Wireless LAN using IEEE 802.11 networks are now widely deployed at
home by residential users or in hot spots by telecommunication
operators. A hot spot is a place where a set of access points (APs)
are located nearby each other and can serve many users. Since
perturbations can degrade the quality of the signal, a careful
channel assignment to each AP has to be done. Channel assignment of
APs at hot spots, and more generally setup configuration and
management, is still often done manually. In this paper, we consider
a modeling that enables optimization of channel assignment with
respect to the dynamic behavior of end-users. We prove our problem's
formulation to correspond to the Minimum Interference Frequency
Assignment Problem, and hence the problem to be NP-hard. We propose
and compare three different tabu search methods to solve the
problem of channel assignment in 802.11 WLAN networks. The first
one, called TabuObj, tackles the problem using directly the
objective function associated with the model. The second one, called
TabuApproxObj, uses a simplified and approximate objective
function in order to visit more solutions during the same amount of
time, i.e. to be quicker than TabuObj. The third one, called
TabuLevel, is even more quicker and is based on the following
philosophy: under time constraints, it could be judicious to explore
very quickly lots of solutions, rather than spending much
computation time for the evaluation of each solution, and hence only
considering a few solutions. Those three methods are then compared
based on time constraints and on the quality of their solutions.