The need to establish wavelength-routed connections in a service-differentiated fash­ ion is becoming increasingly important due to a variety of candidate client networks (e. g. IP, SDH/SONET, ATM) and the requirements for Quality-of-Service (QoS) de­ livery within transport layers. Up until now, the criteria for optical network design and operation have usually been considered independently of the higher-layer client signals (users), i. e. without taking into account particular requirements or constraints originating from the users' differentiation. Wavelength routing for multi-service net­ works with performance guarantees, however, will have to do with much more than finding a path and allocating wavelengths. The optimisation of wavelength-routed paths will have to take into account a number of user requirements and network con­ straints, while keeping the resource utilisation and blocking probability as low as pos­ sible. In a networking scenario where a multi-service operation in WDM networks is assumed, while dealing with heterogeneous architectures (e. g. technology-driven, as transparent, or regenerative), efficient algorithms and protocols for QoS-differentiated and dynamic allocation of physical resources will playa key role. This work examines the development of multi-criteria wavelength routing for WDM networks where a set of performances is guaranteed to each client network, taking into account network properties and physical constraints.

Original study of service-differentiated wavelength routing and connection set-up

1 Introduction.- 1.1 This thesis.- 1.2 Overview.- 2 A QoS-based optical networking.- 2.1 From quality attributes to QoS in optical networks.- 2.2 Wavelength-routed network architecture.- 2.3 A QoS-selective architecture.- 2.4 Basic management and control issues.- 2.5 Restoration in wavelength-routed networks.- 3 Service-differentiated connection set-up.- 3.1 Wavelength-routed services: a debate.- 3.2 Client layer perspectives.- 3.3 The basic model for connection management.- 3.4 Connection and resource management architecture.- 3.5 Two methods for connection set-up.- 4 The methods based on graph transformation.- 4.1 Two methods for QoS-routing revisited.- 4.2 Abstraction of the network state representation.- 5 Algorithms for QoS-based wavelength routing.- 5.1 Wavelength routing update.- 5.2 Benefits of wavelength shifting.- 5.3 Algorithms for service-specific wavelength routing.- 5.4 Methods for service-specific restoration.- 6 Performance study and numerical results.- 6.1 Basic assumptions.- 6.2 Traffic generation.- 6.3 Network topology.- 6.4 Shortest path algorithms revisited.- 6.5 Wavelength routing without service-specific requirements.- 6.6 Service-specific wavelength routing.- 7 Conclusions and future work.- 8 References and further reading.- 9 Abbreviations.- 10 Index.