In this 'Viewpoint', Ian Philip our Technical Manager, provides some insight on DWDM and its importance in todays communication networks.
Wavelength-division multiplexing (WDM) and particularly Dense Wavelength Division multiplexing (DWDM) is a term usually applied to fibre optic communications. It is a technology that allows multiple optical signals to reside on the same optical fibre. These signals are produced by lasers of differing wavelengths (colours). DWDM makes efficient use of fibre cabling by increasing its capacity and in effect making it appear as if multiple fibres are in use where only one really is.
Let's take a specific example – assume we have a 10Gbps link between 2 locations running over a pair of fibres. With DWDM technology we could increase this to 80 x 10Gbps links running over the same fibre pair. Thus increasing the capacity 80 fold without any additional infrastructure.
Other benefits of DWDM technology are:-
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Enables rapid expansion of network capacity
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It saves time, cost and effort of installing new fibre infrastructure
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It's transparent in operation so no upgrade of existing equipment is necessary
It appears that some are a little confused by the apparent differences between CWDM (Coarse Wavelength Division Multiplexing) & DWDM, but it really comes down to capacity and application, i.e.:
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CWDM typically provides 8 channels and is used widely in Enterprises, whereas
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DWDM provides up to 80 channels so is commonly used by Carriers.
At Lanode we have been providing a range of CWDM products for some time including:
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A 2U optical transport system designed to multiplex, de-multiplex and switch high-speed data for storage, video and voice applications
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1.25G, 2.5G, 2.7G & 10G Transponder cards
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Optical Add-Drop Mux & Line Protection cards and finally
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A 4U 24-Slot Passive Rack and 4-Channel Transponder Platform.
And as recently announced we now have a wide range of DWDM equipment that supports client data rates up to 10Gbps (With 100Gbps available very soon!). Our 10G Transport Platform is a high performance and flexible carrier-class transmission system allowing the amalgamation of Ethernet / IP, SDH, traditional TDM as well as HD Video sources. Developed to the highest production engineering standards this robust family of products consist of a 6 U chassis for high density applications and a compact 2 U chassis for low density applications. The platform also includes optical multiplexers (Mux/DeMux), reconfigurable optical add/drop multiplexers (ROADM) and optical amplifiers (OA).
Lanode supports the optical multiplexing of up to 80 x 10G channels (can be extended to 160 channels) with transmission distances of up to 2500 km (using optical EDFA and Raman line amplifiers).
We've always felt at Lanode that we need to stay abreast of leading edge technology changes so that we are able to provide clear, independent and objective advice to our customers – ensuring that they are optimising their existing network infrastructure today while being ready to update and expand their network capabilities in the future.
If you have any thoughts around CWDM & DWDM we'd be very pleased to hear from you, and if you'd like to discuss how these technologies may be best used in your organisation then please contact us.
