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2. History of Telecommunication
1. History of Communication
The history of communication technologies (media and appropriate inscription tools) have evolved in tandem with shifts in political and economic systems, and by extension, systems of power. Communication can range from very subtle processes of exchange, to full conversations and mass communication. The history of communication itself can be traced back since the origin of speech circa 100,000 BCE. The use of technology in communication may be considered since the first use of symbols about 30,000 years BCE. Among the symbols used, there are cave paintings, petroglyphs, pictograms and ideograms. Writing was a major innovation, as well as printing technology and, more recently, telecommunications and the Internet.
Primitive Times
Human communication was initiated with the origin of speech approximately 100,000 BCE. Symbols were developed about 30,000 years ago. The imperfection of speech allowed easier dissemination of ideas and eventually resulted in the creation of new forms of communications, improving both the range at which people could communicate and the longevity of the information. All of those inventions were based on the key concept of the symbol.
The oldest known symbols created for communication were cave paintings, a form of rock art, dating to the Upper Paleolithic age. The oldest known cave painting is located within Chauvet Cave, dated to around 30,000 BC. These paintings contained increasing amounts of information: people may have created the first calendar as far back as 15,000 years ago. The connection between drawing and writing is further shown by linguistics: in Ancient Egypt and Ancient Greece the concepts and words of drawing and writing were the same (Egyptian: 's-sh', Greek: 'graphein').
Petroglyphs
The next advancement in the history of communications came with the production of petroglyphs, carvings into a rock surface. It took about 20,000 years for Homo sapiens to move from the first cave paintings to the first petroglyphs, which are dated to approximately the Neolithic and late Upper Paleolithic boundary, about 10,000 to 12,000 years ago.
It is possible that Homo sapiens (humans) of that time used some other forms of communication, often for mnemonic purposes - specially arranged stones, symbols carved in wood or earth, quipu-like rocks, tattoos, but little other than the most durable carved stones has survived to modern times and we can only speculate about their existence based on our observation of still existing 'hunter-gatherer' cultures such as those of Africa or Oceania.
Pictograms
A pictogram (pictograph) is a symbol representing a concept, object, activity, place or event by illustration. Pictography is a form of proto-writing whereby ideas are transmitted through drawing. Pictographs were the next step in the evolution of communication: the most important difference between petroglyphs and pictograms is that petroglyphs are simply showing an event, but pictograms are telling a story about the event, thus they can for example be ordered chronologically.
Pictograms were used by various ancient cultures all over the world since around 9000 BC, when tokens marked with simple pictures began to be used to label basic farm produce, and become increasingly popular around 6000–5000 BC.
They were the basis of cuneiform and hieroglyphs, and began to develop into logographic writing systems around 5000 BC.
Ideograms
Pictograms, in turn, evolved into ideograms, graphical symbols that represent an idea. Their ancestors, the pictograms, could represent only something resembling their form: therefore a pictogram of a circle could represent a sun, but not concepts like 'heat', 'light', 'day' or 'Great God of the Sun'. Ideograms, on the other hand, could convey more abstract concepts.
Because some ideas are universal, many different cultures developed similar ideograms. For example, an eye with a tear means 'sadness' in Native American ideograms in California, as it does for the Aztecs, the early Chinese and the Egyptians.
Ideograms were precursors of logographic writing systems.
Early Scripts
The oldest-known forms of writing were primarily logographic in nature, based on pictographic and ideographic elements. Most writing systems can be broadly divided into three categories: logographic, syllabic and alphabetic (or segmental); however, all three may be found in any given writing system in varying proportions, often making it difficult to categorise a system uniquely.
The invention of the first writing systems is roughly contemporary with the beginning of the Bronze Age in the late Neolithic of the late 5th millennium BC. The first writing system is generally believed to have been invented in prehistoric Sumer and developed by the late 4th millennium BC into cuneiform. Egyptian hieroglyphs, and the undeciphered Proto-Elamite writing system and Indus Valley script, also date to this era, though a few scholars have questioned the Indus Valley script's status as a writing system.
The original Sumerian writing system was derived from a system of clay tokens used to represent commodities. By the end of the 4th millennium BC, this had evolved into a method of keeping accounts, using a round-shaped stylus impressed into soft clay at different angles for recording numbers. This was gradually augmented with pictographic writing using a sharp stylus to indicate what was being counted. Round-stylus and sharp-stylus writing was gradually replaced about 2700–2000 BC by writing using a wedge-shaped stylus (hence the term cuneiform), at first only for logograms, but developed to include phonetic elements by 2800 BC. About 2600 BC cuneiform began to represent syllables of spoken Sumerian language.
Finally, cuneiform writing became a general purpose writing system for logograms, syllables, and numbers. By the 26th century BC, this script had been adapted to another Mesopotamian language, Akkadian, and from that to others such as Hurrian, and Hittite. Scripts similar in appearance to this writing system include those for Ugaritic and Old Persian.
The Chinese script may have originated independently of the Middle Eastern scripts, around the 16th century BC (early Shang dynasty), out of a late neolithic Chinese system of proto-writing dating back to c. 6000 BC. The pre-Columbian writing systems of the Americas, including Olmec and Mayan, are also generally believed to have had independent origins.
Alphabet
The first pure alphabets (properly, "abjads", mapping single symbols to single phonemes, but not necessarily each phoneme to a symbol) emerged around 2000 BC in Ancient Egypt, but by then alphabetic principles had already been incorporated into Egyptian hieroglyphs for a millennium (see Middle Bronze Age alphabets).
By 2700 BC, Egyptian writing had a set of some 22 hieroglyphs to represent syllables that begin with a single consonant of their language, plus a vowel (or no vowel) to be supplied by the native speaker. These glyphs were used as pronunciation guides for logograms, to write grammatical inflections, and, later, to transcribe loan words and foreign names.
However, although seemingly alphabetic in nature, the original Egyptian uniliterals were not a system and were never used by themselves to encode Egyptian speech. In the Middle Bronze Age an apparently "alphabetic" system is thought by some to have been developed in central Egypt around 1700 BC for or by Semitic workers, but we cannot read these early writings and their exact nature remains open to interpretation.
Over the next five centuries this Semitic "alphabet" (really a syllabary like Phoenician writing) seems to have spread north. All subsequent alphabets around the world[citation needed] with the sole exception of Korean Hangul have either descended from it, or been inspired by one of its descendants.
Scholars agree that there is a relationship between the West-Semitic alphabet and the creation of the Greek alphabet. There is debate between scholars regarding the earliest uses of the Greek alphabet because of the changes that were made to create the Greek alphabet.
The Greek alphabet had the following characteristics:
- The Greek lettering we know of today traces back to the eighth century B.C.
- Early Greek scripts used the twenty-two West-Semitic letters, and included five supplementary letters.
- Early Greek was not uniform in structure, and had many local variations.
- The Greek lettering was written using a lapidary style of writing.
- Greek was written in a boustrophedon style.
Scholars believe that at one point in time, early Greek scripts were very close to the West-Semitic alphabet. Over time, the changes that were made to the Greek alphabet were introduced as a result of the need for the Greeks to find a better way to express their spoken language in a more accurate way.
Storytelling
Verbal communication is one of the earliest forms of human communication, the oral tradition of storytelling has dated back to various times in history. The development of communication in its oral form can be based on certain historical periods. The complexity of oral communication has always been reflective based on the circumstance of the time period. Verbal communication was never bound to one specific area, instead, it had and continues to be a globally shared tradition of communication. People communicated through song, poems, and chants, as some examples. People would gather in groups and pass down stories, myths, and history. Oral poets from Indo-European regions were known as "weavers of words" for their mastery over the spoken word and ability to tell stories. Nomadic people also had oral traditions that they used to tell stories of the history of their people to pass them on to the next generation.
Nomadic tribes have been the torch bearers of oral storytelling. Nomads of Arabia are one example of the many nomadic tribes that have continued through history to use oral storytelling as a tool to tell their histories and the story of their people. Due to the nature of nomadic life, these individuals were often left without architecture and possessions to call their own, and often left little to no traces of themselves. The richness of the nomadic life and culture is preserved by early Muslim scholars who collect the poems and stories that are handed down from generation to generation. Poems created by these Arabic nomads are passed down by specialists known as sha'ir. These individuals spread the stories and histories of these nomadic tribes, and often in times of war, would strengthen morale within members of given tribes through these stories.
In its natural form, oral communication was, and has continued to be, one of the best ways for humans to spread their message, history, and traditions to the world.
Timeline of Writing Technology
- 30,000 BC – In ice-age Europe, people mark ivory, bone, and stone with patterns to keep track of time, using a lunar calendar.
- 14,000 BC – In what is now Mezhirich, Ukraine, the first known artifact with a map on it is made using bone.
- Prior to 3500 BC – Communication was carried out through paintings of indigenous tribes.
- 3500s BC – The Sumerians develop cuneiform writing and the Egyptians develop hieroglyphic writing.
- 16th century BC – The Phoenicians develop an alphabet.
- 105 – Tsai Lun invents paper.
- 7th century – Hindu-Malayan empires write legal documents on copper plate scrolls, and write other documents on more perishable media.
- 751 – Paper is introduced to the Muslim world after the Battle of Talas.
- 1250 – The quill is used for writing.
- Timeline of printing technology
- 1305 – The Chinese develop wooden block movable type printing.
- 1440 – Johannes Gutenberg invents a printing press with metal movable type.
- 1844 – Charles Fenerty produces paper from a wood pulp, eliminating rag paper which was in limited supply.
- 1849 – Associated Press organizes Nova Scotia pony express to carry latest European news for New York newspapers.
- 1958 – Chester Carlson presents the first photocopier suitable for office use.
History of Telecommunication
The history of telecommunication - the transmission of signals over a distance for the purpose of communication - began thousands of years ago with the use of smoke signals and drums in Africa, America and parts of Asia. In the 1790s the first fixed semaphore systems emerged in Europe however it was not until the 1830s that electrical telecommunication systems started to appear.
Pre-electric
- AD 26–37 – Roman Emperor Tiberius rules the empire from the island of Capri by signaling messages with metal mirrors to reflect the sun.
- 1520 – Ships on Ferdinand Magellan's voyage signal to each other by firing cannon and raising flags...
https://en.wikipedia.org/wiki/History_of_communication
2. History of Telecommunication
The history of telecommunication began with the use of smoke signals and drums in Africa, Asia, and the Americas. In the 1790s, the first fixed semaphore systems emerged in Europe. However, it was not until the 1830s that electrical telecommunication systems started to appear. This article details the history of telecommunication and the individuals who helped make telecommunication systems what they are today. The history of telecommunication is an important part of the larger history of communication.
Ancient Systems and Optical Telegraphy
Early telecommunications included smoke signals and drums. Talking drums were used by natives in Africa, and smoke signals in North America and China. These systems were often used to do more than announce the presence of a military camp.
In Rabbinical Judaism a signal was given by means of kerchiefs or flags at intervals along the way back to the high priest to indicate the goat "for Azazel" had been pushed from the cliff.
Homing pigeons have occasionally been used throughout history by different cultures. Pigeon post had Persian roots, and was later used by the Romans to aid their military.
Greek hydraulic semaphore systems were used as early as the 4th century BC. The hydraulic semaphores, which worked with water filled vessels and visual signals, functioned as optical telegraphs. However, they could only utilize a very limited range of pre-determined messages, and as with all such optical telegraphs could only be deployed during good visibility conditions.
During 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 was during the Spanish Armada, when a beacon chain relayed a signal from Plymouth to London that signaled the arrival of the Spanish warships.
In 1774, the Swiss physicist Georges Lesage built an electrostatic telegraph consisting of a set of 24 conductive wires a few meters long connected to 24 elder balls suspended from a silk thread (each wire corresponds to a letter). The electrification of a wire by means of an electrostatic generator causes the corresponding elder ball to deflect and designate a letter to the operator located at the end of the line. The sequence of selected letters leads to the writing and transmission of a message.
French engineer Claude Chappe began working on visual telegraphy in 1790, using pairs of "clocks" whose hands pointed at different symbols. These did not prove quite viable at long distances, and Chappe revised his model to use two sets of jointed wooden beams. Operators moved the beams using cranks and wires. He built his first telegraph line between Lille and Paris, followed by a line from Strasbourg to Paris. In 1794, a Swedish engineer, Abraham Edelcrantz built a quite different system from Stockholm to Drottningholm. As opposed to Chappe's system which involved pulleys rotating beams of wood, Edelcrantz's system relied only upon shutters and was therefore faster.
However, semaphore as a communication system suffered from the need for skilled operators and expensive towers often at intervals of only ten to thirty kilometers (six to nineteen miles). As a result, the last commercial line was abandoned in 1880.
Smoke Signal
The smoke signal is one of the oldest forms of long-distance communication. It is a form of visual communication used over a long distance. In general smoke signals are used to transmit news, signal danger, or to gather people to a common area.
In ancient China, soldiers along the Great Wall sent smoke signals on its beacon towers to warn one another of enemy invasion. The colour of the smoke communicated the size of the invading party. By placing the beacon towers at regular intervals, and situating a soldier in each tower, messages could be transmitted over the entire 7,300 kilometres of the Wall. Smoke signals also warned the inner castles of the invasion, allowing them to coordinate a defense and garrison supporting troops.
In ancient Sri Lanka, soldiers stationed on the mountain peaks would alert each other of impending enemy attack (from English people, Dutch people or Portuguese people) by signaling from peak to peak. In this way, they were able to transmit a message to the King in just a few hours.
Misuse of the smoke signal is known to have contributed to the fall of the Western Zhou Dynasty in the 8th century BCE. King You of Zhou had a habit of fooling his warlords with false warning beacons in order to amuse Bao Si, his concubine.
Polybius, a Greek historian, devised a more complex system of alphabetical smoke signals around 150 BCE, which converted Greek alphabetic characters into numeric characters. It enabled messages to be easily signaled by holding sets of torches in pairs. This idea, known as the "Polybius square", also lends itself to cryptography and steganography. This cryptographic concept has been used with Japanese Hiragana and the Germans in the later years of the First World War.
North American indigenous peoples also communicated via smoke signal. Each tribe had its own signaling system and understanding. A signaler started a fire on an elevation typically using damp grass, which would cause a column of smoke to rise. The grass would be taken off as it dried and another bundle would be placed on the fire. Reputedly the location of the smoke along the incline conveyed a meaning. If it came from halfway up the hill, this would signify all was well, but from the top of the hill it would signify danger.
Smoke signals remain in use today. The College of Cardinals uses smoke signals to indicate the selection of a new Pope during a papal conclave. Eligible cardinals conduct a secret ballot until someone receives a vote of two-thirds plus one. The ballots are burned after each vote. Black smoke indicates a failed ballot, while white smoke means a new Pope has been elected.
Colored smoke grenades are commonly used by military forces to mark positions, especially during calls for artillery or air support.
Smoke signals may also refer to smoke-producing devices used to send distress signals.
- - https://en.wikipedia.org/wiki/Smoke_signal
Drum languages
In Africa, New Guinea and the tropical America, people have used drum telegraphy to communicate with each other from far away for centuries. When European expeditions came into the jungles to explore the local forest, they were surprised to find that the message of their coming and their intention was carried through the woods a step in advance of their arrival. African drummers can transmit a message at the speed of 100 miles per hour.
Among the famous communication drums are the drums of West Africa (see talking drum). From regions known today as Nigeria and Ghana they spread across West Africa and to America and the Caribbean during the slave trade. There they were banned because they were being used by the slaves to communicate over long distances in a code unknown to their enslavers.
Talking drums were also used in East Africa and are described by Andreus Bauer in the 'Street of Caravans' while acting as security guard in the Wissmann Truppe for the caravan of Charles Stokes.
The traditional drumming found in Africa is actually of three different types. Firstly, a rhythm can represent an idea (or signal); secondly it can repeat the accentual profile of a spoken utterance; or thirdly it can simply be subject to musical laws.[clarification needed]
Drum communication methods are not languages in their own right; they are based on spoken languages. The sounds produced are conventionalized or idiomatic signals based on speech patterns. The messages are normally very stereotyped and context-dependent. They lack the ability to form new combinations and expressions.
In Central and East Africa, drum patterns represent the stresses, syllable lengths and tone of the particular African language. In tone languages, where syllables are associated with a certain tone, some words are distinguished only by their suprasegmental profile. Therefore, syllable drum languages can often transfer a message using the tonal phonemes alone.
In certain languages, the pitch of each syllable is uniquely determined in relation to each adjacent syllable. In these cases, messages can be transmitted as rapid beats at the same speed as speech as the rhythm and melody both match the equivalent spoken utterance.
Misinterpretations can occur due to the highly ambiguous nature of the communication. This is reduced by context effects and the use of stock phrases. For example, in Jabo, most stems are monosyllabic. By using a proverb or honorary title to create expanded versions of an animal, person's name or object, the corresponding single beat can be replaced with a rhythmic and melodic motif representing the subject. In practice not all listeners understand all of the stock phrases; the drum language is understood only to the level of their immediate concern.
- - https://en.wikipedia.org/wiki/Drums_in_communication
Electrical Telegraph
Experiments on communication with electricity, initially unsuccessful, started in about 1726. Scientists including Laplace, Ampère, and Gauss were involved.
An early experiment in electrical telegraphy was an 'electrochemical' telegraph created by the German physician, anatomist and inventor Samuel Thomas von Sömmerring in 1809, based on an earlier, less robust design of 1804 by Spanish polymath and scientist Francisco Salva Campillo. Both their designs employed multiple wires (up to 35) in order to visually represent almost all Latin letters and numerals. Thus, messages could be conveyed electrically up to a few kilometers (in von Sömmerring's design), with each of the telegraph receiver's wires immersed in a separate glass tube of acid. An electric current was sequentially applied by the sender through the various wires representing each digit of a message; at the recipient's end the currents electrolysed the acid in the tubes in sequence, releasing streams of hydrogen bubbles next to each associated letter or numeral. The telegraph receiver's operator would visually observe the bubbles and could then record the transmitted message, albeit at a very low baud rate. The principal disadvantage to the system was its prohibitive cost, due to having to manufacture and string-up the multiple wire circuits it employed, as opposed to the single wire (with ground return) used by later telegraphs.
The first working telegraph was built by Francis Ronalds in 1816 and used static electricity.
Charles Wheatstone and William Fothergill Cooke patented a five-needle, six-wire system, which entered commercial use in 1838. It used the deflection of needles to represent messages and started operating over twenty-one kilometres (thirteen miles) of the Great Western Railway on 9 April 1839. Both Wheatstone and Cooke viewed their device as "an improvement to the [existing] electromagnetic telegraph" not as a new device.
On the other side of the Atlantic Ocean, Samuel Morse developed a version of the electrical telegraph which he demonstrated on 2 September 1837. Alfred Vail saw this demonstration and joined Morse to develop the register—a telegraph terminal that integrated a logging device for recording messages to paper tape. This was demonstrated successfully over three miles (five kilometres) on 6 January 1838 and eventually over forty miles (sixty-four kilometres) between Washington, D.C. and Baltimore on 24 May 1844. The patented invention proved lucrative and by 1851 telegraph lines in the United States spanned over 20,000 miles (32,000 kilometres). Morse's most important technical contribution to this telegraph was the simple and highly efficient Morse Code, co-developed with Vail, which was an important advance over Wheatstone's more complicated and expensive system, and required just two wires. The communications efficiency of the Morse Code preceded that of the Huffman code in digital communications by over 100 years, but Morse and Vail developed the code purely empirically, with shorter codes for more frequent letters.
The submarine cable across the English Channel, wire coated in gutta percha, was laid in 1851. Transatlantic cables installed in 1857 and 1858 only operated for a few days or weeks (carried messages of greeting back and forth between James Buchanan and Queen Victoria) before they failed. The project to lay a replacement line was delayed for five years by the American Civil War. The first successful transatlantic telegraph cable was completed on 27 July 1866, allowing continuous transatlantic telecommunication for the first time.
Telephone
The electric telephone was invented in the 1870s, based on earlier work with harmonic (multi-signal) telegraphs. The first commercial telephone services were set up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven, Connecticut in the US and London, England in the UK. Alexander Graham Bell held the master patent for the telephone that was needed for such services in both countries. All other patents for electric telephone devices and features flowed from this master patent. Credit for the invention of the electric telephone has been frequently disputed, and new controversies over the issue have arisen from time-to-time. As with other great inventions such as radio, television, the light bulb, and the digital computer, there were several inventors who did pioneering experimental work on voice transmission over a wire, who then improved on each other's ideas. However, the key innovators were Alexander Graham Bell and Gardiner Greene Hubbard, who created the first telephone company, the Bell Telephone Company in the United States, which later evolved into American Telephone & Telegraph (AT&T), at times the world's largest phone company.
Telephone technology grew quickly after the first commercial services emerged, with inter-city lines being built and telephone exchanges in every major city of the United States by the mid-1880s. The first transcontinental telephone call occurred on January 25, 1915. Despite this, transatlantic voice communication remained impossible for customers until January 7, 1927 when a connection was established using radio. However no cable connection existed until TAT-1 was inaugurated on September 25, 1956 providing 36 telephone circuits.
In 1880, Bell and co-inventor Charles Sumner Tainter conducted the world's first wireless telephone call via modulated lightbeams projected by photophones. The scientific principles of their invention would not be utilized for several decades, when they were first deployed in military and fiber-optic communications.
The first transatlantic telephone cable (which incorporated hundreds of electronic amplifiers) was not operational until 1956, only six years before the first commercial telecommunications satellite, Telstar, was launched into space.
Radio and Television
Over several years starting in 1894, the Italian inventor Guglielmo Marconi worked on adapting the newly discovered phenomenon of radio waves to telecommunication, building the first wireless telegraphy system using them. In December 1901, he established wireless communication between St. John's, Newfoundland and Poldhu, Cornwall (England), earning him a Nobel Prize in Physics (which he shared with Karl Braun) in 1909. In 1900, Reginald Fessenden was able to wirelessly transmit a human voice.
Millimetre wave communication was first investigated by Bengali physicist Jagadish Chandra Bose during 1894–1896, when he reached an extremely high frequency of up to 60 GHz in his experiments. He also introduced the use of semiconductor junctions to detect radio waves, when he patented the radio crystal detector in 1901.
In 1924, Japanese engineer Kenjiro Takayanagi began a research program on electronic television. In 1925, he demonstrated a CRT television with thermal electron emission. In 1926, he demonstrated a CRT television with 40-line resolution, the first working example of a fully electronic television receiver. In 1927, he increased the television resolution to 100 lines, which was unrivaled until 1931. In 1928, he was the first to transmit human faces in half-tones on television, influencing the later work of Vladimir K. Zworykin.
On March 25, 1925, Scottish inventor John Logie Baird publicly demonstrated the transmission of moving silhouette pictures at the London department store Selfridge's. Baird's system relied upon the fast-rotating Nipkow disk, and thus it became known as the mechanical television. In October 1925, Baird was successful in obtaining moving pictures with halftone shades, which were by most accounts the first true television pictures. This led to a public demonstration of the improved device on 26 January 1926 again at Selfridges. His invention formed the basis of semi-experimental broadcasts done by the British Broadcasting Corporation beginning September 30, 1929.
For most of the twentieth century televisions used the cathode ray tube (CRT) invented by Karl Braun. Such a television was produced by Philo Farnsworth, who demonstrated crude silhouette images to his family in Idaho on September 7, 1927. Farnsworth's device would compete with the concurrent work of Kalman Tihanyi and Vladimir Zworykin. Though the execution of the device was not yet what everyone hoped it could be, it earned Farnsworth a small production company. In 1934, he gave the first public demonstration of the television at Philadelphia's Franklin Institute and opened his own broadcasting station. Zworykin's camera, based on Tihanyi's Radioskop, which later would be known as the Iconoscope, had the backing of the influential Radio Corporation of America (RCA). In the United States, court action between Farnsworth and RCA would resolve in Farnsworth's favour. John Logie Baird switched from mechanical television and became a pioneer of colour television using cathode-ray tubes.
After mid-century the spread of coaxial cable and microwave radio relay allowed television networks to spread across even large countries.
Semiconductor Era
The modern period of telecommunication history from 1950 onwards is referred to as the semiconductor era, due to the wide adoption of semiconductor devices in telecommunication technology. The development of transistor technology and the semiconductor industry enabled significant advances in telecommunication technology, led to the price of telecommunications services declining significantly, and led to a transition away from state-owned narrowband circuit-switched networks to private broadband packet-switched networks. In turn, this led to a significant increase in the total number of telephone subscribers, reaching nearly 1 billion users worldwide by the end of the 20th century.
The development of metal–oxide–semiconductor (MOS) large-scale integration (LSI) technology, information theory and cellular networking led to the development of affordable mobile communications. There was a rapid growth of the telecommunications industry towards the end of the 20th century, primarily due to the introduction of digital signal processing in wireless communications, driven by the development of low-cost, very large-scale integration (VLSI) RF CMOS (radio-frequency complementary MOS) technology.
Videotelephony
The development of videotelephony involved the historical development of several technologies which enabled the use of live video in addition to voice telecommunications. The concept of videotelephony was first popularized in the late 1870s in both the United States and Europe, although the basic sciences to permit its very earliest trials would take nearly a half century to be discovered. This was first embodied in the device which came to be known as the video telephone, or videophone, and it evolved from intensive research and experimentation in several telecommunication fields, notably electrical telegraphy, telephony, radio, and television.
The development of the crucial video technology first started in the latter half of the 1920s in the United Kingdom and the United States, spurred notably by John Logie Baird and AT&T's Bell Labs. This occurred in part, at least by AT&T, to serve as an adjunct supplementing the use of the telephone. A number of organizations believed that videotelephony would be superior to plain voice communications. However video technology was to be deployed in analog television broadcasting long before it could become practical—or popular—for videophones.
Videotelephony developed in parallel with conventional voice telephone systems from the mid-to-late 20th century. Only in the late 20th century with the advent of powerful video codecs and high-speed broadband did it become a practical technology for regular use. With the rapid improvements and popularity of the Internet, it became widespread through the use of videoconferencing and webcams, which frequently utilize Internet telephony, and in business, where telepresence technology has helped reduce the need to travel.
Practical digital videotelephony was only made possible with advances in video compression, due to the impractically high bandwidth requirements of uncompressed video. To achieve Video Graphics Array (VGA) quality video (480p resolution and 256 colors) with raw uncompressed video, it would require a bandwidth of over 92 Mbps.
Satellite
The first U.S. satellite to relay communications was Project SCORE in 1958, which used a tape recorder to store and forward voice messages. It was used to send a Christmas greeting to the world from U.S. President Dwight D. Eisenhower. In 1960 NASA launched an Echo satellite; the 100-foot (30 m) aluminized PET film balloon served as a passive reflector for radio communications. Courier 1B, built by Philco, also launched in 1960, was the world's first active repeater satellite. Satellites these days are used for many applications such as GPS, television, internet and telephone.
Telstar was the first active, direct relay commercial communications satellite. Belonging to AT&T as part of a multi-national agreement between AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National PTT (Post Office) to develop satellite communications, it was launched by NASA from Cape Canaveral on July 10, 1962, the first privately sponsored space launch. Relay 1 was launched on December 13, 1962, and became the first satellite to broadcast across the Pacific on November 22, 1963.
The first and historically most important application for communication satellites was in intercontinental long-distance telephony. The fixed Public Switched Telephone Network relays telephone calls from land line telephones to an earth station, where they are then transmitted a receiving satellite dish via a geostationary satellite in Earth orbit. Improvements in submarine communications cables, through the use of fiber-optics, caused some decline in the use of satellites for fixed telephony in the late 20th century, but they still exclusively service remote islands such as Ascension Island, Saint Helena, Diego Garcia, and Easter Island, where no submarine cables are in service. There are also some continents and some regions of countries where landline telecommunications are rare to nonexistent, for example Antarctica, plus large regions of Australia, South America, Africa, Northern Canada, China, Russia and Greenland.
After commercial long-distance telephone service was established via communication satellites, a host of other commercial telecommunications were also adapted to similar satellites starting in 1979, including mobile satellite phones, satellite radio, satellite television and satellite Internet access. The earliest adaption for most such services occurred in the 1990s as the pricing for commercial satellite transponder channels continued to drop significantly.
Realization and demonstration, on October 29, 2001, of the first digital cinema transmission by satellite in Europe of a feature film by Bernard Pauchon, Alain Lorentz, Raymond Melwig and Philippe Binant.
Computer Networks and the Internet
On September 11, 1940, George Stibitz was able to transmit problems using teletype to his Complex Number Calculator in New York City and receive the computed results back at Dartmouth College in New Hampshire. This configuration of a centralized computer or mainframe with remote dumb terminals remained popular throughout the 1950s. However it was not until the 1960s that researchers started to investigate packet switching a technology that would allow chunks of data to be sent to different computers without first passing through a centralized mainframe. A four-node network emerged on December 5, 1969 between the University of California, Los Angeles, the Stanford Research Institute, the University of Utah and the University of California, Santa Barbara. This network would become ARPANET, which by 1981 would consist of 213 nodes. In June 1973, the first non-US node was added to the network belonging to Norway's NORSAR project. This was shortly followed by a node in London.
ARPANET's development centred on the Request for Comments process and on April 7, 1969, RFC 1 was published. This process is important because ARPANET would eventually merge with other networks to form the Internet and many of the protocols the Internet relies upon today were specified through this process. The first Transmission Control Protocol (TCP) specification, RFC 675 (Specification of Internet Transmission Control Program), was written by Vinton Cerf, Yogen Dalal, and Carl Sunshine, and published in December 1974. It coined the term "Internet" as a shorthand for internetworking. In September 1981, RFC 791 introduced the Internet Protocol v4 (IPv4). This established the TCP/IP protocol, which much of the Internet relies upon today. The User Datagram Protocol (UDP), a more relaxed transport protocol that, unlike TCP, did not guarantee the orderly delivery of packets, was submitted on 28 August 1980 as RFC 768. An e-mail protocol, SMTP, was introduced in August 1982 by RFC 821 and a protocol that would make the hyperlinked Internet possible was introduced in May 1996 by RFC 1945.
However, not all important developments were made through the Request for Comments process. Two popular link protocols for local area networks (LANs) also appeared in the 1970s. A patent for the Token Ring protocol was filed by Olof Söderblom on October 29, 1974. And a paper on the Ethernet protocol was published by Robert Metcalfe and David Boggs in the July 1976 issue of Communications of the ACM. The Ethernet protocol had been inspired by the ALOHAnet protocol which had been developed by electrical engineering researchers at the University of Hawaii.
Internet access became widespread late in the century, using the old telephone and television networks.
Digital Telephone Technology
MOS technology was initially overlooked by Bell because they did not find it practical for analog telephone applications. MOS technology eventually became practical for telephone applications with the MOS mixed-signal integrated circuit, which combines analog and digital signal processing on a single chip, developed by former Bell engineer David A. Hodges with Paul R. Gray at UC Berkeley in the early 1970s. In 1974, Hodges and Gray worked with R.E. Suarez to develop MOS switched capacitor (SC) circuit technology, which they used to develop the digital-to-analog converter (DAC) chip, using MOSFETs and MOS capacitors for data conversion. This was followed by the analog-to-digital converter (ADC) chip, developed by Gray and J. McCreary in 1975.
MOS SC circuits led to the development of PCM codec-filter chips in the late 1970s. The silicon-gate CMOS (complementary MOS) PCM codec-filter chip, developed by Hodges and W.C. Black in 1980, has since been the industry standard for digital telephony. By the 1990s, telecommunication networks such as the public switched telephone network (PSTN) had been largely digitized with very-large-scale integration (VLSI) CMOS PCM codec-filters, widely used in electronic switching systems for telephone exchanges and data transmission applications.
Wireless Revolution
The wireless revolution began in the 1990s, with the advent of digital wireless networks leading to a social revolution, and a paradigm shift from wired to wireless technology, including the proliferation of commercial wireless technologies such as cell phones, mobile telephony, pagers, wireless computer networks, cellular networks, the wireless Internet, and laptop and handheld computers with wireless connections. The wireless revolution has been driven by advances in radio frequency (RF) and microwave engineering, and the transition from analog to digital RF technology.
Advances in metal–oxide–semiconductor field-effect transistor (MOSFET, or MOS transistor) technology, the key component of the RF technology that enables digital wireless networks, has been central to this revolution. Hitachi developed the vertical power MOSFET in 1969, but it was not until Ragle perfected the concept in 1976 that the power MOSFET became practical. In 1977 Hitachi announce a planar type of DMOS that was practical for audio power output stages. RF CMOS (radio frequency CMOS) integrated circuit technology was later developed by Asad Abidi at UCLA in the late 1980s. By the 1990s, RF CMOS integrated circuits were widely adopted as RF circuits, while discrete MOSFET (power MOSFET and LDMOS) devices were widely adopted as RF power amplifiers, which led to the development and proliferation of digital wireless networks. Most of the essential elements of modern wireless networks are built from MOSFETs, including base station modules, routers, telecommunication circuits, and radio transceivers. MOSFET scaling has led to rapidly increasing wireless bandwidth, which has been doubling every 18 months (as noted by Edholm's law).
Timeline
Visual, auditory and ancillary methods (non-electrical)
- Prehistoric: Fires, Beacons, Smoke signals, Communication drums, Horns
- 6th century BCE: Mail
- 5th century BCE: Pigeon post
- 4th century BCE: Hydraulic semaphores
- 1500 Korean hwacha net uses hwachas arrows to send mails throughout a town.
- 15th century CE: Maritime flag semaphores
- 1672: First experimental acoustic (mechanical) telephone
- 1790: Semaphore lines (optical telegraphs)
- 1867: Signal lamps
- 1877: Acoustic phonograph
- 1900; optical picture
Basic Electrical Signals
- 1838: Electrical telegraph. See: Telegraph history
- 1830s: Beginning of attempts to develop "wireless telegraphy", systems using some form of ground, water, air or other media for conduction to eliminate the need for conducting wires.
- 1858: First trans-Atlantic telegraph cable
- 1876: Telephone. See: Invention of the telephone, History of the telephone, Timeline of the telephone
- 1880: Telephony via lightbeam photophones
Advanced Electrical and Electronic Signals
- 1896: First practical wireless telegraphy systems based on Radio. See: History of radio.
- 1900: first television displayed only black and white images. Over the next decades, colour television were invented, showing images that were clearer and in full colour.
- 1914: First North American transcontinental telephone calling
- 1927: Television. See: History of television
- 1927: First commercial radio-telephone service, U.K.–U.S.
- 1930: First experimental videophones
- 1934: First commercial radio-telephone service, U.S.–Japan
- 1936: World's first public videophone network
- 1946: Limited capacity Mobile Telephone Service for automobiles
- 1947: First working transistor (see History of the transistor)
- 1950: Semiconductor era begins
- 1956: Transatlantic telephone cable
- 1962: Commercial telecommunications satellite
- 1964: Fiber optical telecommunications
- 1965: First North American public videophone network
- 1969: Computer networking
- 1973: First modern-era mobile (cellular) phone
- 1974: Internet (see History of Internet)
- 1979: INMARSAT ship-to-shore satellite communications
- 1981: First mobile (cellular) phone network
- 1982: SMTP email
- 1998: Mobile satellite hand-held phones
- 2003: VoIP Internet Telephony
