A novel congestion control scheme for delay tolerant networks

Due to limited storage capacity in the DTN nodes, storage congestion occurs when too many bundles are contending for this scarce resource. As a result, bundle loss increases and the delivery ratio of the network suffers. In a proactive scheme, a node can decide whether to accept or reject the custody of a new bundle based on its current storage status. In this paper, we propose a novel proactive congestion control scheme for DTN. Our scheme ranks the incoming bundles using their priority and TTL. When congestion occurs, a node accepts or rejects the bundles based on their ranks. We also use the concept of head of line blocking, confidence level, and dropping probability of the bundles to facilitate better decision making. Simulation results show that our scheme achieves 20% to 25% higher delivery ratio than that of the existing schemes.