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Agenda: VoIP, Simulcasts and OCAP

Voice-over-Internet protocol rollouts, moves toward digital simulcast and work on OpenCable TV applications will top the list of issues for senior cable engineering executives as they head into next week’s Society of Cable Telecommunications Engineers Emerging Technologies conference in Huntington Beach, Calif.

“From a development standpoint, we’re heavily focused on OCAP [the OpenCable Applications Platform],” said Time Warner Cable senior vice president of subscriber technologies and advanced services Mike Hayashi. “It’s a big year for us. It’s the first year we’ll be getting close to deployment.

“We hope to be in a position to be able to support OCAP TV towards the end of the year.”


Comcast has VoIP and digital simulcast on the horizon for 2005. And on the digital ad-insertion side, there’s a lot of work to be done on simulcasting.

“Digital simulcast is the first step towards all-digital,” said chief technology officer David Fellows.

The MSO plans to announce its plans for VoIP beyond the three-market test it will conduct later in January. Analysts, working from Comcast guidance, have said they expect the top U.S. cable company to be marketing VoIP to half of its customer base by the end of this year, and to the rest by the end of 2006.

VoIP and digital simulcast also figure into Insight Communications Co.’s plans, said chief technology officer Charles Dietz. “We’ve been doing [VoIP] lab tests for almost a year,” he said. “We’ll be launching to friendly employees soon.”

Time Warner’s Hayashi has been tasked with looking at developments on the set-top front. The MSO has started to deploy multiroom digital video recorders, considered a key extension of that popular service.

“We’ve been in testing for quite a long time,” he said.

OpenCable will be a big focus, too, Hayashi said. “I need an OCAP headend” to get away from today’s proprietary networks, he said. “Today we use S-A’s file system, so when I take an application download, there is a very specific method on how the bits are to be sent. We have to migrate to an OCAP sending model, but that is well on its way.”

Integrating the Data Over Cable Service Interface Specification signal gateway, or DSG, technology is another aspect of the OpenCable headend, Hayashi said.

“DSG makes things easy,” he said. Time Warner plans to conduct DSG technical trials later this year.

“Then you have the middleware piece,” Hayashi said. Time Warner Cable joined with Comcast on an OpenCable joint venture to hammer out common standards and that work will continue, he said.

Applications are another key aspect to 2005 OpenCable development work — including work on applications that aren’t tied to a specific channel.

“That’s a very important piece,” Hayashi said. “That’s the how consumers choose and pick the channels. HBO may have, 'Press here if you want more information on this actor.’ ”

Another OCAP integration issue: Extending applications in DVR set-tops.


Although Time Warner Cable is looking at digital simulcast, the company also keeps an eye on switched broadcast-video technology as a means of saving bandwidth, Hayashi said.

“When we look at fiber [and] coax, as time evolves, the cost structures do change,” he said. “What was once prohibitive may not be the case today. We know that fiber costs have come down.”

Couple that trend with the fact that some channels that are watched infrequently, and Hayashi is left to ponder SBV technology. Cablevision Systems Corp. also plans to use switched-broadcast to offer tiers of ethnic programming.

“I’m hopeful we would come to some decisions on SBV,” Hayashi said.

One key hurdle is making sure a consumer never gets a busy signal, even for a lightly viewed channel.

“I don’t want a busy signal on my TV set,” he said. “We have to understand that threshold. What happens if you have whole bunch of people who like to leave their TV on one particular channel?”

On the VOD front, Hayashi said Time Warner Cable is approaching 2,400 hours on its servers, “and that may continue to go up.” VOD’s old math calculated rates of peak usage, said Hayashi. As content choices expand, “the new math is, how many sessions are you managing?”

The MSO is looking at adding an extra 6-Megahertz slot or two for VOD as usage rates rise.

“We have to be deliberate about managing our inventory of spectrum,” he said. “I’d rather not be caught with nothing.”


Insight’s Dietz said the MSO is taking its first steps towards digital simulcast.

“We are doing lab testing, looking at different encoders,” he said.

As a first step, “we’ve started loading some select signals on our SONET [synchronous optical network] ring, to move them around a couple of states,” he said.

Dietz has also tested the digital signals on large TV sets, to determine picture quality.

“We put the signals on a 35-inch TV in the headend; you’re not going to see a big difference,” he said. “You put it on a 50-inch HD screen digital, you can definitely see some differences.”

Insight is looking at VoIP tests, which would complement the constant-bitrate phone service available in about one-third of its markets, a vestige of its former telephone-backbone arrangement with AT&T Corp.

“We’ve been doing lab tests for almost a year and we have selected a couple of vendors,” he said.

Dietz expects Insight to launch VoIP in a greenfield market later this year.

Insight has a SONET network that joins the majority of its systems in Illinois, Indiana and Kentucky, covering about 80% of its total subscriber base. For those Insight markets not in the current ring, “we’re looking at agreements to trade some fiber with other people,” he said.

The SONET ring, which has already paid dividends with VOD, also will help in VoIP rollouts and digital-simulcast implementations.

“With a digital overlay, we’re looking at doing all the [analog-to-digital signal] conversions and encoding them at a single location,” he said. The operator will then use SONET transport to get them to every Insight system.

Comcast is further along in its digital simulcast conversion, which includes a large amount of work on digital ad insertion on upwards of 80 channels. Comcast plans to spend $150 million on digital ad-insertion and encoding equipment.


The digital ad-insertion issue is one of the more complex challenges in digital simulcast.

At present, a Comcast headend might insert ads on 40 basic analog networks. A market like Philadelphia might have 30 different ad zones, Fellows said, which requires Comcast to originate 1,200 “channels” to cover the entire network and ad-zone lineup.

In theory, a single local ad pod could include 30 different commercials targeted to 30 different ad zones.

But only one signal is delivered to a specific ad zone, so the local network isn’t burdened by 1,200 channels at the node level. Despite this, the origination complexity of 1,200 channels for analog ad insertion will have to be repeated on the digital ad-insertion side.

Comcast does not currently insert ads on digital networks, but the scale and complexity of digital simulcast raises those issues to a whole new level, Fellows said.

SeaChange International Inc. and nCUBE Corp. (now owned by C-COR Inc.) currently supply digital ad-insertion equipment to Comcast. Fellows said the MSO is talking those vendors and others about digital ad-insertion equipment for the 40-plus analog channels set for conversion.

Over the longer haul, once digital ad-insertion equipment is in place, the MSO would have little need for analog ad-insertion equipment because all networks with local advertising will now “originate” in digital.

And, over time, Fellows said Comcast will continue to reclaim analog channels, such as pay-per-view channels, to create more bandwidth for HDTV.

How soon other analog channels can be converted to digital becomes a program-network and MSO marketing and packaging issue, he said.

About 90% of Comcast’s markets use equipment from Motorola Inc. The company’s DCT-7000 is the primary low-end digital set-top Comcast is looking at, Fellows said.

Although Scientific-Atlanta Inc. has focused on high-end set-tops, a spokesman said the company would build lower end set-tops if a customer wanted such a model. Comcast also could use Sony Corp.’s Passage or concepts from the next-generation architecture specifications to get non S-A set-tops in Comcast systems with S-A headends, Fellows said.

Comcast hasn’t determined whether it will charge for the low-end box.


Digital cable subscribers have an average of 2.5 to 3.5 television sets in their homes, noted Fellows, but average just 1.5 digital set-tops. With the availability of CableCARDs for TVs over time, consumers would be able to access services via digital cable-ready sets, eliminating the need for a low-end digital set-top.

“Our network has the capacity that will last for years,” he said. “It’s converging on a common IP platform.”

Comcast has a backbone deal with Level 3 Communications Inc.

Fellows said Comcast has already lit up the Boston to Washington, D.C., corridor. The backbone passes through Denver and its Comcast Media Center, which will be used increasingly to encode and distribute VOD content.

If Comcast gets to 40,000 hours of VOD content, it will be downloaded via the Level 3 backbone nationwide to server sites in individual systems.