Communication technology has evolved from ancient gestures and language, through the telegraph and telephone, to modern cell phones, satellite communications, artificial intelligence, and the Internet of Things. Early wired communication began with telegraphs using electromagnetic induction, and wireless communication developed based on Marconi’s wireless telegraph and Maxwell’s theory of electromagnetic waves. Today, both wired and wireless are used, and stable and high-quality communication is possible through multi-connection technologies, optical fibers, microwaves, etc.
From ancient times to the present day, communication technology has come a long way. Ancient communication began with gestures, the birth of language, and the use of various vehicles to communicate over long distances. For example, the ancient Greeks used votive flames to transmit information over long distances, and during the Han Dynasty in China, drums and smoke were used to send signals. Since the 1800s, there has been a rapid development of communication, which has increased the interaction between civilizations and contributed greatly to the development of global civilization.
In modern times, communication has become ubiquitous and essential to our lives, with cell phones, computers, and other devices all around us. Nowadays, we can communicate with people on the other side of the world in real time through the Internet, and we can easily search for various information. Satellite communications have also made it possible to get real-time weather information from around the world. Let”s take a look at how these communications have evolved and what technologies are used today. First, let”s take a look at the development of telecommunications.
Communication technology started with wired communication. The theoretical basis of wired communication began with Faraday”s electromagnetic induction. This theory led to the invention of the telegraph by Morse in 1837. The telegraph used a signal that could only be understood by a person who had undergone a long period of training called Morse code through the process of letter-translation-Morse code-electrical conversion-electrical signal-mechanical conversion-Morse code-translation-text. In addition, the telegraph used a medium called paper tape, where the sender wrote Morse code on the paper tape and the receiver received a paper tape with Morse code on it, so it took time to write Morse code and decipher the original Morse code.
A telephone that could communicate by voice that could solve these problems was developed 20 years later by Graham Bell. Bell used the already known telegraph lines to send voice information so that the other party could hear it directly. Bell used a different and revolutionary principle: he used different frequency bands on the same wire. To make a voice communication, you need to send both telegraphic and voice information, and Bell sent the telegraphic information on a higher frequency band and the voice information on a lower frequency band. The reason for this is that if multiple signals are sent in adjacent bandwidths, electromagnetic interference will cause the symbols to be scrambled. This method of sending information at multiple frequencies on a single wire is called frequency division multiplexing.
While wired communication was being developed, wireless communication was also being developed. The theoretical basis for wireless communication was created in 1864 by James Clerk Maxwell and Heinrich Rudolf Hertz. Maxwell’s equations for the four electromagnetic waves and Hertz’s experimental confirmation of the correctness of Maxwell’s equations paved the way for the realization and practical use of electromagnetic waves.
It was not until 30 years later, in 1895, that wireless communication was made possible using practical theory. Marconi developed a wireless communication device in 1895, obtained a British patent for wireless telegraphy in 1896, and started a wireless communication business by founding the Marconi Wireless Telegraph and Telegraph Company in London in 1897. In 1901, Marconi succeeded in transatlantic wireless communication, which opened the era of wireless communication using radio waves as well as wired communication through wires. The invention of the triode vacuum tube in 1907 and the two world wars led to the rapid development of wireless communication. During World War II, radar was developed and used. In 1959, intercontinental communication via satellite was successfully experimented with and the era of satellite communication began. Since the 1980s, cellular telephony has been commercialized and personal cell phones have become a common means of communication. In addition, the Global Positioning System (GPS), which was developed by the United States in the 1960s and used for military purposes, was opened to civilians in the 1980s, and numerous applications and software such as vehicle navigation systems based on it appeared.
So far, we’ve covered the development of communication. In the next part, we’ll talk about modern communication technologies. Currently, both wired and wireless communication are used, and the reason why wired communication is still used is that it is more expensive than wireless communication and it is difficult to transmit radio waves far away, but it has the advantage of ensuring a stable and high-quality transmission route and being able to branch out in the middle. Currently, Korea relies on wired communication for local communication and wireless for intercity communication.
The difference between wired communication and wireless communication is that the types of transmission lines have changed, and nowadays, fiber optic cables are used for faster communication, or bounce technology is used to save the cost of sending data over long distances. Carrier technology is a technology that accurately and reliably transmits information such as voice or data at a low cost using metal cables or fiber optic cables as a transmission medium. The principle is based on running multiple signal currents of different frequencies through two wires and paralleling multiple communications at once. This allows up to 2700 people to communicate simultaneously.
Unlike wired communication, wireless communication is used in many ways. Wireless transmissions mainly use microwaves because their high frequency allows communication with relatively small antennas, and their wide bandwidth makes them suitable for transmitting broadband signals. Higher frequencies are not used because they are highly attenuated in the atmosphere, making it difficult to transmit over long distances. Wireless communications are less susceptible to natural disasters and cheaper to install and operate than wired communications, but because they propagate through the atmosphere, there is a risk of interference.
To eliminate this risk, multiple access technology is used. Multiplexing technologies include quadrant multiplexing, frequency division multiplexing, and code division multiplexing. The basic principle is that, for example, frequency division divides the frequency into different channels and each channel is used by different users. Code splitting or quadranting works in the same way, only with a different division variable. This way, different users use different frequencies, reducing the risk of confusion.
As you can see, communication technology has evolved steadily, and along the way, different theories and technologies have been introduced. Nowadays, artificial intelligence (AI) and Internet of Things (IoT) technologies are being combined with telecommunications to realize smart homes, smart cities, and more. In the future, communication technology will continue to develop further, making our lives easier and safer.
This concludes our brief explanation of telecommunications technology and its development. From ancient times to the present, communication technology has been developed by many great minds, and today’s communication is not only about communication on Earth, but also about communication with other planets in the universe. We look forward to seeing what new possibilities the future of communication technology will bring us.
