3. Multiplexing
•Information transfer over an optical fiber
communication can be maximised by multiplexing
several signals on to a signal fiber.
•These multichannel signals can be multiplexed in
the electric time or frequency domain.
4.
5. Types of multiplexing
Some of the multiplexing techniques used are :
1) TDM- In time division multiplexing pulses from multiple channels are interleaved &
transmitted sequentially, it enhance the bandwidth utilization of a single fiber link.
2) WDM- When number of optical sources operates at different wavelength are to be sent
on single fibre link, wavelength division multiplexing is used.
3) OTDM- The method to increase the bit rate of a digital fiber system that can create
capability beyond the bandwidth available with drive electronics is optical time division
multiplexing.
4) SCM- It involves use of higher frequency microwave subcarriers which are multiplexed
with respect to the frequency.The subcarrier multiplexing can transmit multiple multiple
broadband signals over a single mode fiber.
6. WDM Network
• In WDM, optical signals with number of different peaks wavelengths
are transmitted in parallel over a single optical fiber.
• WDM is used when number of optical sources operates at different
wavelength are to be sent on single fiber link.
• Each intensity modulated channel of the WDM can have access to the
entire fiber bandwidth which can be in the range of several GHz.
7.
8. OTD Multiplexing
• OTD multiplexing means Optical time division multiplexing .
• It is the method to increase the bit rate of a digital fiber system.
• It can create capability beyond the bandwidth available with drive
electronics is termed as optical time division multiplexing.
9.
10. SCM
• SCM means Subcarrier multiplexing which involves use of higher
frequency microwave subcarrier which are multiplexed with respect
to the frequency.
• These multiplexed subcarriers are then applied to intensity modulate
high speed injection laser source.
• SCM can transmit multiple broadband signals over a single mode
fiber.
11. Applications
• Long transportation of optical networks either in point-to-point or
ring topology.
• Expanding the capacity of an existing optical network.
• Capacity leasing for network wholesalers.
