ARRL Cites 'Additional Authorities' to Address BPL Reconsideration:
from
The ARRL Letter, Vol 24, No 27
on
July 15, 2005
Website:
http://www.arrl.org/
View comments about this article!
ARRL Cites 'Additional Authorities' to Address BPL Reconsideration:
The ARRL has cited the conclusions of a UK study and of the FCC itself to
further support its call for the Commission to "reconsider, rescind and
re-study" the broadband over power line (BPL) rules it adopted last October.
In its Petition for Reconsideration last February in the BPL proceeding, ET
Docket 04-37, the League argued that in permitting unlicensed Part 15
devices such as BPL, the Commission's main obligation is to establish a
radiated emission level low enough so that the devices "will predictably not
interfere" with licensed services.
"Unless this conclusion can be fairly reached, the Commission has no
statutory authority to permit the facilities to operate on an unlicensed
basis," the League maintains in a Citation of Additional Authority
(Citation) filed July 8. Furthermore, the League says, the FCC itself
affirmed the ARRL's argument in another proceeding.
The League cited a Commission conclusion in last December's Second Report
and Order and Second Memorandum Opinion and Order in the Ultra-Wideband
(UWB) proceeding, ET Docket 98-153. The FCC held in its UWB Order that a
reasonable reading of Section 301 of the Communications Act would limit
licensing to "any apparatus which transmits enough energy to have a
significant potential for causing harmful interference." The FCC, the League
asserts in its Citation, cannot authorize BPL--although it's an
unintentional radiator--due to "acknowledged (and field-proven) substantial
interference potential to licensed services." The solution, the ARRL said,
is to establish radiated emission limits at a level that would make the
chances of interference negligible.
Accompanying the Citation are studies of BPL systems in Scotland conducted
by Ofcom, the UK's telecommunications regulator. Ofcom says concern over
signal leakage is one reason for BPL's small UK market share compared with
DSL and cable. "Although efficient for their primary purpose, electricity
supply cables are not designed, screened or balanced for high frequency use,
and in this application they produce significant leakage emissions," the
Ofcom study said, adding that the emissions potentially can interfere with
radio communication services "including short wave broadcasts."
In its Citation, the ARRL again argues that the FCC "incorrectly rejected"
the League's recommendation for a 20 dB extrapolation factor in measuring
BPL signal decay on HF based on distance from the signal's source. Instead,
the FCC opted to apply the existing--and less stringent--40 dB/decade factor
in Part 15.
"The existing Part 15 standard is clearly inapplicable and underestimates
the BPL field strength by up to 11.5 dB," the ARRL said, pointing to the
Ofcom studies to support its assertion. The League called the FCC's adopted
40 dB/decade factor "inappropriate." The ARRL also said the Ofcom studies
clearly show that notching is ineffective to mitigate interference and that
certain BPL systems cannot even meet the FCC's "overly liberal" Part 15
field strength.
The League further noted that the FCC already applies a 20 dB/decade
standard to measure signal decay of Part 18 Industrial, Scientific and
Medical devices that can operate below 30 MHz.
In last October's BPL Order, the League pointed out, the FCC stated that if
new information became available auguring in favor of alternative emission
limit/distance standards or extrapolation factors, it would revisit the
issue.
"There is no time like the present," the ARRL urged.
A copy of the ARRL's Citation is on the League's Web site
LINK.
Source:
The ARRL Letter
Vol. 24, No. 27
July 15, 2005
This article has expired. No more comments may be added.
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ARRL Cites 'Additional Authorities' to Address BPL
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by W9WHE-II on July 18, 2005
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Mail this to a friend!
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"The solution, the ARRL said, is to establish radiated emission limits at a level that would make the chances of interference negligible"
Funny, when this was suggested YEARS ago by hams posting here, ARRL staffers balked. Instead, ARRL set out to kill BPL. As a consequence, they lost that battle AND lost an opportunity to be a major player in setting standards. Currently, at 40 dB, BPL may be permitted to radiate almost 20 times as much hash as an industrial/medical device.
WAY TO GO ARRL!
W9WHE
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RE: ARRL Cites 'Additional Authorities' to Address
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by W1RFI on July 22, 2005
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Mail this to a friend!
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> Funny, when this was suggested YEARS ago by hams
> posting here, ARRL staffers balked.
What ARE you talking about? ARRL's first filings with the FCC set out to have the limits set at a low-enough level as not to cause interference. Can you tell us what staffer balked at setting limits at a low-enough level to not interfere with amateur radio?
> Instead, ARRL set out to kill BPL.
ARRL set out to address BPL interference. Until Motorola came along, being against interference and against BPL were one and the same.
> As a consequence, they lost that battle AND lost an
> opportunity to be a major player in setting
> standards.
If proposing reasonable limits were all that ARRL needs to do, it has done so, so your premise is inaccurate and imcomplete.
I serve on the following standards committees:
o ANSI C63 EMC committee, chair of Subcommitte 5, Immunity and chair of its BPL Working Group
o IEEE P-1775 BPL EMC working group
o IEEE EMC Society Standards Development Committee, chair of its BPL study project
I would think that serving as chair of subcommittees and working groups would be seen as most as being a major player. Thanks for the opportunity for me to explain that.
> Currently, at 40 dB, BPL may be permitted to radiate
> almost 20 times as much hash as an industrial/medical device.
First, "at 40 dB" has no technical meaning unless you reference it to something. BPL does operate about 40-50 dB greater than the typical noise floor at amateur stations. Is that what you are trying to say? BPL emissions are at the same level as other Part-15 devices. The danger to BPL is that it operates at those limits over a wide swath of spectrum and along overhead lines, strong for at least a half mile from the injection point.
Under Part-18 rules, ISM devices are allowed unlimited emissions in the ISM bands. Outside the bands, they need to meet Part-15 levels, for the most part, so I don't know where your "20 times" figure came from. Can you post your reference and explain its import to us?
I realize that it takes a bit of work to be informed, but your posts would be more helpful if they were factual. I suggest that you research a bit more before you post.
Ed Hare, W1RFI
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