TORONTO – Now that they have started to embrace IP video technology, cable engineers are busily figuring out the best way to make the big transition to all-IP service delivery.
Speaking at the SCTE Canadian Summit here earlier this week, MSO technologists spelled out various ways that they could use bonded DOCSIS 3.0 broadband channels to transmit IP video signals to customers’ homes.
“We see the future as getting IP content to the home,” said Dermot O’Carroll, senior vice president of access networks for Rogers Communications. “In a cable company, getting IP to the home means using DOCSIS.”
In a short interview after participating in the industry leaders panel, O’Carroll said cable operators will need anywhere from eight to 20 DOCSIS 3.0 channels to transmit IP video programming to subscribers. He said the range depends upon their node and service group sizes and the extent of their fiber lines.
During the panel, O’Carroll (pictured) said cable operators may also need another 12 or more DOCSIS channels to deliver data downstream speeds of 150 Mbps or greater to subscriber homes. But, he noted, that may not prove necessary because customers would likely use such high speeds just to get IP video content on their own. So operators might be able to get away with lower downstream speeds if they’re already offering IP video.
Some other cable engineering executives have set the bar even higher, though. Speaking on a separate panel at the SCTE conference, John Ulm, a fellow on Motorola Mobility’s technical staff, said cable operators will need 24 to 32 QAM channels (roughly 132MHz to 196MHz of capacity) to put their entire video lineups on IP. Ulm recommended that cable operators start moving in the IP direction by deploying specialized transcoding devices or hybrid QAM/IP video gateways in homes and serving the second and third screens in the home.
“The video gateway is part of the migration strategy,” he said. “Ultimately, you want the transcoding to be done in the [cable] headend.”
Other cable technologists agree. At a cable broadband strategies conference hosted by Light Reading in Denver last week, for instance, former Charter Communications CTO Marwan Fawaz also estimated that cable operators will need to set aside 24 to 32 QAM channels to replicate their entire video lineups in IP and tack on such new services as network DVRs.
In a keynote address, Fawaz, a founding principal of Sarepta Advisors, argued that a full IP simulcast would likely be the easiest transition path for cable operators. But he noted that this heavy bandwidth load could also be the costliest, making the approach a non-starter for some operators. He also noted that it would probably require MSOs to reclaim most, if not all, of their analog spectrum and recycle it for the IP simulcast.
If cable operators don't have that much capacity available to them, Fawaz suggested that they start off in smaller stages, such as by moving video-on-demand (VoD) services and some "niche" networks over to IP and supporting them with hybrid QAM/IP set-tops or gateways. He said another option would be to use specialized transcoding in the home, which would convert QAM video to IP and beam those streams to tablets, PCs and other IP-enabled devices over the home's Wi-Fi network.
Like O’Carroll and Ulm, Fawaz views cable's IP video transition as inevitable. "It's not a matter of if, but when, to make it, and how," he said. But he conceded that the migration will take some time, even for the largest MSOs.
Alan Breznick is a Toronto-based senior analyst at Heavy Reading, part of the Light Reading Communications Network. He covered the SCTE Canadian Summit for Cartt.ca.
Photo courtesy SCTE.
