TYPES OF COMMUNICATION:
WIRE BASED COMMUNICATION:
In this mode of
communication physical transmission medium is used. Data travel on a network
through physical wires like twisted pair cable, coaxial cable and fiber optics,
etc.
WIRELESS COMMUNICATION:
In this mode of
communication wireless transmission medium is used. Data travel on a network
through radio waves, micro waves, and infrared rays, etc.
ANALOG SIGNALS:
An analog signal is a
continuous signal that contains time varying quantities. An analog signal has
constant fluctuations. Analog signals can be used to measure changes in some
physical quantities such as light, sound, pressure, or temperature. Even in
digital devices, there is typically some analog component that is used to take
in information from the external world, which will then get translated into
digital form (using an analog-to-digital converter)
DIGITAL SIGNALS:
A digital signal
refers to an electrical signal that is converted into a pattern of bits. A digital
signal has a discrete value at each sampling point. The precision of the signal
is determined by how many samples are recorded per unit time. A digital signal
is easily represented by a computer because each sample can be defined with a
series of bits that are either in the state of 1 or 0. Digital signals can be
compressed and can include additional information for error correction.
COMPONENTS OF A COMMUNICATION SYSTEM:
A data communication
system consists of following five components:
SENDER:
A computer or any
other device (cell phone, digital camera, etc.) that sends messages over a
network is called a sender.
RECEIVER:
A computer or any
other device (cell phone, printer, etc.) that receives messages or instructions
from a network is called a receiver.
MESSAGE:
A message is the
information, data or instructions to be communicated over a network.
PROTOCOL:
Protocol is a set of
rules that governs data communication. Protocol is defined as before the
communication takes place between two devices.
TRANSMISSION MEDIUM:
It is the physical
path through which message passes from sender to the receiver. It can be guided
(twisted pair cable, coaxial cable or fiber optics) media or unguided (radio
waves, micro waves, or infrared waves) media.
PROPETIES OF GOOD COMMUNICATION SYSTEM:
The effectiveness of
communication system is based on the following three properties:
1. Delivery
2. Accuracy
3. Timeliness
DELIVERY:
The data must be
delivered to the right device or user. It means data must be received by the
intended device or user.
ACCURACY:
The data must be
delivered accurately without alteration. The data that have been altered in
transmission and left uncorrected is unusable.
TIMELINESS:
The communication
system must deliver data in time. Data delivered late is useless.
0 Comments