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Notice:

Physical Layers:
One of the major functions of the physical layer is to move data in the form of
electromagnetic signals across a transmission medium. Whether you are collecting
numerical statistics from another computer, sending animated pictures from a design
workstation, or causing a bell to ring at a distant control center, you are working with the
transmission of data across network connections.
Generally, the data usable to a person or application are not in a form that can be
transmitted over a network. For example, a photograph must first be changed to a form
that transmission media can accept. Transmission media work by conducting energy along
a physical path.
Analog and Digital Data:
Data can be Analog or Digital. The term analog refers to information that is continuous;
digital data refers to information that has discrete states. For example, an analog clock that
has hour, minute, and second hands gives information in a continuous for; the movements
of the hands are continuous. On the other hand, a digital clock that reports the hours and
the minutes will change suddenly from 8:05 to 8:06.
Analog Data:
Analog data, such as the sounds made by a human voice, take on continuous values. When
someone speaks, an analog wave is created in the air. This can be captured by a
microphone and converted to an analog signal or sampled and converted to a digital
signal.
Digital Data:
Digital data take on discrete values. For example, data are stored in computer memory in
the form of 0s and 1s. They can be converted to a digital signal or modulated into an
analog signal for transmission across a medium.
Data can be analog or digital. Analog data are continuous and take continuous
values Digital data have discrete states and take discrete values.


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Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online
Physical Layers,Analog and Digital Data | lecture 1 | by Education Hub online