Colt Technology Services became the first provider to deploy 800G technology in the L-band across a terrestrial network. This was attained using Ciena’s Reconfigurable Line System (RLS), WaveLogic 5 Extreme coherent optics, and Manage, Control and Plan (MCP) domain controller.

This makes Colt the first service provider to offer proven 100G/400G Wave services using industry-leading coherent technology across both C+L bands, enabling double the data transport capacity offered by a single fibre pair.

Colt is transforming its optical network to deliver the next generation of high bandwidth services and unparalleled end user experience over a fully programmable on demand optical network, while maximizing the efficiency of its fibre assets. This latest announcement follows recent news of the provider’s industry-first offering of 400GE Wave and Private Wave services across Europe and Asia Pacific, using Ciena’s WaveLogic 5 Extreme (WL5e) technology.

Colt IQ Network comprises more than 29,000 on net buildings and over 900 data centres across Europe, Asia and North America’s largest business hubs, making it a truly global network that powers today’s rapid and ongoing digital transformations.

This latest step makes Colt an early adopter of C+L-band technology.

Modern long distance optical fiber networks are taking advantages of the low-loss 1550nm Window of optical fiber, as shown in the following figure.

Characteristics of Optical Fiber Cable


The low-loss 1550nm Window of optical fiber is further split into two optical spectrum bands, the Conventional-band (C-band) with optical wavelength of 1530 - 1565nm, and the Long-band (L-band) with optical wavelength of 1565nm to 1625nm. Each of C-band and L-band has an optical spectrum bandwidth of approximately 4.5THz. Using both C-band and L-band (or C+L-band), the transimission capacity of a fiber pair can be doubled.




Modern long distance optical fiber networks are commonly deployed with C-band technology only, no matter terrestrial networks or subsea networks.

So far, PLCN is the only one subsea cable system deployed with C+L-band technology.