NTIA`s BPL Position a Moving Target;
Agency Edges Closer to FCC`s
Stance

http://www.arrl.org/news/stories/2004/10/07/3/?nc=1

NEWINGTON, CT, Oct 7, 2004 --- The
position of the National
Telecommunications and Information
Administration (NTIA) with respect
to BPL appears to be a moving target.
From expressing ``broad
concerns`` about BPL in August 2003 to
claiming BPL could help
alleviate power line noise this past
June, the NTIA now has brought
its position even closer into line
with that of the FCC --- already
an unapologetic proponent of the technology. At the same time, the
agency`s amended recommendations repeatedly recognize that any
spectrum BPL uses will suffer potentially harmful interference. They

further suggest a ``not-in-my-backyard`` attitude toward BPL
deployment in the vicinity of government radio systems.

In a cover letter to one of two separate filings, NTIA Office of
Spectrum Management Associate Administrator Fredrick R. Wentland
says
the agency believes the ``less burdensome proposals`` it filed with
the FCC last month will ``adequately protect federal radio
communication systems from locally generated BPL emissions while
minimizing restrictions on BPL.``

An agency of the US Department of Commerce, the NTIA now says it
``fully supports`` the FCC`s proposed method to extrapolate the
level
of BPL emissions from power lines. It`s also dropped its call for a
``height correction`` for measurements below 30 MHz. Based on the
NTIA`s own earlier studies, the method the agency now supports could

result in measurements that fail to accurately reflect actual
emission levels by as much as 20 dB.

Additionally, the NTIA says it now prefers the FCC`s proposal to
measure BPL field strength ``at various specific locations along a
power line`` instead of along the length of the line. ``NTIA`s
extensive further analysis shows that the overall peak field
strength
that would be found in an exhaustive search along the power line
would not significantly exceed the peak level measured using the
streamlined approach`` the FCC`s BPL Notice of Proposed Rule Making
(NPRM) proposes, the agency said. In its June 4 comments on the
NPRM,
the NTIA had recommended ``a comprehensive search for the peak field

strength along the power lines at a height of one-meter`` because
its
modeling had demonstrated that interval measurements ``may not
consistently reveal the peak level of radiated emissions.``

The NTIA also has reconsidered its earlier proposals to exclude
certain frequency bands, geographical zones and voluntary
coordination to prevent BPL interference to critical federal
government radio systems. Since filing those comments, Wentland
said,
the NTIA has worked with agencies of the Interdepartment Radio
Advisory Committee (IRAC) to narrow the scope of specific bands and
areas where ``special protection mechanisms`` regarding BPL should
apply.

``Federal radio communications not specifically addressed in the
proposed restrictions should be, for the most part, adequately
protected in the near term by the baseline interference prevention
mechanisms specified in the NPRM (eg, field strength limits,
compliance measurement guidelines, and the prohibition of harmful
interference),`` Wentland concluded in a cover letter. Part of the
NTIA, the IRAC is charged with helping to assign frequencies to
federal government users and ``developing and executing policies,
programs, procedures, and technical criteria pertaining to the
allocation, management and use of the spectrum.``

The NTIA says its revised recommendations would exclude Access BPL
operation nationwide from less than 2.18 percent of the HF and low-
VHF spectrum and from a minuscule portion --- 0.0007 percent --- of
the HF spectrum ``in limited geographic areas.`` That`s less than
half the spectrum the NTIA`s largely scientific Phase 1 report
initially suggested be protected from BPL interference. The Phase 1
report, already part of the proceeding, clearly established BPL`s
interference potential. A Phase 2 report providing ``additional
guidance`` on contending with BPL interference issues is still
pending.

The NTIA says excluded bands primarily should be those used for
safety communications ``in situations where co-channel emissions
from
numerous BPL devices may be received via line of sight and
ionospheric interfering signal paths.`` Exclusion zones would
include
``sensitive radio astronomy sites,`` generally located in remote,
sparsely populated areas where there would be ``little or no actual
constraint on Access BPL market penetration,`` the NTIA said.

Coordination areas would apply to receivers ``at known locations
that
must operate with very weak desired signals and where harmful
interference must be prevented`` beforehand with a high degree of
certainty rather than ``after discovery.``

Prior coordination of BPL deployment using certain frequencies, the
NTIA now says, should apply ``in limited geographic areas wherein
BPL
deployment will not necessarily be constrained, depending on details

of the planned BPL deployment.`` The NTIA also said it could no
longer support a requirement for BPL systems to transmit
identification codes.

The agency does not appear to have backed away from its
recommendation that the FCC apply its more stringent certification,
rather than verification, procedures, to authorize BPL systems.
``Because Access BPL systems pose relatively high interference
risks,`` the NTIA said in its comments last June, ``certification
rather than verification should be required.`` The ARRL also
supports
certification, which would require independent testing or review of
test results, as opposed to having a BPL operator merely attest that

its system complies with FCC rules.

Metavox Inc and ARRL staff have measured BPL emissions well above
Part 15 limits in certain systems. The League asserts that
certification offers a higher degree of confidence that deployed BPL

systems will not continue to exceed Part 15 limits.

The FCC is expected to consider a Report and Order in the BPL
Proceeding, ET Docket 04-37, when it meets in open session Thursday,

October 14.

For additional information, visit the ``Broadband Over Power Line
(BPL) and Amateur Radio``page on the ARRL Web site. To support the
League`s efforts in this area, visit the ARRL`s secure BPL Web site.

Copyright © 2004, American Radio Relay League, Inc. All Rights
Reserved (via John Norfolk, dxldyg)
===============================================

dxAce
Michigan