On Thu, Sep 14, 2017 at 04:49:42PM +0200, Andreas Mohr wrote: > Dear Sir / Madam, > > we have initiated a WiFi SAR/RF testing/certification effort of our current device > (handheld, TI WL1271 WLAN/Bluetooth BLE module, current Linux distribution: Ubuntu 12.04 LTS, to be modernized). > > During our activities with Korean KC certification body, the following request has been made (T?V Korea): > > Mail 2016-06-14: > " > Please keep the power limit of less than 20mW as sent in our previous e-mail (if not fulfilled, the test will be failed). > <red>Please do not send out samples before it complies to the requirement.</red> > " > > 20mW equals 13dBm. > > We already successfully applied a modified signed regulatory.bin to have (and thus use) the reduced limit, > however obviously we'd strongly prefer to have an official upstream release binary which: > - where not up-to-date (e.g. older distribution base) can be custom-applied > - where already up-to-date vs. upstream implicitly does have/receive all necessary future updates > - is signed with official wireless-regdb / distro keys > > We then asked for a paper trail (specs document, black-and-white dead-tree notice etc.) > in order to file a thoroughly/legitimately claimed request for conformance update of wireless-regdb > (simply due to properly knowing the root cause / explanation for this request! > Details on why this limit has been imposed, when it got required, which modulation types it applies to, ...), > however that turned out to be difficult. > We ultimately succeeded in receiving the proper reference (Korean document, available upon request) > which lists the 20mW requirement. > > Also, a prior Internet search for > "dBm site:rra.go.kr" had resulted in > https://www.rra.go.kr/FileDownSvl?file_type=research2&file_parentseq=1044&file_seq=1 > (4.??????????????????????.pdf , a nice UTF-8 mis-transcoding of originally Korean cp949 4.???.pdf 4.[uCCB4 uD638 uCC45].pdf) > which appears to list device measurements, and where notably > many 802.11g values of various company device models appear to be restricted to the 13dBm (i.e., 20mW) area. > > > Due to other delays, this issue has not been pursued here (sorry!). > Unfortunately it looks like > wireless-regdb HEAD (9b3317bd4) does not yet have any change which would fulfill this certification requirement. > > Thus, I am now proposing (RFC) the following minimum (potentially extended/documented) update. > I decided to restrict the limitation to 2.4GHz area only since > the current certification effort (and thus the limit request) is about 2.4GHz. I can't read the document you reference above, and my own searches don't seem to turn up anything authoritative. I consider the source of the original 20 dBm limit reliable, but it was added in 2013 so it's possible things have changed since then. I'll give a few days for any other comments, and if there are none I will apply the change. Thanks, Seth > Thank you! > > Yours sincerely > > Andreas Mohr > > > From 0added12024197148e87633c28959334795cbd02 Mon Sep 17 00:00:00 2001 > From: Andreas Mohr <andim2 at users.sf.net> > Date: Wed, 13 Sep 2017 11:51:54 +0200 > Subject: [PATCH] wireless-regdb: reduce power level limit of KR (Korea) > 802.11b/g/n to the certification-requested "20mW" (13dBm). > > Signed-off-by: Andreas Mohr <andim2 at users.sf.net> > --- > db.txt | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/db.txt b/db.txt > index e48f9a6..97b22b0 100644 > --- a/db.txt > +++ b/db.txt > @@ -668,7 +668,7 @@ country KP: DFS-JP > (5735 - 5815 @ 20), (30) > > country KR: DFS-JP > - (2402 - 2482 @ 40), (20) > + (2402 - 2482 @ 40), (13) > (5170 - 5250 @ 80), (20), AUTO-BW > (5250 - 5330 @ 80), (20), DFS, AUTO-BW > (5490 - 5710 @ 160), (30), DFS > -- > 2.9.5 >
