Physical layer is the last layer from sender and first layer of receiving side in the OSI model.
Note: Generally we assume the numbering of OSI layers according to Receiver Side.
- It transmits the individual bits from one node to another node through communication Medium.
- It establishes, maintains and terminates the physical connection of network.
Functions Of Physical Layer
- Communication Channel: It defines how devices can be connected physically i.e. coaxial cable, fiber optic etc.
- Data Rate: It tells about the No of bits delivered in one second.
- Hardware’s: Repeater and Hubs are mostly used in Physical layer.
- Data Transmission: It defines the transmission mode i.e. simplex, half-duplex or full-duplex mode between the two devices on the network.
- Physical Topology: It defines the way how network devices are arranged i.e. star, bus, ring etc.
- Signals: It determines the type of the signal (digital or analog) used for transmitting the information.
- Encoding: It defines the encoding method where the bits are encoded into electrical signals before to transmission. There are various encoding methods are used for this purpose.
- Multiplexing & De-Multiplexing: Mostly layers use Multiplexing & De-Multiplexing. In physical layer it requires when multiple senders need to send data at a time over the single transmission Medium.