Guimerà Manrique, RogerArenas, ÀlexDíaz Guilera, AlbertGiralt, Francesc2011-07-072011-07-0720021063-651Xhttps://hdl.handle.net/2445/18787We study the dynamical properties of a collection of models for communication processes, characterized by a single parameter $\xi$ representing the relation between information load of the nodes and its ability to deliver this information. The critical transition to congestion reported so far occurs only for $\xi=1$. This case is well analyzed for different network topologies. We focus of the properties of the order parameter, the susceptibility and the time correlations when approaching the critical point. For $\xi<1$ no transition to congestion is observed but it remains a cross-over from a low-density to a high-density state. For $\xi>1$ the transition to congestion is discontinuous and congestion nuclei arise.8 p.application/pdfeng(c) American Physical Society, 2002Física matemàticaDinàmica molecularXarxes de comunicacionsFenòmens crítics (Física)Transformacions de fase (Física estadística)Mathematical physicsMolecular dynamicsCommunication networksCritical phenomena (Physics)Phase transformations (Statistical physics)info:eu-repo/semantics/article502561info:eu-repo/semantics/openAccess