MEMORY LANE: Reversal of fiber

Thu, 04/30/2009 - 8:25pm
Stewart Schley, Media & technologywriter, Denver, Colo.

Today’s HFC cable networks rely on
laser-infused optical networks to do their heavy lifting.

With its Victorian-style houses and quiet, tree-lined streets, the city of Alameda, Calif., exudes little of the urban hurriedness of nearby cities Oakland or San Francisco. Alameda, which is located on a small island, looks and feels like Stewart Schleysmall-town America. Among its few notable creations are the Popsicle and the snow cone. The flavored-ice treats were introduced at a local amusement park, Neptune Beach, which was popular in the 1920s and 1930s.

In the annals of cable telecommunications, though, Alameda owns a unique status: It was the site of the first large-scale deployment of a cable network using fiber-optic lines to transmit video signals.

But that’s only part of the story. Equally absorbing is the fact that the cable system serving Alameda got the fiber part backwards.

Flash forward: Today’s hybrid fiber/coax cable networks rely on laser-infused optical networks to do their heavy lifting. Hundreds of video channels and a sea of data packets representing Internet content and phone calls flow outward from transmitters through high-capacity fiber lines. They end up at neighborhood-serving nodes, where the signals hop from fiber over to shielded coaxial cables that carry them to a few hundred nearby homes.

The idea is to get signals out to the neighborhood using highly reliable fiber strands, and then to hand off signals to existing coax for their final ride to the home. By parsing an entire regional cable network into neighborhood nodes, providers effectively create thousands of miniature cable systems, each fed by their own discrete swath of fiber-fed bandwidth. It’s the architecture that makes video-on-demand and high-speed Internet services over cable possible.

But VOD and broadband data services were faint and futuristic dreams when Denver-based United Cable Television began wiring Alameda for cable service in 1983. There was no Internet to be harnessed and no engineering model in the works that envisioned replacing cable’s amplified trunk lines with nimble, high-capacity fiber.

Even so, Alameda offered United Cable a proving ground for a new technology the company was willing to explore. A Connecticut company, Times Fiber Communications, was promoting fiber optics as a medium for improving signal quality. That idea was attractive to Alameda, which owned its own power utility and had progressive ideas about how its citizens should be served.

Times Fiber’s “Mini-Hub” technology was a reflective opposite of the HFC architecture. Instead of using fiber to deliver signals from a headend deep into the network, the Mini-Hub employed fiber only at the network edge. United’s tree-and-branch system used heavy coaxial “trunk” cable to get signals to the neighborhood, and then transferred them to fiber lines that served groups of 24 homes. In a way, it was sort of a truncated version of a fiber-to-the-home network. Fiber lines ran directly to home-mounted interface boxes, and channels were switched not at the set-top, but at the intersection of the trunk lines and the fiber – the meeting ground Times Fiber called its Mini-Hub.

As with many early-stage technology deployments, there was an unforeseen complication. Because channel tuning occurred in the network, not in the home, the electricity cost associated with tuners was borne by United Cable, not the customer. The powering costs were far higher than what United had anticipated, recalls John Holobinko, a BigBand Networks vice president who worked for Times Fiber in the 1980s. And there was no apparent way to recapture the costs. Superior signals or not, United Cable was strictly rate-regulated by the city of Alameda, which was not about to approve a surcharge for the privilege of changing the channel.

Since United Cable began its fiber-optic experimentation in Alameda in the early 1980s, the city continued to elude the norm for cable telecommunications. In 2001,

Alameda’s municipally owned utility, Alameda Power & Telecom, issued a $40 million bond to build its own cable system in direct competition with Comcast, the successor to United Cable. For several years, the two companies battled in an unusual public vs. private competition, with each proclaiming roughly a 40 percent share of the market.

Their rivalry ended last November, when Comcast acquired the Alameda Power system, making Comcast the city’s dominant provider. Today, Comcast, like most U.S. cable operators, uses fiber-optic lines to transmit signals to Alameda neighborhood nodes, HFC style. That choice continues a technology heritage that began more than 25 years ago in the quaint island city. Except now, architecturally speaking, it’s the other way around.



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