[wireless-regdb] [PATCH] wireless-regdb: Update regulatory rules for Taiwan (TW)

[Chen-Yu Tsai]

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