Network performance optimization is a polyparametric task where usually the physical network topology is already provided and given. The latter is mainly defined by the geographical needs and the business models developed in a region that reflect the particular data traffic requirements. However, during the design of a new network, the physical topology can be considered as an additional parameter, and this work aims to study the potential impact of a network topology in the performance of the network. Two relevant metrics of optical WDM networks are evaluated, throughput and blocking ratio. Through the simulation of 350k implementations of more than 500 network topologies, we demonstrate a performance variation on networks with the same number of nodes and edges up to 73.9% on the total network load under same levels of requests blocking ratio, and up to 17.3% on the network throughput.

No abstract

At the verge of the launch of the first commercial fifth generation (5G) system, trends in wireless and optical networks are proceeding toward increasingly dense deployments, supporting resilient interconnection for applications that carry higher and higher capacity and tighter latency requirements. These developments put increasing pressure on network backhaul and drive the need for a re-examination of traditional backhaul topologies. Challenges of impending networks cannot be tackled by star and ring approaches due to their lack of intrinsic survivability and resilience properties, respectively. In support of this re-examination, we propose a backhaul topology design method that formulates the topology optimization as a graph optimization problem by capturing both the objective and constraints of optimization in graph invariants. Our graph theoretic approach leverages well studied mathematical techniques to provide a more systematic alternative to traditional approaches to backhaul design. Specifically, herein, we optimize over some known graph invariants, such as maximum node degree, topology diameter, average distance, and edge betweenness, as well as over a new invariant called node Wiener impact, to achieve baseline backhaul topologies that match the needs for resilient future wireless and optical networks.

No abstract

This paper describes an ontology model (conceptual model) based on the ITU-T Recommendation G.805 for transport network architectures. The goal is to take a step forward to the autonomic applications for transport network operation and management. Besides the conceptual model description and explanation, including its main elements (classes, properties and constraints), this paper also includes the description of the G.805 recommendation main concepts characteristics. Furthermore, the paper elaborates on the advantages of using an ontological model, as well as the technologies used for ontology conceptual modelling and ontology implementation.Finally, this paper presents a case study using a simple OTN unidirectional network, in which automated inferences could be verified. In conclusion, the methodology and reference conceptual model of transport networks presented here constitutes a contribution towards autonomic network applications.