Experts Assess Video Quality
As cable operators offer more HD programming, VOD options, and interactivity over multiple platforms, video management and quality become more critical and more challenging, according to panelists at Wednesday’s first NCTA technical papers session, "Quality Matters: Assuring Performance across Multiple Platforms."
It could be time for cable to "steal" concepts from other paradigms, said S.V. Vasudevan, director, cable video architectures, Cisco Systems. By integrating best practices already used by Internet data center architectures, including virtualization, cable could turn its traditional headends into multiservice video data centers.
"Content management and scaling content will become equally as important as infrastructures get built," Vasudevan said. "To scale millions of titles and millions of subscribers will take a different way of thinking (about) how content is distributed and stored and cached."
Michael Adams, vice president, application software strategy, for Tandberg Television, also spoke of scalability. Content distribution models that use a traditional pitcher and catcher model make it difficult to scale more than 10,000 titles, he said, because every asset is pushed out and stored at every headend.
Adams suggested using a content delivery network model for long-tail assets, updating metadata, and lesser-used formats such as MPEG-4. In this scheme, the content is pulled from a central server when requested. "This is how a lot of Web content is delivered," Adams said.
Quality control
The final two panelists cited statistics indicating that 40 percent of customer churn can be attributed to quality problems, and that 80 percent of new digital customers with service calls within the first year disconnect.
Cable operators need an end-to-end video management system and a unified dashboard approach for problem domain isolation, said Asha Kalyur, marketing manager for Cisco Systems. This would include a database to view mapping between channels and multicast addresses. "Before a customer calls, (the operator) can figure out what are the different channels this multicast is carrying and fix it."
Cable operators need to be aware that all areas of the video delivery chain can impact quality of the video service. "The overall end-to-end performance of the system is what the customers end up viewing in their homes," said Dave Higgins, vice president of quality assurance, Comcast Media Center. "Each touch point can have dramatic impact on video quality."
In the old days, relative quality on an analog video signal could be objectively measured. The digital world is different. CMC uses Imagine Communications’ system to subjectively rate programming based on impairments an expert viewer might see vs. the average user. The original source receives a score of 100; less than 95 means even the average consumer will see impairments.
"We compile weekly data and share with (all) markets taking video feeds," Higgins said, noting that they also trend data to make sure repeated problems are corrected.
"Given the complexity and potential impact on customers, (the industry) should have a more authoritative stance on this topic," Higgins added.
– Monta Monaco Hernon
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