Cognitive wireless mesh networks: A connectivity preserving and interference minimizing channel assignment scheme

Recent studies show that most of the licensed bands are under-utilized at certain time and location. The emergence of cognitive radio made it possible for nodes to use licensed channels, as well as unlicensed ones for data transmission provided that there is no licensed user active simultaneously. This leads to a new challenge, where nodes need efficient mechanisms to sense the spectrum bands and identify the spectrum holes. Based on this information, nodes will pick the best channel among all available channels, while maintaining the priority of licensed users and minimizing the network interference at the same time. By formulating the problem as an integer linear programming (ILP) problem, we try to minimize the network interference in different scenarios, assuming nodes are equipped with cognitive radios and they are able to use licensed bands when appropriate.