Improving performance through topology management and wireless scheduling in military multi-hop radio networks

Abstract

We investigate two distinct problems in military radio networking. In the first problem, we study a mobile airborne multi-hop wireless network. The mobility of the nodes leads to dynamic link capacities requiring changes to the topology by adding and removing links. Changes are intended to minimize maximum link load. Mixed integer linear programming is used to periodically find topological modifications resulting in optimal performance. To reduce computation and the rate of changes to the topology, we design and employ heuristic algorithms. We present several such algorithms of differing levels of complexity, and model performance using each. A comparison of the results of each method is given. In the second problem, we study a ground multi-hop wireless network. Scalability is an issue for such ground tactical radio networks, as increasing numbers of nodes and flows compete for the capacity of each link. The introduction of a relay node allows additional routes for traffic flows. Greater benefit is achieved by fixing the relay node at a higher elevation to allow it to broadcast to all other nodes simultaneously, thereby reducing the number of hops packets must travel. We use a combination of linear programming (LP) and novel bounds on the achievable network performance to investigate the benefits of such a relay node. We show that a relay node provides moderate improvement under an all-to-all unicast traffic model and more substantial improvement for broadcast traffic patterns.