FCC Must Return to BPL Technical Issue

Richard Rucker rrucker at mac.com
Wed Apr 30 11:10:57 CDT 2008


Frank,

Thanks for that interesting bit of history!  I added part of what you  
wrote to the story of Chris Imlay's talk given to QCWA Chapter 91 two  
Saturdays ago. That story is found here:
http://homepage.mac.com/rrucker/chapter91/recent_events/

I trust that was OK with you.

73,
Dick Rucker, KM4ML
Ch91 web master

On Apr 29, 2008, at 9:09 PM, Frank Gentges wrote:

> Tacoistas,
>
> The ARRL has posted information on the court review of the FCC and its
> decision on BPL.  In particular the US Court of Appeals for the  
> District
> of Columbia Circuit today released its decision on the ARRL's Petition
> for Review of the FCC's Orders adopting rules governing broadband over
> power line (BPL) systems.
>
> We gathered AMRAD members André Kesteloot, Bernie Keiser and myself
> along with Paul Rinaldo and the ARRL counsel, Chris Imlay.  We met at
> the ARRL office to help craft the ARRL submission to the FCC on BPL.
>
> One of the issues we examined was how the signal strength should fall
> off as function of distance from a radiating power line.  The AMRAD
> group helped the ARRL develop an argument that it should fall off at a
> rate of 20 dB per decade as that more closely represents how a line
> source should act.  Key was a drawing showing the line radiating out  
> as
> a horizontal cylinder as opposed to the more familiar sphere.  The FCC
> decided that it should fall off at a rate of 40 dB per decade which
> represents a point source and sphere. After all, that is how
> they have always done it.
>
> Now, it looks like our argument of a cylinder as presented by ARRL
> counsel convinced the court it should be reexamined by the FCC.  As  
> the
> ARRL writes:
>
> Quote
> With regard to the extrapolation factor, the Court ordered: "On  
> remand,
> the Commission shall either provide a reasoned justification for
> retaining an extrapolation factor of 40 dB per decade for Access BPL
> systems sufficient to indicate that it has grappled with the 2005
> studies, or adopt another factor and provide a reasoned explanation  
> for
> it." The studies in question were conducted by the Office of
> Communications, the FCC's counterpart in the United Kingdom, and were
> submitted by the ARRL, along with the League's own analysis showing  
> that
> an extrapolation factor closer to 20 dB per decade was more  
> appropriate,
> as part of the record in its petition for reconsideration of the FCC's
> BPL Order. The Court said that the FCC "summarily dismissed" this data
> in a manner that "cannot substitute for a reasoned explanation." The
> Court also noted that the record in the FCC proceeding included a  
> study
> by the National Telecommunications and Information Administration that
> "itself casts doubt on the Commission's decision."
> Unquote
>
> We hope the FCC goes back to basics and considers the fundamental
> physics involved here.  Using the FCC mandated number, calculations  
> will
> underestimate the field strength of the interference.
>
> So much time has expired since our comments went to the FCC on  
> this.  We
> are given to wonder how much has been invested in systems based on a
> flawed model.  This sunk investment will make it harder to decide on
> changes at this late date.
>
> This seems to vindicate the work done by the assembled AMRAD group.
> AMRAD can make a difference.
>
> Frank K0BRA



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