Weighted 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 Weighted Epidemic Routing (WER). WER appropriately arranges the priority of messages for forwarding or deleting through assigning a weight for each of them when the buffer size of nodes and contact duration are limited. The weight of a message is determined by TTL and replications density that is a novel metric to estimate the amount of copies around an infected node. Meanwhile, an ACK vector exchange mechanism is employed by WER to purge the redundant messages. Simulation results show that WER outperforms Epidemic with Drop-tail and FIFO drop policy by a factor of about 6.8 and 0.66 respectively when buffer size is low.