1. Data transmission

1.1 History and performance

Data transmission goes back a long way, and has used many different media. The first media used were based on the human senses: voice, hearing and vision. We only have to go back to the novels and comic strips of our childhood to encounter communication systems such as smoke signals and tom-toms, but also, in ancient history lessons, the fires of Greek sailors, then, closer to home, the semaphores of Chappe* and the telegraphs of Morse** and Baudot***, to arrive at the inventions of the telephone, radio, television, cell phones, etc.