Before revision: Recently, it has been shown that CSMA-type random access algorithms are throughput optimal since they achieve the maximum throughput while maintaining the network stability. However, the optimality is established with the following unrealistic assumptions; i-) the underlaying Markov chain reaches a stationary distribution immediately, which causes large delay in practice; ii-) the channel is static and does not change over time .
After revision: It has been known that load unaware channel selection in 802.11 networks results in high level interference, and can significantly reduce the network throughput. In current implementation, the only way to determine the traffic load on a channel is to measure that channel for a certain duration of time. Therefore, in order to find the best channel with the minimum load all channels have to be measured, which is costly and can cause unacceptable communication interruptions between the AP and the stations .