Optimised Design and Analysis of All-Optical Networks

This PhD thesis presents a suite of methods for optimising design and for analysing blocking probabilities of all-optical networks. It thus contributes methodical knowledge to the field of computer assisted planning of optical networks. A two-stage greenfield optical network design optimiser is developed, based on shortest-path algorithms and a comparatively new metaheuristic called simulated allocation. It is able to handle design of all-optical mesh networks with optical cross-connects, considers duct as well as fibre and node costs, and can also design protected networks. The method is assessed through various experiments and is shown to produce good results and to be able to scale up to networks of realistic sizes. A novel method, subpath wavelength grouping, for routing connections in a multigranular all-optical network where several wavelengths can be grouped and switched at band and fibre level is presented. The method uses an unorthodox routing strategy focusing on common subpaths rather than individual connections, and strives to minimise switch port count as well as fibre usage. It is shown to produce cheaper network designs than previous methods when fibre costs are comparatively high. A new optical network concept, the synchronous optical hierarchy, is proposed, in which wavelengths are subdivided into timeslots to match the traffic granularity. Various theoretical properties of this concept are investigated and compared in simulation studies. An integer linear programming model for optical ring network design is presented. Manually designed real world ring networks are studied and it is found that the model can lead to cheaper network design. Moreover, ring and mesh network architectures are compared using real world costs, and it is found that optical cros..

Analysis and dimensioning of a single-layer optical network based on a "switchless" concept in relevant scenarios

The "switchless" all-optical network is an alternative networking approach, developed in the framework of the ACTS project named SONATA (Switchless Optical Network for Advanced Transport Network), which aims to provide a future single-layer, advanced transport architecture on a national scale. The single-hop, shared-access network employs time and wavelength agility, using fast tunable transmitters and receivers. The dimensioning of this type of network is one of the main tasks for the design of the network, which serves a certain number of customers, connected together by means of Passive Optical Networks (PONs). This paper reports an analytical model which allows network dimensioning, according to relevant design parameters: number of customers per PON, number of PONs, offered traffic per single user (residential or business), number of total wavelength converters, and the required system performance expressed in terms of blocking probability