Complexity and Robustness in the Spanish Optical Telecommunication Network

LUIS G. MOYANO; M. L. VARGAS; J. P. CARDENAS; M. L. MOURONTE; R. M. BENITO

Venecia

Conferencia; NETSCI 09 - International Workshop and Conference on Complex Networks and their Application; 2010

CNR-INFM

In this communication we present a study of the topology and robustness of the SDH telecommunication network operated by Telefónica in Spain. SDH (Synchronous Digital Hierarchy) networks transport different traffic types, such as voice, video, multimedia, and data packets (as those generated by IP) over the same fiber wire. Our results showed emergent complexity in all the Spanish provincial networks analyzed, despite being largely dependent on strict planning policies. Particularly, we found power-law scaling in the degree distribution and properties of small-world networks, signs of self-organization in the evolution of complex systems. These complex topological properties have been related to the robustness of systems. Thus, complex networks are considered robust against random failures but sensitive to planned attacks in highly connected nodes. Under this perspective, in this work we also present a study of the robustness of the Spanish SDH network by the simulation of direct attacks to those equipments that control the flow of information. We have found that the robustness depends not only on the connectivity of equipments but also on the capacity and type of links associated to those equipments. Consequently we have also observed that the robustness of SDH networks depends on the particular initial design and evolution of each Spanish province