2016 Volume 24 Issue 4 Pages 647-659
Delay and disruption tolerant networks (DTNs) adopt the store-carry-and-forward paradigm. Each node stores messages in a buffer storage and waits for either an appropriate forwarding opportunity or the message's expiration time, i.e., its time-to-live (TTL). There are two key issues that influence the performance of DTN routing: the forwarding policy that determines whether a message should be forwarded to an encountered node, and the buffer management policy that determines which message should be sent from the queue (i.e., message scheduling) and which message should be dropped when the buffer storage is full. This paper proposes a DTN routing protocol, called spray-and hop-distance-based with remaining-TTL consideration (SNHD-TTL) which integrates three features: (1) binary spray; (2) hop-distance-based forwarding; and (3) node location dependent remaining-TTL message scheduling. The aim is to better deliver messages which are highly congested especially in the “island scenario.” We evaluate it by simulation-based comparison with other popular protocols, namely Epidemic as a baseline and PRoPHETv2 that performs well according to our previous study. Our simulation results show that SNHD-TTL is able to outperform other routing protocols, significantly reduce overhead, and at the same time, increase the total size of delivered messages.
