Buffer Managed Multiple Replication Strategy Using Knapsack Policy for Intermittently Connected Mobile Networks

Abstract

Intermittently Connected Mobile Networks (ICMNs) are a kind of wireless network where, due to mobility of nodes and lack of connectivity, there may be disconnections among the nodes for a long time. To deal with such networks, store-carry-forward method is adopted for routing. This method buffers the messages in each node for a long time until a forwarding opportunity comes. Multiple replications are made for each message. It results in an increase in network overhead and high resource consumption because of uncontrolled replications. Uncontrolled replications are done due to lack of global knowledge about the messages and the forwarding nodes. The authors introduce a new simple scheme that applies knapsack policy-based replication strategy while replicating the messages residing in a node buffer. The numbers of replications are controlled by appropriately selecting messages based on the total count on replications already made and the message size. In addition, the messages are selected for forwarding based on the relay node goodness in contacting the destination and the remaining buffer size of that relay node. Therefore, useful replications are made based on the dynamic environment of a network, and it reduces the network overhead, resource consumption, delivery delay, and in turn, increases the delivery ratio.