An adaptive threshold method to address routing issues in delay-tolerant networks

Many wireless environments face long delays and intermittent connectivity anomalies. A promising solution is delay-tolerant networks, but these networks have inherent issues with routing. Popular mobile ad hoc routing protocols such as AODV and OSPF rely on the existence of an end-to-end path. These protocols first establish a path before traffic is sent. A delay-tolerant network, however, is characterized by intermittent connectivity and consequently for these types of networks, traditional routing protocols fail. This paper proposes an adaptive threshold routing algorithm that builds upon the threshold method proposed in [1]. An adaptive algorithm is an ideal approach for dynamic, challenged, network environments. The adaptive threshold method takes into account changes in the network structure and adjusts the algorithm parameters to optimize performance in terms of reducing network load, lowering the delivery rate of packets, and maximizing packet throughput. Experimental results show that as the network topology changes, the adaptive threshold method not only maintains a high throughput while lowering the network load, it also outperforms the threshold method by reducing the average packet delivery rate.