Broadcasting in Multi-Channel Wireless Infrastructure Networks Employing Directional Antenna

Multi-channel wireless networks are increasingly being employed as infrastructure networks in metro areas. In addition, nodes in these networks employ directional antennas to improve spatial throughput. In such networks, we consider the problem of finding a broadcast tree from a given root with channel assignment such that all the links in the broadcast tree can be active simultaneously without interfering with each other. We prove that finding such a tree is an NP-hard problem. Hence, we formulate the problem as an integer linear program (ILP) and develop heuristics to find the broadcast tree with channel assignment. We evaluate and compare the performances of the developed heuristics with respect to their success rate, average depth of the obtained tree, and average path length from root to a node in the network.