[CWN-Summit] Re: Need help gathering evidence

[David Young]

On Wed, Feb 02, 2005 at 12:03:43PM -0600, cwn-summit-request at lists.cuwireless.net wrote:
> Message: 1
> Date: Tue, 01 Feb 2005 12:08:01 -0500
> From: Harold Feld <hfeld at mediaaccess.org>
> Subject: [CWN-Summit] Need help gathering evidence
> To: Network Summit Mailing List <cwn-summit at cuwireless.net>
> Message-ID: <6.1.2.0.0.20050201115841.0cb1ade8 at mail.his.com>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
> 
> There appears to be interest at the FCC on cracking down on folks who abuse 
> the unlicensed rules by using always on equipment primarily to shut out 
> others, if such allegations could be proved.  I'd like to go after the 
> worst offenders and easiest cases first.  In particular, I am looking for 
> any equipment manufacturer or service provider that explicitly advertises 
> itself as holding channels open whether they are actually needed or 
> not.  The more explicit the advertising (e.g., "use us and you will shut 
> out all 802.11b devices using listen before talk") the better.
> 
> At this point, I do not want to try to go after folks like SBC who use the 
> cheapest possible equipment and who blast at the loudest power.  We want 
> something really deliberate.  OTOH, simple suggestions for improving 
> efficiency (such as any factory set defaults that could be changed to make 
> it less likely devices will pollute)  are also good.
> 
> I am hoping to file a request for a declaratory statement from the FCC that 
> would explicitly prohibit certain forms of marketing and would urge 
> industry to manage the spectrum effectively through simple steps (such as 
> shipping devices with the most efficient default settings).  I don't know 
> that I'll _get it_mind. All I've gotten so far is some unofficial interest 
> in knowing about potentially abusive practices, but I think there is an 
> opportunity to help make spectrum use more efficient.

Harold,

Here are some suggestions for improving efficiency.  All of my remarks
apply to 802.11.

        * 802.11 APs should send beacons (periodic messages that say
          "I'm here! I'm an access point!") less often, or not at all.
          99% of the time, these broadcasts are just pollution.

        * All APs should scan all of the available 802.11 channels
          for users, and choose the least-busy channel.  Some APs are
          already doing this.  There is already source code to do this
          in open source, so nobody can argue that it costs too much.

        * Use transmit power control.  There are more or less
          sophisticated ways to do this, but it is important to treat
          the common case that arises in living rooms across America:
          one AP screams at one laptop that is scarcely 20 feet away,
          which screams back.  This keeps your nextdoor neighbors'
          from re-using the same channel, and it affects your privacy.
          New APs and clients can and should detect that they're using
          too much power and turn it down.

        * Carefully match sensing range to transmit range, so that
          "listen before talk" is fair.  It is bad for spectrum
          sharing if the loudest nodes are also hard of hearing,
          because then they speak out of turn.  It is also bad if nodes
          with exquisitely sensitive receivers are always waiting for
          distant nodes to talk.  Devices that use "listen before talk"
          should be carefully calibrated at the factory, and/or they
          should automatically recalibrate their sensing/transmit range.
          (I am not a big fan of listen-before-talk, but I am a fan of
          $10 802.11 listen-before-talk radios!)

Dave

-- 
David Young             OJC Technologies
dyoung at ojctech.com      Urbana, IL * (217) 278-3933