Broadband access networks continue to experience customer growth and higher capacity demands year over year. Early and ongoing analysis of these demand trends enabled Comcast to develop a Distributed Access Architecture (DAA) that enabled us to keep up with capacity needs and enhance customer satisfaction with appreciable capital economics.
Successfully virtualizing complex portions of our network, including the CMTS, resulted in network simplification and the harmonization of multiple purpose-built platforms into one common entity.
However, DAA deployments require headend and field modifications as part of the deployment. Even before the 2020 spike in capacity demands created by the COVID pandemic, and its consequent work from home requirements, efforts were underway to accelerate the virtualization, and associated benefits, of our networks, and to separate headend-centric innovations from those in field construction. These parallel efforts enabled us to press forward more rapidly in the adoption of virtualized CMTS technology.
A new concept was developed called a Hybrid Fiber Shelf (HFS) that integrates with virtualized CMTS/DAA Switches at one end, and with transmit/receive analog optical signals on the other end into the outside plant. This innovation provides rapid and economically sustainable increases in capacity, by independently accelerating vCMTS integrations while DAA construction proceeds in other areas of the network. HFS improves critical infrastructure in headends by saving wasted space, power and time inherent in RF combining and splitting circuits. Extending HFS into secondary headends (SHEs) also enables significant fiber reclamation. Locating these assets in secondary facilities closer to the traditional HFC nodes improves performance in ways that translate into enhanced capacity with upstream profile management tools also presented at this SCTE.
In this paper, we begin with a description of the optical and RF innovations that enabled a hybrid fiber shelf concept, and its theory of operations. We then describe the end performance and the impressive improvements in headend critical infrastructure. We finally describe the commonalities and nuances of this approach and its fit within the overall DAA architecture.