- Functions of Physical Layer
- Data and Signals
- Data Transmission Media
- Bandwidth Utilization
- Telephone, Mobile and Cable network for Data Communications
Functions of Physical Layer
The main function of physical layer is to transmit the bitstream over a physical medium. The electricals and mechanical specifications of the interface and transmission medium deals by this layer. However it doesn’t deal with the actual physical medium like light in fiber optics and copper in the wire.
- Representations of bits : Basically, it involves a stream of bits (what we call as 0s and 1s) without any interpretation. In order to transmit these sequence of 0s and 1s must be encoded into the signals, either that can be in the form of electrical or optical or some waves.
- This layer defines the type of encoding of those bits
- It is responsible for the bit-by-bit delivery of the data to its upper layer called the MAC layer (we will discuss about that in next chapter).
- It is responsible for delivering the signals from a cable, a wi-fi router or an optical fiber
- Data Rate :
- Synchronization of bits :
- Line Configuration :
- Physical Topology :
- Transmission Mode :