| Abstract | We define efficient algorithms for channel management (channelassignment and load balancing among APs) in 802.11-based WLANs
that lead to better usage of the wireless spectrum. These algorithms
(called CFAssign) are based on a “conflict-free set coloring” for-
mulation that jointly perform load balancing along with channel
assignment. Such a formulation has a number of advantages. First,
it explicitly captures interference effects at clients. Next, it intrinsi-
cally exposes opportunities for better channel re-use. Finally, algo-
rithms based on this formulation do not depend on specific physical
RF models and hence can be applied efficiently to a wide-range of
in-building as well as outdoor scenarios.
We have performed extensive packet-level simulations and mea-
surements on a deployed wireless testbed of 70 APs to validate
the performance of our proposed algorithms. We show that in ad-
dition to single network scenarios, CFAssign algorithms are well
suited for channel assignment in scenarios where multiple wireless
networks share the same physical space and contend for the same
frequency spectrum. Our results over a wide range of scenarios
indicate that CFAssign reduces the interference at clients by about
50-70% in comparison to current best-known techniques.
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