On Wed, Jul 22, 2015 at 3:56 PM, Chen-Yu Tsai <wens at csie.org> wrote: > On Wed, Jul 22, 2015 at 3:40 PM, Chen-Yu Tsai <wens at csie.org> wrote: >> On Thu, Jul 9, 2015 at 11:15 PM, Seth Forshee >> <seth.forshee at canonical.com> wrote: >>> On Wed, Jul 08, 2015 at 11:07:20AM +0800, Chen-Yu Tsai wrote: >>>> > Thanks. I think there should be a written document about what the >>>> > rules should be like, or what is expected: >>>> > >>>> > 1. WiFi channel boundaries or band boundaries >>>> > 2. peak output power or peak power spectral density >>>> > >>>> > In http://lists.infradead.org/pipermail/wireless-regdb/2015-July/000856.html >>>> > you mentioned the software is smart enough to work out how to combine >>>> > different bands and what channels to use, so I see no reason to explicitly >>>> > chop up contiguous spectrum, unless there are explicit rules forbidding >>>> > combined use of bands with different regulatory rules. AFAIK the FCC >>>> > only requires one to satisfy all rules when usage crosses band boundaries. >>>> > >>>> > http://lists.infradead.org/pipermail/wireless-regdb/2015-July/000857.html >>>> > also raises a similar question. >>> >>> I was really commenting about the transmit power updates in your patch. >>> I just compared the frequency changes to the documentation you linked to >>> and those do look okay to me. >> >> I see. >> >>>> >> I would however consider an update for 5.15-5.25 GHz and 5.6-5.65 GHz >>>> >> provided that there's official documentation to substantiate the change. >>>> >> I unfortunately cannot read Chinese, so I would need some assistance to >>>> >> confirm the documentation. >>>> > >>>> > I could possibly ask around, though I'm not optimistic. The "official" >>>> > documents are just transcripts from NCC hosted Q&A sessions regarding >>>> > the latest regulations. Proposals/questions are submitted by vendors, >>>> > and the NCC responds and puts together an aggregated transcript. >>>> >>>> Just got off the phone with the NCC. Their position is, spectrum allocation >>>> is not within their purview, but the Ministry of Transportation and >>>> Communications. As noted in the patch, they have already opened up the >>>> spectrum to U-NII and low power radio usage. What remains is that the >>>> NCC revise its testing standards. Until then, their position is that, >>>> since their testing standards are modeled after FCC standards, vendors >>>> can just test under FCC standards, then convert the reports into LP0002 >>>> format, and cite the FCC test report. >>>> >>>> There is no formal English version of the Q&A transcript, at least not >>>> until some foreign testing body requests it. The person in charge just >>>> asked me to translate it myself... >>> >>> If you send a patch which updates only the frequencies I would likely >>> apply that after allowing a week or so for others to either ack or nack >>> it (and running the stuff you linked to through google translate and >>> seeing if I could make any sense of the output). >> >> Got it. >> >>> I think the power updates are probably based on a misunderstanding, and >>> may not even be completely correct. For the most part after they've been >>> converted to EIRP (eirp = 10 * log10(mW)) they don't turn out to be >>> substantially different than what we have now. I think the value in >>> 5250-5350 MHz is probably incorrect however. Based on my quick skim of >>> the document you linked to it should be 50 mW rather than 250. 50 mW >>> also roughly matches to the 17 dBm which is in the database today, >>> whereas 250 mW is closer to 24 dBm. >> >> Yes. About the first part, it seems dbparse.py converts values in mW >> into EIRP anyway. However I don't think EIRT equals "peak power spectral >> density". > > Sorry, this part applies to the US rules, not part of this patch. I just realized that what I misunderstood as PSD was the fact that no one had updated the power limits of U-NII-1 for the US. I've added such a patch to my series. Sorry for the noise. >> About the second part, yes the current values match the ones in LP0002. >> However as I stated, the regulatory body has explicitly allowed certifying >> under the latest FCC rules, which effectively raises the limits from >> 50 mW to 250 mW. >> >>> My suggestion would be update the frequencies but not the existing >>> transmit power limits, unless you discover that any of the power limits >>> are definitely incorrect. >> >> I'll split up the patch into 3: >> >> 1. Add the new 5150 - 5250 frequency band, using current LP0002 >> limits if any, otherwise FCC limits. >> >> 2. Tweak frequency boundaries for the remaining bands to make >> them contiguous and properly reflect the regulations rather >> than the WiFi channel frequencies. >> >> 3. Update power limits and DFS requirements to latest FCC standards. >> >> Each patch will then explain why and how the regulations changed >> along with references, in English if available. >> >> You can then decide on whether to merge all three or just the first >> two. >> >> >> Regards >> ChenYu
