Literaturverz. S. 421 - 425

Techn. Univ., Diss.--Hamburg-Harburg, 2002.

Techn. Universiẗat, Diss., 2007--Darmstadt.

Zugl.: Hannover, University, Diss., 2006.

Zugl.: Aachen, Techn. Hochsch., Diss., 2008.

Zugl.: Dresden, Techn. University, Diss., 2008.

Zugl.: München, Techn. Univ., Diss., 2009

Techn. University, Diss., 2005--Berlin.

In dieser Arbeit werden verschiedene Methoden zur Erhöhung der Systemtoleranz optischer Übertragungssysteme theoretisch analysiert, durch numerische Simulationen untersucht und in Experimenten und Feldversuchen praktisch überprüft. Der Schwerpunkt lag dabei auf empfängerseitigen elektronischen sowie optischen Entzerrern. Diese Entzerrer verbessern die Signalübertragung, in dem sie die Augenöffnung des Signals am Empfänger vergrößern oder in dem sie durch digitale Logikschaltungen das gesendete Signal aus einem gestörten Signal rekonstruieren. Der Schwerpunkt dieser Arbeit liegt jedoch auf der Untersuchung der Entzerrer auf Systemebene, d.h. es wird das Verhalten in einem kompletten optischen Übertragungssystem bestehend aus Sender, Glasfaserstrecke und Empfänger bewertet. Zur Untersuchung wurde eine Simulationsumgebung in der Programmiersprache FORTRAN erstellt, in der die unterschiedlichen Entzerrer in verschiedenen Netz-Szenarien untersucht wurden. Zur praktischen Untersuchung wurde außerdem eine Testumgebung im verlegten Glasfasernetz aufgebaut und eine Realisierung eines Entzerrers experimentell untersucht. / In this thesis, several methods for the enhancement of the tolerance of optical transmission systems are analyzed theoretically, investigated in numerical simulations and evaluated in experiments and field trials. The investigations were thereby focused on receiver sided electronic and optical equalizers. Those devices improve the signal transmission by increasing the eye-opening at the receiver or by reconstructing the original signal from the distorted received signal by the use of digital signal processing. However, this thesis is focused on the investigation of different equalizers on a system level where the performance of a complete transmission system consisting of a transmitter, transmission fiber and receiver is evaluated. For those studies a simulation environment was created using the programming language FORTRAN where the different equalizers were evaluated in different network scenarios. For practical investigations, a test environment was created using the deployed fiber infrastructure and specific equalizer realization were evaluated experimentally.

Fiber-deployment of future telecommunications networks ("Next Generation Access" - NGA) is currently a major challenge for sector-specific regulators as well as for investing firms. Although the future socio-economic importance of new telecommunications networks is uncontroversial, the related investment activities vary substantially in international comparison. This work intends to identify the most important determinants of previous NGA deployment using data from the EU27 member states for the years 2005 to 2010. For our analysis, we employ latest data on NGA deployment, relevant competition and regulatory indicators as well as other supply and demand side controls. Our econometric model incorporates: i) aggregated country level data; ii) structurally modeled dynamics of the deployment process which allows us to disentangle long-term and short-term effects; finally, iii) we argue that there is no endogeneity problem with respect to investment activities and regulation since we refer to regulation in preceding broadband markets. For our econometric analysis, we employ several dynamic panel data methods, such as GMM and LSDVC. Our results indicate that stricter previous broadband access regulation has a negative impact on NGA deployment. As regards the dynamics of the adjustment process, we find that there are severe adjustment costs and stickiness towards the desired long-term level of NGA infrastructure. (author's abstract) / Series: Working Papers / Research Institute for Regulatory Economics