G.Lite: Mass Market ADSL- August 17, 1999
Once upon a time, 1200 bps was a fast modem and 230 kbps
LocalTalk was a decent network speed. That was a long time ago. Today, most modems are of the
56k variety -- although the name is something of a
misnomer. These 56k or v.90 modems can download files
at up to 53 kbps. In the real world, download speeds of
44-48 kbps are typical. On the flip side, v.90 modems have limited upload
bandwidth, with a 33.6 kbps ceiling. In fact, the faster
your download, the slower your upload, and vice versa. Phone
lines only have a total bandwidth of about 64 kbps,
bandwidth which must be shared by data moving in both
directions. V.90 modems manage their trick of breaking the 33.6
barrier by operating in digital mode for downloads. However,
the nature of phone lines restricts them to analog operation
when sending data. ISDNThe next speed step beyond analog modems is ISDN, which
uses one or two digital phone lines and offers 56-64 kbps
per line. My home network uses ISDN with a total bandwidth
of 128 kbps -- over twice what a 56k modem can do and nearly
four times what a strictly analog modem (33.6 kbps or
slower) could offer. But it comes at a price. I'm paying about $50 per month
for the phone lines, then pay my ISP an higher-than-usual
rate for the faster service. I've grown past 56k, but the step up to ISDN was
expensive and doesn't provide nearly the bandwidth I'd
like. ADSLFor the past few years, vendors have been working on ADSL
(asymmetrical digital subscriber line) technology. Unlike
older modems, the various DSL designs send a high speed
digital signal over your phone lines. And unlike ISDN, DSL
can maintain a full-time internet connection while leaving
your phone line available for phone calls and faxes. The problem has been a lack of standards. Some DSL
designs can potentially reach 6-8 Mbps download speeds,
providing close to ethernet performance. Others have been
less ambitious, trying to keep cost down and offer a broader
network. (The faster a DSL connection, the closer you must
be to a phone company switching station.) Enter G.LiteThe personal computer industry is rapidly embracing
G.Lite, a cost effective DSL technology with good enough
performance for most users most of the time. If you read PC Magazine, you may have noticed that Compaq
includes G.Lite modems with some models, promising up to 1.5
Mbps internet connections. Of course, the fine print says it
may not be available yet, but the same modem also works with
regular 56k service. Compaq is very forward-looking. I hope Apple will do the
same with the next generation iMac. G.Lite has the potential
to displace analog modems and ISDN connections about as
quickly as the phone companies and ISPs can implement
it. G.Lite is asymmetrical, promising download speeds as high
as 1.5 Mbps and upload bandwidth of 384 kbps. That's over
25x the speed of a 56k modem for downloads, and nearly 12x
the speed for uploads. Compared with dual channel 128 kbps
ISDN, download bandwidth is up to 12x faster and uploads up
to 3x faster. Best of all, you won't need a digital phone line --
G.Lite works on your regular line, although it requires your
phone company to switch that line to allow high speed data
transfers. G.Lite modems will cost about what 56k modems did when
they were introduced, somewhere around $200. And, like 56k
modems, they're sure to drop in price over time. Beyond speed, G.Lite and other DSL protocols have two
huge advantages over analog modems and ISDN: - You have a full-time connection, so you don't have to
wait while your computer or network reconnects to the
internet. (Well, maybe after a power outage or if you've
powered down your modem.)
- Cost. Although initially expected in the US$50-80
range, G.Lite rates will eventually drop to the US$30
range as the market expands and various companies vie for
your business.
If G.Lite were available here today, I'd switch in a
heartbeat. Eliminating the $50 a month to Ameritech for two
ISDN lines would cover the cost of G.Lite service. At the
same time, I'd have a much faster internet connection. The only question I have is, "When will they offer it in
Grand Rapids, Michigan?"  Further ReadingRecent articles on Online Tech Journal
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