International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2013): 6.14 | Impact Factor (2015): 6.391 Volume 5 Issue 7, July 2016 www.ijsr.net Licensed Under Creative Commons Attribution CC BY Analysis of Delay Tolerant Network Routers by Implementing Selfish Node Detection Algorithm with an Incentive Strategy Rajesaheb Kadam 1 , Manoj Bangare 2 1 Research Scholar, Department of Information Technology, SKNCOE Pune, Savitribai Phule Pune University, Pune-411041, India 2 Assistance Professor, Department of Information Technology, SKNCOE Pune,Savitribai Phule Pune University, Pune-411041, India Abstract: Delay-Tolerant networks (DTNs) provide solution to applications where end to end connectivity is weak and not available so to support these applications DTN has characteristics like delay tolerance capacity in packet delivery, intermittent connectivity, scheduled contacts, high error rate and long or variable propagation delays. In DTN, to overcome weak end to end connectivity DTN nodes uses store-carry and forward protocol to relay messages from source to destination node. In DTN in- transits -packet we call it as bundle and bundle is opportunistically forwarded to the destination through intermediate nodes. In opportunistic routing, DTN use hypothesis of each node in DTN is cooperative with other nodes and willing to forward in-transit bundle to the destination nodes through intermediate nodes, with this hypothesis DTN perform well in routing but in real time applications of DTN, entities using DTN behaves rational and will not participate in bundle relaying to destination to reserve it’s resources like buffer space and energy. This behaviour of a entity or node is called as selfish behaviour of DTN node. Such selfish behaviour of node causes very large impact on bundle routing and decreases the performance of bundle delivery due to packet dropping by selfish node so single selfish node can jeopardise whole network and causes violation of DNT hypothesis. Hence, to overcome selfish behaviour of node we can use basic incentive scheme to promote selfish nodes to take part in bundle forwarding and selfish node detection algorithm to detect selfish node and ban and punish them in bundle routing protocol. We have implemented selfish node detection algorithm with incentive scheme and analysed it with different DTN routers for packet delivery ratio and number of selfish nodes detected. Keywords: Delay Tolerant Network, Selfish Node, Selfishness 1. Introduction A Delay Tolerant Network is a network of regional networks and DTN has characteristics like opportunistic and scheduled contacts, long propagation delay, asymmetric data rate and high error rate. DTNs support interoperability of the networks which covers it by including long delays between and within regional networks, and by translating between regional network communications characteristics. DakNet project of India is a typical example of DTN [1]. In providing with these functions, DTNs accommodate limited energy resource and the mobility of evolving wireless communication devices. The DTN technology has the wider scope; it includes radio frequency (RF), ultra wide band (UWB), and free space optical and ultrasonic technologies [1]. Several networks including the internet also may not have assumptions which Delay Tolerant Network has. Characteristic of Delay Tolerant Networks [4] are Opportunistic contact- connectivity between peer to peer is not always persists and nodes gets connected with each other on opportunity mean when they are in range of each other. Traditional network doesn‟t support this, it requires guaranteed connectivity. Intermittent connectivity-DTN supports intermittent connectivity means connections are available at irregular intervals and not continuous or steady because of this intermittent connectivity traditional TCP/IP protocol doesn‟t work. Long or variable Delay- bundles in DTN would be a live for long delays due to store-carry and forward protocol but in TCP/IP protocol packet will not survive for long delay and causes packet dropping in the routing path. Scheduled Contacts-in this characteristics of DTN nodes are get in contact with each other on scheduled moment like in planetary network where satellite gets in contact with each other on particular scheduled moment. 2. Selfishness of Node in DTN In real time application of DTN entities used in are resource constraint battery operated hand held devices like mobile cell phones, personal digital assistances and laptops. These devices are portable to use in DTN and carry out but are energy and buffer constraint. These resource constraint entities sometimes will not participate in bundle routing and drop the bundle, this behaviour of node is called selfish behaviour. Node is forced to behave selfish because of the limited power, the buffer and so on. A lot of bundle routing algorithms are existing for DTN based on the assumption of each node in DTN is willing to take participation in bundle forwarding but in real time application entities are rational and behaves selfish to reserve their resources and ignores the bundle forwarding. The selfish behaviour causes catastrophic damage. Xin Jiang and Xiang-Yu Bai [2] have discussed various types of incentive strategies and emphasize on the selfishness problem of nodes in the DTN network. In DTN, there are four types of nodes in context to the bundle forwarding. These are as follow, Type1-In this type of nodes, they help in bundle forwarding and follow the DTN message relaying assumption. These nodes earn more reputation and credit values from the TAs Paper ID: ART2016290 701