OpenCable, the name attached to the project that lured Silicon Valley and the
consumer-electronics industry to cable, is like a chameleon in its scope. Sometimes
process, sometimes product, and now the industry's retail face in Washington, D.C.,
OpenCable is a critical definition of the advanced digital future. Overseeing it all is
Laurie Schwartz, who was recently promoted to vice president status at Cable Television
Laboratories Inc. Schwartz found some time in a crammed schedule to discuss the changing
colors of OpenCable with Leslie Ellis, senior technology editor of Multichannel News.
An edited transcript follows:
MCN: OpenCable seems to be so many different things -- it's
a product and a process, and it's the industry's retail face in Washington, D.C. You're at
the helm of OpenCable. How do you define it?
Schwartz: First of all, it's a way for the industry to get
consensus. So, the 'process' characterization is pretty accurate. It's a way for us to
work together, as an industry, to define the next-generation digital devices and all of
the system support that is required to make it happen. OpenCable is also a spec that
someone could build a device from.
MCN: One spec?
Schwartz: Multiple specs. A spec for the device for the
device itself, as well as for all of the things that it could possibly interface with.
Right now, I think, in Washington, it's viewed as the way to get to retail for cable
devices. Currently, OpenCable is the leading effort to define that. It's going
MCN: Even with CEMA [the Consumer Electronics Manufacturers
Schwartz: Yes, even with them. I'm encouraged.
MCN: Can you describe the multiple specifications that
Schwartz: It starts with what we call the "functional
requirements" for the device itself. Then, there's the interface to the security
module, or what we're calling the POD [point-of-deployment] module.
Third is the interface to all of the other consumer devices
in the home, with the primary concern being the [IEEE] 1394 interface. Then, there's the
interface to the network. There's an interface from the headend to outside networks. That
one is specific to the [cable] operators, really. And then we're considering -- but we
haven't done much work on -- interfaces to billing and support systems. But the primary
ones are those that evolve around the device itself, in the home.
MCN: So there are six interfaces?
Schwartz: I think that's right. Oh, and the software spec.
That one is very important. So, seven.
MCN: What about PacketCable? Will you link somehow to that?
Schwartz: We've been dealing with both DOCSIS [Data Over
Cable Service/Interoperability Specification, the cable-modem standard] and PacketCable,
because there will be some modems in OpenCable devices.
There will also be, potentially, PacketCable clients in
OpenCable devices. So, in some ways, OpenCable is becoming an umbrella. Certainly, from a
branding and certification standpoint, we've been looking at it more and more that way.
MCN: Let's drill down some more and take these specs one by
one. Functional requirements: What is that?
Schwartz: That is what the box needs to do to be
OpenCable-compliant. So it has to do with things like graphics and performance.
MCN: Chip performance?
Schwartz: Things like that, yes, although we've been taking
a benchmarking approach to that.
MCN: Meaning that a chip has to do at least this much, or
Schwartz: Right. It has to do with things like the really
hard-core stuff, like radiation, so that you don't burn down people's houses.
MCN: The physical specs.
Schwartz: Right. It also tries to break down things like:
Does the device have a modem in it or not? Does it support two-way or not? So, it
identifies all of those things, like transmitters and QAM [quadrature amplitude
modulation] and all of the basic stuff. It's pretty motherhood and apple pie.
MCN: And the security interface?
Schwartz: We call that OCI-C2.
MCN: What does that clever acronym stand for?
Schwartz: 'Open Cable Interface,' the 'C' is for client
side, and the '2' is because there are two of them right now. It is the interface to the
POD, and it addresses mostly physical and signaling interfaces to address conditional
access and security and out-of-band signaling.
MCN: Is this the one that's under consideration by the
Schwartz: Well, copy protection is associated with it, and
that's a huge issue. Copy protection is going to be a big issue across the board. But it
does hit the POD, yes.
MCN: Now, we're at the interface to other consumer devices
in the home -- fire wire.
Schwartz: Or 1394. It defines how an OpenCable set-top
could talk to an HDTV [high-definition television set] over a digital interface. We're
also looking at a component analog interface. And in both cases, there are copy-protection
issues that are still being worked out.
The interface to the security module and the interface to
HDTV have both been circulated widely now, in the cable industry and in the
consumer-electronics industry, so they're nearing completion. The POD interface is at the
SCTE [Society of Cable Telecommunications Engineers].
MCN: When did that happen?
Schwartz: In September, three months ahead of schedule. And
now we're up to, I think, the interface to the network. That one is all about how the
headend talks to the device. It includes things like: How do you register the device on
the network? How do you manage the device on the network? How do you make sure that it
doesn't babble to the network and bring the network down? So, protecting the network.
MCN: So it's like a media-access control?
Schwartz: It is like PHY [physical layer] and MAC, yes. It
also will specify that there is an MPEG [Motion Picture Expert Group] stream, and that
there is QAM. So, in some ways, it overlaps with the functional-requirements spec. But, as
long as they're consistent, I think we're OK.
Then, there's the interface from the headend to the outside
network. That really is for our [cable company] members, as they think about what sort of
modifications they may have to make to their headend to support common data streams.
For example, if we were going to have a common format for
guide data, that would potentially impact our members. We haven't all agreed to that, so
it's not done. But that's the kind of thing that we're talking about -- common data
formats for supporting enhanced TV. So we'll help them to make decisions about their
The same is true for billing and operations. If we have
common messages to manage OpenCable devices, then they may have to modify their headends
to support that.
MCN: Of all of those specs, which are the furthest along?
Schwartz: The functional requirements of the device, the
interface to the POD and the interface to HDTV. The interface to the network is actually
going to be released shortly, for the second time. It's been to member review; now it will
go to the vendors.
MCN: And the software spec?
Schwartz: That will be a first-quarter-1999 deliverable.
MCN: So that one is a little late?
MCN: Is that because it's so complicated, or ?
Schwartz: Because it's complicated, yes. And decisions had
to be made about the underlying device before we could move forward. Also, because we are
working with outside groups -- or, at least, looking at outside standards efforts. In some
ways, it's who gets to go first, them or us. Coordinating that takes longer.
MCN: Which spec do you feel the most challenged by?
Schwartz: It depends. The technical challenge is the
software -- getting that right.
On the other hand, getting copy protection is the biggest
political challenge, because you're dealing with Hollywood, and you're also dealing with a
number of different groups in the consumer-electronics industry that have different
And then, our members are concerned about cost and time.
Any new solution will have an impact, and we're under requirement to have these PODs by
July 2000. Right now, we're getting awfully close to running out of time.
MCN: You just got a promotion -- congratulations. What does
it mean for you and for OpenCable?
Schwartz: It means that I get more people to help me.
MCN: What does the staffing look like for OpenCable? How
Schwartz: I have four full-time people, three part-time
engineers, a few contractors and my first visiting engineer. Now, I'll get a full-time
project director, so that I can be more strategic. And we're still looking for a systems
integrator and a security specialist.