Multiplexing combines multiple signals into a single transmission medium. There are several types of multiplexing including frequency division multiplexing (FDM), time division multiplexing (TDM), wavelength division multiplexing (WDM), and code division multiplexing (CDM). FDM combines analog signals onto different frequencies. TDM divides the transmission signal into time slots and allocates each signal to a time slot. WDM combines multiple optical carrier signals onto a single optical fiber by using different wavelengths of laser light. CDM combines signals by using spread spectrum technology and coding.

2. Multiplexing & Types

3. Group Members
Abdullah Hashmi 15091519-127
Khizra Mazhar 15091519-001
Amina Kalsoom 15091519-109
Noor Amna 15091519-068

4. M. Abdullah Hashmi

5. Definition
Multiplexing - To combine
multiple signals (analog or
digital) for transmission
over a single line or media.
01
Owen Squier is credited
with the development of
multiplexing in 1910
02
For example :
telecommunication
03

6. Description
 A common type of
multiplexing combines
several low-speed signals
for transmission over a
single high-speed
connection.
 Muxing is used for
sharing of a medium and
its link by two or more
devices.
 It can provide both
Efficiency and Privacy.

7. Concept
The signal from 4 different
devices is combined and carried
by this single line.
At the receiving side, a
demultiplexer takes this signal
from a single line & breaks it into
the original signals and passes
them to the 4 different receivers.

8. MUX and DE-MUX

9. Khizra Mazhar

10. When not use multiplexing
 If no multiplexing is used between the users at two different sites that are distance
apart.
 This is not only costly but also become difficult to manage.
 If multiplexing is used then, only one line is required.
 This leads to the reduction in the line cost and also it would be easier to keep
track of one line than several lines.
 Multiplexing efficient for utilization of bandwidth.

11. Types
There are four types of Multiplexing
 1- Frequency Division Multiplexing (FDM)
 2- Time Division Multiplexing (TDM)
 3- Wavelength Division Multiplexing (WDM)
 4- Code Division Multiplexing (SDM)

13. Frequency Division Multiplexing
 The FDM is an analog multiplexing that combines analog signals.
 FDM is applied when the bandwidth of the link is greater than the combined
bandwidth of the signals to be transmitted.
 When FDM is used to allow multiple users to share a single physical
communications medium the technology is called frequency-division multiple
access (FDMA).
 Twentieth century telephone companies used FDM for long-distance connections
to multiplex thousands of voice signals through co-axial cable systems.

14. Amina Kalsoom

15. Time-Division Multiplexing
 Time division multiplexing is a technique used to transmit a signal over a single
communication channel by dividing the time frame into slots – one slot for each
message signal.
 Time-division multiplexing is primarily applied to digital signals as well as analog
signals.
 Several low speed channels are multiplexed into high-speed channels for
transmission.
 Based on the time, each low-speed channel is allocated to a specific position,
where it works in synchronized mode.

16. Types of TDM
Time division multiplexing is classifieds into four types:
 Synchronous time-division multiplexing
 Asynchronous time-division multiplexing

17. Synchronous Time Division Multiplexing
 Synchronous time division multiplexing can be used for both analog and digital
signals. In synchronous TDM, the connection of input is connected to a frame. If
there are ‘n’ connections, then a frame is divided into ‘n’ time slots – and, for
each unit, one slot is allocated – one for each input line. In this synchronous
TDM sampling, the rate is same for all the signals, and this sampling requires a
common clock signal at both the sender and receiver end. In synchronous TDM,
the multiplexer allocates the same slot to each device at all times.

18. Asynchronous Time-Division Multiplexing
 In asynchronous time-division multiplexing, the sampling rate is different for
different signals, and it doesn’t require a common clock. If the devices have
nothing to transmit, then their time slot is allocated to another device. Designing
of a commutator or de-commutator is difficult and the bandwidth is less for
time-division multiplexing. This type of time-division multiplexing is used in
asynchronous transfer mode networks.

19. Noor Amina

20. Wavelength Division Multiplexing
 Wavelength division multiplexing (WDM) is a technology in fiber optic
communications.
 For the high capacity communication systems, wavelength division multiplexing is
the most promising concept.
 WDM is designed to use the high data rate capability of the fiber optic cable.
 Data rate of this cable is higher than the metallic transmission cable’s data rate.

21. Code Division Multiplexing
 Code division multiplexing (CDM) is a networking technique in which multiple
data signals are combined for simultaneous transmission over a common
frequency band.
 When CDM is used to allow multiple users to share a single communications
channel, the technology is called code division multiple access (CDMA).