Single-Fiber PON Protection via 2x2 Splitter Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing passive optical networks face challenges in providing cost-effective protection against single link failures, implementing fast fault detection, and efficiently rerouting traffic without significant increases in cost or optical power loss, particularly in access networks.
Innovation Solution
A single-fiber passive optical network utilizing 2-by-2 splitters/combiners with a detector to monitor optical power levels and switch between active and standby transmitters, enabling fast fault detection and rerouting, and incorporating an auto-discovery process to update routing tables and establish dedicated paths for affected traffic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ring splitters/combiners are used to provide protection against single link failures, then reliability is improved, but optical power loss increases due to multiple stages of splitting
Solution Approach 1:
The patent extracts the protection function from multiple ring splitters/combiners and consolidates it into a single 2-by-2 splitter/combiner. By removing the redundant splitting stages, the system maintains single link failure protection while eliminating the cumulative optical power loss that occurred with multiple splitting stages in prior art solutions.
Solution Approach 2:
The patent merges the protection functions of multiple ring splitters/combiners into a single 2-by-2 splitter/combiner device. This consolidation combines the protective capabilities while reducing the total number of optical components, thereby minimizing optical power loss and simplifying the network architecture.
2Speed
If 1+1 architecture with two overlaid PONs is used for protection, then fast protection switching is achieved, but bandwidth requirement doubles and cost increases
Solution Approach 1:
The single 2-by-2 splitter/combiner serves multiple functions: it provides both the working and protection path routing capabilities that previously required two separate PONs. This multi-functional device enables fast protection switching while utilizing the same bandwidth infrastructure, eliminating the need for doubled bandwidth requirements.
Solution Approach 2:
Instead of creating a complete duplicate protection PON with full bandwidth allocation, the patent uses a single splitter/combiner to create a virtual copy of the protection path. This allows fast switching capability without the full bandwidth overhead of a physical duplicate network.
3Reliability
If multiple ring splitters/combiners are used for protection, then protection coverage is improved, but device complexity and cost per user increase
Solution Approach 1:
The patent extracts the essential protection function from a complex arrangement of multiple ring splitters/combiners and isolates it to a single 2-by-2 splitter/combiner. This extraction removes unnecessary components while preserving the core protection capability, thereby reducing device complexity and cost per user.
Solution Approach 2:
The single 2-by-2 splitter/combiner is designed to perform multiple protection functions that previously required several separate devices. By making this single component multi-functional, the system achieves comprehensive protection coverage with minimal hardware, reducing both complexity and cost.
Data Source
AI summary
A solution for detecting and recovering from a failure in a protected single-fiber passive optical network. A detector is used to detect the degradation in power level of optical signals. Furthermore, the invention discloses a variable symmetric split ratio approach to improve the number of splits (e.g. the number of ONUs). A single-fiber passive optical network is disclosed that uses a plurality of passive nodes connected in the optical fiber between the interfaces, wherein in the passive nodes 2-by-2 splitters/combiners are used to couple optical power from and into the optical fiber at a predetermined split ratio.