Sniffing Out Video Failures

How do cable operators know if the video signals going into a subscriber’s TV set are acting screwy?

Often the first indication is when an irritated customer calls up to complain, according to Jim Chiddix, a longtime cable engineer whose career has included 15 years as Time Warner Cable’s chief technology officer.

“Historically, there’s really been no feedback mechanism for video quality,” he said.

Now Chiddix is helping pitch what promises to be a better way to sniff out technical video issues, before customers even realize there’s an issue.

Symmetricom, whose primary products provide timing-synchronization capabilities for telecommunications gear and other devices, has developed a system for cable operators to monitor video and audio and look for various impairments.

Called V-Factor, it includes a headend video analyzer that evaluates the quality and integrity of source video and detects encoding impairments. Then, it uses network probes and software agents that run on set-top boxes to compare the video delivered throughout the network with the source to determine if there are any problems.

Chiddix, a Symmetricom board member, claimed the need for a system like V-Factor is growing as cable video-delivery networks become increasingly complex.

“With the advent of video on demand and now switched digital video … there are lots of things that can go wrong and be degraded in different ways,” he said.

Joyce Kim, vice president of marketing in Symmetricom’s quality of experience assurance division, said the V-Factor system filters its analysis through a “human vision” system: “We’ve done a comprehensive job of figuring out what impairments matter to a viewer.”

Symmetricom is introducing the system to the cable space after providing a similar solution for Internet Protocol TV monitoring to telcos, including two of Europe’s biggest providers, Telecom Italia and France Telecom.

The V-Factor system requires an “initial investment” of between $20,000 and $50,000, Kim said, adding that full-scale deployments would cost much more than that. The set-top client software may be installed on all subscriber boxes, or just a sampling.

Symmetricom developed V-Factor based on technology from two acquisitions last year: Paris-based QoSmetrics and Genista, a video-quality measurement firm based in Singapore.