SCTE Cable-Tec Expo: Cox SDV trial shows bandwidth savings, leaves questions open

Recognizing the increasing needs for bandwidth management in the light of increased competition from new and existing competitors and the growth of subscriber demand, Cox Communications set out on a switched digital video (SDV) trial to find out how much content would finally overwhelm a switch and cause a problem.

While the MSO learned many things in the trial, including that some "broadcast channels" are accessed less often than some of the longer tail content placed on the switch--and vice versa--and that its two-way networks can either handle the new load of content or be repaired to do so, it never found out how much was too much when it came to content.

"We don't have enough content today to simulate this behavior," said John Civiletto, executive director with Cox Communications during a presentation at SCTE Cable-Tec Expo in New Orleans.

What Cox did learn is that even using large service groups to "stress the infrastructure a little more" and throwing everything short of the kitchen sink on the switch, "we had excess capacity," Civiletto said.

Statistics showed that only about half the channels stored on a switch are accessed at peak times and about 70 percent of tuners are in use during that same time. It also showed the value of a good program guide in reducing channel surfing and those pulling still more content from the bandwidth.

As for when the system reaches the "infinity" point that Cox and its partner BigBand were hoping to learn--"how far can we go?" as Civiletto put it, "we don't have enough content yet to reach that point. We don't quite have enough data yet."

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