**2. Related work**

There exist a large number of studies which address the channel assignment problem in wireless mesh networks. Several works have proposed MAC protocols for utilizing multiple channels (So & Vaidya, 2004, Gong & Midkiff, 2005), but these multi-channel protocols require changes to existing standards and therefore cannot be deployed by using existing hardware. In (Adya et al., 2004) was proposed a link-layer solution for transmitting data over multiple radio interfaces, but this approach is designed for scenario where the number of radio interfaces is equal to the number of channels. In (Gupta & Kumar, 2000) the performance of multi-channel ad-hoc networks was studied, where each channel was assigned to an interface. In (Draves et al., 2004) several methods for increasing the performance in single-channel per interface were proposed. The most studies is focused only to one problem to find the efficient channel assignment method, but did not suggest the optimal number of radio interfaces per node. In (Husnain et al., 2004) were compared different static centralized algorithms, but for evaluation of optimal number of radio interfaces was used only one parameter - total interference (number of links in conflict graph). (Raniwala et al., 2004) proposed centralized channel assignment and routing method, where results about number of radio interfaces were shown but only for network cross-section goodput. In (Chi Moon Oh et al., 2008) the study of optimal number of radio interfaces was created but only for grid network, using simple channel assignment method and for one QoS parameter (throughput).
