how-to block ads
|
PDXPLT
join:2003-12-04
Banks, OR
| reply to rf_engineer
Re: who'd a guessed?
I've done that a few times here in the past.
Their argument is that Section 301 of the Communications Act of 1934 (the law that created the FCC), prohibits the FCC from permitting unlicensed operation of any kind. The FCC maintains that the Section only applies to signals that can be detected across state lines (interstate "commerce"). The ARRL maintains it applies to all unlicensed operation. | |
rf_engineer
join:2003-08-04
USA
| Please quote where they have made that argument. Since you say they made it, it should be easy to find. I'll make it even easier for you by linking to relevant ARRL articles:
»www.arrl.org/news/stories/2007/0···00/?nc=1
»www.arrl.org/news/stories/2007/10/25/102/ | |
rf_engineer
join:2003-08-04
USA
| reply to PDXPLT
said by PDXPLT  :I've done that a few times here in the past. Perhaps you're referring to this post back in 2006:
»Re: not quite
You're wrong because you're leaving out text later in the paragraph:
"ARRL has urged that the Section 301 licensing requirement is, on its face absolute, and that unlicensed devices can be authorized only if it can be found that the operating parameters proposed for a given Part 15 device are such that the devices, individually and in the aggregate, will have no substantial interference potential to licensed radio services"
ARRL is clearly arguing that devices can be authorized under Part 15 only if they won't have significant interference potential to licensed services, not for abolishment of Part 15 devices as you have been claiming. | |
W1RFI
join:2003-05-12
Burlington, CT
| ARRL has worked cooperatively and productively with most of the unlicensed noise sources. The premise that it is against all Part 15 devices is inaccurate and not at all supported by the evidence at hand.
There is no doubt that locally, if Part 15 devices emit at the level of the Part 15 rules, local interference will result. To avoid interference, it is essential that any Part 15 device avoid the use of spectrum that is in operation near it. Unlicensed devices should not use spectrum that is in common use in residential neighborhood. This includes Amateur Radio, but it also includes broadcast television, cellular telephones and a number of other spectrum in which unlicensed devices should not have significant emissions. I would imagine that all who use cell phones would take the position that unlicensed devices should not use "their" band.
ARRL has taken the position that unlicensed devices should not intentionally generate signals at the FCC limits in the licensed Amateur bands. Part 15 rules control interference two ways: the rules set emissions limits that limit the geographical area over which interference is likely. The rules also require that if harmful interference occurs, the operator of the device must correct the interference.
ARRL's position has been that rules and levels should be sufficient to reduce the number of interference to a small-enough number of occurences that it is practical to address inteference that does happen on a case-by-case basis. See »www.google.com/search?hl=en&q=ar···basis%22.
That doesn't look like ARRL being opposed to all BPL to me. ARRL has also not sougth to change the rules for devices with a more reasonable interference potential than BPL. Many unlicensed devices, such as the computer I am using to type this message, generate radio noise. These devices have an interference footprint only near the premise in which they are installed. They are not on all the time. They do not emit on all frequencies. Although they occasionally do make noise in the Amateur bands, most do not cause harmful interference, and the few that do can be addressed on a case-by-case basis.
Contrast that to a device that operates on overhead power lines, with an interference footprint for long distances along that line, with a spectrum occupancy that is not just found on a few spot frequencies, but that fully fills large swaths of spectrum, operates continuously and may be built as big as an entire state. The premise that ARRL's using this as the worst example of why Part 15 should not regulate devices that have a significant potential for interference proves that ARRL is opposed to all Part 15 devices is ridiculous.
ARRL has worked with the BPL industry. It worked with HomePlug on in-premise BPL before access BPL was even a dream. Http://p1k.arrl.org/~ehare/bpl/HomePlug_ARRL.pdf. It worked with Motorola on BPL that was well designed to not cause interference to Amateur Radio. ARRL staff have presented at industry events and told the participants that with millions of HomePlug devices deployed, ARRL has no reports of interference to Amateur Radio involving HomePlug device. It worked with Current Technologies, with ARRL staff being quoted in ARRL and lay publications as saying that Current systems have deployed without major interference problems.
ARRL worked directly with DS2, a BPL chipset manufacturer, to help test its improvements to notching technology. ARRL staff have reported that in carefully installed systems, the notching was effective in addressing interference.
ARRL has worked with the Home Phone Networking Alliance and the VDSL industries to help it plan industry specifications that have been successful at preventing major interference problems. ARRL maintains contact with many industries to help prevent interference problems. It occupies seats on major IEEE and ANSI-accredited EMC standards committees, sometimes in positions of elected leadership.
Those that claim that ARRL is opposed to all unlicensed operation have simply not done enough research into what ARRL has done to work effectively, cooperatively and productively with the unlicensed emitter industry.
These models work. Avoiding locally used spectrum with sufficient filtering can and does avoid EMC problems. Good rules and industry standards are needed to reflect these successful models. The FCC did not do this industry any favors by giving it a poor set of rules. A good set of rules, such as was given to cable TV, will help this industry find its success.
I once asked on of the Board of Directors of the Society of Cable Telecommunications Engineers what success the cable industry would have had if the FCC had given it a set of rules as poor as the BPL rules. He replied that they would have 12 analog channels and they wouldn't work that well. He had just given a presentation on what the cable industry had to do to improve the cable system to make it sheilded well enough and noise-free enough to let it reliably carry broadband.
Ed Hare, W1RFI@arrl.org
Laboratory Manager
225 Main St
Newington, CT 06111
Tel: 860-594-0318 | |
|
