Wdm In Optical Network

Contents

• WDM
• WDM Components
• Need of OEQ

What is WDM ?

A technology used to transmit multiple optical signals by multiplexing into an one signal. It is commonly described frequency division multiplexing while it is used in RF radio carriers.

• In Dense Wavelength Division Multiplexing, Only 1550 nm Wavelength band is used.
• C band (1525 - 1565 nm) and L band (1570 - 1610 nm), These bands works well with the EDFAs.

WDM Components :

1. Transponder
2. Muxponder
3. Mux/Demux
4. OADM
5. ROADM
6. Supervisory, DCF, VOA, Amplifiers.
7. OLP
8. Transponder cum OLP
9. Muxponder cum OLP
10. Regenerator.

The Relation between Transponder, Muxponder, Mux/Demux

Re-generator:

It lies between the two MDXs to provide power to increase the travel distance of optical signals.

WDM - NE Types:

1. Terminal.
2. Dual-Terminal.
3. ILA/OLA (Inline/Optical Line Amplifier)
4. OADM
5. ROADM

OADM

OADM means the Optical Add and Drop Multiplexing which is used in optical link. The major parts are,

1. FBG - Fiber Bragg Grating
2. Circulators. These are used for this optical operation.

OADM

Abbreviations

• TPDR Algorithm - Tunable-Parameter Deflection Routing Algorithm
• OLP - Optical Line Protection.
• FMS - Fiber Management System.
• OSC - Optical Supervisory Channel.
• DSF - Dispersion Compensating Fiber.
• OADM - Optical Add and Drop Multiplexing.
• ROADM - Reconfigurable OADM.

What is the need of OEQ ?

Optical Equalizer is used to maintain a standard power on the link where independent wavelengths are passed between two ROADM.