Investigation on replication schemes for pervasive information transfer in intermittently connected mobile Ad Hoc networks

Abstract

In a network of wireless mobile nodes communication between a pair of nodes is possible at a particular instant when the distance between the nodes is less than their transmission range Sometimes even if the messages are forwarded through other intermediate nodes there is no guarantee of finding a feasible continuous path between the source and destination due to mobility of nodes broken link and insufficient resources like battery and buffer The wireless networks which have frequent disruptions like this are called Intermittently Connected Mobile Ad hoc Networks In IC MANET scenario communication is enabled by buffering messages at intermediate nodes for a longer time than usual MANET queuing times There are many routing schemes devised for IC MANETs They are classified as auxiliary nodes assisted routing schemes and multiple replication routing schemes Auxiliary nodes assisted routing employs special nodes like Message Ferries which carry messages between the source and destination when they are far apart In multiple replication based schemes epidemic routing is introduced which is a flooding like mechanism In epidemic routing, if two nodes meet they exchange their buffered messages which they don t have already This flooding mechanism consumes resources heavily because of uncontrolled replication There are many controlled replication schemes like Spray and Wait Fuzzy Spray and Multi periodic Spraying In these routing schemes the number of replications for a message newlineis limited to fixed numbers But these routing schemes fail when nodes have newlineconstrained mobility In order to improve the Quality of Service in these networks further it is possible to exploit the mobility of a subset of nodes to bring messages closer to their destination by choosing the best intermediate nodes newline newline