Dear Raja,

From what I understand a selfish node in ad-hoc net aims to benefit itself. It may not forward packets from other nodes, to spare energy; if there are routing based on incentives it may forward packets only enough to transmit its own.

So doing selective forwarding or no forwarding at all by these nodes will degrade the network.

Used them or not will depend on the necessity and the incentive it may have to be used. But it also raises the issue of how to detect them.

"ad hoc routing incentive based" in Google scholar gives several results that may provide further information.

This will also touch routing security, where the work from Jean Yves Le Boudec should be looked at. That will tackle detection and penalties.

Hope it helps,

Best

Pedro

Hi,

The performance of MANETs is highly affected by the behaviour of its constituting nodes, which must cooperate in order to provide the basic networking functionality.

Selfish (misbehaving) nodes, which agree to route packets for other nodes and subsequently drop these packets. Such misbehaviour is of direct effect on quality of service (QoS) solutions, namely the QoS goodput metric.

A. Perti and P. Sharma has peresented a paper "Reliable AODV (R-AODV) Protocol for Wireless Ad Hoc Networking", will be usefull for you. They simulated multiple variations of mobile ad hoc environments, according to the hostility degree, mobility scenario and traffic load with using NS2.

RAODV is a security aware protocol that detects and avoids the misbehaving nodes for supporting end to end QoS goodput. Its main objective is to prevent misbehaving nodes that agrees to send packets to other nodes but subsequently drops these packets. R-AODV increases QoS performance and quality of cooperating nodes in mobile ad hoc network.

[1] A. Perti and P. Sharma, ”Reliable AODV Protocol for Wireless Ad Hoc Networking,” in Advance Computing Conference, 2009. IACC 2009. IEEE International, 2009, pp. 675-680.

[2] "Network Simulator ns-2," http://www.isi.edu/nsnam/ns/.

As MANET is self-constrained network, here each node should collaborate with each other to perform functions of the network but sometimes node may behave selfishly to conserve their resource like batter power,bandwidth,etc. Such nodes are called selfish node and selfishness disturb the network and take away the network from their regular mission.

The term selfish node mainly comes from a  specific class of AdHoc Networks known as

cooperative networks,  where different autonomous and as well as heterogeneous nodes (possibly owned by different individuals)  form a network and agree to forward each others packet   in cooperative manner.

The biggest problem in this type of network  is "selfish node problem", where some may start dropping the packets of others just for its own benefit (to save the power)

There are two commonly known techniques to with the selfish node problem:  reputation based and incentive based or the combination of both.

This particular area of research is closely related with game theoretic approaches to solve as well analyze the problem.

Dear raja

A node that perform different than normal behavior  (drop packets, distrub routing mechanism and save their resources by not forward the other node packets) is known as selfish node.

Dear Raja,

Actually selfish nodes are the one who behave abnormally to save its power.to do this it violet the normal working of Ad-Hoc n/w.