Quota-control routing in delay-tolerant networks

Delay-tolerant networks (DTNs) are network environments that are subject to delays and disruptions. Traditional end-to-end routing protocols fail in such challenging network conditions because of intermittent connections and/or long delays. Research results have shown that per-hop forwarding of multiple copies of the same message to the destination can produce satisfactory routing performance in DTNs. Current methods rely on the fixed setting of a quota value to limit the number of message copies. This paper proposes a dynamic quota-control mechanism, allowing routing to operate effectively with different traffic loads. To remove useless message copies from the network, a low-cost probability-based method is also presented. The proposed routing framework is then extended to interest-based information dissemination, which is used to efficiently disseminate an event message to all interested users. A performance evaluation was conducted using a real social contact trace, and performance comparisons with other DTN routing protocols are provided.