Hi, The only project I've heard of that implements such functionality is https://github.com/thuehn/Minstrel-Blues. On Thu, Jan 4, 2024 at 12:02 PM <b.K.il.h.u+tigbuh@xxxxxxxxx> wrote: > > Ideally, TPC should be a fully automatic mechanism that reduces > transmit power between the two points to as low of a level as possible > while delivering the same quality of service. The purpose is to reduce > the excess headroom in each link. I.e., if you could still link with > 65Mb/s towards a given direction using 14dBmW, you should not transmit > with 20dBmW. > > Some only set the AP TX power globally (i.e., same towards all of its > connected clients at the moment) to tackle the hidden/exposed node > problem, but again must do this adaptively and change this constantly > without human intervention. There exist multiple advanced algorithms > for this, some proprietary tuned for corporate deployment. > > Actually, if we accepted automatically retuning tx power with iw based > on actual link stats of momentarily connected clients every 60s with > cron, this could be added to OpenWrt pretty easily. > > > Class A devices control their transmit power within ±3 dB and class B devices control their power within ±9 dB. > > - https://www.litepoint.com/blog/wi-fi-6-ofdma/ > - https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_RRM_White_Paper/tpc.html > > On Thu, Jan 4, 2024 at 10:42 AM Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > > > On Thu, 2024-01-04 at 10:07 +0100, b.K.il.h.u+tigbuh@xxxxxxxxx wrote: > > > You can find a wording in most such regulations that if TPC is not > > > supported, the maximal TX power must be reduced by 3 dBmW. Hence in > > > all such cases, the entries in db.txt contain 3 less than the maximum. > > > > > > If, on the other hand, you know of a country that specifies that > > > devices lacking TPC may not use the band at all, all such band entries > > > must be omitted (commented out along with a URL). > > > > Yeah, that's how we (currently) handle things. > > > > I'm not even sure what the requirements would be for "TPC" to be > > implemented, tbh. > > > > > > As far as I know the kernel doesn't have facilities to support TPC or > > > > transmit power control, > > > > Right. I have, however, heard the interpretation that the fact that we > > have - even if nobody uses it - the "iw set txpower" command means that > > we *do* have TPC ... Not really sure what to make of that though. > > > > > > nor does the wireless-regdb database. > > > > Correct. With the new regdb format we could add something that would > > enable these ranges in the kernel only with some additional > > requirements, but > > (a) we don't implement that now, and > > (b) I don't know what the requirements would actually be, e.g. would > > it be enough that the driver promises it implements "TPC" in some > > way? Or even the manual setting? > > > > > > And so > > > > in the database we would either omit rules that require TPC, or include > > > > alternative rules (as specified by local regulations) not requiring TPC. > > > > Am I right? > > > > Right. > > > > johannes >
