Optical Loss Budget Classification in Passive Optical Network Upgrades
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring optical losses in Passive Optical Networks (PON) during upgrades are inaccurate, leading to uncertainty in selecting appropriate transceivers, and existing solutions require costly and complex manual measurements across multiple endpoints.
Innovation Solution
A method involving the OLT stepwise reducing optical output power while monitoring system performance indicators at ONUs to determine the system power margin, allowing for the selection of suitable transceivers with improved accuracy without manual field force effort, utilizing existing transceiver functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual power measurements are performed across multiple endpoints using existing methods, then measurement coverage is achieved, but measurement precision is insufficient (±3 dB accuracy) and device complexity increases
Solution Approach 1:
The OLT performs self-measurement of optical loss by stepwise reducing its own optical output power and monitoring the system performance indicator at the ONU. The OLT determines the system power margin by identifying when the performance indicator drops below the threshold, eliminating the need for external power meters and manual field measurements. This self-service approach achieves precise measurements while reducing device complexity.
Solution Approach 2:
The system implements a feedback mechanism where the ONU monitors the system performance indicator and reports back to the OLT during the stepwise power reduction process. The OLT uses this feedback to determine the system power margin by identifying the power level at which the performance indicator drops below the threshold. This feedback loop enables accurate measurement without requiring complex external measurement equipment.
2Measurement precision
If manual field force measurements are deployed across customer premises, then comprehensive optical loss data is obtained, but ease of operation deteriorates and loss of time increases
Solution Approach 1:
The measurement process is automated and performed remotely through the existing PON management and control interfaces. The OLT autonomously executes the stepwise power reduction and the ONU autonomously monitors the performance indicator, eliminating the need for field force deployment to customer premises. This self-service automation dramatically improves ease of operation while maintaining comprehensive measurement coverage.
Solution Approach 2:
The system performs preliminary measurements during the test phase before final transceiver selection. By conducting the stepwise power reduction and system performance monitoring in advance, the optical loss budget classification is determined beforehand, allowing for proper transceiver selection without requiring subsequent field adjustments or re-measurements.
3Device complexity
If existing transceiver power measurement functions are used, then device complexity is minimized, but measurement precision remains insufficient for reliable transceiver class selection
Solution Approach 1:
Instead of relying on direct power measurements from transceivers, the system uses feedback from the system performance indicator monitored at the ONU. The OLT stepwise reduces its optical output power and the ONU monitors whether the performance indicator remains above the threshold. This indirect feedback-based measurement approach achieves high precision for transceiver class selection while using only existing transceiver functionality without additional complex measurement equipment.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A method for power measurement is disclosed, to be applied in case of upgrade of a passive optical network PON comprising an optical line termination OLT (111), an optical distribution network ODN (120) and optical network units ONUs (131-13n). The method comprises: - the OLT (111) transmitting in a test phase (202) an optical signal starting at the current operational optical output power (210) and stepwise reducing the optical output power (211-214); - the ONUs (131-13n) measuring in subsequent steps of the test phase (202) a predetermined system performance indicator; - a controller (310; 410) determining the difference between the current operational optical output power (210) and the optical output power (214) in a step of the test phase (202) wherein the predetermined system performance indicator drops below a predetermined performance threshold for an ONU, thereby obtaining a system power margin; - determining from the system power margin the minimum optical loss budget of an optical transceiver suitable for the ONUs (131-13n) after upgrade of the PON.