Dynamic topology control in ad hoc networks with directional links

Networks emerging as increasingly significant to US DoD visions comprise dynamic, heterogeneous terrestrial, airborne, and/or space-based nodes, some of whose links are directional, variable performance, and inherently unstable. Our work investigates an approach for managing the topology of such ad hoc networks with free-space optical (FSO) links that optimizes network performance metrics, e.g., the total network throughput. Unlike previous approaches, our dynamic approach to topology control incorporates node motions and link quality to drive connectivity decisions and multiple topology updates accordingly in order to maintain connectivity and maximize throughput. In addition to incorporating the constraints and limitations of the network capabilities and resources, the approach features a model formulation of link impairment for a generic FSO system. We describe this model and show how it can be used to guide topology control decisions for optimal network performance. We then present a formulation of a multi-period, multi-layer (network and physical) topology control decision problem and compare example solutions to alternative approaches.