Deadline-constrained routing based on power-law and exponentially distributed contacts in DTNs

During a large-scale disaster, there is a severe destruction to physical infrastructures such as telecommunication and power lines, which result in the disruption of communication, making timely emergency response challenging. Since Delay Tolerant Networks (DTNs) are infrastructure-less, they tolerate physical destruction and thus can serve as an emergency response network during a disaster scenario. To be effective, DTNs need a routing protocol that maximizes the number of messages delivered within deadline. One obvious approach is to broadcast messages everywhere. However, this approach is impractical as DTNs are resource-constrained. In this work, we propose a cost-effective routing protocol based on the expected delivery delay that optimizes the number of messages delivered within deadline with a significantly low network overhead. Simulations using real-life mobility traces show that with our scheme, up to 95% of messages are delivered within deadline, while requiring on average less than three message copies.