to 295 exabytes in 2007, doubling roughly every 3 years. Database Management Systems (DMS) emerged in the 1960s to address the problem of storing and retrieving large amounts of data accurately and quickly. An early such system was IBM 's Information Management System (IMS), which
7280-517: The years, many types of mobile phone, notably smartphones, require an operating system to run. Popular mobile phone operating systems in the past have included Symbian , Palm OS , BlackBerry OS and mobile phone versions of Windows . As of 2022, the most used operating systems are Google's Android and Apple's iOS . Before the era of smartphones, mobile phones were generally manufactured by companies specializing in telecommunications equipment, such as Nokia , Motorola , and Ericsson . Since
7371-503: Was able to handle the processing of more data. Scholarly articles began to be published from different organizations. Looking at early computing, Alan Turing , J. Presper Eckert , and John Mauchly were considered some of the major pioneers of computer technology in the mid-1900s. Giving them such credit for their developments, most of their efforts were focused on designing the first digital computer. Along with that, topics such as artificial intelligence began to be brought up as Turing
7462-461: Was an impedance matching transformer to make it compatible with the impedance of the line. The Edison patents kept the Bell monopoly viable into the 20th century, by which time the network was more important than the instrument. Early telephones were locally powered, using either a dynamic transmitter or by the powering of a transmitter with a local battery. One of the jobs of outside plant personnel
7553-496: Was beginning to question such technology of the time period. Devices have been used to aid computation for thousands of years, probably initially in the form of a tally stick . The Antikythera mechanism , dating from about the beginning of the first century BC, is generally considered the earliest known mechanical analog computer , and the earliest known geared mechanism. Comparable geared devices did not emerge in Europe until
7644-739: Was dissolved in November 1998 when BAe purchased Sema's 50% share for £77 million. By December 1991 Sema had acquired the Cambridge-based consultancy Baddeley Associates, from which it created Sema Group Consulting. In 1997, Sema acquired British Rail Business Systems for £27m which was sold off by the UK Government as part of the Privatisation of British Rail . In the same time frame, Sema also acquired Syntax in Italy, formerly
7735-436: Was introduced, packaged in three parts. The transmitter stood on a stand, known as a " candlestick " for its shape. When not in use, the receiver hung on a hook with a switch in it, known as a "switchhook". Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user was less likely to leave the phone "off the hook". In phones connected to magneto exchanges,
7826-539: Was invented by Captain John Taylor in 1844. This instrument used four air horns to communicate with vessels in foggy weather. Johann Philipp Reis used the term in reference to his invention, commonly known as the Reis telephone , in c. 1860. His device appears to be the first device based on the conversion of sound into electrical impulses. The term telephone was adopted into the vocabulary of many languages. It
7917-468: Was the Manchester Baby , which ran its first program on 21 June 1948. The development of transistors in the late 1940s at Bell Laboratories allowed a new generation of computers to be designed with greatly reduced power consumption. The first commercially available stored-program computer, the Ferranti Mark I , contained 4050 valves and had a power consumption of 25 kilowatts. By comparison,
8008-435: Was the master patent of the telephone, from which other patents for electric telephone devices and features flowed. In 1876, shortly after Bell's patent application, Hungarian engineer Tivadar Puskás proposed the telephone switch, which allowed for the formation of telephone exchanges , and eventually networks. In the United Kingdom, the blower is used as a slang term for a telephone. The term came from navy slang for
8099-426: Was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business , government , and in households . The essential elements of a telephone are a microphone ( transmitter ) to speak into and an earphone ( receiver ) which reproduces
8190-591: Was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963. The invention of the transistor in 1947 dramatically changed the technology used in telephone systems and in the long-distance transmission networks, over the next several decades. With the development of stored program control and MOS integrated circuits for electronic switching systems , and new transmission technologies such as pulse-code modulation (PCM), telephony gradually evolved towards digital telephony , which improved
8281-423: Was to visit each telephone periodically to inspect the battery. During the 20th century, telephones powered from the telephone exchange over the same wires that carried the voice signals became common. Early telephones used a single wire for the subscriber's line, with ground return used to complete the circuit (as used in telegraphs ). The earliest dynamic telephones also had only one port opening for sound, with
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