Identifying high dissemination capability nodes in opportunistic social networks

Although social-aware opportunistic networking paradigms are considered to have broad potential applications, so far very little is known about which nodes are more important in both sustaining the network topology and forwarding or disseminating messages. To address this issue, this paper redefines the concept of walk and extends traditional Katz Centrality measurement to dynamic opportunistic social networks. Based on the Time Evolving Graph model, we derive a convenient formula to identify each node´s information dissemination capability through computing the product of the adjacent matrix of each snapshot along the direction of time. The resulting matrix, in which the spatial and temporal dependency of the network nodes are fully captured, can conveniently be used to evaluate each node´s relative dissemination capability. We apply our method to two real experiment trace datasets and the results show that, several mobile nodes with highest communicability identified by our method are more efficient in message dissemination than the others in the whole network. Those nodes can be chosen as good candidates when some interventions, such as accelerating or suppressing the speed of information spreading in network, are required to be made on network.