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Planning, Optimization and Operation of Access and Ethernet Optical Networks for the Provisioning of High-Speed Symmetrical Services

Ph.D. Thesis, Universidad Carlos III, Madrid, Spain (2016)


Today more than ever before, service providers are under enormous pressure to reduce operational costs while increasing business effectiveness. This often means optimizing cur- rent infrastructure investments and implementing novel networking technologies. Customer demand is quickly evolving away from traditional one-way content consumption to a much more participative social network model that demands high capacity bidirectional information flows. Ethernet-based networking technology has become ubiquitous in both the enterprise and home broadband arenas. The combination of simplicity and rigorous specification has permitted a degree of integration and commoditization that other networking technologies could not achieve. On the other hand, optical fiber has become the technology of choice in the medium and long term in the access and metro networks, thanks to its speed, reach and future-proof. While it seems clear that fiber is the right technology to support emerging services in the access network, there are a large variety of technologies available in the industry. This thesis reviews the main technologies available today for access and metro networks, and proposes contributions about network planning and optimization. Firstly, main innovations added to Ethernet are analyzed, namely improvements related to scalability, OAM functionality and forwarding capabilities, in order to permit Ethernet to assume a much larger role in metro networks. After that, some of the Ethernet enhancements previously discussed are applied to access networks. Specifically, physical and link-layer information are combined in order to effectively set management procedures for passive optical networks (PON). We propose an Integrated Troubleshooting Box (ITB) and show its applicability in a number of realistic troubleshooting scenarios, including failure situations involving either the feeder fibre or one of its branches. Secondly, this thesis explores fiber access protocols available in the industry to support high-speed symmetrical services. It compares four Next-Generation PON protocols from a performance and economical perspective in a real scenario, and analyzes under which conditions 1 Gb/s symmetrical services can operate by selecting the right parameters of quality of service, oversubscription and split ratio. Finally, a novel access network planning method is proposed to provide 1Gb/s symmetrical services in a mixed environment of business and residential services. In this case, a converged cost-optimized access network is implemented, using Integer Linear Programming, which guarantees respective service level specifications in a real scenario.