Re: WLAN Regulatory Domain Germany

[Kurt Garloff <garloff@suse.de>]

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Johannes,

On Mon, May 24, 2010 at 10:37:26AM +0200, Johannes Berg wrote:
> > 8<------------------------------------------------------------------------
> > 
> > # Data from "Frequenznutzungsplan" (as published in April 2008), downloaded from 
> > # http://www.bundesnetzagentur.de/cae/servlet/contentblob/38448/publicationFile/2659/Frequenznutzungsplan2008_Id17448pdf.pdf
> > # For the 5GHz range also see 
> > # http://www.bundesnetzagentur.de/cae/servlet/contentblob/38216/publicationFile/6579/WLAN5GHzVfg7_2010_28042010pdf.pdf
> > # The values have been reduced by a factor of 2 (3db) for non TPC devcies
> > # (in other words: devices with TPC can use twice the tx power of this table).
> > 
> > country DE:
> > 	# entries 279004 and 280006
> > 	(2400 - 2483.5 @ 40), (N/A, 100 mW)
> > 	# entry 303005
> > 	(5150 - 5250 @ 40), (N/A, 100 mW), NO-OUTDOOR
> > 	# entries 304002 and 305002
> > 	(5250 - 5350 @ 40), (N/A, 100 mW), NO-OUTDOOR, DFS
> > 	# entries 308002, 309001 and 310003
> > 	(5470 - 5725 @ 40), (N/A, 500 mW), DFS
> 
> I haven't verified the entries in the Frequenznutzungsplan itself, but
> according to the second document this seems fine. I think there ought to
> be a comment in the db.txt file indicating the rationale for using 100mW
> rather than 200mW.
                                                                                              
OK, new suggestion.

8<------------------------------------------------------------------------                    

# Data from "Frequenznutzungsplan" (as published in April 2008), downloaded from
# http://www.bundesnetzagentur.de/cae/servlet/contentblob/38448/publicationFile/2659/Frequenznutzungsplan2008_Id17448pdf.pdf
# For the 5GHz range also see
# http://www.bundesnetzagentur.de/cae/servlet/contentblob/38216/publicationFile/6579/WLAN5GHzVfg7_2010_28042010pdf.pdf
# The values have been reduced by a factor of 2 (3db) for non TPC devices
# (in other words: devices with TPC can use twice the tx power of this table).
# Note that the docs do not require TPC for 5150--5250; the reduction to
# 100mW thus is not strictly required -- however the conservative 100mW
# limit is used here as the non-interference with radar and satellite
# apps relies on the attenuation by the building walls only in the
# absence of DFS; the neighbour countries have 100mW limit here as well.

country DE:
	# entries 279004 and 280006
       (2400 - 2483.5 @ 40), (N/A, 100 mW)
       # entry 303005
       (5150 - 5250 @ 40), (N/A, 100 mW), NO-OUTDOOR
       # entries 304002 and 305002
       (5250 - 5350 @ 40), (N/A, 100 mW), NO-OUTDOOR, DFS
       # entries 308002, 309001 and 310003
       (5470 - 5725 @ 40), (N/A, 500 mW), DFS

8<------------------------------------------------------------------------

Can we actually put several entries covering the same frequency range?
Then we could put 200mW for DFS and 100mW for non-DFS.
This would also address the next issue you raise ...

> Also note that there are different requirements depending on the channel
> bandwidth, which will eventually come up in Linux too. But I think for
> that we need the new database format for that ... yet another thing to
> do before we can support 5/10 MHz channels.

Indeed. For 5150 -- 5350, the spectral power density may not exceed
10mW/MHz (and overall emitted power in the range per device not 200mW);
this gives a limit of 200mW for 20MHz channels or 100mW if no TPC is 
used for 5250 -- 5350. (For 5470--5725 use 5x those values.)
I'm not aware of WLAN devices with narrower channels yet, but if they 
come into existence, we'd have to reflect it somehow ...

Best,
-- 
Kurt Garloff, VP OPS Partner Engineering -- Novell Inc.

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