DEC shapes a community multimedia network, but it ain’t no MTV

Anyone who has ever installed an Ethernet-based LAN has noted the more than passing resemblance between thin Ethernet coaxial cable and cable TV coax. True, the stuff used to wire offices is a much higher grade than what the cable companies use to bring MTV into your home, but it is at least from the same genus, if not species.

Several members of Digital Equipment Corp.’s Advanced Development Group made the connection between cable TV and Ethernet wiring and invented Ethernet via Cable Television (ETV). We spoke with Jim Albrycht, senior consultant with the group, who gave a presentation on ETV at the Digital World conference last month.

‘Ethernet everywhere.’ The concept is that Ethernet can be piggybacked on cable TV wiring to provide Ethernet network services to anyone connected to an “online” cable TV system. All that is required to get an ETV service off the ground is a little Vax computer with communications software to connect to your host computer–wherever that is–and appropriate Ethernet modems at the cable head-end, attached to each PC in each building or home that’s online. Once the switch is flipped, users can share files and network services just like those attached to genuine thin Ethernet cabling (or 10BaseT, or thick cable) at the host site–at the full 10-megabit-per-second speed of Ethernet.

According to Albrycht, ETV was the result of DEC’s search for a better mode of data communications for employees working at home. DEC has always been a strong believer in “home” computing, with early employees taking home VT52s and VT 100s–and even the ill-fated Rainbow–to telecommute in the evenings, on weekends, or on snowy days. As one of the early pioneers in popularizing Ethernet, DEC felt it was uniquely positioned to “reinvent” it.

A LAN waiting to happen
ETV reinvents Ethernet by:

• Extending 10-Mbps Ethernet from two cable kilometers to 56 cable kilometers (35 cable miles);
• Fitting into and between any standard 6-MHz TV channel;
• Seamlessly bridging the data center, the campus, and the community; and, not coincidentally,
• Opening up the full 100-plus million cable TV-wired U.S. dwellings to DEC’s network services.

As specified, ETV is simply an expansion of the local network’s domain from the workgroup to the community. Indeed, it is distributed computing to the nth degree; it extends high-bandwidth Ethernet services to a community-wide domain. With 85 percent of the country wired (to the curb) via cable TV, the cable network is what you might call “a LAN waiting to happen.”

Win-win-win. As DEC sees it, ETV is win-win-win. The cable TV customer (“remote end user,” in computer terms) wins because he now can access his data files and applications at Ethernet speeds rather than dial-up telecom speeds. The cable TV operator wins because he has an additional, two-way service that generates far more revenue per subscriber than he can normally get (generally by a factor of 10 or more over usual cable TV rates). And DEC wins because, well, go figure–if ETV takes off, it could mean the sale of many little Vaxes, Ethernet modems and other DEC software and gear.

Although DEC is, quite naturally, drawing the flow diagrams with its own equipment plugged in, there is no reason why anyone couldn’t build an ETV system. Off-the-shelf technology to connect Ethernet to cable TV systems is available from a variety of vendors. DEC’s value-added is its strong Ethernet connectivity expertise and a pre-existing product suite that plugs together seamlessly, offering one-stop shopping for any company trying to get into ETV in a hurry.

Who needs CNN? ETV is only part of the story, however. DEC’s Advanced Development team sees it as one step in the road toward making a “Community Multimedia Network” (CMN) a reality. The idea behind CMN is to provide an “online, anytime” alternative to telephone-based information services such as Prodigy, taking advantage of the flexibility offered by cable TV’s 24-hour-a-day availability. Via ETV, more than one data network can be made available to an end user, providing the capability for multiple entities to provide information online within a community.

The idea here is that there should be no change in the way people work–the same tools would be available–but such a system would vastly increase an individual’s flexibility to work whenever and wherever appropriate.

The worldwide day. With CMN also comes the notion of a “worldwide day,” which addresses the problem of telecommuting on an international scale. At any given point in time one-third of the world is working, one-third is asleep and one-third is somewhere in between. Using satellite links and other technology common to the cable and telecommunications industries, it’s possible to extend the ETV network beyond current geographical limits, effectively time-shifting one’s workday and enhancing the ability to carry on international business.

This paradigm is appropriate not only for the corporate community, but also for academia, medical establishments, the publishing industry, etc.

Moreover, the high bandwidth of Ethernet makes it possible to include multiple media in the data stream being sent down the wire–indeed, DEC’s own Compound Document Architecture (CDA) supports a variety of data types, including still and moving video and sound. Down the pike, DEC envisions user-defined programming, intelligent information filters, and peer-level automated agents, all run on an ETV network to make computing life easier and to provide a variety of interactive services.

TV, you’re no MTV. It’s important to realize, however, that ETV is simply the infrastructure required for providing these services. Content, or programming, is still a function of the host to which the user is connected. Think of the networked PC or Mac in your own office. What you see and get there, you would also see and get at home–but at 10-Mbps Ethernet, rather than 2,400-or 9,600-bps dial-up speeds. Still, the hard part is thinking up innovative interactive multimedia services that make sense to run over networks. In cable TV terms, ETV is the wiring protocols that bring such shows as MTV into your home; it isn’t MTV itself.

But ETV represents a breakthrough because it liberates data communications from the bottleneck of Ma Bell’s slow dial-up phone lines at a cost that is on par with Ma Bell’s rates. It is also available today, which means that information providers and corporations don’t have to wait for digital telephony like ISDN to arrive to start enjoying some of its promised benefits.

Craig Cline