Hi, I have this strange behaviour down below, for which I also opened a ticket because I think this should not be like that ;)
Does anyone have an idea where the problem could originate from and how to fix it? Thanks Nico On 07/29/2015 12:37 AM, OpenWrt wrote: > #20222: 2.4Ghz limited to 50mW in DFS-ETSI > ----------------------+---------------------------------- > Reporter: nicoduck | Owner: developers > Type: defect | Status: new > Priority: normal | Milestone: Chaos Calmer (trunk) > Component: kernel | Version: Trunk > Keywords: wndr3800 | > ----------------------+---------------------------------- > I have got a Netgear WNDR 3800 running with openwrt since quite a while. > I now upgraded to the latest version (trunk) and wanted to use WLAN within > the regulations here in Germany but also wanted to max out the output > power (within the regulations). > Switching the country to Germany limits the maximum output power to 17dBm, > although it does show as being limited on 20dBm: > root@OpenWrt:/# iwinfo wlan0 txpower > 0 dBm ( 1 mW) > 1 dBm ( 1 mW) > 2 dBm ( 1 mW) > 3 dBm ( 1 mW) > 4 dBm ( 2 mW) > 5 dBm ( 3 mW) > 6 dBm ( 3 mW) > 7 dBm ( 5 mW) > 8 dBm ( 6 mW) > 9 dBm ( 7 mW) > 10 dBm ( 10 mW) > 11 dBm ( 12 mW) > 12 dBm ( 15 mW) > 13 dBm ( 19 mW) > 14 dBm ( 25 mW) > 15 dBm ( 31 mW) > 16 dBm ( 39 mW) > * 17 dBm ( 50 mW) > 18 dBm ( 63 mW) > 19 dBm ( 79 mW) > 20 dBm ( 100 mW) > > What I did: reset the device, flash it with various builts from trunk and > try to figure out what was going on. > I now modified my regdb and was able to isolate the source of the problem: > country DE: DFS-ETSI > # entries 279004 and 280006 > (2400 - 2483.5 @ 40), (100 mW) > # entry 303005 > (5150 - 5250 @ 80), (200 mW), NO-OUTDOOR, AUTO-BW > # entries 304002 and 305002 > (5250 - 5350 @ 80), (100 mW), NO-OUTDOOR, DFS, AUTO-BW > # entries 308002, 309001 and 310003 > (5470 - 5725 @ 160), (500 mW), DFS > # 60 gHz band channels 1-4, ref: Etsi En 302 567 > (57000 - 66000 @ 2160), (40) > Thas does not work and has the mentioned behaviour, 2.4Ghz is limited at > 17dBm. It also does not depend on which values are set in the regulatory > database for the 2.4Ghz channels, anything over 17dBm will be limited to > 17dBm. > running "iw phy phy0 set txpower fixed 2000" gives no error but does not > change it to 20dBm. Changing the value to anything below 17dBm works > though. > > country DE: DFS-FCC > # entries 279004 and 280006 > (2400 - 2483.5 @ 40), (100 mW) > # entry 303005 > (5150 - 5250 @ 80), (200 mW), NO-OUTDOOR, AUTO-BW > # entries 304002 and 305002 > (5250 - 5350 @ 80), (100 mW), NO-OUTDOOR, DFS, AUTO-BW > # entries 308002, 309001 and 310003 > (5470 - 5725 @ 160), (500 mW), DFS > # 60 gHz band channels 1-4, ref: Etsi En 302 567 > (57000 - 66000 @ 2160), (40) > > Thad does work. The only change to the entry above is "DFS-FCC" instead of > "DFS-ETSI". I can now select any powerlevel between 1 and 20dBm and it is > also reported as being used: > root@OpenWrt:/# iwinfo wlan0 txpower > 0 dBm ( 1 mW) > 1 dBm ( 1 mW) > 2 dBm ( 1 mW) > 3 dBm ( 1 mW) > 4 dBm ( 2 mW) > 5 dBm ( 3 mW) > 6 dBm ( 3 mW) > 7 dBm ( 5 mW) > 8 dBm ( 6 mW) > 9 dBm ( 7 mW) > 10 dBm ( 10 mW) > 11 dBm ( 12 mW) > 12 dBm ( 15 mW) > 13 dBm ( 19 mW) > 14 dBm ( 25 mW) > 15 dBm ( 31 mW) > 16 dBm ( 39 mW) > 17 dBm ( 50 mW) > 18 dBm ( 63 mW) > 19 dBm ( 79 mW) > * 20 dBm ( 100 mW) > > > I have no idea why but there seems to be a bug in the code parsing the DFS > regulations, limiting 2.4Ghz to lot lower values than allowed. Changing it > to DFS-FCC works for using the applicaple output power but does not seem > to be in compliance which German law. > > Do you have an idea where the problem could be? I'm happy to try out more > builds and future versions. > > Also (kind of off-topic): Do you know why 5Ghz channels 36-48 are forced > to be 17dBm only on the WNDR3800? I found two possible explanations: > either because of the factory calibration (is it possible to get them in a > human readable form somehow? The hexdump is not really readable and I have > not been able to find the code which pases them) or because these channels > are considered as "edge-channels" and someone thought it would be safe to > limit the power, to not disturb any other systems running on even lower > channels. The latter explanation is kind of weird because it would make no > sense to limit these 4 channels but no other ones. I find it especially > strange because that is typically the job of regulatory authorities, to > define those power levels. > > -- > Ticket URL: <https://dev.openwrt.org/ticket/20222> > OpenWrt <http://openwrt.org> > Opensource Wireless Router Technology > _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
