Tesis doctoral de Siamak Azodolmolky
Core optical networks using reconfigurable optical switches and tuneable lasers appear to be on the road towards widespread deployment and could evolve to all-optical mesh networks in the coming future. No matter which architecture is considered, the main goal of these architectures is to provide the required infrastructure for end-to-end connection establishment in a cost effective manner. efficient planning and operation of transparent optical network introduces interesting challenges, which are addressed in this study. when selecting a lightpath (route and wavelength), a routing and wavelength assignment (rwa) algorithm for a transparent or translucent network has to take into account the physical layer impairments as well as the wavelength availability. With static traffic (i.E., Network planning), the entire set of connection requests is known in advance, and the static (off-line) rwa problem of setting up these connection requests is named the offline impairment aware rwa (ia-rwa) problem. There are quite few proposals that address the resilience and protection issues in the ia-rwa algorithms for network planning. In static (off-line) case, there is enough time between the planning and provisioning (i.E., Actual lightpath establishment) processes such that any additional equipment required by the plan can be deployed. In this context, the main goal is to accommodate the whole demand set. in a dynamic traffic scenario, the connections are requested in some random fashion, and the lightpaths have to be set up as needed. In dynamic traffic scenario, there is little time between planning and provisioning, and demands are generally processed one at a time. It is assumed that the demand set must be accommodated using whatever equipment is already deployed in the network. Thus, the ia-rwa proposal must take into account any constraints posed by the current state of the network, which may force a demand to be routed over a sub-optimal path. One big challenge for ia-rwa algorithms is the quality of transmission (qot)-awareness, in the sense that they must ensure (during admission control) that all lightpaths in the network meet a qot constraint (e.G., Ber) without disrupting previously established lightpaths. in addition to simulation studies, experimental and some analytical models are available to evaluate the performance of the proposed algorithms. None of the surveyed works considers the inaccuracy of the physical impairment information (analytically computed or measured) into their ia-rwa algorithms. The proposed adaptive ia-rwa algorithms simply change their decisions assuming that the physical information are completely accurate. in the first chapter, the evolution of optical networking, the hierarchical model and layered models, along with the evolution of configurable optical networks and planning and operation of them is compiled. in the second chapter of this ph.D. Dissertation a comprehensive study on current proposals on impairment aware optical networking is compiled. The general approach to address the ia-rwa problem can be divided in two main categories. The first trend utilizes traditional rwa algorithms and after selecting the lightpath the physical constraints are verified. The second approach is to use some metrics, which are related to the physical layer impairments as cost of the links in order to compute the shortest path(s). The physical impairments and ia-rwa algorithms can be incorporated in control planes using various integration schemes. evaluating the performance of the physical layer and the impact of physical layer impairments on the optical signals plays an important role. In the third chapter (chapter 3) the physical layer impairments, their classification and impacts, the proposed models and also the qot estimator, which is utilized in the contributed algorithms are presented. In fact the qot estimator is one of the key building blocks for impairment aware planning and operation of optical networks.
Datos académicos de la tesis doctoral «Physical impairments aware planning and operation of transparent optical networks«
- Título de la tesis: Physical impairments aware planning and operation of transparent optical networks
- Autor: Siamak Azodolmolky
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 25/02/2011
Dirección y tribunal
- Director de la tesis
- Josep Sole Pareta
- Tribunal
- Presidente del tribunal: jordi Domingo pascual
- biswanath Mukherje (vocal)
- emmanouel Varvarigos (vocal)
- andrzej Jajszczyk (vocal)