Bantering About Bandwidth at Cable-Tec Expo

The buzz here last week was all about bandwidth.

Is cable truly running out of it? What can the industry do to get more of it? What part does the next-generation architecture initiative by the three top MSOs play in this conversation?

Those were the key issues debated in the halls and sessions by the 11,000 attendees of the Society of Cable & Telecommunications Engineers’ annual Cable-Tec Expo.

Several prominent cable engineers tried to hammer home one point to Wall Street and the press: Cable is not running out of bandwidth for new services.

“The worries that we are out of bandwidth are unwarranted,” said Chris Bowick, senior vice president and chief technology officer at Cox Communications Inc. “I know we’ve got enough.”

But other vendors aren’t so sure, pointing to the sizable number of 550-Megahertz systems that are beginning to get constrained under HDTV rollouts.

Still, most of the major MSOs have upgraded to 750-MHz plant, and engineers say they’ve got plenty of tools at their disposal. Bowick said that at Cox only 18% of its quadrature amplitude modulation units are operating at 256 QAM.

“We’ve got 40% efficiency in a move to 256 QAM,” he said.

“The same thing holds true with high-speed Internet,” where only 30% to 34% of the QAMs are at 256, Bowick added. “We’ve got plenty of growth there. And all the upstreams are at QPSK [quartenary phase shift keying].

“There is a lot of growth available there, too. The tools are available to us to optimize bandwidth. We just have to get on with it. I’m convinced we’ve got the bandwidth we need. It’s just a matter of timing.”

It’s also an issue of efficiencies, said Adelphia Communications Corp. chief technology officer Marwan Fawaz.

“You can change the modulation,” he said. “If we’re smart with statmuxing [statistical multiplexing], we can free up 10% to 15% bandwidth. We’ve got many, many tools to get 20 channels of HD. In smaller systems, MSOs can start the migration from analog to digital.”

Charter Communications Inc. has led the all-digital charge with its simultrans analog-and-digital system in Long Beach, Calif., which “saves” upward of 70 channels. The next step is to take one or two nodes in that system to all digital, according to the MSO’s chief technology officer, Wayne Davis.

“We’re trying to understand all the issues in the home,” he said. “We need to understand how many outlets are out there and the implications.”

Davis added that the MSO also wants to study what all digital in those nodes does to churn and to cable theft, since the system is much more secure.

Charter will take another node and partially convert it to all digital to study customer reaction from a marketing standpoint, he said. A lifeline tier would be analog but all other services would be digital.

The big difference customers see to date is the consistency in video and audio quality from channel to channel, Davis said.


Going all-digital — and saving bandwidth in the process — is just one part of the next-generation architecture movement started by Cox, Time Warner Cable and Comcast Corp. The goal of NGA, said Bowick, is to develop a reference design for cable’s next-generation architecture — much as cable did years ago with the process that evolved into the Data Over Cable Service Interface Specification — and move video transport to the Internet-protocol platform.

“It’s a very similar kind of process,” Bowick said. “The goal is to look at the fundamental next-generation architecture that leverages the [hybrid fiber coaxial] platform, that makes use of next-generation technology and that opens the architecture for any and all vendors to play in the game.

“It also opens us up for retail sale with the consumer-electronics industry, and we’re working with [Cable Television Laboratories Inc.] to define this architecture. Once that reference architecture is identified, that will evolve through the standard bodies.”

Bowick said vendors are responding to an request for information. “We want to help funnel research and development money in a common direction for everyone,” he said.

Said Fawaz: “We think NGA is terrific. They’ve got some terrific ideas to migrate in an elegant way to all-digital systems. You could take DOCSIS and use that as way to control traffic in our network.”

Davis urged the industry to take a “holistic” view.

“It all needs to come together,” he said. “CableLabs is a very important piece. That’s what CableLabs was designed to do. That’s the right platform for that going forward.”


The CTOs said their systems were ready for the July 1 implementation date for CableCARD conditional-access devices within third-party consumer-electronics products. Training is the key issue going forward, they said.

“We’re ready,” said Fawaz. Adelphia has upgraded 71 Scientific-Atlanta Inc. and 32 Motorola Inc. systems.