Tapping Into Internet TV Technology
The Slow Embrace Of IP Video
By Todd Spangler -- Multichannel News, 9/23/2007 8:00:00 PM
Cable operators and technology vendors are starting to examine specific ways to deliver high-quality video over existing hybrid fiber-coaxial networks using Internet Protocol infrastructure.
These steps toward Internet video technologies can’t exactly be called “IPTV over cable” — at least, not yet — but some see the industry’s embrace of IP video as inevitable.
Today, operators have no need to rip out the existing digital-video delivery systems that transmit their core multichannel video services, typically in MPEG-2 streams over HFC.
In fact, it would be foolish to do so, given that cable has invested billions building out networks designed to do that.
“Overall it doesn’t make a lot of sense to go to IP,” Scientific Atlanta technical director for subscriber network systems Bill Wall said. “Certainly we don’t see a wholesale movement to IP. We have such a good economic model today using non-IP transport into the set-top.”
So when and where is cable looking at embracing IP-video technologies?
There are certain scenarios, operators and equipment vendors say, where IP might provide more flexibility or cost advantages in delivering video services. And eventually — say, in 10 or 15 years — cable may find that moving to a full IPTV infrastructure a cost-effective option.
Two initial areas cable is scoping out for IP video are delivering programming to multiple non-TV devices and pulling that content in from multiple sources.
To CableLabs chief technology officer Ralph Brown, IP video delivery starts to make sense only when you’re talking about getting content to devices other than a TV.
“The television doesn’t natively understand IP. The television understands television,” he said.
Charter Communications CTO Marwan Fawaz similarly sees the immediate potential of IP video as providing a way to capture Internet content and then deliver that to PCs in a higher-quality service than consumers would be able to get over the unregulated Web.
“With the proliferation of YouTube-like sites, there is a need to take that content and make it available to our subscribers through the HFC network,” he said.
In Fawaz’s view, making IP-based content available on a video-on-demand basis will deliver a better customer experience than today’s model of passing Internet video through broadband connections.
Such a service would take advantage of higher-speed Data Over Cable Service Interface Specification 3.0 connections, which operators might deploy commercially as soon as mid-2008. CableLabs’ DOCSIS 3.0 specification can support downstream links of 160 Megabits per second or higher, using virtually bonded channels — well more than enough for several streams of IP-based high-definition-grade TV.
The business aspects of who pays whom, and how much, have yet to be worked out, Fawaz conceded. But the technical elements have already come into view.
“It’s having the best of both worlds,” he said. “MPEG over HFC is still the most cost-effective way to stream video to our subscribers. DOCSIS 3.0 takes advantage of that network by offering an alternate way to deliver Internet video directly to subscribers.”
Providing such enhanced IP-based video services — say, being able to watch your favorite cable shows, live or recorded, on your mobile phone — will be key for cable to defend its market share from telephone companies, according to John Mattson, senior director of Cisco’s cable-modem termination system products.
“It’s about creating a big pool of content that follows you everywhere,” he said. “IP really lends itself well to distribution.”
| Cable’s IP Video Plays | |||
|---|---|---|---|
| The industry is exploring various ways to exploit video-over-IP. | |||
| Description | Outlook | Why Not MPEG? | |
| SOURCE: Multichannel News research |
|||
| Web video | Short clips, TV shows and other content via public Internet or private IP network | Operators already provide video on portals (e.g., Comcast’s Fancast.com); programmers also expanding Web video | Non-MPEG formats like Flash are optimized for Web |
| Video over DOCSIS to non-TV devices | Content for PCs, game consoles and other devices via private IP network | Could allow new services for nontraditional video devices | IP is more flexible for distributing content beyond set-tops |
| Hybrid MPEG/IP set-tops | Some live or on-demand video delivered to TVs over private IP network | Enables incremental new services like multipicture mosaics | Existing MPEG set-tops not well-suited for new applications |
| Full IPTV infrastructure | All live and on-demand video content delivered to set-tops over IP | MPEG a far better option today for cable, as it leverages existing infrastructure | At some point, all-IP may be more cost effective |
BLENDED APPS
Then there are potential IP video applications for cable set-top boxes. The three major suppliers of set-top silicon — Broadcom, STMicroelectronics and Conexant Technologies — have each introduced chips that allow a set-top to set up a high-speed IP pipe through DOCSIS channel-bonding.
What could you do with such an IP-enabled set-top? SA’s Wall has a few ideas. For example, an operator could use it to let subscribers set up a customized video mosaic, showing perhaps a half-dozen channels at once.
Say you wanted to watch six different sporting events. If those were delivered on different quadrature amplitude modulation (QAM) channels, Wall said, you’d need six tuners in the digital set-top to display them on one screen. “In an IP environment, you can just pull off the video,” Wall said. “You’d want to composite that mosaic right at the set-top.”
Internet-video services are already offering this capability, Wall pointed out. The recently redesigned ESPN360.com live-sports portal, for example, offers subscribers the ability to watch up to 10 live screens at once. “It’s just a question of demand and how quickly operators can put the [user interface] together to offer those services,” he said.
SA boxes with embedded DOCSIS channel-bonding capability are currently being tested by cable customers, Wall added: “Whether [operators] are doing anything with that today, I’m not sure, but it’s certainly there in the silicon.”
Such cable services may not be far off, considering that Verizon Communications’ FiOS TV uses a hybrid Motorola set-top that uses IP to deliver VOD content and traditional cable radio-frequency technology for linear channels.
Cable also could employ DOCSIS-enabled boxes to deliver VOD more efficiently than using dedicated radio spectrum, said Tom Cloonan, CTO of Arris Group’s broadband division.
“DOCSIS is not 100% utilized all the time,” he said. “It may be smart to deliver VOD over DOCSIS.” Plus, he noted, “today, VOD networks are not architected to support everybody watching a different stream.”
BYPASS OPERATIONS
Whether cable ends up offering video from the Internet — or delivering existing content in IP format to set-tops — some cable-equipment vendors maintain that there’s enough promise in the concept to require a mechanism for offloading video from the cable modem termination system.
In these approaches, proposed by Motorola, Harmonic and others, IP video streams would bypass a CMTS by getting routed directly over QAM channels to a DOCSIS-compliant cable modem. The cable modem then passes the IP video stream through to a display or storage device.
Mike Patrick, Motorola’s data networking architect for CMTS products, said surging VOD usage will suck up much more bandwidth than traditional high-speed Internet traffic does. Up to 95% of the bits going down to a fiber node will be video within the next few years, according to Patrick’s forecasts.
“We believe that the vast majority of growth in per-node bandwidth will be video,” he said.
That video traffic, Patrick continued, should be kept off the CMTS core because all the extra management functions required for regular cable-modem data transmissions simply waste processing power in a video context. Motorola has proposed DOCSIS IPTV Bypass Architecture (DIBA) as a means of doing that; the theory is that edge-QAM devices will be less costly than CMTS interfaces.
“The challenge is to minimize the cost of video delivery,” Patrick said.
Arris’s Cloonan said DIBA would create yet another piece of infrastructure that a cable operator would have to manage.
“The Motorola DIBA proposal feels a little premature,” he said. “It’s not giving DOCSIS 3.0 the chance to live up to the promises.” Cloonan said he believes the cost of downstream CMTS interfaces and edge-QAMs will ultimately not be significantly different.
DOCSIS 3.0 includes certain built-in hooks that were designed to support IP video, according to CableLabs’ Brown, such as source-specific multicast and quality-of-service guarantees for multicast. The group’s PacketCable Multimedia spec, meanwhile, provides for session-based QOS “for any kind of service, not just voice — it’s video, multimedia, gaming, whatever,” he said.
“We’re providing a very general tool kit,” Brown added. With a DOCSIS-enabled set-top box, “you could do IPTV if you wanted to. Again, the idea is to let operators use the best tool at hand.”
CableLabs has other IP-video initiatives cooking, too. Last month the cable R&D organization, in conjunction with four major movie studios, approved a technical specification developed by the Digital Transmission Licensing Administrator (DTLA) — a group formed by Hitachi, Intel, Panasonic, Sony and Toshiba — that will let set-top boxes and other devices send premium cable programming in an encrypted format over IP home networks.
The deal lets licensees of CableLabs’ digital-cable technologies use the DTLA’s Digital Transmission Copy Protection (DTCP) over IP specification to distribute cable programming to other devices that comply with the specification.
“IP transport of video clearly has merit and value,” Brown said. “The question is: Where?”
THE IPTV FUTURE
Down the road, some believe cable’s move to IPTV is just a matter of time.
“MPEG is going to be out there for a hell of a long time,” Arris’s Cloonan said. “But there’s this: No matter which technology has battled against Ethernet and IP, they’ve all lost.”
In the long run, it’s simpler to manage a single IP infrastructure, BigBand Networks chief cable architect Doug Jones said. Cable operators already have built IP backbone networks, over which they distribute encapsulated MPEG video. Basically, only in the last mile is piped down to the home as MPEG-based video streams.
“It makes sense to move networks to all-IP,” Jones said. “It’s really just the transport. If it’s architected and built properly, it’s just a network.”
Moreover, the four large cable operators that formed SpectrumCo — Comcast, Cox Communications, Time Warner Cable and Advance/Newhouse Communications — are presumably looking to deploy new wireless networks over the spectrum they have acquired. “Their wireless networks are going to be IP all the way to the end point,” Jones said.
And, he suggested, if a cable operator were someday to offer an over-the-top multichannel-video service on a network they don’t control — that, of course, would be delivered over IP too.
Microsoft obviously is another party that sees IPTV as an inexorable wave of the future.
Joe Seidel, director of global partner development for the Microsoft TV business unit, acknowledged that cable’s switched-digital video rollouts over HFC will add more channel capacity. But, he said, the underlying HFC network is still fundamentally not designed to be two-way the way an IP network is.
When connected to an IP network, TV becomes “more of a social, personalized and connected service,” Seidel said. “The whole planet is moving to an IP-based platform, whether [cable operators] want to admit it or not.”
Before cable goes all-IP, however, some in the cable industry will have to overcome a reflexive distaste for anything labeled “IPTV.” It’s a term, after all, being used by the likes of AT&T and other telephone companies to disparage incumbent cable services.
'A LOT OF HYPE’
CableLabs’ Brown, for one, calls the term “IPTV” meaningless. “What’s amazed me is that when you sprinkle Internet fairy dust on something, it makes it very magical,” he said. “There’s an awful lot of hype about IPTV. Since it’s IP, that means it has all this wonderful 'Internet stuff.’”
Still, Brown said, IP video has a place in cable networks. Ultimately, consumers don’t (or shouldn’t) care whether their video service comes in through an analog, MPEG or IP transport.
“Cable operators are always positioning themselves to take advantage of what economically makes the most sense,” he said. “When the economics make sense, it’s going to be very straightforward for them to deploy this.”
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