Selfishness-Aware Application-Layer Multicast

To address the selfishness issue in application-layer multicast, we present a selfishness-aware application-layer multicast (SAM). SAM defines an altruism value for each node associative to its contributions to the system. Nodes are first partitioned into topologically-aware clusters using the binning scheme. Within the cluster, the subtree is constructed to place the nodes with greater altruism value at the higher layer of the tree. As compared to other studies in this area, SAM exhibits innovative advantages in both altruism value computation and multicast tree construction. Firstly, the node´s altruism value is generated from the feedback from its parent and children which enables the system to detect the selfish nodes effectively. Peers don´t need the extra probe messages to measure the QoS of their neighbors. During the process of tree construction and maintenance, only O(logN) nodes need to be adjusted. Lastly, the altruism value calculation and multicast tree construction are realized in a decentralized manner without any single point of failure. Simulation results show that even with a significant portion of nodes being selfish, SAM is able to build a dissemination tree that provides high overall streaming quality with low control overhead.