2. INTRODUCTION
DATA COMMUNICATIONS:
The term telecommunication means communication
at a distance. The word data refers to information
presented in whatever form is agreed upon by the
parties creating and using the data. Data
communications are the exchange of data between
two devices via some form of transmission medium
such as a wire cable.
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4. 1. Message:
The massage is the information (data) to be communicated
for example. Text, number, pictures, Audio, Vedio etc.
2. Sender:
The sender is the device that sends the data
massage.
3.Reciever:
The receiver is the device which receive the
massage.
4.transmission medium:
The transmission medium is the physical path by
which a message travels from sender to reciever.
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5. CONTINUE:
5.Protocols:
A protocol is the set of rules that governs
data communication.
it represents an agreement between the
communication devices.
Without protocols two devices may be connected
but not communication.
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8. NETWORKS:
A network is a set of devices (often referred to as
nodes) connected by communication links. A
node can be a computer, printer, or any other
device capable of sending and/or receiving data
generated by other nodes on the network.
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9. TYPES OF CONNECTIONS:
Point-to-Point:
In telecommunications, a point-to-point connection
refers to a communications connection between two
nodes or endpoints.
The entire capacity of the link is reserved for
transmission between two devices.
Communication link may be wire or microwave or
satellite link.
An example is a telephone call, in which one telephone is
connected with one other, and what is said by one caller
can only be heard by the other. 9
10. MULTIPOINTS
A multipoint connection is a connection in which
more than two terminals share one communications
link.
In multipoint environment the capacity of the
channel is shared.
if several devices can use the link
simultaneously, then it is spatially share connection.
If user take turns .it is timeshared connection.
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