Much has been said about the benefits of remote PHY in terms of reduced CAPEX and OPEX, enablement of fiber deep deployments, capacity increase in the access network, and the opportunity to rethink the headend architecture once the PHY layer is moved out. Despite its significant promise, remote PHY had a relatively slow start in 2017 and 2018. Yet, in 2019 we started to see meaningful adoption momentum. This trend will accelerate in 2020.
Remote PHY is a different architecture than the integrated one MSOs have traditionally deployed. In a typical remote PHY distributed access architecture (DAA), the PHY layer is moved to a remote PHY device (RPD) housed in the access node, and traffic out of the headend is IP carried over digital fiber. This is unlike the traditional architecture where RF over analog fiber is used. Additionally, remote PHY can be flexibly deployed in a centralized configuration, or in remote hubs with RPDs housed in a PHY shelf.
Here are some of the key deployment aspects that operators need to plan for when preparing to deploy a remote PHY DAA:
IP replaces RF to connect the headend to the access nodes. This requires a Converged Interconnect Network (CIN) to connect the vCMTS cores to the remote PHY devices (RPD)s. This IP-based network requires new skillsets and methodologies to design and operate.
If the operator is deploying a Converged Interconnect Network (CIN) to connect the CMTS cores to the RPDs, the CIN needs to be evaluated for congestion and the possible need for traffic prioritization.
Timing protocol and network jitter have to be analyzed.
New methodologies for scaling and expandability need to be defined.
All existing services, and planned ones, need to be supported by the new architecture. This includes legacy broadcast and VOD service, set-top-box control, out-of-band signals, as well as data and voice services.
Throughout the past year, cable operators, working closely with vendors, have developed field-proven methodologies to deploy remote PHY at scale. This has led to an increase in market penetration. Cable operators, large and small, have embraced this transformation and invested time and resources to address how to best prepare for deployment. Those efforts have participated in making R-PHY a successful market reality that delivers on its enticing promise.
Transitioning to next-generation technology is most successful when working with a reliable vendor that provides versatile end-to-end solutions. And even more so when those solutions are accompanied by a deep and extensive level of support.
Asaf Matatyaou is Vice President of Solutions and Product Management for the cable access business at Harmonic. In this role, Asaf is responsible for product management, strategy and solution architectures, including Harmonic’s virtual cable access solution, CableOS®. Asaf has over 20 years of experience as an engineer and executive in the cable industry, including roles where he led development of CMTS products and helped drive industry specifications. Asaf earned his BS degree in Computer Science and Engineering from the University of California, Davis.