Deterministic Computations in Time-Varying Graphs: Broadcasting under Unstructured Mobility

Most highly dynamic infrastructure-less networks have in common that the assumption of connectivity does not necessarily hold at a given instant. Still, communication routes can be available between any pair of nodes over time and space. These networks (variously called delay-tolerant, disruptive-tolerant, challenged) are naturally modeled as time-varying graphs (or evolving graphs), where the existence of an edge is a function of time. In this paper we study deterministic computations under unstructured mobility, that is when the edges of the graph appear infinitely often but without any (known) pattern. In particular, we focus on the problem of broadcasting with termination detection. We explore the problem with respect to three possible metrics: the date of message arrival (foremost), the time spent doing the broadcast (fastest), and the number of hops used by the broadcast (shortest). We prove that the solvability and complexity of this problem vary with the metric considered, as w...

• Type: Journal
• Year: 2010
• Where: IFIPTCS
• Authors: Arnaud Casteigts, Paola Flocchini, Bernard Mans, Nicola Santoro
• Keywords: Complete Computability Map, Dynamic Infrastructure-less Networks, IFIPTCS 2010, Theoretical Computer Science, Time-varying Graphs