Telecommunications:

Introduction:

Information can be transmitted using a variety of technologies via wire, radio, optical, or other electromagnetic systems. This is known as telecommunication. As a result, slow systems (like postal mail) are not included in the field. It has its roots in humans' need for communication at a distance greater than what is possible with the human voice, but with a similar level of expediency.

 

Telecommunications

From beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light, the transmission media in telecommunication have progressed through several technological stages. The advantages of multiplexing many concurrent communication sessions are made possible by the division of such transmission pathways into communication channels. The plural of telecommunication is frequently used.

 

Audio communications like loud whistles, lung-blown horns, and coded drumbeats were also used in ancient long-distance communication. The majority of long-distance communication technologies used in the 20th and 21st centuries are electrical and electromagnetic in nature. Examples include the telegraph, telephone, television, teleprinter, networks, radio, microwave transmission, optical fiber, and communications satellites.

 

With the groundbreaking advancements in radio communications made by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909, and other eminent pioneering inventors and developers in the field of electrical and electronic telecommunications, a revolution in wireless communication started in the first decade of the 20th century. These included Edwin Armstrong and Lee de Forest (inventors of radio), Charles Wheatstone and Samuel Morse (inventors of the telegraph), Antonio Meucci and Alexander Graham Bell (some of the inventors and developers of the telephone; see Invention of the telephone), and Vladimir K. Zworykin, John Logie Baird, and Philo Farnsworth (some of the inventors of television).

 

Telecommunication is defined as "Any transmission, emission or reception of signs, signals, letters, images and sounds or intelligence of any sort by wire, radio, optical, or other electromagnetic systems" in Article 1.3 of the Radio Regulations (RR). This definition is the same as that found in the International Telecommunication Union's Constitution and Convention Annex (Geneva, 1992).

 

Telecommunications

The physical medium for signal transmission in the first telecommunication networks was copper wires. These networks were utilized for basic phone services, such as voice and telegrams, for a very long time. As the popularity of the internet has increased since the mid-1990s, voice has increasingly given way to data. This quickly illustrated the data transmission limitations of copper, which sparked the invention of optics.

 

History:

1) Pigeons:

 

Different societies have employed homing pigeons throughout history. The Romans later exploited the Persian-born pigeon post to aid their armies. Frontinus asserted that Julius Caesar sent messages across Gaul using pigeons. The Greeks also used homing pigeons to send the names of the Olympic Games winners to distant places. The technique was utilized in Java and Sumatra by the Dutch administration at the start of the 19th century. Additionally, Paul Julius Reuter began a pigeon service in 1849 to fly stock prices between Aachen and Brussels. This service ran for a year until the telegraph link's gap was closed.

 

On hilltops, chains of beacons were frequently utilized in the Middle Ages to transmit signals. Because beacon chains could only transmit a single piece of information, it was necessary to come to an agreement in advance as to what a message like "the enemy has been sighted" meant. Their employment during the Spanish Armada is notable because a beacon chain carried a signal from Plymouth to London during that time.

 

French engineer Claude Chappe constructed the first fixed visual telegraphy system (also known as a semaphore line) between Lille and Paris in 1792. However, semaphore was hampered by the requirement for expensive towers spaced ten to thirty kilometers apart and expert operators (six to nineteen miles). The final commercial line was abandoned in 1880 as a result of competition from the electrical telegraph.

 

2) Telegraph and telephone:

Sir William Fothergill Cooke and Sir Charles Wheatstone of England exhibited the first commercial electrical telegraph on July 25, 1837. As opposed to being a brand-new invention, both creators saw their creation as "an upgrade to the [existing] electromagnetic telegraph."

 

On September 2, 1837, Samuel Morse made an unsuccessful attempt to show an electrical telegraph that he had independently developed. His code represented a significant improvement over Wheatstone's signaling system. On July 27, 1866, the first transatlantic telegraph wire was successfully installed, opening the way for intercontinental communication.

 

Alexander Bell received a patent for the standard telephone in 1876. In 1876, Elisha Gray also submitted a caveat for it. Gray dropped his caveat, and on March 3, 1876, the examiner granted Bell's patent because he did not oppose Bell's priority. Although Bell was the first to document and test the variable resistance telephone, Gray had already filed his caveat.  Nearly 30 years earlier, in 1849, Antonio Meucci created a system that permitted electrical speech transmission over a line, but it was of limited practical utility because it relied on the electrophonic effect, forcing users to place the receiver in their lips to "hear."The Bell Telephone Company established the first commercial telephone services in the cities of New Haven and London on both sides of the Atlantic in 1878 and 1879.

 

3) Television and radio:

Guglielmo Marconi, an Italian inventor, started working on a wireless communication system in 1894 using the recently discovered phenomena of radio waves. By 1901, he demonstrated that radio waves could be broadcast over the Atlantic Ocean. This marked the advent of radio-based wireless telegraphy. The first radio message from North America to cross the Atlantic was sent on December 17, 1902, from the Marconi station in Glace Bay, Nova Scotia. A for-profit service was started in 1904 to provide nightly news summaries to subscribing ships, who then used them to update their onboard newspapers.

 

The development of radio for military communications was pushed during World War I. Commercial radio AM broadcasting started in the 1920s and rose to prominence as a major news and entertainment medium after the war. The development of radio for military uses such as radar, radio navigation, and aircraft and land communication was once more accelerated by World War II. In order to replace AM as the preeminent commercial standard, stereo FM transmission of radio started in the 1930s in the United States and the 1970s in the United Kingdom.

 

John Logie Baird gave a demonstration of moving picture transmission on March 25, 1925, at Selfridges in London. The mechanical television was created by Baird and was based on the Nipkow disk. It served as the foundation for the British Broadcasting Corporation's experimental transmissions, which got underway on September 30, 1929.  However, televisions relied on Karl Braun's cathode ray tube for the most of the 20th century. Philo Farnsworth created the first prototype of such a television that showed promise, which he showed to his family on September 7, 1927. Television emerged as a significant home entertainment broadcast medium with the resumption of stopped trials following World War II.

 

4) Thermionic valves:

A number of fundamental electronic operations, including signal amplification and current rectification, are performed by thermionic emission of electrons from a heated cathode in a device known as a thermionic tube or thermionic valve.

 

The heated electron-emitting cathode and anode are the only components of the diode, which John Ambrose Fleming created in 1904 and is the simplest vacuum tube. Through the gadget, electrons can only move from the cathode to the anode in one direction. By including one or more control grids inside the tube, the voltage on the grid or grids can be used to regulate the current flowing between the cathode and anode.These innovations were essential to the creation of radio, television, radar, sound recording and reproduction, long-distance telephone networks, and analogue and early digital computers. They also formed a major part of electrical circuits throughout the first half of the 20th century. Although certain applications had used older technology, such as the spark gap transmitter for radio or mechanical computers for computing, it was the development of the thermionic vacuum tube that made these technologies popular and useful, which eventually led to the development of electronics.

 

Solid-state devices, which are more efficient, dependable, and long-lasting than thermionic tubes, are smaller, less expensive, and more versatile thanks to the development of semiconductor devices in the 1940s. The transistor began to take the place of thermionic tubes in the middle of the 1960s. There are still some high-frequency amplifiers that use thermonuclear tubes.

 

Telecommunications

5) Internet and computer networks:

George Stibitz used a teletype on September 11, 1940, to transfer questions for his Complex Number Calculator from New York to Dartmouth College in New Hampshire, where the results were computed. Long into the 1970s, this setup of a centralized computer (mainframe) and distant dumb terminals was still common. Research on packet switching, a method that transmits messages in chunks to their destinations asynchronously without going via a centralized mainframe, began in the 1960s. The ARPANET started as a four-node network on December 5th, 1969, and by 1981 it had expanded to 213 nodes. The ARPANET and other networks eventually came together to establish the Internet.Other networking developments, such as the local area network (LAN) developments of Ethernet (1983) and Token Ring (1994), occurred in industrial laboratories while Internet development was the focus of the Internet Engineering Task Force (IETF), which published a series of Request for Comments documents (1984).

 

6) Transmission capacity expansion:

Through two-way communications networks, the effective capacity to share information increased from 281 petabytes (pB) of ideally compressed data in 1986 to 471 pB in 1993 to 2.2 exabytes (eB) in 2000 to 65 eB in 2007. In terms of information, this equates to two newspaper pages per person day in 1986 and six whole newspapers daily in 2007. Due to this expansion, the telecommunications sector is becoming more and more crucial to the global economy, with a $4.7 trillion market in 2012. In 2010, it was predicted that the global telecommunications business generated service revenues of $1.5 trillion, or 2.4% of the global GDP (GDP).