Abstract
Normally, nodes cooperate with each other in a mobile ad hoc network in which it is under the administration of a single authority. Each node contributes resources to route discovery and packet forwarding. However, in case of civilian applications such as network of cars, the nodes may not belong to a single authority and not pursue a common goal. In such cases, nodes are not forced to cooperate, thus the network functions are not guaranteed. Instead of forwarding packets for others, a node exploits resources of others and contributes nothing, which results in lower power consumption and longer operation time. Indeed, the situation may be severe since the resources (battery power, memory, bandwidth, and CPU cycles) each node owns are extremely limited. This thesis proposes a mechanism which provides the node in a mobile ad hoc network the capability of preventing from being exploited by selfish neighborhood. The mechanism relies on the observed information to determine each neighbor’s importance according to different metrics. After that, the flow rate allocated for each neighbor is figured out based on its importance level respectively. The simulation results show that no packet is forwarded when they are originated from selfish nodes. Besides, only few packets are failed to achieve its destination while respectable amount of forwarding operations are saved on average. The simulation results also show that when the percentage of selfish nodes in the network is small, the network throughput is affected due to fairness consideration. Once the percentage of selfish nodes increases, our mechanism makes the network throughput better compared to the original network.