4. 4
● This is the set of technique that allow the
simultaneous transmission of multiple signals
across a single data link.
MUX DEMUX
1 Links , n Channels
n inputs n outputs
7. 7
● A multiplexing technique working in
the wavelength domain.
● An analog multiplexing technique to
combine optical signal.
8. HISTORY OF WDM
The Concept was first published in 1970,
and by 1978 WDM systems were being
realized in the laboratory. The First WDM
systems only combined two signals.
Modern systems can handle up to 160
signals and thus expand a basic 10 Gbit/s
fiber system to a theoretical total capacity
of over 1.6Tbit/s over a single fiber pair.
9. 9
WDM
In Fiber-optic communications Wavelength-division multiplexing (WDM)
is a technology which multiplexes multiple optical carrier signals on a
single optical fiber by using different (colors) of laser light to carry
different signals.
MUX DEMUX
TP-1(λ1)
TP-2(λ2)
TP-3(λ3)
TP-4(λ4)
TP-5(λ5)
TP-6(λ6)
TP-7(λ7)
TP-8(λ8)
Multiple optical signals on
the same optical fiber
Link 1
Link 2
Link 3
Link 4
Link 1
Link 2
Link 3
Link 4
10. 10
Most WDM systems operate on single mode fiber optical cables, which have a core
diameter of 9μm. Certain form of WDM can also be used in multi-mode fiber cables
(also known as premises cables) which have core diameters of 50 or 62.5μm.
11. Why is WDM used?
with the exponential growth in communications,caused
mainly by the wide acceptance of the internet,many
carriers are finding that their estimates of fiber needs have
been highly underestimated. Although most cables
included many spare fibers when installed, this growth has
used many of them and new capacity is needed.
12. 12
Type of WDM
1) CWDM (Coarse Wavelength Division)
2) DWDM (Dense Wavelength Division)
13. 13
Benefits of WDM
WDM technology allows multiple connectors over one fiber
thus reducing fiber plant management.
This is mainly beneficial for long-haul applications.
Campus applications require a cost benefit analysis.
WDM technology can also provide fiber redundancy.
WDM provides a managed fiber service.