CVSROOT: /cvs
Module name: src
Changes by: s...@cvs.openbsd.org 2020/03/30 13:10:42
Modified files:
sys/net80211 : ieee80211_mira.c
Log message:
Don't let MiRA trigger event-based probing if the current measurement
equals the average measurement, i.e. if the standard deviation is zero.
Change comparisons of current measurement to the average measurement
from >= to > in the "channel becomes good" check, and from <= to < in
the "channel becomes bad" check.
The paper's equations are written with <= and >= and thus so was our
implementation. But checking for equality makes no sense in the context
of event-triggered probing: The intention is to react to changes in
channel quality, which occur for instance when a laptop moves around
or when RF noise comes and goes. When the current measurement and the
average measurement are equal, this means channel quality has not
changed at all and starting to probe for a new rate is not necessary.
We should probably even add a margin to avoid triggering probing
based on small fluctuations, but this can be done later.
ok tb@
