Leveraging routing performance and congestion avoidance in predictable delay tolerant networks

Delay or Disruption Tolerant Network (DTN) architecture has become a promising solution for challenged environments where communications cannot be assumed persistent. In particular, if node dynamics can be predicted like in space-borne networks, routing schemes such as Merugu´s Floyd Warshsall (MFW) and Contact Graph Routing (CGR) can take advantage of the a priori knowledge of the DTN topology. In this work we compare and leverage these popular schemes and propose Cache-CGR: a computationally efficient version of CGR that reduce processing requirements while preserving its features such as local congestion avoidance. We demonstrate the performance gain of C-CGR both by means of simulation and an on-board computer test-bench with Interplanetary Overlay Network (ION) DTN implementation. Finally, we discuss CGR open issues and lay the foundations for future research on DTN global congestion avoidance mechanisms.