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Dan Kegel's ADSL Page
The word NEW on a link indicates updated on or after 1 Aug 96.
U.S. West to deploy ADSL this year?
According to a
from US West, both ADSL and single-pair HDSL lines were used in a technical
trial earlier this year; a market trial will follow in late '96, and
deployment in selected areas in '97.
GTE ADSL Field Trial in Texas
GTE is conducting a six month trial in the Dallas area. Participation
will be limited to two libraries, a bookstore, and GTE employees. The
modems, provided by Westell Technologies and Aware, Inc., will deliver
4 Mbps downlink and 500Kbps uplink. Routers and switches provided by
Bay Networks will interconnect the customers and the Internet.
See GTE's ADSL Home Page or
their ADSL Trial Info page for details.
DSL Modem Cost Down To $2500
PairGain claims they'll be conducting field trials of
consumer DSL gear
this year! And they already have a
distributor for their Campus products. Pairgain's blurb says a home
version will be available for $995 real soon now, but the Campus
version is out now; the distributor is quoting a minimum of USD $2500
for a standalone unit.
They claim maximum range of 8 miles, but that's only at the lowest
speed, 384 kbits/sec, with the best wire, 19 AWG. At higher speeds
or with thinner wire, the max range can drop below 2 miles.
You can use these to surf the net in style right now- if:
- you can order a 'dry pair' from your ISP to you through your Telco,
- your ISP offers a high-speed connect option,
- you have $600 - $1200/month to spend on your ISP's high-speed connect option,
- the total wire length from your ISP through the Telco CO to you is about 2 miles (5 miles for 384 kbits/sec), and
- you have at least $6000 to spend on equipment ($2500 for each DSL modem, and
at least $1000 for routers or high-speed serial ports).
ADSL started out as the phone company's way to compete with cable TV by
delivering both TV and phone service on your plain old copper phone
line. Now it's also a good candidate for high speed Internet access.
The "A" stands for "Asymmetric", meaning the phone company can send
lots of data to you, but you can't send much to them. Originally,
only a tiny uplink of 16 or 64kbps was supported; recent flavors of
ADSL support up to ten times that much.
ADSL is one member of a continuum of last-mile transport systems
called DSL, or Digital Subscriber Line, which can carry about
1 to 6 megabits/sec over copper lines. It does not include
any way to make long distance data calls, or even local calls.
That's another matter entirely-- one which is still up in the air.
ADSL was originally designed so you still can use it as a regular
phone line when the power goes out, which would be a big improvement
over BRI ISDN.
For the moment, the only form of DSL really being deployed is HDSL,
which is more or less a direct replacement for traditional T1 service.
T1 lines have been around forever, but require technicians to tune the
line to perfection; HDSL modems can handle dreadful lines cheerfully,
so should be much cheaper to install and run.
Other kinds of DSL are coming soon. In general, the fastest DSL schemes
only go a couple miles; the slowest can go farther. It's a tradeoff.
For alternatives to ADSL, e.g. cable modems, see one of the many
excellent sites now springing up:
Cisco's Introduction to
Multicast IP Routing explains some of the technology needed
to make serious video distribution over the Internet possible, something
that ADSL will need if it is to avoid completely obliterating
For more info, try these online sources:
ADSL Service Providers
Magazine Articles About ADSL
ADSL Magazines & Periodicals
- The TeleChoice Report on ADSL -- for info: firstname.lastname@example.org
- Telephony and Communications International -- according to the editor of TeleChoice ADSL, these cover ADSL the best from a trades point of view.
- Communications Week
ADSL Hardware Vendors
DSL Mailing List
Thanks to Mubashir Cheema (email@example.com) for setting this up!
This is a good list. You can even
read past messages via the Web.
To subscribe simply send email to firstname.lastname@example.org with
in the body of the message.
Other ADSL Web Pages
Thanks to Brad Knowles for help finding links, and to Rupert Baines for
suggestions and corrections!
HTML 2.0 Checked!
Author: Dan Kegel <email@example.com>
Copyright 1995 Dan Kegel. All rights reserved.