Routing metrics for store and forward satellite constellations

Route computation relies on the definition of performance indicators called routing metrics. Popular metrics are the number of hops, throughput, end-to-end delay and jitter. However, in a store and forward network displaying link disruptions, these metrics are questionable. This contribution defines seven metrics for characterising routes in a store and forward network. These metrics are: number of hops, route lifetime, end-to-end delay, capacity, synchronicity, simultaneousness and discontinuity. Some of these metrics are borrowed or adapted from classical networks, others are specifically conceived for store and forward networks. Simulations for routing in a satellite constellation show that these metrics help to capture the specifics of store and forward networks and therefore improve routing decisions.