Method to Improve the Performance of PROPHET Routing Protocol

PROPHET is a probabilistic routing protocol for Delay Tolerant Networks. In such networks, there is no guarantee that a fully connected path between source and destination exists at any time, rendering traditional routing protocols unable to deliver messages between hosts. In PROPHET, when a message is delivered successfully to its final destination, there is no acknowledgment for this message. Hosts will keep this stale message in their buffers until the TTL of the message has expired. To achieve a high message delivery ratio, the message TTL is usually very long in Delay Tolerant Networks. It means that the redundant copies of one message will stay for a long time in nodes' buffers. In this paper, we propose a method using acknowledgments that are propagated network-wide to remove the stale data from the network, to reduce the required buffer space and to further improve the performance of the PROPHET routing protocol.