Multiplexing is the sharing of a medium or bandwidth by combining multiple signals from multiple sources and transmitting them over a single communication line. There are three main types of multiplexing: frequency division multiplexing, wavelength division multiplexing, and time division multiplexing. Frequency division multiplexing divides the bandwidth into independent frequency channels. Wavelength division multiplexing combines different light sources into a single light source using a multiplexer and separates them using a demultiplexer. Time division multiplexing shares time instead of bandwidth, with each connection occupying a portion of time in the link.
Water Industry Process Automation & Control Monthly - April 2024
class 7
1. (Note on class topic )
Multiplexing
Course Title: Data Communication
Course Code: CSE 313
Submitted To Submitted by
Pronab nath bondhu Fairuz Fatemi
Lecturer ID:1834902087
City University Batch:49(B)Day
B.S.C in CSE
D:04/10/2021
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2. Multiplexing
• Multiplexing is the sharing of a medium or bandwidth. It is the
process in which multiple signals coming from multiple sources are
combined and transmitted over a single communication/physical line.
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4. 1. Frequency Division Multiplexing :
• Frequency division multiplexing is a defined as a type of multiplexing
where the bandwidth of a single physical medium is divided into a
number of smaller, independent frequency channels.
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5. 2. Wavelength Division Multiplexing (WDM)
• In Fiber communications, the WDM is one type of technology. This is
the most useful concept in high-capacity communication systems. At
the end of the transmitter section, the multiplexer is used to combine
the signals as well as at the end of the receiver section, the de-
multiplexer for dividing the signals separately. The main function of
WDM at the multiplexer is for uniting various light sources into only
light sources, and this light can be changed into numerous light
sources at the de-multiplexer.
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7. 3. Time Division Multiplexing :
• Time division multiplexing is a defined as a type of multiplexing
where in FDM, instead of sharing a portion of the bandwidth in the
form of channels, in TDM, time is shared. Each connection occupies a
portion of time in the link.
• In Time Division Multiplexing, all signals operate with same
frequency (bandwidth) at different times.
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9. • There are two types of Time Division Multiplexing :
• Synchronous Time Division Multiplexing
• Asynchronous Time Division Multiplexing
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10. • Synchronous TDM :
• Synchronous TDM is a type of Time Division Multiplexing where
the input frame already has a slot in the output frame. Time slots
are grouped into frames. One frame consists of one cycle of time
slots.
• Synchronous TDM is not efficient because if the input frame has
no data to send, a slot remains empty in the output frame.
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11. • Asynchronous TDM
• In asynchronous TDM, for different signals, the rate of sampling is
also different, and it doesn’t need a general clock. If the device has
nothing for transmitting, then the time slot is assigned to a new device.
The design of a commutator otherwise de-commutator is not easy &
the bandwidth is low for this type, and it is applicable for not
synchronous transmit form network.
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12. • Advantages
• The process which is used to transmit multiple signals over a single
physical medium is known as multiplexing. The main advantages of
multiplexing include the following.
• Above one signal can be transmitted over a single medium.
• The utilization of a medium bandwidth can be done very effectively
• Multiplexing enhances the network’s economic stability because it reduces
both the time as well as cost required for the operation of the physical
medium when a single medium serves many signals or subscribers or
applications.
• In telecommunications, multiplexing plays a key role to reduce the cost of
networks through reducing the number of communications links required
among two points.
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