'Institute of Electrical and Electronics Engineers (IEEE)'
Abstract
We propose a powerful MAC/PHY cross-layer approach
to measuring IEEE 802.11 transmission opportunities in
WLAN networks on a per-link basis. Our estimator can operate
at a single station and it is able to: 1) classify losses caused by
noise, collisions, and hidden nodes; and 2) distinguish between
these losses and the unfairness caused by both exposed nodes and
channel capture. Our estimator provides quantitative measures of
the different causes of lost transmission opportunities, requiring
only local measures at the 802.11 transmitter and no modification
to the 802.11 protocol or in other stations. Our approach is suited
to implementation on commodity hardware, and we demonstrate
our prototype implementation via experimental assessments. We
finally show how our estimator can help the WLAN station to
improve its local performance
