Autonomous Path Construction via PSA Flooding for Loop-Free Routing

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Solution Overview

Problem

Current communication networks face challenges in efficiently routing packets due to reliance on shortest path routing, which leads to congestion and underutilization of alternate paths, and requires computational overhead for path recomputation during topology changes, resulting in potential loops and increased latency.

Innovation Solution

The implementation of autonomous path construction and routing using Path State Advertisements (PSAs) that flood loop-free unequal cost paths across the network, allowing nodes to automatically set up maximum possible paths to a destination without computational overhead, ensuring zero convergence time and loop-free forwarding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If shortest path routing is used, then routing simplicity is maintained, but network resource utilization is poor and congestion occurs

Engineering Contradiction:
Improvenetwork resource utilizationVSAvoidrouting complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the routing information by creating separate Path State Advertisement (PSA) records for each distinct path to a destination. Each PSA contains independent path elements (links and nodes) and cost information, allowing multiple paths to be maintained simultaneously without requiring complex computations at each node. This segmentation enables efficient network resource utilization while keeping individual path records simple and manageable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by pre-computing and advertising multiple paths to each destination through PSA flooding before any routing decision is needed. Nodes receive and store these pre-advertised paths in their routing tables, eliminating the need for complex real-time path computations during packet forwarding. This preliminary establishment of path information resolves the contradiction by enabling rich path selection without runtime computational complexity.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If path recomputation is performed during topology changes, then routing accuracy is maintained, but convergence time increases and loops may occur

Engineering Contradiction:
Improverouting accuracyVSAvoidconvergence time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements feedback through the PSA flooding mechanism, where topology changes are immediately propagated throughout the network via updated PSA advertisements. When a link or node changes state, the affected node generates new PSA information that is flooded to all other nodes, providing immediate feedback about the topology change. This feedback mechanism maintains routing accuracy by ensuring all nodes have current path information while achieving fast convergence without complex recomputation algorithms.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses preliminary action by pre-establishing multiple alternative paths through PSA flooding before failures occur. When topology changes happen, nodes already have backup paths available in their routing tables from previous PSA advertisements, allowing immediate switching without recomputation. This preliminary preparation of alternative routes maintains reliability while minimizing convergence time and preventing loops.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If multiple paths are advertised, then network utilization improves, but advertisement overhead increases

Engineering Contradiction:
Improvenetwork utilizationVSAvoidadvertisement overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent merges multiple path advertisements into a unified PSA structure that can carry information about multiple paths to different destinations. Each PSA contains a destination node field, path elements field, and cost field that can represent an entire path rather than individual link-state information. This merging reduces the total number of advertisements needed compared to traditional link-state protocols, improving network utilization while controlling advertisement overhead through efficient information packaging.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4395263A1Autonomous path construction and routing
Publication Date: 2024.07.03 NOKIA SOLUTIONS & NETWORKS OY
  • EP4395263A1 patent drawingFigure 1~2
  • EP4395263A1 patent drawingFigure 3~4
  • EP4395263A1 patent drawingFigure 5~6

AI summary

Various example embodiments for supporting autonomous path construction and routing in a communication network are presented. Various example embodiments for supporting autonomous path construction and routing in a communication network may be configured to support autonomous path construction based on flooding of path state advertisements within the communication network. Various example embodiments for supporting autonomous path construction and routing in a communication network may be configured to support autonomous path construction based on flooding of path state advertisements including information supporting construction of full sets of loop-free unequal cost paths between all pairs of network elements in the communication network. Various example embodiments for supporting autonomous path construction and routing in a communication network may be configured to support routing based on autonomously constructed paths that include loop-free unequal cost paths between pairs of network elements in the communication network.