Selfish node Detection

MANET nodes rely on network cooperation schemes to properly work, forwarding traffic unrelated to its own use. There is the possibility of existence of selfish nodes MANET without forwarding the data in order to save its own energy. Collaborative watchdog introduces an efficient approach to reduce the detection time of selfish nodes in MANET based on contact dissemination. If one node has previously detected a selfish node using its watchdog it can spread this information to other nodes when a contact occurs.


In a MANET, nodes can freely move around while communicating with each other. These networks may under-perform in the presence of nodes with a selfish behavior, particularly when operating under energy constraints. A selfish node will typically not cooperate in the transmission of packets, seriously affecting network performance.


Reputation scheme is introduced to evaluate the case of malicious or cheating behavior. It provides nodes with incentives in the form of reputations to encourage nodes in honestly participating in the election process. The amount of incentives is based on the Vickrey, Clarke, and Groves (VCG) model to ensure truth-telling to be the dominant strategy for any node.

Solution in NS2

  • Selfish nodes can be modeled and detection algorithm can be implemented in ns2.

  • Detection accuracy of watchdogs that uses using the collaborative approach can be calculated.

  • The overall detection time and cost in term of message overhead can be measured.

  • Improvement in the reliability of data transmission by detecting selfish node can be shown in xgraph.

Related Titles:

  • Improving Selfish Node Detection in MANETs Using a Collaborative Watchdog, IEEE Communication Letters, Vol 16, No.5, May 2012.