Directional Forward Epidemic Routing for Disruption Tolerant Networks

Epidemic routing is an original and effective multicopy routing algorithm in disruption tolerant networks. However, its performance degrades significantly when network resources are limited. In this paper, we proposed a new routing scheme, called directional forward epidemic routing (DFER). DFER caches the position information of neighbors, calculates the directional vectors and angles among these neighbors and the destinations, and hereby chooses the appropriate relays. Meanwhile, an ACK vector exchange mechanism is employed by DFER to purge the redundant messages. Simulation results show that DFER with a threshold of 60 degrees outperforms epidemic routing by a factor of about 1.5 and 1.2 in delivery ratio and delay respectively when the buffer size is low.