Date: Tue, 7 Jul 2015 15:54:18 -0500
From: Seth Forshee <seth.forshee@canonical.com>
To: Chen-Yu Tsai <wens@csie.org>
Cc: wireless-regdb@lists.infradead.org, linux-wireless@vger.kernel.org
Subject: Re: [PATCH] wireless-regdb: Update regulatory rules for Taiwan (TW)
Message-ID: <20150707205418.GC369@ubuntu-xps13> (sfid-20150707_225424_917224_CDCF3780)
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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@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.

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.

Thanks,
Seth