Establishing and initially configuring a Free Space Optical (FSO) backbone is a challenging problem, especially when nodes only have local connectivity information and a limited number of transceivers. The problem of configuring an initial connected topology or bootstrapping a directional FSO network can be formulated as a Minimum Degree Spanning Tree (MDST) problem, which is known to be NP-Complete. Recently, we developed a distributed approximation algorithm, which constructs a spanning tree with maximal node degree at most one larger than that in the optimal solution [1]. In such a distributed approach, nodes need to coordinate their local decisions to collectively set up a connected topology. For that purpose, algorithms and protocols for local information exchange/dissemination and synchronization are required. This paper presents the design, implementation and evaluation of a complete bootstrapping process model for FSO networks. Our model integrates the algorithm presented in [1] with the required communication and synchronization mechanisms to guarantee the efficient emergence of overall network connectivity from local interactions between individual nodes. Time performance results for the overall bootstrapping process are presented. Our scheme allows the network to form a connected topology whenever one exists and shows linear time complexity.

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