Through a corporate blog post, Comcast highlights an innovative use of an existing technology — reconfigurable add-drop multiplexers (ROADMs) – that now greatly increases technicians’ visibility into local network traffic.
ROADMs generally are used in long haul transport. A key element of these devices is optical spectrum analyzer chips that split the light into increasing small beams. This enables the ROADMs to send streams of bytes to their intended destination.
In 2019 – indeed, in true inventor fashion, it was “late one night” – an engineer with Comcast’s Next Generation Access Network team named Venk Mutalik wondered whether it would be possible to use these chips — which grow more powerful over time — in the local access network.
Thus, technology traditionally used in transport scenarios over thousands of miles would be reposition to those over covering hundreds of feet.
“His team got together and built a prototype for a system called the XMF,” according to the post. “By installing these optical spectrum analyzers in our local fiber networks and developing software to leverage the devices’ capabilities in new ways, the team was able to gain unprecedented visibility into performance along every millimeter of those networks.”
An added bonus is that the XMF uses technology from the previous generation. That makes the approach cost effective. The system now continually monitors the optical spectrum and tests the length and quality of hundreds of thousands of local and broadband fiber links every minute. The approach shortens the time it takes to find and isolate a fiber cut from two hours to 90 seconds, the company says.
A handheld version of the XMF now is rolling out.
Mutalik and the XMF is one interesting story of innovation in long term development of cutting edge telecommunication networks. A unique challenge faced by cable operators is that their original networks were built with far larger downstream than upstream capacities that befit a world in which traditional television dominated.
It has worked to gradually increase and equalize speeds. In April, Comcast said that completed a lab test of a DOCSIS 4.0 full duplex system on a chip that will be used in symmetrical systems that eventually will reach 10 Gbps.
