One more parting shot from Cable-Tec Expo from last week: Arris had an IPTV-over-DOCSIS demo in its booth showing what it claimed was more than 50% bandwidth savings possible when delivering IP video over bonded DOCSIS 3.0 channels vs. traditional RF QAM channels.
Arris was pumping 50 concurrent streams of movie trailers (high-action content; hard to compress) from a Verivue MDX9200 VOD server to an Amino IPTV set-top and a PC.
Those 50 streams, using variable-bit-rate MPEG-4 encoding in 720p HD, took up an average of roughly 300 Mbps and peaked at around 320 Mbps, and so they fit within eight bonded DOCSIS channels (i.e., 8 QAMs). By comparison, delivering the same 50 VBR-encoded streams using traditional statmuxing would require at least 12 QAMs, Arris’s analysis found.
Basically, bonding together multiple RF channels to form a bigger total pipe is a more efficient way to deliver IP video streams rather than trying to shoehorn them into discrete 6-MHz QAMs, according to the vendor.
“We’re showing [the gain possible with IP video over bonded DOCSIS 3.0] wasn’t just B.S. — mathematically, it works out,” said Derek Elder, Arris senior VP of product management and marketing. “With four or eight bonded channels, the gains are immense.”
