On Thu, 21 Apr 2016 17:07:21 +0300, Seth Forshee wrote: > This is almost certainly because these frequencies require transmit > power control. We drop the TX power limits by half (i.e. 3 dB) when TPC > is required on account of not supporting TPC. I was under the impression that the underlying kernel infrastructure had support for TPC. What I am observing is that hostapd automatically includes the Power Constraint IE in beacons sent out on any channel with DFS enabled. The default transmit power reduction is 3dBm. This means that the TX power of any clients would be limited to 3dBm below the TX power of the AP even though it's not required. Would there be any merit in providing additional information regarding the TX power and the target average TX power reduction for the system when TPC is supported? > > WAS/RLANs 5150-5250 MHz > > 200 mW maximum mean e.i.r.p. > > 10 mW/MHz maximum spectral density of the mean e.i.r.p. > > If this range doesn't require TPC then it could be bumped up to 200 mW > (23 dBm). Yes, the CRC's list explicitly states that TPC is required in the 5250-5350 MHz and 5470-5725 MHz bands and there's no further comments on the 5150-5250 MHz band. EN 301 893 has the notes below for the 5150-5250 MHz band that could have lead to the 3 dBm drop though, maybe linked to the AUTO-BW flag? > NOTE 1: The applicable limit is 20 dBm, except for transmissions whose nominal > bandwidth falls completely within the band 5 150 MHz to 5 250 MHz, in which > case the applicable limit is 23 dBm. > > NOTE 2: The applicable limit is 7 dBm/MHz, except for transmissions whose > nominal bandwidth falls completely within the band 5 150 MHz to 5 250 MHz, in > which case the applicable limit is 10 dBm/MHz. I changed the TX power values to mW to be consistent with what is stated in the CRC's list. I'll resubmit the patch with the values in dBm and with the 3 dBm drop for the 5250-5350 MHz and 5470-5725 MHz bands. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 819 bytes Desc: OpenPGP Digital Signature URL: <http://lists.infradead.org/pipermail/wireless-regdb/attachments/20160421/278e92fa/attachment.sig>
