Modified Epidemic Routing with Redundant Message Elimination in Delay Tolerant Network

This paper introduces a new scheme to control redundant message copies in Delay Tolerant mobile Ad-hoc networks (MANET) an d also proposes an efficient message buffering strategy. Delay tolerant networks (DTN) generally lack end-to-end connectivity. The researchers in this area had proposed to maintain multiple message copies in routing protocols to transmit messages in DTN. But it increases the network traffic due to a large number of message redundancies. In this work, to control the message redundancy in DTN, we have introduced a predetermined threshold value to the network, and a counter flag to each node for every message. The counter flags record the number of encounters with other nodes having that particular message copy. If the counter flag of a node for a particular message reaches the predefined threshold, the node removes that particular copy. With this proposed scheme message copies are decreased and finally they are removed completely. In addition to this, we have introduced an efficient message buffering strategy. In DTN, each node can contain a limited number of messages. When the message buffer is full, the node deletes the oldest message from its buffer. In this new scheme, the successful delivery efficiency is still the same as epidemic routing and the redundant copies are efficiently controlled to a relatively low level and the message buffer utilization is also high.