Optical networks employing wavelength division multiplexing technology have been well recognized as the core networks for the next generation Internet. In such networks, any fiber cut or node failure may lead to huge data loss. Thus, reliability is of great importance in the design of modern high-speed networks. At the same time, traffic grooming is another important design objective since it addresses multi-granularity traffic. The traditional routing approaches with differentiated services do not consider the traffic grooming case or reconfiguration method. Therefore, they are not resource-efficient for the next generation Internet. In this dissertation, an effective reconfigurable traffic grooming with differentiated reliability scheme is proposed to efficiently use network resources. Compared with the conventional rerouting method, the proposed scheme makes the network more robust and immune from service interruptions. An integer linear programming (ILP) formulation is presented first. By solving the ILP formulation, an optimal solution is obtained for each incoming connection request. However, the solution is so time consuming, a heuristic algorithm is introduced to get an approximate optimal solution. The performance evaluation indicates that the connection blocking probability can be decreased greatly by the proposed scheme.

This thesis deals with RC oscillators applicable in higher frequency ranges with the use of modern active elements. For individual function blocks (conveyor, current feedback amplifier, operational transconductance amplifier, voltage feedback amplifier) suitable models are suggested for the circuit simulator PSpice covering their characteristics on various levels, from an ideal one up to the full description of parasitic effects. On the basis of the study of recommended literature and company documentation various oscillator connections of the ranks 2 and 3 are suggested. By analysis through computer (PSpice, SNAP) the fulfilment of oscillation conditions, onset of oscillations were verified and by means of suitable simulations the effects of the impact on the parasitic characteristics of active elements was examined. Finally there are two oscillator connections stated and verified by simulations with the possibility of electronic retuning.