Cable Engineers Expect Multiple Tech Fixes for Rising Bandwidth Demand

Cable engineers are trying to make more efficient use of existing spectrum, because of exploding bandwidth demand and the competitive need to deploy more advanced services, they said at the Society of Cable Telecommunications Engineers conference and a related seminar staged by PK Worldwide Media this week. Sounding much more assertive than at the same events a year ago, they spelled out complementary steps for reclaiming analog bandwidth, deploying switched digital video (SDV) technology, splitting optical fiber nodes, roll out DOCSIS 3.0 and moving to MPEG-4 digital compression, among other things.

“Without these technologies, we'd have some bandwidth constraint issues,” said Rick Gasloli, senior vice president and group technical adviser for Comcast. “We will be using every single one of them.” Comcast will use technological tools to deliver its planned new Project Infinity offering of more than 1,000 HD “choices” by year-end, along with more than 6,000 video-on-demand movies in 2009.

Urged on by ever more tech vendors, cable engineers are pursuing or exploring varied ways to increase their overall spectrum capacity. Possible approaches include 860 MHZ and 1 GHz plant upgrades, 3 GHz spectrum overlays, deeper fiber builds to the node or home and even adoption of the telecom industry’s rival passive optical networking (PON) technology.

“If we keep doing what we're doing now, we're going to run out of bandwidth,” said Pragash Pillai, vice president- strategic engineering for Bresnan Communications. Bresnan, besieged by DirecTV and EchoStar, wants to be installing MPEG-4 set-top boxes in its Midwest cable systems by the summer and rolling out switched digital in 2009. “We're getting more competition from DBS on HD,” Pillai said. “We have to do everything we can to get that DBS customer back.

At the PK Worldmedia conference, cable technologists presented stark statistics showing the bandwidth crunch’s severity and spread. Tom Cloonan, Arri Group chief technology officer, said peak Internet access speeds have jumped from 56 kbps a decade ago to at least 12 Mbps today. Similarly, he said, cable modem subscriber bandwidth use has risen on average to about 100 kbps. “Both curves are rising at the rate of 1.75 times per year,” he said. “That’s a challenge.”

Extrapolating those growth rates eight years out, Cloonan projected peak cable modem throughput rates of 200 Mbps by 2016. At the same time, average subscriber bandwidth will hit 11 Mbps, he said. “We're on the cusp of incredible change at an incredible rate.”

David Brown, Motorola director of strategic video access marketing, said new and growing services as HD, on-demand content, time-shifting applications, mobile video and targeted advertising will consume additional bandwidth over time. Technical “lines are beginning to blur” among SDV, VoD, time-shifting services like StartOver, broadcast video and high-speed data, he said, but all will gobble bandwidth. “Bandwidth is like a waistline,” he said. “It keeps expanding as we move forward.”

Reframing the issue, Glen Hardin, Time Warner Cable senior director of video systems, advanced technology group, said that a decade ago the average Time Warner system carried about 78 streams of analog TV. Now, he said, that number is 82,548 analog and digital video streams, thanks especially to such new services as HD, SDV and StartOver. “A hockey stick has happened to my network,” he said.

In another sign of industry concern over capacity, cable engineers at the conferences openly debated whether today’s cable HFC networks can handle growing bandwidth use even with planned fixes. His startling forecasts about exploding bandwidth demand aside, for example, Cloonan said today’s typical 750-MHz cable systems should have enough capacity in 2016 if they improve bandwidth efficiency. “We should be able to run with today’s plant if we tweak things enough,” he said, predicting that cable operators still should have 55 spare downstream channels for legacy analog TV, MPEG-2 digital video and possible upstream use.

Other speakers disagreed, saying cable operators must act more radically to maintain their businesses and fend off rivals. Vyyo Senior Vice President Jeff Fryling said cable operators likely will have to do something “disruptive” to HFC networks to meet bandwidth demands, particularly on the oft-neglected upstream side. “There’s no silver bullet here,” he said, noting that various approaches are “feasible and doable but none are easy. None will save the cable industry on its own.”