Optical Mesh Network Routing via Expected Blocking Probability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In optical mesh networks, efficiently allocating paths and spectrum for new circuits while minimizing data blocking and optimizing bandwidth distribution across links is a complex challenge due to the increasing number of nodes and data flows.

Innovation Solution

A computer-implemented method identifies potential paths in a mesh optical network by calculating costs for frequency slots based on optical fiber length, selecting paths with the lowest total cost, and allocating frequency slots to optimize circuit routing and spectrum allocation, considering the lengths of optical circuits that can traverse each link.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If more nodes, data flows, and links are added to the network to increase capacity and connectivity, then network functionality and adaptability improve, but path allocation complexity and difficulty increase

Engineering Contradiction:
Improvenetwork functionalityVSAvoidpath allocation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent transforms the path selection problem from a complex combinatorial optimization into a simpler shortest-path problem by changing the parameter being optimized from bandwidth allocation to expected blocking probability. This is achieved by calculating costs based on link utilization and converting them into expected blocking probabilities, allowing standard shortest-path algorithms to be used instead of complex traffic engineering optimizations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary computational layer that calculates expected blocking probabilities for each link based on current utilization and circuit length. This intermediary metric serves as a mediator between the physical network state and the routing decision, translating complex network conditions into a simple cost metric that can be processed by standard routing algorithms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If bandwidth allocation is optimized to minimize blocking probability, then network reliability improves, but computational complexity and processing time increase

Engineering Contradiction:
Improveblocking probabilityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the optimization parameter from direct bandwidth allocation to expected blocking probability minimization. By expressing link costs in terms of expected blocking probability rather than raw bandwidth metrics, the system achieves better reliability while using simpler shortest-path algorithms instead of complex bandwidth optimization routines.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the routing decision into two independent components: (1) calculating link-specific expected blocking probabilities based on utilization and circuit length, and (2) applying standard shortest-path algorithms using these pre-calculated metrics. This segmentation allows complex reliability optimization to be separated from the routing algorithm itself.

Inventive Principle:
Principle #1Segmentation

3Productivity

If traffic engineering is used to optimize bandwidth distribution, then network efficiency improves, but system complexity and difficulty of implementation increase

Engineering Contradiction:
Improvenetwork efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces expected blocking probability as an intermediary metric that translates complex traffic engineering considerations into simple routing costs. This intermediary layer maintains network efficiency by capturing utilization and circuit length effects while allowing standard routing algorithms to handle the optimization, avoiding the need for complex traffic engineering systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements feedback by continuously monitoring link utilization and adjusting expected blocking probability calculations accordingly. This feedback mechanism allows the system to adapt to changing network conditions and maintain optimal efficiency without requiring complex manual traffic engineering adjustments.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3815315B1Physical layer routing and monitoring
Publication Date: 2023.05.10 GOOGLE LLC
  • EP3815315B1 patent drawingFigure 1
  • EP3815315B1 patent drawingFigure 2
  • EP3815315B1 patent drawingFigure 3

AI summary

Systems and methods for allocating optical circuits on optical mesh networks are disclosed herein. For example, the disclosed methods include identifying a new circuit to be added to a mesh optical network and identifying a set of potential paths for the new circuit. For each optical link in each identified potential path, costs are determined for a plurality of frequency slots of allocating the new circuit to a potential path including the optical link. The cost of allocating a given frequency slot on a given optical link is determined in part based on the lengths of optical circuits that can traverse the given optical link using that frequency slot. Total cost values are calculated for allocating available frequency slots over each of the identified potential paths, and one of the identified potential paths and one or more of the available frequency slots are allocated for the new circuit.