On Mon, Jun 11, 2018 at 12:27:48PM -0700, Ben Greear wrote: > On 06/11/2018 11:51 AM, Jouni Malinen wrote: > >This is not about center frequency, but about matching primary > >channels. Switching pri/sec channels does not really change the > >frequency range. I'd assume it would be possible for the AP interface to > >go through channel switch when the STA interface needs to move (or > >connect initially), but sure, it may be simpler to hardcode channels and > >pri/sec assignment. That last part, though, is likely to be > >non-compliant with the standard requirements for co-existence.. > > As far as I can tell, if a radio uses HT40- for an STA, it cannot simultaneously > run HT40+ in AP mode on the same radio. That sounds quite likely for many radio designs. > In case you must connect an STA to an AP, that STA will negotiate a proper > center freq and primary channel. If you then want to start an AP vdev on the same > radio, you must force it to not do pri/sec switch in order to have it reliably > work. Sure, no issues here; there's obviously an existing AP with the specific pri/sec selection in radio range, so the co-existence rules allow the local AP to be started with same parameters. This should not need any additional changes. > Another use case we have for test equipment: If you want to run one vdev in > HT20 mode and another in HT40 or HT80, then you must force the hostapds to all > use the same primary channel as the HT20 AP or it will fail to work. For test tools, it may be acceptable to be non-compliant with the standard. > I don't know enough about mesh or Peter's use to usefully comment more on > this, but it sounds a lot like the issue I had with STA + AP. I think you could, > for instance, run MESH on one vdev and an AP on another in the same radio > and end up with similar issues to what I had with STA + AP. The commit messages certainly so not seem to point to any extra constraints from virtual interfaces on the local device. What I really want to see here is the exact use case that is being addressed so that I can review whether it makes sense to provide exceptions to certain rules or whether there are better ways of solving the issue (e.g., that STA+AP example case using CSA on the AP). -- Jouni Malinen PGP id EFC895FA _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
