Cloud-Based Multicasting with Feedback in Mobile Social Networks

With the rapid growth of smartphone usage, mobile social networks (MSNs) are becoming increasingly popular. MSN can be considered as a type of delay tolerant network (DTN) which lacks continuous end-to-end connections between nodes, due to the node mobility and limited transmission range. Inspired by the homophily of social networks that friends are usually similar in characteristics, we present a novel concept - cloud, where the nodes in frequent contact with the destinations will form destination clouds. Neighbors in the destination cloud have a special status that can forward the message to the destination directly. We propose a cloud-based multicast scheme with feedback in MSNs with two phases: pre-cloud and inside-cloud. In the pre-cloud process, the message holder will forward the copy of the multicast message to the encountered node, based on a given forwarding metric. The forwarding metric can be iteratively refined from a feedback control mechanism. In the inside-cloud process, the message holder will wait until it meets with the destinations. We analytically formulate the multicast problem into a continuous Markov chain problem, and formally analyze the latency in this model. Extensive trace-driven simulations show that our scheme significantly improves the performance compared to existing schemes.