On Fri, Mar 28, 2014 at 11:15:06AM +0100, Cedric VONCKEN wrote: > Hi all, > > I am currently using 802.11s for a project using openWrt mesh portals. > All mesh points use 802.11a (non HT) and minstrel. Airtime metric uses a > "rate" > which is ultimately computed using sta->last_tx_rate from minstrel. > > This last_tx_rate is also updated by minstrel attempts at lower and > higher speeds. Even if these occasional attempts are outnumbered by > frames at max_tp_rate[0], they cause unexpected airtime metric > variations resulting in unneeded mesh path changes. > My idea is to use max_tp_rate[0] (from minstrel) instead. This rate is > not subject to minstrel attempts and directly reflects the speed used > for the vast majority of the frames. Interesting -- I tried this exact thing once before, but got mixed results in my testing. Can you share your testing strategy? It's true that last_tx_rate is sub-optimal here, but I feel like using max_tp_rate directly is a layering violation. Many rate controllers won't have that concept, and some rate controllers will exist entirely in firmware. So I think perhaps fixing the concept of "last_tx_rate" or adding a new "best_tx_rate" field that excludes probes and such might be the way forward, rather than calling into the rate controllers. -- Bob Copeland %% www.bobcopeland.com -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
