Hey, On Fri, May 10, 2013 at 02:12:00AM -0700, Adrian Chadd wrote: > On 10 May 2013 00:26, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > On Thu, 2013-05-09 at 20:10 +0200, a@pandem0nium wrote: > > > >> Comments: > >> * Is there any special requirement for handling beacons? For example, > >> rates are halfed or quartered, but some rates could not be represented > >> in the rate IEs. For example, 2.25 mbit/s can not be represented as > >> multiple of 500 kbps. > >> * therefore, all rates are handled like the corresponding 20 MHz > >> rates > >> internally, which makes a lot of things easier (no changes required > >> for rc-algos, beacon creation, etc...). We might consider adjusting > >> the > >> output of rates for nl80211 or radiotap, though. > > > > This seems completely wrong, since Clause 18 says: > > > > The OFDM system also provides a “half-clocked” operation using > > 10 MHz channel spacings with data communications capabilities of > > 3, 4.5, 6, 9, 12, 18, 24, and 27 Mb/s. The support of > > transmitting and receiving at data rates of 3, 6, and 12 Mb/s is > > mandatory when using 10 MHz channel spacing. The half-clocked > > operation doubles symbol times and clear channel assessment > > (CCA) times when using 10 MHz channel spacing. The regulatory > > requirements and information regarding use of this OFDM PHY are > > in Annex D and Annex E. > > > > IOW, it treats the rates as actually the rate they should be. Besides, > > what's so hard about rounding up? (8.4.2.4) > > > > and bits 6 to 0 are set to the data rate, if necessary rounded > > up to the next 500kb/s, in units of 500 kb/s. > > > > > > I also think you really need to handle this. If you just want a hack for > > 5/10 MHz, you can put it into drivers' debugfs, if not, then it should > > be done properly :-) > > I think net80211 from FreeBSD and madwifi do this. Ie, they advertise > the half and quarter rate speeds as their real speeds at half/quarter > rate. Ah, OK. > > If anything, interoperability would be nice. Yes interoperability would be nice of course - I'll re-work the patchset to use the according half and quarter rates. Meanwhile, what do you guys think about enabling HT too? Cheers, Simon > > > > > Adrian
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