Time-varying graphs and dynamic networks

Abstract

The past few years have seen intensive research efforts carried out in some apparently unrelated areas of dynamic systems -delay-tolerant networks, opportunistic-mobility networks, social networksobtaining closely related insights. Indeed, the concepts discovered in these investigations can be viewed as parts of the same conceptual universe; and the formal models proposed so far to express some specific concepts are components of a larger formal description of this universe. The main contribution of this paper is to integrate the vast collection of concepts, formalisms, and results found in the literature into a unified framework, which we call TVG (for time-varying graphs). Using this framework, it is possible to express directly in the same formalism not only the concepts common to all those different areas, but also those specific to each. Based on this definitional work, employing both existing results and original observations, we present a hierarchical classification of TVGs; each class corresponds to a significant property examined in the distributed computing literature. We then examine how TVGs can be used to study the evolution of network properties, and propose different techniques, depending on whether the indicators for these properties are a-temporal (as in the majority of existing studies) or temporal. Finally, we briefly discuss the introduction of randomness in TVGs.

Computational challenges of dynamic channel assignment for military MANET

“…Rather than just a series of snapshots, temporal graphs have structure in themselves that can be considered as a whole [28]. Casteigts et al [80] provide an overarching framework of time-varying graphs in pursuit of general properties, and mention that very little work has been done in this area. In a seminal work, [81] describes the use of such graphs to consider time-varying MANETs.…”

Routing in Disruption Tolerant Networks with Limited Storage

“…• It is assumed that the storage capacity of each relay node is finite and store-and-forward mechanism is used to transmit data. Consider a set of entities V (or nodes) and a set of relations E (edges) between these nodes in the network, which can be described by a time-varying graph, or TVG [11], G = (V, E). The opportunity to communicate over an edge is called a contact, which is characterized by parameters below:…”

Efficient Information Dissemination in Dynamic Networks

“…Time-Varying Graph (TVG) [20] is a general dynamic network model, which integrates previous models with a unified framework. With TVG, a dynamic network is modeled as G=(V, E, T, ρ, ζ), where V and E are the vertex and edges in the topology graph respectively, T is the lifetime of the network, ρ indicates whether a given edge is available and ζ represents the time taken to cross an edge.…”