Technology goes one step beyond ISDN for Internet connections
By Shawn McCarthy
In the Dr. Seuss book, On Beyond Zebra, a boy tells his friend about the
fantastical letters he's invented that go beyond the standard alphabet.
In that spirit, let's tackle the technologies that are "On Beyond ISDN" for
Internet access. Unlike the Seuss book, these are very real and can compete with
Integrated Services Digital Network and leased T1 lines as standard Internet connections.
*Asymmetric Digital Subscriber Line (ADSL) could become your local telephone provider's
main way of delivering Internet access in the future. ADSL also supports digital video and
phone service over the plain copper wires now in place.
Asymmetric means the phone company establishes a broadband connection to you, but you
have only a 64-kilobit/sec connection back to it. The downstream connection at 384
kilobits/sec can stretch for eight miles. ADSL splits the available transmission bandwidth
into three parts for streamlined use. To read more about it, see the World Wide Web page
put together by Knut C. Aas at http://www.nta.no/telektronikk/4.93.dir/adsl.html.
ADSL's target market is high-rate inbound transmission of video, audio or Internet
services; the outgoing signals would have to be mostly simple control requests, such as
form entries or Web page hot-link selections.
GTE Corp. is testing ADSL connections at some Dallas libraries. This fall, U.S. West
likely will become the first local provider to offer ADSL as a subscriber service. But the
equipment remains expensive.
The ADSL modems are about $2,400. Add routers to connect a LAN, and the cost tops
$6,000. This setup would be useful only if your Internet service provider can give you a
high-speed connection, which will cost another $1,200 or so per month.
ADSL probably isn't destined for success at agencies that maintain popular Web sites or
ship lots of files to other locations.
*Cable modems have the most promise for high bandwidth at a reasonable price, but it
will be hard for government offices to take immediate advantage because few have cable
connections, and very few cable companies offer Internet service yet.
But the momentum is there. Motorola Inc.'s CyberSurfr cable modem claims throughput of
up to 10 megabits/sec plus a 786-kilobit/sec upstream path, with a street price around
$1,000. In theory, the only other cost would be a cable connection, about $30 per month.
ADSL can't compete with that pricing.
So where would the Internet content come from if there's no local service provider? At
least one company, @Home of Mountain View, Calif., will specialize in feeding Internet
services to cable TV systems through a national, multimegabit backbone. The price for such
a connection hasn't been established yet.
Government agencies with national backbones in place could set up a similar scheme for
themselves at very low cost, with local offices tapping into the backbones via local cable
For a list of companies that plan to support cable modems, visit http://www.cablemodems.com/providers.html
. Cable users can surf the Net, watch an analog television signal and talk on the phone
all at the same time. An added bonus: Computers could be left signed on to the network 24
hours a day without using any system resources, except when data transfers are initiated.
*Satellite downlink via Hughes Network Systems' DirectPC service has taken the idea of
one-way Internet traffic to new heights. Hughes, of Germantown, Md., recently expanded the
DirectPC service options.
Subscribers receive a satellite antenna, adapter card and software that lets them place
outgoing requests over a telephone line. Requested data beams back to their PCs. Just as
your Ethernet card picks your data packets out of the stream on the LAN, DirectPC picks
your requested data out of the firehose of data pouring down from the satellite.
DirectPC subscriber time costs about $39.95 for 130M per month.
What all this means is that government offices have many choices beyond ISDN for
broadband Internet connectivity.
Leased lines and ISDN still may be your best bets, especially if you need a big
upstream pipe. But offices that do a lot of Internet browsing and research can improve
their service levels significantly. Compare prices and see what's available in your area.
Shawn P. McCarthy is a computer journalist, webmaster and Internet programmer. He
is developing and maintaining a corporate Web site for GCN's parent, Cahners Publishing