60 Vol. 40 No. 3 - August 2018 Issue The burning plant maintenance question is not if testing is still needed as distributed access architectures are rolled out, but how that testing will take place. The same changes that will allow Gigabit services to millions of subscribers across hybrid fibre coaxial networks will necessitate changes in processes and the tools used to keep plants running at maximum efficiency. By VIAVI Solutions Remote PHY is Coming Test and the Evolving Hybrid Fibre Coaxial Network The race is on for service providers to allow delivery of Gigabit speeds with unprecedented service reliability. Hybrid fibre coaxial (HFC) networks are rapidly evolving to meet these demands. New technologies, such as DOCSIS 3.1 and distributed access architectures (DAA), like Remote PHY, leverage much of the existing infrastructure to deliver Gigabit speeds and extend the life of the HFC plant. These changes are effectively pushing out or eliminating the need to pull fibre to each subscriber location. Even more advanced technologies, such as Full-Duplex DOCSIS, are on the horizon with the promise of enabling symmetrical Gigabit offerings. These exciting network evolutions will enable new service offerings, such as wide-scale 5G mobile backhaul, creating the possibility of new revenue streams for service providers. Whilst exciting, these evolutions create HFC plant monitoring and maintenance challenges. The need for critical test capabilities, upon which operators have relied for years, is stronger than ever but the processes and tools used to provide those capabilities must evolve with the changing HFC. All these changes are being implemented in the face of important day- to-day challenges, such as customer churn resulting from poor service quality and holding the line on OPEX since the average revenue per user remains stagnant. All of this creates the perfect storm for HFC maintenance tools and processes. How are hybrid fibre coaxial networks eolving? Several changes are happening to keep up with subscriber demand. This article focuses on distributed access architectures (DAA). Cable operators are deploying node splits at a rapidly increasing rate, reducing the size of downstream service groups to enable delivery of Gigabit services - in some cases, doubling or tripling the number of nodes over just a two- or three-year technical