OSI Model Physical Layer | Computer Networks Tutorial | Minigranth
Physical Layer : OSI
Model
Physical Layer is the bottom-most layer in
the layered architecture of the
OSI Model and it is associated with all
the electrical, mechanical and functional aspects of the transmission
media for information transmission(Sending or Receiving) over the
internet.
Physical layer deals
with all the physical devices that can be used for data communication in a
network including the types of cables and transmission modes such as Simplex Mode, Half Duplex Mode and Full Duplex
Mode.
Also, the topology
of any network which forms the fundamental structure of any network is
defined under the Physical-Layer.
Physical Layer :
Functions & Features
The basic function
of Physical-Layer in the OSI Model is to send and receive bits in the form
of “1 & 0”(Binary Value) only.
Physical Layer is
responsible only for transmitting the data bits through the network with the
help of physical devices (such as cables, HUBs, Repeater etc.) connected in
the network irrespective of what data the bits actually
holds.
Also, physical layer
defines how the data received from above layers will be encoded into
binary(0 & 1) and then how will the
data bits be further decoded to its original form. The Physical Layer is
responsible for it.
Defining and dealing
with the synchronization, physical topologies, bandwidth, rate of
transmission and data channel are some of the other features of the Physical
Layer.
The interface for
the data transmission to Data Link Layer is provided by the
Physical-Layer.
Consider some data
is received by the Physical-Layer from one device and needs to be
transmitted in a network. Then the data will first be converted into data
bits using encoders and then will be transmitted to physical layer of other
device where these bits will be further decoded and later will be sent to
Data Link Layer in the original for.