Telecommunications of one kind or another are not a modern invention. The first successful attempts at telecommunication systems included signal fires which were used since ancient times. The 18th Century saw the invention of optical telegraphy communications systems, also known as semaphore lines while the late 19th Century gave rise to radio technology. Today, we use the Internet and telephones for the vast majority of our telecommunications although there is an even wider variety of telecommunication systems in use today.
Optical telecommunication is the oldest and simplest type. Optical telecommunications systems include everything from signalling flags used on boats to the semaphore optical telegraphy lines of the past. Although fibre optic communication falls into the same category, it is rather different to every other form of optical telecommunication in that it relies on converting data into beams of light. These may be carried over fibre optic cables or by using an infrared connection.
Radio Telecommunication Systems
Radio technology allows for wireless communication over large distances. Radio broadcasts are sent out by radio transmitters and then decoded at the other end in real time. Perfected about the turn of the 20th Century, radio remains one of the main forms of communication in the world today. Television is also a form of radio communication.
Today's telephones, cellphones and most forms of Internet access are full-duplex systems. Full-duplex means both parties can communicate with each other at the same time.
Radio communications are a good example of half-duplex communication systems since only one party can send a message at a time. In a half-duplex system, the recipient has to wait for the message before sending out a new one. Some types of Internet connection work the same way.