1.
Cuba
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Cuba, officially the Republic of Cuba, is a country comprising the island of Cuba as well as Isla de la Juventud and several minor archipelagos. Cuba is located in the northern Caribbean where the Caribbean Sea, the Gulf of Mexico, and it is south of both the U. S. state of Florida and the Bahamas, west of Haiti, and north of Jamaica. Havana is the largest city and capital, other cities include Santiago de Cuba. Cuba is the largest island in the Caribbean, with an area of 109,884 square kilometres, prior to Spanish colonization in the late 15th century, Cuba was inhabited by Amerindian tribes. It remained a colony of Spain until the Spanish–American War of 1898, as a fragile republic, Cuba attempted to strengthen its democratic system, but mounting political radicalization and social strife culminated in the dictatorship of Fulgencio Batista in 1952. Further unrest and instability led to Batistas ousting in January 1959 by the July 26 Movement, since 1965, the state has been governed by the Communist Party of Cuba. A point of contention during the Cold War between the Soviet Union and the United States, a nuclear war broke out during the Cuban Missile Crisis of 1962. Culturally, Cuba is considered part of Latin America, Cuba is a Marxist–Leninist one-party republic, where the role of the vanguard Communist Party is enshrined in the Constitution. Independent observers have accused the Cuban government of human rights abuses. It is one of the worlds last planned economies and its economy is dominated by the exports of sugar, tobacco, coffee, according to the Human Development Index, Cuba is described as a country with high human development and is ranked the eighth highest in North America. It also ranks highly in some metrics of national performance, including health care, the name Cuba comes from the Taíno language. The exact meaning of the name is unclear but it may be translated either as where fertile land is abundant, authors who believe that Christopher Columbus was Portuguese state that Cuba was named by Columbus for the town of Cuba in the district of Beja in Portugal. Before the arrival of the Spanish, Cuba was inhabited by three distinct tribes of indigenous peoples of the Americas, the Taíno, the Guanajatabey, and the Ciboney people. The ancestors of the Ciboney migrated from the mainland of South America, the Taíno arrived from Hispanola sometime in the 3rd century A. D. When Columbus arrived they were the dominant culture in Cuba, having a population of 150,000. The name Cuba comes from the native Taíno language and it is derived from either coabana meaning great place, or from cubao meaning where fertile land is abundant. The Taíno were farmers, while the Ciboney were farmers as well as fishers and hunter-gatherers, Columbus claimed the island for the new Kingdom of Spain and named it Isla Juana after Juan, Prince of Asturias. In 1511, the first Spanish settlement was founded by Diego Velázquez de Cuéllar at Baracoa, other towns soon followed, including San Cristobal de la Habana, founded in 1515, which later became the capital
2.
NTSC
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The first NTSC standard was developed in 1941 and had no provision for color. In 1953 a second NTSC standard was adopted, which allowed for television broadcasting which was compatible with the existing stock of black-and-white receivers. NTSC was the first widely adopted broadcast color system and remained dominant until 1997, North America, parts of Central America, and South Korea are adopting or have adopted the ATSC standards, while other countries are adopting or have adopted other standards instead of ATSC. After nearly 70 years, the majority of over-the-air NTSC transmissions in the United States ceased on January 1,2010, the majority of NTSC transmissions ended in Japan on July 24,2011, with the Japanese prefectures of Iwate, Miyagi, and Fukushima ending the next year. In March 1941, the committee issued a standard for black-and-white television that built upon a 1936 recommendation made by the Radio Manufacturers Association. Technical advancements of the side band technique allowed for the opportunity to increase the image resolution. The NTSC selected 525 scan lines as a compromise between RCAs 441-scan line standard and Philcos and DuMonts desire to increase the number of lines to between 605 and 800. The standard recommended a frame rate of 30 frames per second, other standards in the final recommendation were an aspect ratio of 4,3, and frequency modulation for the sound signal. In January 1950, the committee was reconstituted to standardize color television, in December 1953, it unanimously approved what is now called the NTSC color television standard. The compatible color standard retained full backward compatibility with existing black-and-white television sets, Color information was added to the black-and-white image by introducing a color subcarrier of precisely 315/88 MHz. These changes amounted to 0.1 percent and were tolerated by existing television receivers. The FCC had briefly approved a different color standard, starting in October 1950. However, this standard was incompatible with black-and-white broadcasts and it used a rotating color wheel, reduced the number of scan lines from 525 to 405, and increased the field rate from 60 to 144, but had an effective frame rate of only 24 frames per second. CBS rescinded its system in March 1953, and the FCC replaced it on December 17,1953, with the NTSC color standard, later that year, the improved TK-41 became the standard camera used throughout much of the 1960s. The NTSC standard has been adopted by countries, including most of the Americas. With the advent of television, analog broadcasts are being phased out. Most US NTSC broadcasters were required by the FCC to shut down their analog transmitters in 2009, low-power stations, Class A stations and translators were required to shut down by 2015. NTSC color encoding is used with the System M television signal, each frame is composed of two fields, each consisting of 262.5 scan lines, for a total of 525 scan lines
3.
Analog television
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Analog television or analogue television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by variations of either the amplitude. Analog signals vary over a range of possible values which means that electronic noise. So with analog, a weak signal becomes snowy and subject to interference. In contrast, a moderately weak signal and a very strong digital signal transmit equal picture quality. Analog television may be wireless or can be distributed over a network using cable converters. All broadcast television systems preceding digital transmission of digital television used analog signals, analog television around the world has been in the process of shutting down since the late 2000s. The earliest systems were mechanical systems which used spinning disks with patterns of holes punched into the disc to scan an image. A similar disk reconstructed the image at the receiver, synchronization of the receiver disc rotation was handled through sync pulses broadcast with the image information. However these mechanical systems were slow, the images were dim and flickered severely, camera systems used similar spinning discs and required intensely bright illumination of the subject for the light detector to work. Analog television did not really begin as an industry until the development of the cathode-ray tube, the electron beam could be swept across the screen much faster than any mechanical disc system, allowing for more closely spaced scan lines and much higher image resolution. Also far less maintenance was required of an all-electronic system compared to a spinning disc system, all-electronic systems became popular with households after the Second World War. Broadcasters using analog television systems encode their signal using different systems, the official systems of transmission are named, A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the number of lines, channel width, vision bandwidth, vision-sound separation, each frame of a television image is composed of lines drawn on the screen. The lines are of varying brightness, the set of lines is drawn quickly enough that the human eye perceives it as one image. The next sequential frame is displayed, allowing the depiction of motion, the analog television signal contains timing and synchronization information, so that the receiver can reconstruct a two-dimensional moving image from a one-dimensional time-varying signal. The first commercial systems were black-and-white, the beginning of color television was in the 1950s. A practical television system needs to take luminance, chrominance, synchronization, and audio signals, the transmission system must include a means of television channel selection
4.
Radio
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When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form, Radio systems need a transmitter to modulate some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation. Radio systems also need an antenna to convert electric currents into radio waves, an antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected, the electromagnetic wave is intercepted by a tuned receiving antenna. Radio frequencies occupy the range from a 3 kHz to 300 GHz, a radio communication system sends signals by radio. The term radio is derived from the Latin word radius, meaning spoke of a wheel, beam of light, however, this invention would not be widely adopted. The switch to radio in place of wireless took place slowly and unevenly in the English-speaking world, the United States Navy would also play a role. Although its translation of the 1906 Berlin Convention used the terms wireless telegraph and wireless telegram, the term started to become preferred by the general public in the 1920s with the introduction of broadcasting. Radio systems used for communication have the following elements, with more than 100 years of development, each process is implemented by a wide range of methods, specialised for different communications purposes. Each system contains a transmitter, This consists of a source of electrical energy, the transmitter contains a system to modulate some property of the energy produced to impress a signal on it. This modulation might be as simple as turning the energy on and off, or altering more subtle such as amplitude, frequency, phase. Amplitude modulation of a carrier wave works by varying the strength of the signal in proportion to the information being sent. For example, changes in the strength can be used to reflect the sounds to be reproduced by a speaker. It was the used for the first audio radio transmissions. Frequency modulation varies the frequency of the carrier, the instantaneous frequency of the carrier is directly proportional to the instantaneous value of the input signal. FM has the capture effect whereby a receiver only receives the strongest signal, Digital data can be sent by shifting the carriers frequency among a set of discrete values, a technique known as frequency-shift keying. FM is commonly used at Very high frequency radio frequencies for high-fidelity broadcasts of music, analog TV sound is also broadcast using FM. Angle modulation alters the phase of the carrier wave to transmit a signal
5.
Telephony
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The history of telephony is intimately linked to the invention and development of the telephone. The term is used frequently to refer to computer hardware, software, and computer network systems. In this context the technology is referred to as Internet telephony. The first telephones were connected directly in pairs, each user had a separate telephone wired to the locations he might wish to reach. This quickly became inconvenient and unmanageable when people wanted to communicate with more than a few people, the inventions of the telephone exchange provided the solution for establishing telephone connections with any other telephone in service in the local area. Each telephone was connected to the exchange via one wire pair, nearby exchanges in other service areas were connected with trunk lines and long distance service could be established by relaying the calls through multiple exchanges. Initially the switchboards were manually operated by an attendant, a switchboard operator, when a customer cranked a handle on the telephone, it turned on an indicator on the board in front of the operator who would plug the operator headset into that jack and offer service. The caller had to ask for the party by name, later by number. If the called station answered the operator disconnected their headset and completed the station-to-station circuit, trunk calls were made with the assistance of other operators at other exchangers in the network. In modern times, most telephones are plugged into telephone jacks, the jacks are connected by inside wiring to a drop wire which connects the building to a cable. Cables usually bring a number of drop wires from all over a district access network to one wire center or telephone exchange. Most of the exchanges in the world are interconnected through a system of larger switching systems, today, telephony uses digital technology in the provisioning of telephone services and systems. This advancement has reduced costs in communication, and improved the quality of voice services, the first implementation of this, ISDN, permitted all data transport from end-to-end speedily over telephone lines. This service was made much less important due to the ability to provide digital services based on the IP protocol. The integration of software and computer systems is a major development in the evolution of the automated office. The term is used in describing the services of call centers. Its also sometimes used to describe the ability to use your personal computer to initiate, CTI is not a new concept and has been used in the past in large telephone networks, but only dedicated call centers could justify the costs of the required equipment installation. Dialed Number Identification Service on a scale is wide enough for its implementation to bring value to business or residential telephone usage
6.
Advanced Mobile Phone System
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It was the primary analog mobile phone system in North America through the 1980s and into the 2000s. As of February 18,2008, carriers in the United States were no longer required to support AMPS and companies such as AT&T and Verizon have discontinued this service permanently. AMPS was discontinued in Australia in September 2000, in Pakistan by October 2004. and Brazil by 2010 The first cellular network efforts began at Bell Labs and with research conducted at Motorola. In 1960, John F. Mitchell, an engineer who had graduated from the Illinois Institute of Technology. Mitchell oversaw the development and marketing of the first pager to use transistors, Motorola had long produced mobile telephones for automobiles, but these large and heavy models consumed too much power to allow their use without the automobiles engine running. Mitchells team, which included the gifted Dr, the first system was successfully deployed in Chicago, Illinois, in 1979. Motorola and others designed and built the cellular phones for this, in 1992 the first smartphone, called IBM Simon, used AMPS. Frank Canova led its design at IBM and it was demonstrated that year at the COMDEX computer-industry trade-show, a refined version of the product was marketed to consumers in 1994 by BellSouth under the name Simon Personal Communicator. The Simon was the first device that can be referred to as a smartphone. AMPS is a first-generation cellular technology that uses separate frequencies, or channels and it therefore required considerable bandwidth for a large number of users. What really separated AMPS from older systems is the back end call setup functionality, in AMPS, the cell centers could flexibly assign channels to handsets based on signal strength, allowing the same frequency to be re-used in various locations without interference. This allowed a number of phones to be supported over a geographical area. AMPS pioneers coined the term cellular because of its use of small hexagonal cells within a system, AMPS suffered from many weaknesses compared to todays digital technologies. As an analog standard, it was susceptible to static and noise, in the 1990s an epidemic of cloning cost the cellular carriers millions of dollars. An eavesdropper with specialized equipment could intercept a handsets ESN and MDN or CTN, the Electronic Serial Number, a 12-digit number sent by the handset to the cellular system for billing purposes, uniquely identified that phone on the network. The system then allowed or disallowed calls and or features based on its customer file, a person intercepting an ESN/MDN pair could clone the combination onto a different phone and use it in other areas for making calls without paying. Cellular phone cloning became possible with off-the-shelf technology in the 1990s and this signal would feed into the sound-card audio-input of the PC, and Banpaia would decode the ESN/MDN pair from this signal and display it on the screen. The hacker could then copy that data into the Oki 900 phone and reboot it, the problem became so large that some carriers required the use of a PIN before making calls
7.
GSM
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As of 2014 it has become the de facto global standard for mobile communications – with over 90% market share, operating in over 219 countries and territories. This expanded over time to include communications, first by circuit-switched transport, then by packet data transport via GPRS. Subsequently, the 3GPP developed third-generation UMTS standards followed by fourth-generation LTE Advanced standards, GSM is a trademark owned by the GSM Association. It may also refer to the most common voice codec used, the decision to develop a continental standard eventually resulted in a unified, open, standard-based network which was larger than that in the United States. In February 1987 Europe produced the very first agreed GSM Technical Specification, the MoU drew-in mobile operators from across Europe to pledge to invest in new GSM networks to an ambitious common date. In 1989, the Groupe Spécial Mobile committee was transferred from CEPT to the European Telecommunications Standards Institute, in parallel, France and Germany signed a joint development agreement in 1984 and were joined by Italy and the UK in 1986. In 1986 the European Commission proposed reserving the 900 MHz spectrum band for GSM, the former Finnish prime minister Harri Holkeri made the worlds first GSM call on July 1,1991, calling Kaarina Suonio using a network built by Telenokia and Siemens and operated by Radiolinja. In the following year,1992, saw the sending of the first short messaging service message, work began in 1991 to expand the GSM standard to the 1800 MHz frequency band and the first 1800 MHz network became operational in the UK by 1993 called and DCS1800. Also that year, Telecom Australia became the first network operator to deploy a GSM network outside Europe and the first practical hand-held GSM mobile phone became available. In 1995, fax, data and SMS messaging services were launched commercially, in the same year, the GSM Association formed. Pre-paid GSM SIM cards were launched in 1996 and worldwide GSM subscribers passed 100 million in 1998, in 2000 the first commercial GPRS services were launched and the first GPRS-compatible handsets became available for sale. In 2001 the first UMTS network was launched, a 3G technology that is not part of GSM, worldwide GSM subscribers exceeded 500 million. In 2002 the first Multimedia Messaging Service were introduced and the first GSM network in the 800 MHz frequency band became operational, EDGE services first became operational in a network in 2003 and the number of worldwide GSM subscribers exceeded 1 billion in 2004. By 2005, GSM networks accounted for more than 75% of the cellular network market. In 2005 the first HSDPA-capable network also became operational, the first HSUPA network launched in 2007. Worldwide GSM subscribers exceeded three billion in 2008, GSM is a second-generation standard employing time-division multiple-Access spectrum-sharing, issued by the European Telecommunications Standards Institute. GSM, for the first time, set a standard for Europe for wireless networks. It was also adopted by many countries outside Europe and this allowed subscribers to use other GSM networks that have roaming agreements with each other
8.
Mobile telephony
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Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Mobile phones connect to a cellular network of base stations. Both networks are interconnected to the switched telephone network to allow any phone in the world to be dialed. In 2010 there were estimated to be five billion mobile cellular subscriptions in the world. S, public mobile phone systems were first introduced in the years after the Second World War and made use of technology developed before and during the conflict. The first system opened in St Louis, Missouri, USA in 1946 whilst other countries followed in the succeeding decades, the UK introduced its System 1 manual radiotelephone service as the South Lancashire Radiophone Service in 1958. Calls were made via an operator using handsets identical to ordinary phone handsets, the phone itself was a large box located in the boot of the vehicle containing valves and other early electronic components. Although an uprated manual service was extended to cover most of the UK and these cellular systems were based on US Advanced Mobile Phone Service technology, the modified technology being named Total Access Communication System. In 1947 Bell Labs was the first to propose a cellular telephone network. In 1956 the MTA system was launched in Sweden, both problems were solved by Bell Labs employee Amos Joel who, in 1970 applied for a patent for a mobile communications system. However, a consulting firm calculated the entire U. S. As a consequence, Bell Labs concluded that the invention was of little or no consequence, the invention earned Joel induction into the National Inventors Hall of Fame in 2008. The first call on a mobile phone was made on April 3,1973 by Martin Cooper. Bell Labs went on to install the first trial cellular network in Chicago in 1978. This trial system was licensed by the FCC to ATT for commercial use in 1982 and, as part of the arrangements for the breakup of ATT. The first commercial system opened in Chicago in October 1983, a system designed by Motorola also operated in the Washington D. C. /Baltimore area from summer 1982 and became a full public service later the following year. Japans first commercial service was launched by NTT in 1978. The first fully automatic first generation system was the Nordic Mobile Telephone system, simultaneously launched in 1981 in Denmark, Finland, Norway. NMT was the first mobile phone network featuring international roaming, the Swedish electrical engineer Östen Mäkitalo started to work on this vision in 1966, and is considered as the father of the NMT system and some consider him also the father of the cellular phone
9.
Internet
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The Internet is the global system of interconnected computer networks that use the Internet protocol suite to link devices worldwide. The origins of the Internet date back to research commissioned by the United States federal government in the 1960s to build robust, the primary precursor network, the ARPANET, initially served as a backbone for interconnection of regional academic and military networks in the 1980s. Although the Internet was widely used by academia since the 1980s, Internet use grew rapidly in the West from the mid-1990s and from the late 1990s in the developing world. In the two decades since then, Internet use has grown 100-times, measured for the period of one year, newspaper, book, and other print publishing are adapting to website technology, or are reshaped into blogging, web feeds and online news aggregators. The entertainment industry was initially the fastest growing segment on the Internet, the Internet has enabled and accelerated new forms of personal interactions through instant messaging, Internet forums, and social networking. Business-to-business and financial services on the Internet affect supply chains across entire industries, the Internet has no centralized governance in either technological implementation or policies for access and usage, each constituent network sets its own policies. The term Internet, when used to refer to the global system of interconnected Internet Protocol networks, is a proper noun. In common use and the media, it is not capitalized. Some guides specify that the word should be capitalized when used as a noun, the Internet is also often referred to as the Net, as a short form of network. Historically, as early as 1849, the word internetted was used uncapitalized as an adjective, the designers of early computer networks used internet both as a noun and as a verb in shorthand form of internetwork or internetworking, meaning interconnecting computer networks. The terms Internet and World Wide Web are often used interchangeably in everyday speech, however, the World Wide Web or the Web is only one of a large number of Internet services. The Web is a collection of interconnected documents and other web resources, linked by hyperlinks, the term Interweb is a portmanteau of Internet and World Wide Web typically used sarcastically to parody a technically unsavvy user. The ARPANET project led to the development of protocols for internetworking, the third site was the Culler-Fried Interactive Mathematics Center at the University of California, Santa Barbara, followed by the University of Utah Graphics Department. In an early sign of growth, fifteen sites were connected to the young ARPANET by the end of 1971. These early years were documented in the 1972 film Computer Networks, early international collaborations on the ARPANET were rare. European developers were concerned with developing the X.25 networks, in December 1974, RFC675, by Vinton Cerf, Yogen Dalal, and Carl Sunshine, used the term internet as a shorthand for internetworking and later RFCs repeated this use. Access to the ARPANET was expanded in 1981 when the National Science Foundation funded the Computer Science Network, in 1982, the Internet Protocol Suite was standardized, which permitted worldwide proliferation of interconnected networks.5 Mbit/s and 45 Mbit/s. Commercial Internet service providers emerged in the late 1980s and early 1990s, the ARPANET was decommissioned in 1990
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