A Publish/Subscribe Forwarding Scheme Based on Mobility Information for Opportunistic Networks

This paper presents PuFLo, a publish/subscribe forwarding strategy, to deliver content to interested nodes in opportunistic networks. Most of the existing schemes typically use temporal or social knowledge when building routing tables. Instead, PuFLo considers node mobility information when making forwarding decisions. Initially, a node stores the ID of each location it visits in a sequence list. When a node contact occurs, PuFLo selects suitable relays based on two forwarding metrics: mobility similarity and centrality. The former evaluates the mobility diversity of two nodes based on dynamic time warping. The latter assesses node activeness based on Shannon entropy, which reflects the variation of previously visited places. Finally, the two metrics are integrated using the entropy weight method to define the PuFLo forwarding utility. Extensive simulations using the ONE simulator show that PuFLo consistently outperforms Epidemic and SimBet routing in terms of dissemination efficiency, latency, and cost.