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

[Chen-Yu Tsai]

On Wed, Jul 8, 2015 at 4:54 AM, Seth Forshee <seth.forshee at canonical.com> wrote:
> On Tue, Jul 07, 2015 at 04:07:15PM +0800, Chen-Yu Tsai wrote:
>> Taiwan's Ministry of Transportation and Communications revised its
>> frequency allocation rules [1], specifically opening up 5.15 GHz ~
>> 5.25 GHz and 5.6 GHz ~ 5.65 GHz for U-NII applications, as well as
>> explicitly mentioning U-NII applications and DFS requirements for
>> the related frequency ranges.
>>
>> LP0002 [2], the technical standard for low power radio devices, hasn't
>> been updated,though work is under way. The NCC, Taiwan's equivalent of
>> the US FCC, has explicitly [3][4] allowed certification under the newest
>> FCC Part 15E limitations, though unwanted emissions must still conform
>> to LP0002 sections 2.7 ~ 2.8:
>>
>>   - 5150 MHz ~ 5250 MHz is not restricted to indoor usage.
>>
>>   - 5250 MHz ~ 5350 MHz and 5470 MHz ~ 5725 MHz devices should have DFS
>>     capabilities, and conform to latest FCC radar standards.
>>
>>   - 5250 MHz ~ 5350 MHz without DFS capabilities are limited to indoor
>>     usage, under current LP0002 restrictions.
>>
>> In addition, large channels across multiple U-NII bands are allowed
>> under the same rules as FCC KDB 644545 [5].
>>
>> This patch updates the regulatory rules for Taiwan (TW) to reflect the
>> changes noted above, and corrects transmit power limits for 5470 MHz ~
>> 5725 MHz. In addition, the format of the rules has been modified:
>>
>>   - List band boundaries, instead of channel boundaries, and add AUTO-BW
>>     for adjacent bands.
>>
>>   - List maximum transmit power using mW instead of dBm. This is easier
>>     to find from the related documents.
>>
>> [1] http://www.motc.gov.tw/websitedowndoc?file=post/201411171137330.doc&filedisplay=Table+of+radio+frequency+allocation.doc
>> [2] http://www.ncc.gov.tw/english/show_file.aspx?table_name=news&file_sn=681
>> [3] http://www.rheintech.com/our-blog/item/585-taiwan-ncc-opens-5150-5250-mhz-for-wireless-devices
>> [4] Proposal #10312260 (p.6, Chinese),
>>     http://www.etc.org.tw/_library/K00/%E9%9B%BB%E4%BF%A1%E7%B5%82%E7%AB%AF%E8%A8%AD%E5%82%99%E5%AF%A9%E9%A9%97/1031223_nccqa56.pdf
>> [5] Proposal #10202205 (p.3, Chinese),
>>     http://www.etc.org.tw/_library/K00/%E4%BD%8E%E5%8A%9F%E7%8E%87%E8%A8%AD%E5%82%99%E5%AF%A9%E9%A9%97/1020221_nccqa50.pdf
>>
>> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
>> ---
>>
>> Hi everyone,
>>
>> First of all, I am _not_ a regulatory or wireless expert, nor is my
>> field of work related, unless you count deploying access points as
>> related.
>>
>> Last week I bought and deployed a new "Tri-band" 802.11ac wireless
>> router, and it was using channels 36~44, which previously was not
>> available in Taiwan. After asking around, a friend at the vendor
>> said that Taiwan recently opened up that part of the spectrum.
>>
>> Unfortunately, [4][5] are Q&As transcripts with the regulatory body.
>> I cound only find them in Chinese. Suffice to say, Taiwan's NCC
>> follows the FCC closely whenever possible when it comes to wireless
>> stuff.
>>
>> As such, I also looked at the US rules. It seems they are using
>> "peak power spectral density" instead of "peak power output".
>> I believe this is wrong. My crude understanding is the former
>> is the amount of power in a single chunk of the complete channel,
>> while the latter is the actual power put out by the transmitter.
>> The former would be used to enforce a more uniform power distribution
>> over the wireless channel, while the later actually limits transmission
>> power, and thus range.
>
> I certainly don't qualify as a regulatory expert either. But the rules
> you're proposing to change came from Qualcomm Atheros, and I do have
> considerable confidence in their regualtory expertise. Therefore I'd
> want an ack from QCA before I'd consider applying this patch.

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 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.

Regards
ChenYu