This
story appeared on Network World Fusion at
http://www.nwfusion.com/columnists/2001/1015bradner.html
'Net
Insider:
Will the wrong wireless
succeed?
By
Scott Bradner
Network World, 10/15/01
At
one time it looked like there was a roadmap, a confusing one perhaps, but a
roadmap nonetheless. Wireless Internet was going to be everywhere, but you were
going to use different wireless technologies depending on just where you were.
This original roadmap seems to be getting overtaken by events, and a far
simpler one may be emerging.
The original wireless roadmap looked
something like this: Local communications, say between your cell phone and
palmtop, would use Bluetooth; connections to your office LAN would use 802.11;
at home you would use HomeRF; and when out wandering the world you would use 3G
or maybe someday 4G. Come to think of it, I never did figure out how you or
your mobile computing devices would know where you were so as to know what
technology to use.
Each technology has been optimized for its
particular role. Bluetooth is low power and short range (30 feet or so), and
slow - less than 1M bit/sec.
Then there's 802.11, which offers a range
of speeds from a few megabits per second to about 50M bit/sec at a few hundred
meters. HomeRF only needs to cover a house and runs at a few megabits per
second. The next-generation cell phone services, 3G and 4G, will offer a few
megabits per second at distances of up to several miles.
But maybe
optimization is not needed. Supporters of most of the technologies in this
fuzzy picture might want to consider that "good enough" rather than
"optimization" may just be taking over.
No, 802.11 is not
just for office LANs anymore. It's showing up in classrooms, hotels, airports
and Starbucks. You would expect this, since these environments have basically
the same requirements as office LANs. It also should be obvious that for simple
Internet access-type services, 802.11 would work just fine at home. But now
802.11 is starting to show up in places that it would not seem all that well
suited for.
For instance, 802.11 is starting to show up as competition
to cellular-based Internet connectivity such as 3G. See this site for a list of
San Francisco-area providers.
And with the improvements in the power
efficiency of future generations of 802.11 chips, Bluetooth does not seem so
important. While 802.11 is far from perfect, the current versions - 802.11b and
802.11a - have significant security and quality-of-service (QoS) issues, and
having two versions could be a problem. But dual-mode chips that support both
versions are now shipping and the IEEE, the developer of 802.11, is busily
working on security and QoS improvements. (IEEE documents are now available for
free at grouper.ieee.org/groups/802/11/).
Indeed, 802.11 is yet
another example of generalization winding up being more important than
optimization. In this case, there may be rough times ahead for providers of
more ideal solutions such as Bluetooth, HomeRF and, most dramatically, 3G,
where the $150 billion spent for frequency licenses may have been mostly
wasted.
Disclaimer: Wasting $150 billion is beyond even Harvard's
ability, and the above is my opinion.
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