Ed Hare is on travel and has not had a chance to review the document yet. Neither Chris nor I feel comfortable commenting on the technical aspects until we hear from Ed. However, for what they’re worth here are my impressions based on my own initial review.

The Commission has seen fit to increase the required notch depth below 30 MHz from 20 dB to 25 dB. That’s a step in the right direction and does provide another 5 dB of protection for mobile operations in particular. Regrettably, the Commission has not taken the next step of requiring that the amateur bands be notched. The rationale for not doing so appears to be that there are relatively few interference complaints. (The complaint we submitted in December 2010 is referred to as having been “…submitted recently and is under investigation at this time.” Apparently the Commission is not embarrassed by a complaint languishing for 10 months and sees no inconsistency between that and the stated objective of the rules being to ensure “… that any instances of harmful interference that may occur can be quickly identified and resolved.”)

The Commission uses the online BPL database as its reference in claiming that there are BPL systems operating in “more than 125 zip codes.” In fact, after one removes the entries for non-existent zip codes there are 200 zip codes listed in the online BPL database and none has been added since February 2011. However, the vast majority of these are “paper” systems that were never deployed, systems that have been taken out of service, and systems that are at some planning stage or are only offering service to customers within a small pilot area. The basis for using the figure 125 instead of 200 is not explained. The FCC’s own report on the status of internet access services as of December 31, 2010 shows no more than 6,000 customers nationwide receiving service via “power line and other” connections. The reason there are not more interference complaints is not because the existing rules are adequate; it is because there is very little BPL deployed and most of the few systems that are in operation voluntarily notch the amateur bands.

The FCC spends a great deal of time defending its 40 dB/decade extrapolation factor and arguing that the scientific basis for the 20 dB/decade extrapolation factor that we prefer is no stronger. However, they have amended the rules to make the extrapolation factor somewhat less significant by requiring that measurements be made at a distance of 30 meters whenever possible and by specifying in the rules that when an extrapolation factor is employed the slant-range distance from the power line is to be used. (Previously the slant-range distance was specified in the measurement guidelines but not in the rules themselves.) Ed Hare needs to weigh in on the significance of these changes and the revisions to the procedures for site-specific determination of the distance extrapolation factor.

In paragraph 91 I did find one sentence with which we are in strong agreement: “Whether the extrapolation factor is 20 dB or 40 dB or somewhere in between is far less important than the fact that harmful interference must be corrected under any circumstances.” We wish the Commission’s enforcement deeds matched these words.

Dave K1ZZ

From: arrl-odv-bounces@reflector.arrl.org [mailto:arrl-odv-bounces@reflector.arrl.org] On Behalf Of Sumner, Dave, K1ZZ
Sent: Tuesday, October 25, 2011 11:20 AM
To: arrl-odv
Subject: [arrl-odv:20279] FCC BPL remand order is out

I have not read the 76-page document carefully, but a quick scan doesn’t reveal much good news.

Dave

<<FCC-11-160A1.doc>>