Nodes Density Adaptive Opportunistic Forwarding Protocol for Intermittently Connected Networks

Opportunistic routing is the major routing strategy for intermittently connected networks (ICNs) that are characterized by frequent link disruptions. These disruptions limit the formation and stability of continuous end-to-end paths between any arbitrary source-destination node pair. This paper proposes a novel opportunistic routing/forwarding protocol, Nodes Density Adaptive Opportunistic (NDAO) forwarding protocol. NDAO´s primary objective is to disseminate messages to a large number of receivers while using the minimum possible number of message transmissions. Numerical simulations provide a robust evaluation of the performance of NDAO and a comparison with four widely used forwarding protocols, namely: i) Epidemic Routing (ER), ii) Spray-and-Wait (SW), iii) Prophet and iv) MaxProp. The performance metrics consider both the delivery ratio and the average end-to-end latency. Simulation results show that NDAO can increase the delivery ratio and decrease the delivery latency simultaneously.