Mail was the main means of communication just 100 years ago with mailmen physically delivering the news. The cutting-edge communication method then was sending a letter in a capsule shaped like a rocket through underground pipes using compressed air. There was a complex network of such underground pipes in Paris, which worked as a mail delivery system. This was the fastest and most innovative communication method at that time.
In the past, physicists frequently wrote letters as people write emails these days. The obvious difference is that one can now receive an email quickly after it is sent. All scientific exchanges, which used to be written in ink on paper, are now stored as digital signals on the Internet, hard disk or mobile phones. Human-to-human exchanges have remained, just in different methods.
It was not long ago when the first wireless communication system was developed. A researcher at the Bell Telephone Laboratories in the U.S. was working on how a telephone wire could be removed in the 1970s, which led to the 1G mobile communication device. The wireless phone only supported voice calls and was called a “brick” for its heavy weight. It also had the price tag comparable to the lease fee for an apartment unit in Seoul. As a switch was made from analog to digital since then, the 2G mobile communication era opened with devices allowing the transmission of voice and data. The unit of data transmission speed then was kilobits per second (Kbps). With the introduction of 3G smartphones, competition for faster data speed began. The current 5G service offers 20 Gbps speed, which far exceeds the old speed. It is only natural that such fast speed is affecting all areas in society as people’s life itself is chasing such speed.
Data demands will be overwhelming by 2030 when the Internet of Things technology is expected to become widely available with 5G networks utilized in various areas. As an alternative, research institutions in South Korea, the U.S., Finland, and China are developing the next communication method, 6G. The new technology will utilize multiplex transmission technology based on the quantum mechanics concept of orbital angular momentum to increase transmission speed. The 6G technology will allow data to be transmitted five times faster than the current level, which means virtual worlds that have been featured in sci-fi movies can be realized on the web.