[CWN-Summit] RE: [Unlicensed_advocates] RE: [Openspectrum] Spectrum updates

Harold Feld hfeld at mediaaccess.org
Tue Jul 5 15:11:15 CDT 2005


At 06:59 PM 6/29/2005, Patrick Leary wrote:

>Two, the Commission has not "shunned" all the work we involved with WiMAX
>have done.

I certainly agree that the Commission bears no animus toward WiMAx.  At the 
same time, the Commission recognized the importance of mesh and other users 
that prefer contention-based protocols as a logical means of facilitating 
traffic from multiple users.  WiMax developers are, of course, encouraged 
to think of ways to employ WiMax or WiMax-like technologies that conform to 
the Commission's final rules, which are designed to be technology neutral.

The notion of a dichotomy between 802.11 and WiMax is, in essence, 
false.  The question is whether the Commission maximized the use of the 
band by requiring contention-based protocols as a basis for operation 
within the band.  Those on the non-commercial mesh-network side with whom I 
spoke, most notably CUWIN engineers but others as well, proposed a number 
of means of trying to ensure that mesh networks could operate successfully 
in the band.  The FCC, however, rejected to most of the proposals CUWIN and 
others suggested (e.g., making power levels dependent upon population 
density, limiting high-power to point-point links, requiring "smart" 
sectorized antennas for higher power).  The adoption of a requirement for 
contention-based protocols was seen by staff as the best compromise among a 
multitude of would-be users and developers, many of whom were concerned 
that combining high-power with "always on" technology was a recipe for 
disaster in the band or would effectively prevent new entrants after the 
first few entities deployed.

To the extent WiMax is designed to work as an always on, broadcast 
technology, it will not function in the band under the proposed 
rules.  While this potentially has its downsides, it also creates a space 
for a variety of new technologies and service models that are not rooted in 
WiMax.  Since a large number of bands, both licensed and unlicensed, are 
available for WiMax, the creation of a band that will promote a 
contention-based protocols will not inhibit WiMax deployment.  Furthermore, 
encouraging multiple technological approaches is prudent and serves the 
public interest.

Pat has already countered that elimination of the contention-based 
protocols requirement would both facilitate WiMax and deployment of other 
technologies.  While I confess I am not an engineer, I am informed by those 
that are that while theoretically true, the practical effect will be to 
make contention-based technology impossible and to limit the utility of the 
band to licensee using WiMax and using 365-3700 MHz as a "spillover" band 
to lower their costs.

To make a poor analogy, WiMax is something like the Northern Snakehead (aka 
Frankenfish).  The snakehead is a perfectly fine species in its home 
waters, has enormous flexibility and durability for a fish, and is reported 
to be quite tasty.  But let it loose in the Potomac and it will quickly 
drive off or kill many of the native species.

Perhaps the Northern Snakehead deserves a "level playing field" in the 
Potomac, and the local fish should just learn to deal with it.  But the 
Snakehead is not endangered and does just fine in the environment God and 
nature designed it for.  Similarly, I would like to think there is room in 
the spectrum "ecology" for all manner of uses and technologies.  Just as 
not every body of water needs to be colonized by Northern Snakeheads, not 
every band of available spectrum needs to be colonized by WiMax.

Harold



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