Q&A: Cisco's Dave Clark


As operators work to expand their existing high-definition offerings, some are already beginning to think about the next generation of HD programming and services. Dave Clark, director of product strategy and management at Cisco's Service Provider Video Technology Group, recently spoke with HD Update's George Winslow about some of the newer formats and how quickly they might make their way into the market. An edited transcript follows:

Q: When you think of the next-generation of HD, what are some of the first things we might be seeing in terms of higher resolution?
A: I think after we see some people dabble with 1080p 30 [frames per second), the next big one will be 1080p 60 [frames per second]. But a lot has to happen [before that gets into the market place]. If you look at the ATSC specifications, you'll find 1080p 24 and 1080p 30 but 1080p 60 is outside of the boundaries of the standard. So an agreement on a standard will have to come into play.
Even with that, when you talk about 1080p 60, you're talking about a wholesale change in the food chain. You're not just talking about the television sets. You're talking about getting content that is actually shot in 1080p and then transmitted in that form to the display without going through a whole bunch of generations. We are not close to that yet. All the folks in the food chain will have to reach an agreement on stepping up the resolution.

Q: How far away is that?
A: I'm not aware of any 1080p content that is being delivered by cable operators. We have gotten a lot of questions about it recently and there will be a lot of testing but it isn't supported at the moment from an end to end perspective.
Bandwidth is the key item here. 1080p 30 is comparable to 1080i 60, which is a normal format that we see today. So, I don't think there is a huge bandwidth impact for operators starting to offer 1080p 30 content.
But when you reach 1080p 60 you are significantly increasing your resolution and your bandwidth. In the current period where everyone is trying to offer consumers the most HD channels, be they 720p or 1080i, moving to a format that requires even more bandwidth becomes a challenge.
This is where MPEG-4 comes into play. Everyone wants most efficient bandwidth so they can put more bandwidth intensive programs into their lineup.
Because it will be a bandwidth management challenge to migrate to 1080p 60, which is essentially double the bandwidth, my guess is that MPEG-4 solutions will be the first to take advantage of 1080p 60.
I see it as being a very slow ramp. We are working on it. We are testing it. There are discussions about everything from how it is compressed, encoded, decoded ... everything ... I'm hesitant to make a crystal-ball guess, but it's likely there will be programs going into homes in 1080p 60 in the next few years.
The amount of bandwidth that will be required is kind of daunting right now, but we thought HD was daunting when first started talking about it in early and mid 1990s.

Q: What about 3D in HD?
A: We saw a fair amount of 3D out at the Consumer Electronics Show and there will be more of it. It adds a new element to the way people can experience the content and it will give the creative folks that drive content a new avenue to explore.
With 3D, the challenge is to see if there is a way for it to work with the technology in the settop box. Is there a level of set-top box that could do it with a software download? Whether that can be done with the boxes that are shipping this year or whether it will be the boxes shipping in three years, is an interesting discussion.
In terms of bandwidth, it requires double the bandwidth but there maybe a way of reducing that depending on how you implement it.
Another part is developing a standard. How processor intensive or how memory intensive the standard is will have an impact on the kind of applications we'll see.
It is a little too early to know how those things will turn out. But we are keeping an extremely close eye on it right now.

Q: Some argue that once operators reclaim analog bandwidth and deploy switched digital systems, that their capacity constraints, which are quite serious right now for HD content, will open up and allow them to deploy some of these higher bandwidth HD formats. How do you see that?
A: In a sense, they're right. If they can kill or scale back on their analog, that would be a great help.
We provide a number of bandwidth enhancements solutions. Going to one gigahertz, is one example; our MPEG-4 set-top boxes are another. We are deploying switched digital video to a number of operators. It is already running in a number of markets and it continues to roll out.
So there is a lot of different options in terms of bandwidth optimization. Once you reclaim all that analog spectrum there are digital interactive service and higher speed services as well as more HD that they offer.