1. 1 Simple provisioning, complex consolidation – An approach to improve the efficiency of provisioning oriented optical networks Tamás Kárász Budapest University of Technology and Economics, Department of Telecommunications E-mail:karasz@hit.bme.hu

2. 2 Outline Motivations Fast provisioning in optical networks Network consolidation „Simple provisioning – complex consolidation” approach Summary and Conclusions

3. 3 Motivations Paradigm changes in the transport network development: - POTS era: the design and dimensioning were based on traffic forecasts (dominant voice traffic, models, measurements) - Internet era: the permanently increasing data traffic becomes the largest traffic component → the modelling and forecasting of services and traffic growth are significantly more difficult → intelligent configuration flexibility or inefficient capacity over-dimensioning are needed → Traffic Engineering (IP layer) → fast provisioning (optical layer)

4. 4 Fast provisioning in optical networks Clients generate permanent, long lasting optical channel requests spread in time and space Distributed signalling and switching intelligence in the optical network nodes Routing and wavelength allocation (RWA) problem is solved on-line Suboptimal decisions Consolidation

5. 5 Provisioning Oriented Optical Networks Three-phase lifecycle: Provisioning: - to set up optical lightpaths performing on-line decisions and configuration actions → suboptimal decisions - the decisions cover both path selection and wavelength assignment - different resilience options can be specified for the optical channel requests Consolidation: - reconfiguration decisions based on the knowledge of a certain group of optical channel requests is definitely more efficient - sequence of reconfiguration actions is needed to set up the obtained optimal network state - different objective functions can be used Extension of the network - additional resources are designed and installed to remove network bottlenecks

6. 6 Network consolidation Some questions to be answered: when (how frequently) what (which subset of accommodated demands) how (which network parameters to modify) limitations (operational cost, service risk, live traffic)

7. 7 When to consolidate? Predefined fixed periods Network state dependent adaptive periods

8. 8 What to consolidate? Total: each already arrived and accommodated demands Selective: demands meeting specific rules

9. 9 How to consolidate? Total: re-design and re-configure demand accommodations (working and backup path and wavelength) Selective: e.g. re-design and re-configure backup path and wavelength only Architectural: provisioning parameter, resilience architecture

10. 10 Simple provisioning, complex consolidation Provisioning with dedicated path protection Consolidation with shared (backup) path protection Different consolidation strategies: - fixed working path and wavelength - fixed working and protection path - optimal allocation

11. 11 Simple provisioning, complex consolidation Different frequently consolidation:

12. 12 Summary and Conclusions Three phase lifecycle for Provisioning Oriented Optical Network Design When, what, how to consolidate For higher efficiency the consolidation can be extended to a higher architectural level of networks „Simple provisioning – complex consolidation” approach

13. 13 Thank you for your attention!