Physical Layer

The physical layer coordinate the functions required for the transmission of a bit stream over a physical medium. It deals with the interface and transmission medium. It is concerned with the following:

• The physical characteristics of interface between medium and devices.
• At physical layer data must be in 0 and 1 (bit form). So it define the encoding.
• Tha data rate is defined that how many bits per second are sent.
• The sender and receiver must be synchoronised at bit level.
• The line configuration is also concerend with physical layer. It may be point to point or multipoint.
• The topology used for the network is also concerned with the physical layer.e.g; star,mesh,ring etc.
• The transmission mode is also concerned with physical layer. It may be simplex,half or full duplex.