Open Spectrum: Take It or Lose It

Over at ZDNet,
Kevin
Werbach suggests
a
cure for bandwidth blues that looks as subversive and
fundamental as both the Internet and Linux. It's called Open
Spectrum. Here's how he draws the big picture:The concept is that wireless frequencies could be
shared among many users rather than assigned in exclusive licenses
to individual companies. Smart devices subject to rules ensuring
that no one player could hog the airwaves would replace networks
defined by governments and service providers. Spectrum would be
used more efficiently. Bandwidth would be cheaper and more
ubiquitous.We have a taste of this already with
WiFi, or
802.11b, which is how most of us connect wirelessly to the Net. But
WiFi is just what we've squeezed out of the
small
wedge of spectrum. Already, Kevin reports, there are 10
million WiFi devices and 4,000 public wireless access points, and
they're growing like weeds. You can walk down some streets in San
Francisco with a wireless laptop and sense a dozen different base
station signals. Some are wireless company intranets. Some are paid
public access points (like
MobileStar's, which
are in many Starbucks cafes, and
WayPort's, which are in
many airports and hotels). Others are cooperatives serving the
public or only their members. Those include
NoCatNet (by some O'Reilly
folks in Sonoma County, CA),
Consume.net in London,
SeattleWireless.net
and SFLan in San
Francisco. But let's face it, these are a few wireless drops in the
wired Net's bucket. Geographically, the ratio ought to be the other
way around.To get what's possible here, you have to break loose from the
idea that a wireless link has to be nailed down to a specific
frequency, and that bandwidth will vary mostly with signal
strength. Thanks to
spread spectrum
technology, many signals can share (or roam among) many
frequencies using very low power signals in a given locality. They
don't need to crowd each other out or step on each other. Here's
how Kevin puts it:... if the receivers are smart enough, many
transmitters can send signals with low power over a wider range of
bands and not interfere. The signals are split up into coded chunks
that are reassembled on the other end, much as routers manage
traffic on the Internet. Everyone in the room can talk at once, as
long as they do so quietly. And if you listen carefully, you'll
recognize the unique pitch of a friend's voice across the room
despite the distance and the large number of simultaneous
conversations.And where would Linux come in? Lots of places, but especially
where it gets embedded:Using smart "software-defined" radios, nodes in
unlicensed wireless networks could cooperate actively. Devices can
act as repeaters for traffic between nodes. They could dynamically
select power levels and coding schemes based on the behavior of
other nodes. And they could cooperatively sample and adapt to
background noise. Through these mechanisms, which could be
encouraged through equipment certification rules, the spectrum
would go from a fixed resource to one that expands with additional
computing power and technical innovation. New users could actually
increase the bandwidth available by contributing to the cooperative
intelligence of the network.So what's keeping us from making this happen? In a word, the
Feds. We need enough spectrum to make it work. Toward that end,
Kevin has written an
Open
Letter to the FCC on Spectrum Policy in which he makes a
number of specific recommendations, including adoption of the
"intelligent radio bill of rights" suggested by Bran Ferren, the
former head of R&D for Disney Imagineering.Kevin, by the way, is a former insider with the FCC, having
served as Counsel for New Technology policy there. He also helped
make the FCC hip to the Web in the first place, designing the
agency's first web site. In law school at Harvard, Kevin was
publishing editor of the Law Review (he says
he actually enjoyed law school, which is maybe why he went into
other work--like writing and pushing out the Net's envelope). These
days he's busy driving the Open Spectrum cause as editor of
Release
1.0, published by Esther Dyson's EDventure
Holdings.
Open
Spectrum: The Paradise of the Commons is his lead piece in
the current issue of the publication.The big question for me isn't "Can we get behind this?" It's
"What can we do?" and "What's being done already that we can
support?"I have a bad feeling about what will happen if we don't. One
of Michael Powell's
most-quoted
lines since he became FCC chairman is "Openness is not
always good." On the plus side, this issue isn't about open vs.
closed. It's about public vs. private. All we're asking for is some
open, public spectral space--just enough to do what we've already
done with the Net.Doc Searls is Senior Editor
of Linux Journal.

email: doc@ssc.com