Abstract

SDH ( Synchronous Digital Hierarchy) is the standard technology for 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 this work we show that the SDH network operated by Telefonica in Spain presents a power-law scaling in the degree distribution (P(k) similar to k(-gamma)) both at the national and provincial levels. The empirically obtained scaling exponents gamma are consistent with those observed in other heterogeneous complex networks. The Spanish SDH network also displays small world properties with a high clustering and short path length similar to the Internet routers network. The province sub-networks experience similar traits with regards to such properties. Considering factors such as network design policies, user demand, geographical location and types of equipment, we propose an ad hoc computational model in order to reproduce these topological properties.