By Venk Mutalik, Dan Rice, Rick Spanbauer, Simone Capuano, Rob Gonsalves & Bob Gaydos, Comcast
Today, the access fiber plant carries large amounts of varied data content deeper into the network. Analog wavelengths support traditional Hybrid Fiber-Coax (HFC) plant, 10 Gbps wavelengths support Distributed Access Architecture (DAA) network segments and other MetroE applications, while newer Coherent Optics modules support “Switch on a Pole” (SOAP) type architectures. As use of the fiber footprint grows, so too will the need for comprehensive monitoring, to optimize the efficiency of access optical assets with the ability to inventory bidirectional wavelengths. These optimizations aid with capacity planning and to locate fiber cuts and other impairments across the plant, in real time, while identifying effective mitigation options.
For too long, such monitoring has solely been the purview of long-haul networks, but recent innovations in optical technology pioneered in part at Comcast enable automatic, continuous and pervasive monitoring of access optical assets without active user intervention. These cost effective, switched optical devices, comprising an optical spectrum analyzer and optical time domain reflectometers modules, are co-located with access headend optics and continuously scan links to detect fiber cuts or individual wavelength outages. These headend tools are augmented with the same cost-effective optical measurement technology implemented in handheld meters for field testing. Headend and handheld tools together provide real time optical data to the cloud for data-analytics. Locating an access fiber-cut in real time, and automatically guiding the Comcast response team to its exact location, results in exceptional uptime, which enhances customer satisfaction -- especially in periods of disaster recovery.
In this paper, we begin with a description of the optical innovations and powerful techniques that enable this extraordinary tool set. We then describe the infrastructure that was stood up to intake, visualize and “event” this data, and detail our preliminary experience using this technology in the COVID lock down period. We will then venture into the future of continuous pervasive monitoring of access optical assets, and the positive impact such next-gen monitoring has on network robustness, which, in turn, enhances the customer experience.