Channel assignment scheme for virtual hierarchical wireless mesh networks

To gain high user diversity and routing stability in wireless mesh network, a virtual hierarchical structure was proposed, in which the nearby nodes were aggregated to virtual cells. Nodes inside the virtual cell can communicate with each other and take the identical traffic relay functions. The bottom-level virtual hierarchical architecture is formed by node's direct connection inside each virtual cell, while the top-level virtual hierarchical architecture is consisted of virtual cells taking in routing functions. A generalized set T-coloring model, a kind of graph coloring model, was devised for the channel assignment algorithm of this virtual hierarchical architecture. Based on virtual cells, the radio frequency interference was introduced as the optimized indicator so as to reduce wireless channel interference and maximize the channel's utilization while maintaining network connectivity. The cell splitting strategy was utilized to improve the network capacity and the fairness of the channel assignment scheme. The validity of the proposed scheme is proven by the simulation result.