Topology formation for tactical networks with directional RF and free-space optical links

This work addresses the graph theoretical under-pinning of forming a topology during the deployment of directional RF or free space optical (FSO) based tactical networks. The objective is to construct a topology that not only has a good reliability, but also supports the maximal delivery of traffic. Given the fact that each node has a limited number of transceivers, the design problem falls into the category of (node) degree-constrained topology optimization problem, for which an exhaustive search or integer programming approach becomes prohibitive for larger networks. As such, we focus on first developing a design guideline based on theoretic analysis and then proposing algorithms. The algorithms consist of two components. The first component involves forming a minimum spanning tree (MST) or traveling salesman path (TSP) to guarantee a networkpsilas connectivity. The second component involves iteratively connecting node pairs based on an updated criterion, which takes into considerations of traffic, hop distance, link bandwidth, and network load. Extensive tests demonstrate that the proposed algorithms produce optimal or close-to-optimal solutions. Compared with existing approaches, the proposed algorithms outperform in traffic delivery; while they have similar performance in network reliability.