By Tanuja Maneesh, Rogers Communications
Since the COVID-19 crisis, the demand for broadband communication services has soared, with some providers experiencing as much as 30-50% increase in internet traffic. Network operators are searching for economical ways to increase capacity to keep pace with the demand of data-intensive services.
With Optical transmission systems growing exponentially every year, and operating close to the theoretical Shannon’s limit, we often get challenged about what is next for scaling optical transmission.
In the recent years, from the traditional C- band (80 wavelengths with 50 GHz channel spacing) to the extended C- band (96 wavelengths with 50 GHz channel spacing) and then to the Super C- band (120 wavelengths with 50 GHz channel spacing), the industry has continuously expanded the scope of the Cband spectrum, improving the transmission capacity.
With the continuous growth of bandwidth intensive applications such as IP Video,4K streaming, cloud computing, gaming, AR & VR,5G, our network gets pushed to a limit where we cannot sustain further growth and bandwidth demands without deploying a new architecture with flexgrid capability, due to the shift to 100G & beyond. Clearly, Rogers had every reason to move past the legacy C-band only fixed grid optical networks. We understood that the optical spectrum needs to be expanded to C+L band. Expanding network deployment to the L-band is a cost-effective approach to enable operators to reduce operational expenditure (OPEX) for dark fiber/IRU leases.
Optical fiber deployment is slow and optical fiber resources are precious. The most effective way to address yearly network traffic growth is to reuse existing optical fiber resources and expand the spectrum of optical fibers to increase the single-fiber capacity.
Submarine cables too, carrying over 99% of international data traffic, are nearing its capacity limits.
Operators are adopting advanced coherent optical transmission and L-band technology to boost data throughput without laying new cables, optimizing existing infrastructure to meet growing internet demands. This innovation is crucial for sustaining global connectivity.
This paper presents a discussion on the business drivers, technical strategy, challenges, and opportunities for C-L Colorless, Directionless, Contentionless-Flex Grid (CDC-F) Dense Wave Division Multiplexing (DWDM) system deployment at Rogers Cable. Finally, we compare C & C-L systems, and proving how the latter can increase the total system capacity on a deployed fiber.