Qos-Based Wavelength Routing in Multi-Service Wdm Networks

ISBN-13: 9783211836255 / Angielski / Twarda / 2001 / 244 str.

Admela Jukan

Opis

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."

Spis treści

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.- 2.2.1 Applications and waveband hierarchies.- 2.3 A QoS-selective architecture.- 2.4 Basic management and control issues.- 2.4.1 QoS management for wavelength-routed networks.- 2.5 Restoration in wavelength-routed networks.- 2.5.1 A simple taxonomy for service restoration.- 2.5.2 Optical network service restoration.- 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.- 3.4.1 Parameter translation between optical and non-optical layers.- 3.4.1.1 Transmission quality.- 3.4.1.2 Restorability.- 3.4.1.3 Manageability.- 3.4.1.4 Security.- 3.5 Two methods for connection set-up.- 3.5.1 The basic flows for the service-specific connection set-up.- 3.5.2 A functional model for service-specific restoration.- 4 The methods based on graph transformation.- 4.1 Two methods for QoS-routing revisited.- 4.2 Abstraction of the network state representation.- 4.2.1 A few basic notations for graphs.- 4.2.2 Graph transformation.- 4.2.3 Weight labelling.- 4.2.3.1 Network element allocation.- 4.2.3.2 Network element connection.- 4.2.4 Operations with multi-dimensional metrics.- 4.2.5 Solving routing problems with single (mixed) metric.- 4.2.6 Solving routing problems with multiple metrics (QoS-routing).- 4.2.7 Multi-constraint routing problem revisited.- 5 Algorithms for QoS-based wavelength routing.- 5.1 Wavelength routing update.- 5.2 Benefits of wavelength shifting.- 5.2.1 Mathematical modelling.- 5.2.2 Influence of load correlation.- 5.2.3 Sparse and limited-range wavelength shifting.- 5.3 Algorithms for service-specific wavelength routing.- 5.3.1 The methods with service-specific wavelength grouping.- 5.3.1.1 Least quality wavelength allocation.- 5.3.1.2 Minimisation of resource utilisation.- 5.3.1.3 Alternate routing for overloaded multi-wavelength resources.- 5.3.2 The algorithms based on graph transformation.- 5.3.2.1 General algorithm with graph transformation.- 5.3.2.2 Least quality wavelength routing with graph transformation.- 5.3.2.3 Service-specific minimisation of wavelength shifting.- 5.3.2.4 Service-specific signal regeneration.- 5.3.3 Separation of service attributes and routing function.- 5.3.4 A distributed QoS-routing method.- 5.4 Methods for service-specific restoration.- 5.4.1.1 Dynamic path restoration (DPR).- 5.4.1.2 Dynamic link restoration (DLR).- 5.4.1.3 Static path restoration (SPR).- 5.4.1.4 Static link restoration (SLR).- 5.4.1.5 Shared wavelength path restoration (SWPR).- 5.4.1.6 Shared wavelength link restoration (SWLR).- 5.4.1.7 A comparison between different restoration methods.- 5.4.1.8 Link-disjoint path algorithm.- 5.4.1.9 Node-disjoint path algorithm.- 6 Performance study and numerical results.- 6.1 Basic assumptions.- 6.2 Traffic generation.- 6.2.1 Binomial and Poisson distributions.- 6.2.2 Random traffic generation and confidence intervals.- 6.2.2.1 Transient phase.- 6.2.2.2 Method of independent replications and batch means.- 6.3 Network topology.- 6.3.1 Randomly generated graphs.- 6.4 Shortest path algorithms revisited.- 6.5 Wavelength routing without service-specific requirements.- 6.5.1 Benefits of wavelength shifting.- 6.5.1.1 Network load.- 6.5.1.2 Number of wavelengths.- 6.5.1.3 Connectivity.- 6.5.1.4 Network size.- 6.5.1.5 Topology.- 6.5.1.6 Influence of load correlation.- 6.5.1.7 Sparse wavelength shifting.- 6.5.1.8 Final remarks regarding wavelength shifting.- 6.6 Service-specific wavelength routing.- 6.6.1 Regular network operation.- 6.6.2 Service restorability.- 7 Conclusions and future work.- 8 References and further reading.- 9 Abbreviations.- 10 Index.