US West moves hybrid networks east

Oct. 1, 1995

US West moves hybrid networks east

paul palumbo

US West`s Atlanta cable-TV subsidiary, Southern Multimedia Communications Co., has entered the pre-engineering phase of its ambitious two and one-half year upgrade plan, and has begun placing strand and fiber-optic cabling plant, supplied by Antec, into its clustered franchises in Atlanta.

By doing this, Denver-based US West has, in effect, taken on BellSouth on its home turf. How this eastern competition by Colorado-based forces will play out remains to be seen. This move is not a small-scale "probing attack." The $220 million project encompasses the installation of 12,000 miles of plant across eight Georgia counties. In addition, Southern Multimedia has been given the opportunity to provide telephony service in addition to cable-TV service.

The state of Georgia has passed a law opening local exchange carriers to competition. This puts Georgia on a faster track than most of the country, with rules of interconnection, number portability and other components of local competition to be negotiated among carriers.

To intensify competitive forces in Atlanta, BellSouth has been given Federal Communications Commission clearance to provide video services in the Atlanta suburb of Chamblee. As a result, fiber optics emerges as the clear winner in this contest between the two regional holding companies. To illustrate, BellSouth expects to spend $4 billion on its network this year, much of it on fiber-optic cabling plant.

BellSouth spokesperson Kevin Doyle says that "although its trial to test new interactive services is in Atlanta, and that`s where Southern Multimedia [US West] has chosen to make its market entry, BellSouth has to look at its entire nine-state region and come up with architecture answers that fit a number of different markets." Doyle adds that Southern Multimedia is going to be a significant competitor in Atlanta, but BellSouth is going to face numerous other rivals throughout its operating region.

For its part, Southern Multimedia says it plans to replace electronic amplifiers with optical models in addition to hybrid fiber/coaxial cable. According to Gary Donaldson, Southern Multimedia`s director of engineering, "While a lot of fiber can be pre-positioned, the company still must complete a number of other construction projects before interconnecting the optical backbone between the headends and hubs."

First, the headends must be deployed (and brought online with signal), and during the same deployment phase, about 40 distribution hubs must be positioned around the metropolitan Atlanta service area. Steve Lang, US West Multimedia Group spokesperson, confirms that the entire upgrade will require Southern Multimedia to install close to 12,000 miles of fiber, and the whole project will ultimately cost approximately $220 million. The build program will eventually pass more than 1 million homes (and 500,000 current system subscribers), covering multiple franchise properties and municipalities.

While industry debate continues over the relative merits of switched digital video versus hybrid fiber/coaxial-cable architectures, Neil Knight, director of technical planning for Southern Multimedia, says that "there is a different spin [in Atlanta], because there is an embedded architecture already in place that made [hybrid] build-out economies most attractive."

Knight adds that US West looks at the cost analysis and the "service-sets" envisioned on a region-by-region basis, and that typically drives the decision about which architecture to choose. It`s ironic, however, that US West`s initial internal evaluation of that embedded Atlanta plant suggested that a more far-reaching upgrade be made than the one currently planned.

That architecture analysis took a surprise turn, however, because of the company`s strong working relationship with Time Warner Entertainment. US West bought a 25.5% stake in that company for $2.5 billion in late 1993, and Donaldson says that Time Warner`s experience with coaxial cabling plant led to Southern Multimedia`s conclusion that a "lot more coaxial plant was salvageable than was previously thought."

Although some analysts have publicly questioned US West`s investment in Time Warner because it was difficult to quantify on a return-on-investment basis, and others called it weak on overall synergy (for example, too focused on distribution only), Donaldson maintains that a tight working relationship with Time Warner has given Southern Multimedia a great deal of help in the "development thought process, and in formulating the architectural principles and the pre-planning."

Peter Krasilovsky, senior analyst with Arlen Communications, says that "Time Warner has learned invaluable lessons with its [full-service network] trial in Orlando--and it`s an exercise that everybody is glad they don`t have to go through themselves." However, how that experience will pay off for US West in the broadband world remains unclear. Krasilovsky maintains that US West doesn`t necessarily rely on Time Warner for cable deployment advice because it is already a big player in the United Kingdom with partner TCI.

That fact alone is likely to save the company significant investment dollars in architectural planning and roll-outs in its Atlanta systems, and as the company expands its overall cable distribution strategy. Southern Multimedia`s upgrade efficiencies are also investment advantages because the franchises are "clustered" geographically in the metropolitan Atlanta area; those systems control close to 60% of the total subscribers in the area.

One of the reasons hybrid fiber/coaxial-cable builds have become so popular is that the technology is well-understood and capable of delivering those service-sets that will likely make up the first phase of broadband offerings to both the home and business customers.

Even so, according to Donaldson, Southern Multimedia is "pushing the envelope of technology with such components as power-passing taps, power nodes and radio frequency solutions like `block-up conversion`." Those component products are only now coming into mass production, says Donaldson.

Degree of faith

He also points out that while many of the network`s components are "off-the-shelf" and have been around for years, Southern Multimedia is finding new ways of fitting them together as an integrated hardware solution. The upshot, says Donaldson, is that hybrid architecturing today requires a "fair degree of faith that it is all going to work correctly" when rolled out and turned on.

One of the first questions anybody building a hybrid network has to determine is how deep to string the fiber, and what the migration strategy is going to be. At this stage, Southern Multimedia has opted to take fiber to 500-node pockets, without ring redundancy. That redundancy factor may be addressed at a later date, however, if traffic warrants it, according to Donaldson.

But the big constraint, he says, is that Southern Multimedia is not certain at this point just how congested the return spectrum is going to get, and whether or not that unknown warrants taking fiber all the way to the first radio-frequency amplifier. The company is experimenting with "block-up conversion" of that return spectrum as one solution to the return-path noise problem. Return spectrum is the primary architecturing design problem today, says Donaldson.

Without a solution such as block-up conversion, return signals and ingress noises are all funneled back to the headend on a single pipe. Block-up conversion allows those signals to be "stacked" on top of each other into discrete return paths and lessens the "funneling effect," according to Donaldson. Instead of splitting the outbound laser beam three or four times, Southern Multimedia may choose to install individual low-power lasers, which moves that ratio closer to "one-to-one," theoretically utilizing spectrum more efficiently.

The basic design of Southern Multimedia`s network is a synchronous optical network backbone and a 750-megahert¥hybrid fiber/coaxial-cable distribution scheme. The company is using 1550-nanometer lasers in the supertrunks and going exclusively with 1310-nm distribution from the hub. Donaldson says that there was an additional cost incurred to go ahead with "full detection of the 1550-nm signal all the way to the hub" (and doing the optical conversion there), but the upside is that it allows Southern Multimedia to manipulate the radio-frequency signal as it sees fit, and means the company can insert localized programming at the radio-frequency hub. Otherwise, the signals would flow right through the distribution hub as optical, and Southern Multimedia wouldn`t be able to "touch it," says Donaldson.

For example, a local video signal can be routed into different municipalities, with that narrowcast capability taken as far out as the node level. Narrowcast options will also give Southern Multimedia the choice of value-added service insertion such as video-on-demand and other "a la carte" possibilities. Each distribution hub will be serving approximately 20,000 to 30,000 passings. q

Paul A. Palumbo writes from Seaside, CA.