J.P. Cárdenas

MODELING THE TOPOLOGY OF SDH NETWORKS

SDH (Synchronous Digital Hierarchy) is the standard technology for the information transmission in broadband optical networks. Unlike the Internet, SDH networks are strictly planned; rings, meshes, stars, or tree-branches topologies are designed to connect their basic elements. In spite of that, we have found that the SDH network operated by Telefonica in Spain shares remarkable topological properties with other real complex networks empirically analyzed, such as the worldwide web network. In particular, we have found power-law scaling in the degree distribution (P(k) ~ k-γ) and properties of small world networks. Considering real planning directives that take into account geographical and technological variables, we propose an ad hoc computational model that reproduces the aforementioned topological traits observed in the Spanish SDH network.

EFFECT OF MEMORY ON BOOLEAN NETWORKS WITH DISORDERED DYNAMICS: THE K = 4 CASE

In standard Cellular Automata (CA) and Boolean Networks (BN), the new state of a cell depends on the neighborhood configuration only at the preceding time step. The effect of implementing memory in cells on CA, CA on networks and BN with different degrees of random rewiring is studied in this paper paying attention to the particular case of four inputs. As a rule, memory in cells induces a moderation in the rate of changing cells and in the damage spreading, albeit in the latter case memory turns out ineffective in the control of the damage as the wiring network moves away of the ordered structure that features proper CA.

Complexity in Spanish optical fiber and SDH transport networks

Complex networks are important instances of technology-related complex systems. In this work we apply tools from complexity science to characterise two Telefonica Espana transport network systems: the optical fiber network and the SDH transport network. We compare both cases and derive its most important properties. Remarkably, our results show that in both cases several features of heterogeneous, hierarchical complex networks arise.

THE EFFECT OF MEMORY IN CELLULAR AUTOMATA ON SCALE-FREE NETWORKS: THE

In standard cellular automata the new state of a cell depends on the neighborhood configuration solely at the preceding time step. This study analyzes the effect of implementing memory in cells of cellular automata on networks with scale-free topology. As a rule, embedding memory in cells induces a notable depletion in the cell change rate, but it is not so effective in controlling the spread of damage.

\overline{K}=4

Synchronous Digital Hierarchy (SDH) is the standard technology for information transmission in broadband optical networks. Unlike systems with unplanned growth, such as those of natural origin or the Internet network, the SDH systems are strictly planned as rings, meshes, stars or tree-branches structures designed to connect different equipments. In spite of that, we have found that the SDH network operated by Telef?nica in Spain shares remarkable topological properties with other real complex networks as a product of its evolution since 1992. In fact, we have found power-law scaling in the degree distribution (N?P(k) = k??) and small-world networks properties. The complexity found in SDH systems was reproduced by two models of complex networks, one of them considers real planning directives that take into account geographical and technological variables and the other one is based in the compatibility among SDH equipments.