- Physical layer is the actual carrier of information between computers
- It is the most important layer, as communication between computers cannot happen without a physical layer
- Data is actually carried between every adjacent node (computers/routers) by transmission of electromagnetic/optical signals at the physical layer over wired/wireless media
- Physical layer therefore encompasses the set of all protocols/standards used in different types of Wired/Wireless interfaces and the telecommunication links connecting them
- It also includes the mechanical, electrical and timing specifications for different network interfaces
- Typical examples of physical layer protocols are
a) Ethernet/DSL/Optical/WiFi/3G line coding techniques
b) Connector type specifications like RJ11, RJ45 etc.
c) Link/Channel Multiplexing techniques like FDM, TDM etc.
b) Connector type specifications like RJ11, RJ45 etc.
c) Link/Channel Multiplexing techniques like FDM, TDM etc.