PHILADELPHIA — I know that if I want to untether myself from the SCTE press room, and release myself from the delicate aroma of fried chicken and sloppy joes, I can go down to the show floor and sample any number virtual reality demos.
I know that if I put on one of the headsets, I’ll be impressed, wondering how soon cable companies and their two-way connectivity advantage will be able to get in on the ground floor on VR, which does in fact have the ability to change games.
You don’t expect the top technologists for leading vendors to deliver the hard reality checks. They're incentivized to hype this stuff, after all. But credit Arris CPE CTO Charlie Cheevers, Harmonic Video Strategies VP Thierry Fautier and CableLabs CTO Mark Brown for delivering a sober panel that reveals just how far the cable network has to evolve before ubiquitous deployment of VR services by MSOs can become a reality.
As Fautier elegantly pointed out, none of the four current approaches available today — or at least theorized now — are capable of combining the sufficient quality, latency, scalability and bitrate necessary to deliver truly immersive video experiences.
For example, the “Tiled” approach favored by Netflix delivers outstanding UHD video quality, but founders on latency and scalability, and requires a super-high bit rate of 6-10 Mbps.
“On-Demand Transcoding,” meanwhile, requires a much lower bit-rate of under 2 Mbps, but delivers a much lower video resolution.
“It’s still the early days” for VR, Fautier said, summing up his presentation. “There are different approaches with different merits, and there are a number of ways to skin the cat.”
Cheevers’ PowerPoint was queued up next, and his description of the ramp-up was equally ambitious. Full UHD 360 Stereoscopic VR will require more than 10 times today’s video IP bandwidth, he noted.
“Data rates could be as high as 600 Mbps if we don’t use compressed data rates,” Cheevers said.
One of the biggest challenges, among many, he pointed out is bringing network latency down to around 15 milliseconds. We are, after all, talking about a vastly complex two-way communication that has occur. For a live sports event, for example, the flow not only originates from content capture, but all the way back from the user’s head movements, which determine what content is delivered.
“If you don’t hit that 15 milliseconds benchmark, you’re not going to have that experience,” Cheevers said.
In terms of VR as a downloaded file to a client, even with a speedy 1 Gbps connection, it could take over 14 minutes to download a 360-degree gaming file.
Oh, and how about untethering the VR experience from those cumbersome HDMI cables? Cheever suggested a 60 GHz Wi-Fi connection, with the user in the same room as the modem, might do the trick.
So yeah, I get it — it’s definitely the early days, and I shouldn’t get too excited about getting virtual 50-yard-line seats to watch my Trojans lose.
But networks evolve fast. Cheevers reminded the room of a day not too long ago when it took several days to download a 2.5 GB video file.
“It was quicker for a FedEx truck to deliver a DVD,” he said.--Daniel