MAC Layer Based Insubordination Mechanism for Differentiating and Penalizing/Rewarding Opportunist Nodes in 802.11 WLAN Network

We can’t say anything about behavior of a node in a wireless network scenario. We always aspect a good and gentle behavior from a node irrespective of channel utilization or throughput degradation by a particular node. We can easily declare a node as a non- legitimate/suspicious node but we can’t say what we should do with a node responsible for increasing throughput and reducing unused slots if it is not a legitimate/suspicious node. Throughputs may decrease because of suspicious nodes working as a malicious node, but it can also increase because of not following back-of rules will called as an opportunist node. We have emphasis on identification scheme for node characterization. In our model we have identified some parameters at the MAC Sub layer. We can realize and declare a node as an attacker in the network and can be discard it from the network if it crossed the predefine threshold value calculated on the basis of identified parameters. Before a standard threshold value calculated it can be punished by increasing back-off period by a predefined calculated value. Declared opportunist nodes can be promoted by decreased back-off values. We have proposed an algorithm for declaring, blocking and discarding a node if it is a malicious node and also we will give reward to opportunist nodes. The Defense algorithm increasing the received bandwidth and reducing the packet loss of legitimate users.