Pre-cross-connected protection architectures for transparent optical transport networks

• Author / Creator

  Grue, Aden

• This thesis presents a collection of studies on the topic of survivable transparent optical networks. As backbone networks increase in capacity, the issue of their survivability grows correspondingly in importance. The transparent optical network offers many advantages as the optical backbone network of the future, but also faces several challenges with regards to network protection. The fundamental question addressed by this thesis is therefore “How can we achieve high availability and failure resiliency in transparent optical transport networks?” We cover the design, characterization, and comparison of several protection architectures, many of them novel, that share the property of pre-cross-connection, a property that is important for protection of transparent networks. The architectures studied include span p-trees, PXTs, path p-trees, p-cycles, FIPP p-cycles, and UPSR-like p-cycles.

  We first present detailed studies of the PXT, span p-tree, and path p-tree architectures. This includes the development of efficient design algorithms and structural analysis of efficient designs. The results indicate a clear hierarchy of efficiency, with cycles being the most efficient, followed by trails, and then trees. However, we discover that architectures with lower average efficiency can be used to complement more efficient structures in rare cases. We also present a new design method for PXTs that is as capacity-efficient as the prior established method, but produces designs with greatly improved structural characteristics.

  We then move on to address PXT protection under a collection of real-world design constraints. The results show that PXTs strike a balance between efficiency and flexibility under these constraints. A further study on the problem of failure localization in transparent p-cycle networks demonstrates the possibility of integrating low cost failure localization capabilities into p-cycle network designs.

  Finally, we propose UPSR-like p-cycles as a way to combine the simplicity and speed of dedicated protection with the flexibility of mesh-based approaches. The results from our design experiments show that this architecture is able to take advantage of mesh topologies in a way that traditional ring-based approaches cannot. We also demonstrate methods by which UPSR-like p-cycle networks can deliver superior dual failure restorability to a select class of high priority services.

• Subjects / Keywords

  • P-cycles
  • Optical network
  • PXT
  • Protection
  • Pre-cross-connected
  • UPSR-like
  • Restorable network
  • P-segment
  • P-tree
  • Transparent
  • Transport network

• Graduation date

  Fall 2009

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3HQ0R

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.