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Physical Layer


Physical Layer(Layer 1): This is the lowest layer of the OSI model that physically gets connected to the communication channel. It is responsible for movements of individual bits from one node to next i.e. transmission and reception of raw bit streams over a physical medium.

 Functions include:


  • Physical characteristics of interfaces and medium: The physical layer defines the characteristics of the interface between the devices and the transmission medium.
  • Bit Representation: To be transmitted, the bits must be encoded into signals, so this layer is responsible for defining which type of encoding is to be used.
  • Data Rate: Physical layer defines the number of bits which are to be sent each second.
  • Bit Synchronization: It ensures synchronization between the sender and the receiver at the bit level.
  • Physical Topology: It defines how the devices are connected to make a network.
  • Mode of transmission Physical layer is responsible for defining the transmission modes.
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