CSI: A paradigm for behavior-oriented profile-cast services in mobile networks

We propose a new behavior-oriented communication paradigm in mobile networks, profile-cast, motivated by tight user-network coupling in mobile societies. In this novel paradigm, messages are sent to sender-specified target profiles, instead of machine IDs. We present a systematic framework for such services. First, we analyze the spatio-temporal stability of user mobility profiles constructed from empirical data sets, and they turn out to be surprisingly stable. The similarity of the current mobility profile of a user to its future mobility profile remains above 0.6 for five weeks, while the correlation coefficient of the similarity metrics between a user pair at different time instants is above 0.5 for two weeks. Second, we present a protocol for the profile-cast service, named CSI, and provide a fully distributed solution utilizing behavioral profile space gradients and small world structures to selectively diffuse information across the network towards the intended recipients. Leveraging stability in user behaviors, the two modes of CSI achieve good performance compared to the theoretical optimal protocols. Both CSI:Target mode and CSI:Dissemination mode achieve more than 94% delivery ratio. Comparing with the delay-optimal protocol, they show no more than 47% and 32% more delay, respectively, with at most 10% more transmission overhead. Comparing with the overhead-optimal protocol, they use no more than 7% more overhead while achieving dramatic improvement in delay (up to 150% less). Both CSI:T and CSI:D significantly outperform the epidemic routing, using less than 7% overhead, and variants of random walk, where CSI:T doubles the delivery ratio using less overhead, and CSI:D shows at least 50% less delay under similar overhead. We believe the profile-cast paradigm would enable many behavior-oriented services efficiently, such as targeted announcements and profile-based alert notifications, in various mobile networks. (C) 2011 Elsevier B.V. All rights reserved.