Delay Tolerant Network

Abstract

The evolution of wireless devices along with the increase in user mobility has created new challenges such as network partitioning and intermittent connectivity. These new challenges have become apparent in many situations where the transmission of critical data is of high priority. The challenge of establishing communication between devices where end to end connectivity is not possible has led to an evolutionary form of networks called Delay Tolerant Networks (DTNs). Networks with frequent and long duration partitions prevent common Internet protocols from working successfully. This occurs in situations in which no stable infrastructure exists that can guarantee permanent link connectivity. The Internet protocols are not useful for DTNs because link disruptions are not properly handled, causing protocols to timeout and abort. For reliable communication, DTNs use store and forward approach thus routing hop by hop. DTNs use replication and knowledge based protocols for routing. Epidemic routing protocol discussed has least message delivery delay but uses more number of redundant message copies. We propose a protocol which is an improvement over epidemic routing by drastically reducing the number of redundant message copies with appreciable delay.