Hello, Sorry for my late reply. On the Czech regulatory's website, they have a page deliberately speaking about usage of 5.725-5.850GHz frequencies. "V oblasti 5 GHz je možný provoz podle VO-R/12/08.2005-34 a VO-R/10/03.2007-4 v pásmu 5,15–5,35 GHz (pouze uvnitř budov), v pásmu 5,470–5,725 GHz (standard IEEE 802.11a) a s malým výkonem (25 mW e.i.r.p.) též v pásmu 5,725–5,875 GHz.". The last part means "with small output power (25mW e.i.r.p.) also in the 5,725–5,875 GHz frequency range." On the VO-R/10/03.2007-4 they also state that those frequencies are ISM, but maximum allowed e.i.r.p. is 25mW. I don't know if tthis is compliant with EN301 893 or other EU laws. So for now we should let those dubious frequencies off the table. Also, let's do not penalize ourselves by 3dB, I've noted that, for other EU countries, the power limit is the highest allowed (Thanks Luis for explaining what "TPC compliant" means). I'm sending the patch in the next e-mail. Carlos > ------------ Původní zpráva ------------ > Od: Michael Green <Michael.Green@xxxxxxxxxxx> > Předmět: RE: wireless-regdb: Update regulatory rules for Czech Republic (CZ) on > 5GHz > Datum: 04.12.2008 22:27:26 > ---------------------------------------- > Thanks Luis, > > The VO_R_10_03_2007_4.pdf shows 5.725-5.850 (and also 2.4-2.483) under SRD rules > (Short range device) like for wireless microphones, radio control toys and > similar. That's why the tx limit is 25mW EIRP. You will see similar in many > other European and global frequency tables. This is not used for WLAN > operation. Some non-European countries do have ISM band (5.725-5.850) included > in their frequency table. Although not specifically for WLAN use, we do in those > cases enable this upper band for possible use by APs, since the power limits are > usually 1W or more. But trust me, for Europe in this band, we should not enable > this band for any 802.11 product type. This is already reflected in the CRDA > tables for all the countries. So nothing new here. > > > The VO_R_12_08_2005_34.pdf doc clearly shows the WLAN rules in the table that > you referred. These match up to the usual rules frequency table published by > other EU countries and the limits follow the EN301 893 spec. It's all good. > The channel settings for this country should be same as used for all the other > European countries (i.e. 5.15-5.35 & 5.47-5.725 with DFS/TPC). > > The tx power levels are worth discussing more. Even though the European > countries are harmonized on EN301 893 which enforces 200mW EIRP in 5.15-5.35 and > 1W EIRP in 5.470-5.725, vendors must not blindly set new hardware to transmit at > these upper limits. > > Each board design must undergo conformance testing to the applicable RF > conformance spec (in this case 301 893) at which time the vendor will discover > that various other tests in the conformance spec will limit the achievable > compliant tx power for that design and it's associated antennas (i.e. power > spectral density, spurious emissions, etc. So using 200mW and 1W EIRP in code > may be fine as an upper limit, fail safe, users of the code / hardware > developers must be educated to ensure awareness that there is no universal > "compliant tx power" that you can assign for a country that applies to all the > different hardware out there. > > Michael Green > Atheros Communications, Inc. > mgreen@xxxxxxxxxxx > Desk: +1-781-400-1491 > Mobile: +1-508-380-4921 > > -----Original Message----- > From: Luis R. Rodriguez [mailto:mcgrof@xxxxxxxxx] > Sent: Thursday, December 04, 2008 3:52 PM > To: Michael Green > Cc: Johannes Berg; John W. Linville; Carlos Laué > Subject: Re: wireless-regdb: Update regulatory rules for Czech Republic (CZ) on > 5GHz > > On Thu, Dec 4, 2008 at 12:42 PM, Michael Green <Michael.Green@xxxxxxxxxxx> > wrote: > > > > Thanks, > > > > a) Can someone pls email me the pdf's. I had no success trying to retrieve > from the regulator's site. > > > > b) I am glad to give opinion once I read the original docs. But for now, some > initial thoughts... > > > > By "automatic output power regulation" I believe you refer to what the > standards call TPC (transmit power control). For European and most other > regions that include TPC in their rules, it is now basically a hand waving at > enforcing a true TPC feature. For Europe compliance any vendor who shows in the > lab that the client device is capable of being set to lower tx levels (even > manually be end user), then device is considered compliant, even though, the > shipping product may never actually be set as such by end user. So in effect, > no one really penalizes themselves the 3dB when testing against the tx power > limit in the European specs. > > > > And use of 5.725-5.850 by 802.11 devices for Czech Rep. sounds dubious to me. > So I look forward to seeing the docs. > > > > So please let me read the Czech spec you mention and I can compare against the > EN301 893 which is the true pan-European conformance spec which is generally the > target we use for compliance in 5GHz. Thanks for your patience. > > Michael, I've downloaded and attached them to this e-mail. They are in CZ though > so they are all jiberish to me. I'm also CC'ing the person who sent the patch, > as this conversation would probably be more productive with him involved. > > Luis > > > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
