What is a Physical Layer?

The physical layer is vital for transmitting bits from one device to the other device. The physical layer is not concerned with the bits representation, but it manages with physical relation to the structure with communication and signals acceptance.

The physical layer is used to define physical and electrical details, including what will determine a 1 or a 0, how many attachments a network will have, how we will synchronize data and when the network relation may or may not send the data.

The location of the physical layer regarding the communication mode and the data link layer is displayed in the diagram −

The functions of the physical layer are as follows −

  • It can represent the encoding type, i.e., how 0’s and 1’s are transferred to signals.
  • It can represent the communication, i.e., the several bits transmitted per second transmitter and receiver.
  • It can handle the network connection types, such as multipoint and point to point connections.
  • It can deal with physical topologies, i.e., bus, star, ring or mesh.
  • It can deal with media bandwidth, i.e., baseband and broadband transmission.
  • Multiplexing, which deals with combining several data channels into one
  • It can define the characteristics between the devices and the transmission medium.

Connecting devices associated with the physical layer

Passive hubs, simple active hubs, terminators, couplers, cable and cabling connectors, repeaters, multiplexers, transmitters, receivers, and transceivers are associated with the physical layers.

The essential requirement for the transmission of data between the two machines are −

  • A physical interconnecting medium to carry electrical signals between two machines.
  • A technique to convert data massage into electrical signals having suitable characteristics for transmission over the medium like the voltage, current, impedance, rise time etc.
  • A process or ability to reconvert the signals into the original data message.