A sneak peek at cable's battle plan for the future

Fri, 04/30/2004 - 8:00pm
Jeff Baumgartner, Editor

A clandestine project spearheaded by Comcast, Cox and Time Warner Cable
provides a glimpse of how the industry might embark on an all-digital migration
and create a common platform for a range of new IP-based services

One doesn't wage a war of innovation without weighing all of the strategies and tactics available. Based on the resources in hand, is it better to fight a war of attrition or annihilation? Is it possible to flank the enemy without getting outflanked?

Cable operators, clearly at war with DBS and the telcos, have been asking these questions...and getting plenty of answers from the vendor community when it comes to how the industry might embark on an analog-to-digital migration. The challenge, however, has been sifting through those answers and determining which ones are the right ones and which ones should be discarded.

There's a lot at stake in those decisions. How much? Just the industry's future, that's all. And operators will probably get only one chance to get it right. Once the troops are deployed, it's hard to call them back quickly if a mistake is made.

If more capacity is required to handle high-definition television, multiplayer gaming and other bandwidth-intensive services, rebuilding again is not an option. Wall Street simply won't stand for it.

So, what to do? For one, you get some of the industry's largest MSOs and brightest minds on the case.

Enter Next Generation Network Architecture LLC (NGNA), a project being helmed by Comcast Cable, Cox Communications and Time Warner Cable, which collectively serve about 40 million subscribers. Call it cable's loudest secret. Everyone worth their technical salt knows something about it, yet the MSOs behind it aren't in the mood to discuss it publicly.

Still, information is out there. NGNA released a Request for Information (RFI) earlier this year. The 100-plus-page document reveals how MSOs might approach the all-digital transition. The deadline for vendor RFI responses was March 26.

Although the RFI cites an architecture designed to meet the needs of the industry five years out, it's understood that Cox, Comcast and Time Warner Cable plan to get things rolling much sooner than that. Some sources indicate that they want to have NGNA in the hands of CableLabs by June and have the project spec'd out by this fall.

One of the primary goals of NGNA is to fuel the transition to all-digital, a move that will enable operators to reclaim valuable analog bandwidth without undergoing another expensive rebuild. Another goal is to do away with proprietary systems in favor of open ones. Yet another is to nourish innovation, particularly at the CPE level.

It’s not much to look at, but vendors became
well acquainted with the NGNA Web site
during the RFI process.

NGNA is not being billed as a one-size-fits-all solution for the industry, but rather the narrowing of a vision on how cable's next-generation architecture will take shape, and allowing for as much flexibility in that process as possible.

The way it's being drawn up, NGNA is not looking to “flash-cut” everyone to digital all at once, but to move in that direction by gradually reclaiming analog spectrum and installing “transitional” CPE devices in (or on) analog-only homes.

DBS competition is clearly a key driver of the NGNA initiative. Cable operators are growing increasingly frustrated as EchoStar Communications and DirecTV widely deploy DVRs, leaving cable to play catch-up with a small batch of set-top vendors. MSOs hope to level the playing field by adding some new, innovative blood to the mix.

But to do that, the current conditional access (CA) duopoly must be corrected. Today, nearly every U.S. cable system relies on at least one of just two CA providers: Motorola Broadband or Scientific-Atlanta. Although Motorola's MediaCipher and S-A's PowerKEY CAs haven't been hacked by pirates to this point, operators are increasingly of the opinion that Motorola's and S-A's grip on the technology has stifled set-top and “cable-ready” CE innovations. With that in mind, NGNA is calling for the CA to be separated from the network.

But NGNA is digging much deeper than that.

The project also is seeking information on advanced codecs. The RFI references MPEG-4/Part 10 Advanced Video Coding (AVC) and Microsoft Windows Media 9, but notes that “additional approaches will also be considered.” On the audio side, the document says NGNA will also evaluate advanced audio coding schemes that claim improvement over Dolby's AC-3.

Migrating analog signals to digital is just part of the plan. NGNA's backers also make it crystal clear in the RFI that this is not a science project. It will look at bleeding edge technology, as long as it doesn't bleed too much money.

With that in mind, NGNA also is giving weight to technologies that support legacy CAs and out-of-band (OOB) signaling. But how this next-gen architecture will address all of these things is still very much up in the air.

As one cable insider puts it, the industry has found itself in a forest full of ideas and methods, but needs to find the right tree for the job. The RFI is just a first step, meaning the architecture could change, based on vendor feedback.

At the technology layer, NGNA addresses “major” network segments such as the back office, headends and servers, outside plant and consumer premise equipment. It does not address regional and national data networking systems (i.e. transport) because the parties behind NGNA believe that area already “benefits from innovative, competitive market forces and will not represent a bottleneck” to the project's objectives.

Figure 1: NGNA’s video CPE software architecture reference model.


Despite being in the formative stages, NGNA's evolution will likely follow the path DOCSIS traveled back in the early 1990s. Before DOCSIS became a household name, the project, much like NGNA, started as a consortium called Multimedia Cable Network System (MCNS), which was later handed off to CableLabs and renamed. MCNS was funded by four top MSOs: Tele-Communications Inc., Time Warner Cable, Comcast and Cox. Rogers Cable and what was Continental Cable also supplied early input.

CableLabs could take the reins of NGNA as early as this summer. But the role CableLabs will take has yet to be determined. It might weave elements of NGNA into CableHome, OpenCable or other projects, or it could use it to build an entirely new initiative. That will be decided later this year after operators, CableLabs and other “subject matter experts” get a chance to sift through the RFI responses.

And why not duplicate many of the elements that made DOCSIS go? After all, DOCSIS has been a huge success story for cable operators. Centering on an industrywide specification has driven the price of the cable modem from thousands of dollars to less than $50. The uniform technical approach has also helped cable establish a healthy lead over DSL.

But it hasn't been as kind to the vendors. Although there were literally dozens of cable modem vendors a few years ago, thinning margins drove many of them out of the cable modem business or out of business altogether. The CMTS side of the DOCSIS equation has also seen its share of consolidation.

Despite those similarities, there are some key differences. In the days of MCNS, cable operators were working with a high-speed greenfield. MCNS also focused on one specific service. By contrast, NGNA covers aspects of video, voice, data and everything in between.

Breaking down the duopoly

But to obtain the control cable desires and to foster more innovation at the set-top level, operators will have to separate conditional access from the network. There's also federal pressure to consider, too. Remember that U.S. MSOs are required to stop the deployment of set-tops with integrated CAs by July 2006.

Figure 2: Click To ENLARGE
Figure 2: Under the NGNA headend server
architecture model, the control and
RF aspects of the headend servers are
separate so common third-party resource
management and network operations
apps can manage the headend as
an integrated system.

[ click here to enlarge ]
Because of those factors, the S-A/Moto­rola duopoly will dissolve over time, industry insiders predict. “NGNA will certainly accelerate the operators' ability to regain control of that [CA] platform,” says one source familiar with the project. “S-A and Motorola will lose that control in the next 10 years, maybe five,” the source adds.

The RFI proposes that the NGNA Conditional Access System (NCAS) supports the decryption of at least five types of secure transport streams: Motorola's MediaCipher, S-A's PowerKEY, Triple DES, DVB-CSA and AES. The document also references two other CA vendors that could be given hardware support: NDS Group and Nagravision.

NGNA also is putting the microscope to software-renewable conditional access systems.

Though the idea is to separate the CA, operators are keenly aware that they must continue to support millions of deployed digital boxes during the transition. They aren't about to replace them just for the sake of a new CA platform. Instead, they will be looking for solutions that enable them to migrate to an alternative CA while supporting the legacy.

That will certainly open up opportunities for Sony Passage, a system that has already undergone testing with Comcast and Charter Communications. Another possibility, ironically, is Scientific-Atlanta, which is developing a “digital overlay” system that enables operators to put PowerKEY-based set-tops, such as S-A's DVR-capable Explorer 8000 and Explorer 8000HD, on systems that use Motorola's MediaCipher CA. Time Warner Cable has been testing the system in Beaumont, Texas, according to CED sources.

Figure 3: The NGNA initiative seeks information on a wide range of CPE,
including several models that could aid operators with a transparent
transition to an all-digital environment.

NGNA: On the network and at the CPE

NGNA makes some general assumptions about the headend. Cable modem termination systems are to be upgraded to DOCSIS 1.1 and support the DOCSIS Set-Top Gateway (DSG) specification. DSG, much beefier than legacy (and proprietary) out-of-band signaling, will likely be used to handle secure software downloads and configuration management of set-tops and other CPE devices. DSG could also be used to stream video to the set-top box.

NGNA marks a clear shift in how some operators will treat the consumer side of the network in the future.

“Traditionally, [cable operators] have been very passive,” says one cable insider. “It's been the manufacturers and developers who have had to proactively shake the tree to get things going. Now the operators are taking the initiative.”

That's a good news/bad news story for the vendors. It's good in the sense that there will be much more consensus on what the MSOs want, instead of predicting, or worse, assuming what they want and then hoping for the best. Some vendors also fear a potential downside to NGNA: they might have to give up some valuable intellectual property just to be part of it.

By the same token, operators also don't want to get caught up in patent traps and proprietary cages. Or, if they end up locked in to something, they want to make sure they are “locked in to the right answers that allow future flexibility and the ability to be innovative on that platform to launch new services and products,” says one industry insider.

The NGNA RFI gives plenty of attention to what it calls the “Subscriber Video Device” (SVD), a new suite of low-end and high-end all-digital devices. Higher-end, “next-gen” boxes under NGNA will likely support DOCSIS 2.0 and a minimum of OCAP 1.0 middleware if the devices are capable of handling downloadable applications.

In an apparent nod to technologies being spearheaded by vendors such as Digeo Inc., S-A and Ucentric Systems, the document also points to the virtue of whole-home digital video recording products whereby a high-end set-top shares content and applications over a home's coax network with cheaper, thin-client devices. NGNA is also exploring how cable SVDs could access content from the PC via a home network. A home-side network capable of supporting at least four high-definition streams is also under consideration.

The most obvious candidate there is the technology under development by the Multimedia over Coax Alliance (MoCA), an initiative that already has the support of Comcast. HomePlug AV, which plans to handle multiple HD streams, is likely to be another “no new wires” networking technology candidate for the NGNA project.

All-digital migration devices

NGNA, a new acronym in its own right, could add at least two more to cable's customer premises lexicon: ODA, for Outlet Digital Adapter, and VNIU, for Video Network Interface Unit. Both might be used to ease the transition to all-digital, and provide a transparent means to send and convert digital signals to analog customers who do not use set-tops.

Under the first model, operators would install ODAs at each cable outlet to convert digital signals to analog. The RFI references two types of digital adapters: a full-function, two-way ODA and an all-DOCSIS two-way ODA. Both would support MPEG-2 and an advanced video codec. Still another possible variant might support native applications such as electronic program guides and video-on-demand.

Because it's a small device that would reside behind the TV set, the ODA might be better defined as a “set-back” device rather than a set-top. Pace Micro Technology's Digital Cable Adapter (DCA), showcased at the 2003 National Show in Chicago, was the first device to show some of the ODA features referenced in the NGNA RFI.

Because the ODA does not support OCAP, operators, not retailers, would likely supply the device. NGNA's target for the two-way ODA is less than $50 per unit, and about $35 per unit for the all-DOCSIS device.

One of the more interesting (and certainly least intrusive) concepts on the table is the VNIU, another digital-to-analog device targeted to analog subs without set-tops. But it's designed to be even more transparent to the customer than the ODA. Instead of installing one at every cable outlet in the home, just one VNIU, when affixed to the side of the customer's house, would handle the digital-to-analog conversion for every outlet in the home.

The VNIU's initial specs will likely be different than the ODA. For one, the RFI calls for it to support only MPEG-2 and, because it would sit outside, it would have to operate under extreme temperatures. Because it won't support EPGs and other applications, OCAP also won't apply to the VNIU. NGNA is forecasting a cost target of less than $150 per device, in high volume.

NGNA also is taking into account millions of digital televisions that are not capable of decoding anything beyond MPEG-2. If an operator moves to MPEG-4, they can't just leave those TV owners in the lurch. To solve that problem, the project is seeking information on what's being called an “advanced codec transcoder.” That device, which will cost less than $10 in high volume, could accept streams based on advanced codecs and then convert them into MPEG-2 format.

Figure 4: Under the VNIU approach, existing digital signals would be passed
through a VNIU to extant digital boxes or “digital cable-ready” TVs.

NGNA questioned

The secretive nature of NGNA has pressed at least one analyst to raise questions about possible antitrust concerns. That research note, issued by Needham & Company Analyst Anton Wahlman in early March, came out before vendors were completely clear on the possible intellectual property implications. Many of those questions were cleared up at an NGNA probate meeting, where vendors where assured that the creation of NGNA would not stop them from having product conversations with MSOs in isolation, and that the project is there to help them better direct their R&D efforts.

For the record, NGNA will not require vendors to give up their intellectual property, but vendors that “allow royalty-free use will be evaluated most favorably in the next-generation network,” according to the RFI.

CableLabs has established a royalty-free pool for most of its projects, the exception being OCAP (OpenCable Application Platform). OCAP started out as a royalty-free project, but that all changed in late 2001 when the industry decided to incorporate the bulk of Europe's Multimedia Home Platform (MHP), which uses a royalty-bearing model.

Sources familiar with the project believe the project is above board and not subject to any antitrust concerns. Still, it makes one wonder why the MSOs behind NGNA have been developing it in a shroud of secrecy.

For one, vendors tend to be much more honest and able to “advance the ball” if every move they make with the project is not being scrutinized by the stock market and analysts.

“This way, it can move in a more accelerated way to create traction and get something done,” says an industry source, noting that things will open up once the project is handed off to CableLabs and the implementation process begins.

Then, the real shooting can begin.


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