Architectures of dynamically reconfigurable wavelength routing/switching networks

The enormous bandwidth available in single-mode optical fiber far exceeds the speed that it can be accessed by electronics. To utilize more efficiently this huge bandwidth some means of concurrency is needed. The easiest way to access this bandwidth is directly through the wavelength domain, where many wavelengths are multiplexed together. This technique is called wavelength division multiplexing (WDM). This thesis examines new network architectures made possible by utilizing recent advances in WDM technology. We propose several new architectural concepts together with their realizations. The work focuses on design issues and performance analysis taking into account technological constraints. The first contribution is the generalization of classical rearrangeable and non-blocking switching networks to the wavelength dimension, defining the interplay between the space and wavelength dimensions. This results in new network architectures called wavelength-space division switches featuring higher capacity, higher connectivity and less complexity than is possible when using either the space or wavelength dimensions alone. The second contribution is the concept of multi-dimensional switching networks. We generalize the two most commonly used types of WDM networks to the multi-dimensional case resulting in multi-dimensional routing networks and multi-dimensional broadcast networks. Using several dimensions (e.g., wavelength, time, space) results in increased connectivity and reduced complexity, due to reuse of network resources. The third contribution is a new WDM switch design based on wavelength grouping/dilation. Wavelength-dilated switches are high density, low crosstalk wavelength-selective switches. This technique is found to be very useful when implemented in acousto-optic tunable filter (AOTF) technology, suppressing a severe type of coherent crosstalk, making the AOTF practical for sub-nanometer wavelength spacings. The final contribution is a static power control scheme for dynamically reconfigurable networks. We propose a static power distribution rule. This guarantees small fluctuations in power levels and can simplify power control when the network is dynamically reconfigured and the number of wavelengths per link varies in time. Finally, analytical models of distributed networks are provided, and the performance limits due to optical amplifier noise accumulation, crosstalk and dispersion are calculated.