|Thesis abstract: |
Internet traffic has been growing quickly for many years and it is expected to follow this trend in the future as well. The services offered by providers, and in particular Carrier Ethernet services, require not only a huge amount of bandwidth, but also a more flexible access to bandwidth that the traditional transport networks, based on circuit-switching, can hardly provide. An important question is whether the migration to packet switching is cost effective. In addition, network performance should be improved while energy consumption and network complexity should be reduced. This objective can be achieved by using optics instead of electronics in all the network elements, whenever possible. In this context, future interconnection subsystems for switches and routers must overcome the physical limitations of current electronic backplanes in order to achieve an aggregate bandwidth much greater than today¿s. Furthermore, once the transport network is designed and the nodes are deployed, it is necessary to define a multi-domain end-to-end control structure that allows different technologies and domains to inter-work efficiently. Based on this rationale, the main goal of this thesis work is to investigate (i) planning methods to design a high-capacity Carrier Ethernet multi-layer transport network, (ii) Optical Interconnection (OI) architectures to improve the performance of the deployed nodes and (iii) architectures exploiting different algorithms to provide these nodes with end-to-end Quality of Service (QoS) capabilities. The first outcome of the thesis is to provide both a single layer and a multi layer design of a Carrier Ethernet based network. The proposed design solutions aim at minimizing the Capital Expenditure of the network. In the single layer design a set of fundamental parameters to evaluate the pros and cons of migrating from legacy circuit-switched technologies to innovative packet-switched ones are identified and presented. In the multi-layer design of a packet-switched CE network both the electronic and the physical layer impairments are jointly taken into account. Two different procedures are proposed to optimize the network resources deployment. As second outcome of the thesis three OI architectures are presented and analyzed. For each of the proposed architectures a preliminary study to assess the impact of the physical layer impairments on the fabrics is carried out. The performance of the investigated OI architectures is evaluated in terms of scalability (maximum achievable throughput) and in terms of power consumption. The first architecture is based on the Arrayed Waveguide Grating (AWG) devices. The design procedure of the devices and the evaluation of the crosstalk impairment are detailed. Moreover, two crosstalk reduction techniques are presented and their impact on the performance of the architecture is studied. The second proposed OI architecture is based on a structure composed by fixed Micro Ring Resonators (MRRs). The design of the structure components and the optimization of the MRRs parameters are presented. The third architecture is hybrid since its building blocks are both fixed and tunable MRRs. Finally, the third main contribution of the thesis is the definition of a control plane solution based on the cooperation between the Path Computation Element (PCE) architecture and the proposed Domain Sequence Protocol (DSP). Different schemes to provide QoS are presented and their effectiveness is evaluated by means of simulations.