On the relevance of the edge-Markovian evolving graph model for real mobile networks

Aurélie Faure de Pebeyre, Fabien Tarissan et Julien Sopena

IFIP Wireless Days conference (WD’13), Valencia, Spain, 2013

The development of wireless devices led the scientific community to focus more and more on systems of interaction composed of moving entities. In this context, different models have been proposed in an attempt to capture properties of the observed dynamics. Among those models, the edge-Markovian evolving graph model is appealing since it enables to highlight temporal dependencies in the evolution of the graphs. This model relies on two parameters accounting respectively for the creation and suppression of links in the graph. Thus it assumes that these two parameters are sufficient to characterise the dynamics during all the evolution of the graph. In this paper, we test this hypothesis by confronting the model to 6 datasets recording real traces of evolving networks. In particular, we study the proportion of created and deleted links over the time. The results show that 5 of the 6 case studies present an heterogeneous distribution of those fractions which contradicts the underlying hypothesis of the model. Besides, in order to understand the importance this might have as regard structural properties of real networks, we also study the impact the Markovian model has on the mean degree over the time. It turns out that even in the suitable case, the model fails to reproduce correctly this property which indicates its inadequacy for even more complex properties of real evolving networks