Physical layer is the shortest layer in the model. This layer is feasible for initiating, preserving, and deactivating a physical circuit between two end frameworks.
The Physical Layer is vital for transmitting bits from one device to another device. It can change the series of bits into electric signals, light signals, or electromagnetic signals, relying on either the two hubs on a link circuit, fiber-optic circuit, or microwave/radio circuit.
Passive hubs, simple active hubs, terminators, couplers, cables, connectors, repeaters, multiplexers, transmitters and receivers are the devices associated with the physical layer.
The physical layer situation for the transmission channel and the data link layer is displayed in the diagram below.
There are various services of the physical layer, which are as follows −
Representation of Bits: The physical layer data includes a flow of bits without any perception. It represents the encoding (how 0's and 1's is modified to signals).
Data rate: It represents the transmission rate, i.e., the several bits communicated per second.
Transmission Medium: It represents the types of transmission medium.
Synchronization of Bits: The sender and receiver should be integrated at the bit method, i.e., the sender sends data simultaneously in which the receiver is ready to receive.
Line Configuration: Physical layer is concerned with connecting tools to the channel, whether point to point or multipoint.
Physical topology: It is defined in what way the devices are linked to create a network.
Transmission mode: It also defines the mode of transmission, i.e., the services of a message between the two computers. In half-duplex, two computers can send and get the data but not at a similar time. In full-duplex mode, the two devices can send and get data at an equal time.