CWDM Optical Add-Drop Multiplexing Technology

It is more and more instancy to develop All Optical Network(AON)as the progress in area of communication technology. The technology of optical add drop multiplexing(OADM)is one of the key technologies to implement AON.

CWDM OADM can provide multiplex and demultiplexing or the ability to add-drop multiple fibers to one.

Different styles of OADM

OADM (CWDM-MUX-AD-xxxx=):The device allows you to plug the two channels of the same wavelength to a circular optical network in both directions. Another wavelength was sent by OADM. The OADM provided a choice for 8 wavelengths, they are: 1470、1490、1510、1530、1550、1570、1590 and 1610(nm)

4 channel OADM: (CWDM-MUX-4=)

The device allows you to add-drop four channels(with different wavelength) to a circular optical network. Another wavelength was sent by OADM..

Double optical fiber is used to the network and the GBIC (SFP) and connect. Four wavelengths are set to 1470, 1510, 1550 and 1590 nm.

8 channel CWDM-MUX-8= permits you to put the eight independent channel into a pair offiber optic cable.

Double optical fiber are used to network and GBIC(SFP). Eight wavelengths are set to 1470、1490,1510,1530,1550,1570,1590 and 1610 nm.

CWDM-MUX-4-SFx= single fiber with 4 channels allow you to insert four independent channels into a piece of fiber bundle.

Double optical fiber are used to GBIC/SFP, single fiber is used to network connections.

The application of CWDM OADM

There are three kinds of applications for metropolitan area network: point to point application, point to chain application, circling application.

Point to point application is the most basic and most commonly topological structure. It is use to increase transmission capacity of single optical fiber cable and achieve a variety of business access at the same time.

There are two main applications: point to point multi-service and point-to-point access to the various VPNs.

Combination of OADM point to chain application solutions can expand the scope of the access point effectively. The distance between longest nodes and switch is as far as 60 km, which enough to meet the demand in vast majority of accesses to the application. However, the shortage of this kind of structure is inherent. If an obstacle occurs in OADM, the downstream businesses are all being interrupt. So must be well protected. In addition to the protection of the 1 + 1 optical fiber cable protection, also be carried out on the OADM. Planning good power budget is important.

Circle topology use less fiber covering greater physical range. It is suitable for metropolitan area network convergence. With double optical fiber circle, CWDM circle topology can be implemented, such as SDH self-healing circle function.In addition, adopting SDH equipment to build convergence based on SDH loop with CWDM module, not only upgrade and transfer SDH network expansion, at the same time, but also on the ring at the same time doing business transfer, such as GE, ATM transfer, etc.

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