Dynamic lightpath establishment in wavelength-routed networks: Analytical models and new control schemes

As a key transmission technology, wavelength division multiplexing (WDM) has been progressing steadily and can now provide more than 1 Tb/s bandwidth on a single optical fiber. To fully utilize these high data rates, wavelength-routed networks have been proposed, in which all-optical connections, or lightpaths [1], can be established between source and destination nodes. Lightpath-based wavelength-routed networks can provide better flexibility and better network resource efficiency than existing point-to-point based WDM networks.; In legacy backbone networks, traffic is generally static, with connections remaining in the network semi-permanently. However, data traffic of next-generation optical networks is expected to be more and more dynamic. Therefore, dynamic lightpath provisioning will become increasingly important in the future.; In this work, we address the dynamic lightpath establishment problem in wavelength-routed networks. In particular, we consider distributed control schemes in which decisions are distributed to network nodes rather than being made by a central controller. Distributed schemes are more appropriate for large optical networks with bursty traffic loads. The main contribution of this work consists of two parts: analytical models for distributed schemes and novel control schemes.; In Chapter 2, we first provide two analytical models for evaluating the blocking performance of two well-known control schemes: destination initiated reservation (DIR) and source initiated reservation (SIR), respectively. These two schemes were originally proposed for networks without wavelength conversion; however, accurate analytical models of these schemes were not available before this work. In Chapter 3, we extend the analytical model to investigate the performance of DIR in networks with sparse wavelength conversion, in which only a subset of nodes have wavelength converters. The analytical results are verified through simulation and shown to be accurate in all cases.; In Chapter 4, we propose a novel framework for a new class of distributed control schemes, namely, intermediate-node initiated reservation (IIR) schemes. In IIR, the reservation can be initiated at a given set of nodes along the path and multiple wavelength channels may be reserved. We provide several IIR implementations, with single (in Chapter 4) or multiple (in Chapter 5) reservations, for networks with no conversion or with sparse conversion. The analysis and simulation results show that the new schemes can achieve much better performance than the original SIR or DIR schemes.