Physical Layer :
- Physical Layer deals with the functionalities required to transmit a bit stream over a physical medium.
- Transmission unit is Bits
- It is responsible for movements of individual bits from one node to the next.
- It defines the characteristics of the interface between the devices and the transmission media.
- It defines how the bits are encoded into electrical or optical signals
- It also controls Data rate and synchronization of bits
- It also defines the Network Topology and transmission mode.