Applying WDM technology enables transportation of multiple applications over one fiber pair. WDM, or 'Wavelength Division Multiplexing' allows each application to be transported via its own infrared wavelength.
What defines WDM-technology?
For speeds up from 4 Gbps usually DWDM is applied: 'Dense Wave Division Multiplexing' enables long distance transmission of tens to hundreds of channels. That may appear expensive, but since this technology is also available for smaller configurations of 4 to 8 channels, it still proves to be more cost-efficient than leasing extra fiber pairs.
When using lower speeds, e.g. for Gigabit Ethernet or Fibre Channel, usually CWDM is applied: 'Coarse Wave Division Multiplexing' is a less expensive technique, applicable for shorter ranges such as city rings.
Qi ict and WDM
Qi ict at this time has engineered many successful projects applying DWDM as well as CWDM technology. Companies thus have been able to realize high speed connections enhancing their own or leased fiber connection with CWDM or DWDM equipment from MRV Communicatons, Microsens or Cube Optics.