Presto! And It's There -- Cable-Modem Internet Service Does Away With Downtime
With a special modem hooked up to the same cable that brings television into her home, Judy Bara finally has Internet access speedy enough to do justice to the visions of World Wide Web designers who, let's face it, forget that most of us have clunkers for modems.
Looking at the CNN Interactive site, Bara has a choice of two versions of a video clip of a volcano spewing lava.
"We'll download the bigger version - because we can," she says.
Click.
If you are at all familiar with the Internet, what happens next is nothing short of astonishing.
It takes only 21 seconds to download the 3.3-megabyte file - less than the 30 seconds it takes to play the video on Bara's Power Macintosh.
That translates into a download rate of about 1.2 megabits per second - 1,200K. The same download would have taken about 15 minutes at 28.8K, the speed of most modems in home computers.
It is 6 p.m. on a Friday evening, during peak Internet usage. Every Web page Bara visits draws itself in seconds.
Bara, an accountant, and husband Mike, a design engineer, are among the first paying customers in this area for @Home, the Internet service of Tele-Communications , a subsidiary TCI.NET.
@Home is unique in two ways. It delivers the World Wide Web at astonishing speeds. And it does so through TV cable, which means you leave it on all the time. No more dialing up. No more busy signals. No more second phone line.
After about a four-month beta test involving several hundred users, including the Baras, TCI recently announced it is rolling out @Home commercially, first in the Baras' Fauntleroy-area neighborhood of West Seattle and, eventually, throughout the city. The company is not disclosing a timeline. For most people, cable-modem service probably is several years away.
The cost is $150 for installation, which includes a yours-to-keep Ethernet card, if you need one, and $40 a month thereafter, which includes rental of the special Motorola modem.
Seattle joins Hartford, Conn., Arlington Heights, Ill., and Fremont, Calif., on TCI's list of Internet markets. Other companies have similar early cable-modem ventures under way.
@Home comes with a specially modified version of Netscape, but any browser will work and users also can use e-mail programs and client software to connect to proprietary services like America Online and CompuServe.
"Mike and I were thinking of moving into a condo" in another part of the city, where the service isn't yet available, "but we decided to stay because of the modem," Bara said.
Across town, near Seattle University, Jon Staenberg, a high-tech venture capitalist, has been testing a LANcity cable modem provided by Summit Communications of Bellevue, Seattle's other cable-TV company.
"This enables people to work out of their homes," Staenberg said of the speed and the 24-hour link. He has been spending less time at his downtown office.
"I think it's going to create a whole new market," encouraging more people to shun the commute, Staenberg said.
With more than 16 million television subscribers nationwide, TCI is the Goliath of cable companies. Summit is by comparison David, with a mere 40,000 subscribers in all and 13,000 in Seattle.
And yet Summit is only a step behind TCI with its cable-modem test in the Central Area. After more testing and market research, the company plans to roll out service there, where a newly rebuilt system already serves television customers, then in the downtown area.
"The business area is probably going to be a hot market, so I think that may be the area we turn on next," said Summit senior vice president Steven Weed.
Internet service through television cable depends on what is called a hybrid fiber-coax (HFC) system, with fiber-optic wire delivering television and data to neighborhood "nodes," and standard coaxial cable carrying the signals from a node to individual homes.
The fiber trunks emanate from "head ends," where cable systems now assemble the signals of various television channels for transmission to customers. Servers at head ends will be the Internet data traffic cops for what is essentially a giant, shared computer network.
The equivalent of about two television channels is needed to add data service to a cable system. If response time on the network begins to bog down, some users can be switched to different channels (assuming channel capacity isn't a problem). Or more nodes can be added to an area, feeding off other fiber lines (fiber-optic cable usually is strung in bundles).
Throughput - the rate at which data can be transmitted through a given communications setup - is very complicated, says Susan Marshall, TCI.NET's vice president for technology in Englewood, Colo. "It depends on the number of subscribers, the number of active users and what they are doing at given second in time," she says.
Bara's modem, provided by TCI.NET, is capable of receiving data at up to 27,000K and sending at 768K.
But the Internet is clogged, Web-site servers are sluggish and hardware limits throughput at the user end.
Most @Home users, Marshall said, can expect to receive data at nothing slower than 1,000K - about 40 times faster than most modems - and probably a lot faster. The send rate minimum is about 100K. (It's technically easier to send data "downstream" over a cable system, and rarely do users need the capability of sending equal amounts of data "upstream.")
To speed things up, @Home has its own fiber-optic "backbone" connecting its customers to the Internet at the national level. TCI also maintains "mirrors" of the most-popular Web sites and has its servers cache data - both of which methods are transparent to @Home users.
Speed might not be a competitive issue now. The next-fastest, generally available option for home users is ISDN, or integrated services digital network, at 128K in both directions. It requires a separate, dedicated phone line and is not available in all areas.
But phone companies are developing what they hope will be a more-worthy opponent for cable modems with ADSL technology, for asymmetrical digital subscriber line, which promises speeds approaching those of cable modems over existing lines shared by standard telephones.
Microsoft and GTE have been testing ADSL technology in the Redmond area since last summer.
The telephone industry claims wide deployment of ADSL, perhaps beginning this year, will be faster than that of cable modems because fiber-optic cable is not necessary.
Most cable customers are not yet served by hybrid fiber-coax systems. Massive rebuilding is under way, but cable modems will be unavailable to most for months and years.
---------------- Speed comparison ----------------
When downloading a 55-megabyte music video
28.8 kilobit-per-second phone modem: 4 hours, 24 minutes.
Up to 10 megabit-per-second cable modem: 44 seconds.