Last week Mike wrote this depressing post about the potentially pathetic fate of BPL at the hands of the regulatory focus on cost recovery. In the comments to the post the topic of interference came up; in particular, shortwave radio operators have expressed concern that the data transmissions over power lines will interfere with shortwave radio frequencies in the vicinity. This PC World article from January 2004 summarizes the postions in question. This Wired article from February 2003 introduces the technology. This May 2004 Digital Journal article suggests that even when such interference can occur, it is avoidable:
Progress Energy, working with a consultant company, has been able to identify such problems and solve them by notching, that is modifying the frequencies so as not to create interference.
“Given a situation where interference does occur to somebody who has a legitimate claim and has a legitimate interference concern and has experienced, quote-unquote, harmful interference, can this be mitigated around that particular frequency? That is what the company we have been working with here has been able to do, that is, notch out and get away from those bands when, indeed, that situation does occur,” said Matt Oja.
But the question of radio frequency interference is so pressing that the FCC spent much of the past year investigating the claims of interference and the existence of technologies that can minimize or eliminate such interference. The consequence of this examination was a set of rules for adopting BPL in mid-October 2004. The press release addresses the issue of interference:
[T]he Commission recognized the significant concerns of some licensed radio service users regarding the potential of Access BPL systems to cause interference to their operations. The Commission stated that its intention in adopting the Part 15 rule changes was to ensure that Access BPL operations do not become a source of harmful interference to licensed radio services. Based on extensive research and analyses, as well as experience, it concluded that the interference concerns of licensed radio users can be adequately addressed and that Access BPL systems will be able to operate successfully on an unlicensed, non-interference basis under the Part 15 model. The rule changes in the Order establish specific technical and administrative requirements for Access BPL equipment and operators to ensure that interference does not occur and, should it occur, to provide for a timely resolution of that harmful interference without disruption of service to Access BPL subscribers. The Order also sets forth procedures to measure the radio frequency (RF) energy emitted by Access BPL equipment.
The rule refers to Access BPL technology, which according to this primer is
a new technology to carry broadband Internet traffic over medium voltage power lines. BPL modems that electric utilities and their service partners can install on the electric distribution network also are available now. Medium voltage power lines are the electric lines that you see at the top of electric utility poles beside the roadways in areas that do not have underground electric service. Typically there are three electric lines (called phases A, B and C), each carrying several thousand volts. One phase is usually enough to power the houses on a residential street, two or even three phases can be joined together to power the big electric motors in an industrial or commercial area. (You also may see a fourth wire that is the ground wire.)
Note also that BPL provides a powerful technology for achieving a couple of objectives near and dear to the hearts of the folks here at KP. As articulated in a joint statement from Chairman Mike Powell of the FCC and Chairman Pat Wood III of the FERC,
Access BPL may help provide additional power supply system communications and control capabilities to improve reliability and efficiency. Such capabilities include “self-healing” network capabilities; improved security from physical and cyber threats; facilitating use of distributed generation; customer and utility control of appliances and equipment energy use; improved load management and electric grid utilization; and such applications as automated meter reading, extension of supervisory control and data acquisition functions to the end user level, outage detection, and equipment performance monitoring … [T]hese services should be allowed to develop according to market demands with minimal regulation.
Hear hear. I will explore these last issues in a subsequent post, after my grading is done.