C021TV-I4-S3

ICN : 4. Computer and networks architecture 1. Elementary components of a computer 2. Execution principles of a computer program 3. Data transmission principle 4. Network structuring Introduction de la semaine 2/2 Présentation du sommaire global de la semaine : apparition progressive des éléments de la liste, puis mise en évidence de la portion concernée par la vidéo. Mise en évidence = police noire + gras Nom abrégé de cours - Enseignant

bit after bit, byte after byte (serial) Communicate on a wire How does information get transferred? First, let’s consider a wired communication A printer or a phone with a USB cable for example Data is transferred bit after bit, byte after byte (serial) Transmitter’s memory 0111001101… Receiver’s memory 011 0 1 1 0 0 1 Y a aussi des cables paralleles mais de moins en moins Nom abrégé de cours - Enseignant

Transmitting bits on a wire Each bit is associated with an electrical potential value 0 or 5 volts for example That voltage is applied on the transmitter’s side And it is measured on the receiver’s side How can we know to how many bits of 1 corresponds a millisecond with 5 volts? Preliminary agreement on the transmission’s frequency

Types of wired connectors Needs for great distances and high frequency Energy loss (Joule heating) Various connector types Coaxial cable (the « cable », the classical TV antenna) Twisted pair (RJ45, USB, etc.) Optical fiber According to length, frequency, output and interfrency tolerance that is needed

Wireless communication Suppress wire constraints Deployment, mobility, … Use electromagnetic waves Hertzian television, radio, wifi, mobile phones, … Adressing problem To whom is the messasge intended? Enables direct emission towards many receivers

Some orders of magnitude ADSL USB Câble Fibre optique TNT Wifi 3G 4G 25 Mb/s 100 Mb/s 1 Gb/s 100 Gb/s ~10 Mb/s 10-100 Mb/s 1-10 Mb/s ~100 Mb/s 3 Mo/s 10 Mo/s 100 Mo/s 10 Go/s ~1 Mo/s 1-10 Mo/s 0,1-1 Mo/s ~10 Mo/s Transferring a PDF document (100ko) Between 0,01 and 0,1 second towards a USB printer (or in wifi, or in 4G) 10 µs on an optical fiber Tranferring a Full HD movie (1Go) 0,1 second swith an optical fiber, 5 minutes with ADSL Full HD video streaming (1Mo/s) Difficult with Wifi and 3G if reception is bad

Pictures p. 5 : Antenna on town 01.jpg CC-BY-SA-4.0 self via Wikimedia Common https://creativecommons.org/licenses/by-sa/4.0/deed.en