Cross-Layer Path Computation for IP and Optical Networks

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Solution Overview

Problem

Current network path computation methods in IP and optical networks face challenges such as path computation failures due to resource sharing and independent management, leading to inefficient resource utilization and prolonged service provisioning times, especially when multiple paths are computed simultaneously.

Innovation Solution

The method involves an IP PCE triggering an optical PCE for path computation in the optical network, with the optical PCE returning collision resource group information to the IP PCE for recomputation, ensuring successful path establishment by avoiding resource conflicts and improving network resource utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If IP PCE performs path computation in IP network, then IP service routing is established, but path computation fails when optical layer resources are insufficient

Engineering Contradiction:
Improvepath computation success rateVSAvoidresource sharing capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent merges IP layer path computation with optical layer path computation into a unified cross-layer computation process. When IP PCE fails to compute a path, the system automatically invokes optical PCE to compute optical layer paths, and the results are integrated to provide end-to-end path establishment across both layers, resolving the resource conflict between IP and optical networks

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a cross-layer interaction mechanism as an intermediary between IP PCE and optical PCE. When IP layer path computation fails due to resource constraints, the intermediary triggers optical layer computation, which returns collision resource group information to enable IP layer recomputation with adjusted constraints, ensuring successful path establishment

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If multiple paths are computed simultaneously in IP and optical networks, then service provisioning speed is improved, but resource conflicts increase causing computation failures

Engineering Contradiction:
Improveservice provisioning speedVSAvoidpath computation success rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary optical layer path computation before finalizing IP layer path establishment. By pre-computing optical paths and identifying collision resource groups in advance, the system avoids resource conflicts during simultaneous multi-path computation, ensuring both speed and reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where optical PCE returns collision resource group information to IP PCE after optical path computation. This feedback enables IP PCE to adjust its computation by avoiding identified collision resources, allowing multiple paths to be computed simultaneously without conflicts

Inventive Principle:
Principle #23Feedback

3Loss of time

If optical PCE returns failure information and stops computation, then computation time is reduced, but available paths are missed reducing resource utilization

Engineering Contradiction:
Improvecomputation timeVSAvoidnetwork resource utilization
Core Design Contradiction:
Loss of timeVSLoss of energy

Solution Approach 1:

The patent inverts the traditional failure handling approach instead of stopping computation upon optical PCE failure, the system uses the returned collision resource group information to guide IP PCE in alternative path computation. This inversion transforms a failure condition into an opportunity for finding alternative paths through cross-layer resource allocation

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the computation parameters by introducing collision resource group information from the optical layer into the IP layer computation. This parameter change allows IP PCE to recompute paths avoiding identified collision resources, thereby finding available paths that would otherwise be missed and improving overall network resource utilization

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3249858B1Network path computation method, device and system
Publication Date: 2019.02.06 HUAWEI TECH CO LTD
  • EP3249858B1 patent drawingFigure 1a~1b
  • EP3249858B1 patent drawingFigure 2~3
  • EP3249858B1 patent drawingFigure 4a~4b

AI summary

Embodiments of the present invention relate to the field of communications technologies, and disclose a method, an apparatus, and a system for path computation in a network, which can improve network resource utilization. The method of the embodiments of the present invention includes: if an Internet Protocol path computation element IP PCE fails to perform path computation in an IP network, triggering an optical PCE to perform path computation in an optical network; if the optical PCE fails to perform path computation in the optical network, returning, by the optical PCE, optical network collision resource group information to the IP PCE; and recomputing, by the IP PCE, a path from a source node to a destination node according to the optical network collision resource group information. The present invention is applicable to a network path computation scenario.