PON Rogue ONU Detection Using LOS and FEC Error Monitoring
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Solution Overview
Problem
In passive optical networks (PON), rogue ONUs that transmit upstream signals continuously without conforming to bandwidth allocation cause signal collisions and communication disruptions, necessitating real-time detection and recovery to restore normal operation.
Innovation Solution
A method and apparatus that monitors upstream signals for Loss of Signal (LOS) and Forward Error Correction (FEC) errors to identify rogue ONUs, deactivates them, and recovers them to normal operation using pre-stored settings without full reactivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rogue ONU continuously transmits upstream signals without conforming to bandwidth allocation, then the rogue ONU maintains its transmission operation, but communication service of other normal ONUs deteriorates due to interference
Solution Approach 1:
The OLT monitors upstream signals from all ONUs and detects LOS signal information and FEC error information. When abnormal continuous signals are detected, the system provides feedback by transmitting a shutdown instruction to the rogue ONU, causing it to stop transmission and eliminate the interference affecting other ONUs
Solution Approach 2:
The system extracts and identifies the rogue ONU from the group of ONUs by monitoring LOS and FEC error information. Once identified, the rogue ONU is isolated through shutdown instructions, separating it from the normal ONU operations to prevent further interference
2Measurement precision
If real-time monitoring of upstream signals is performed to detect rogue ONUs, then detection accuracy is improved, but system complexity and processing load increase
Solution Approach 1:
The monitoring system utilizes existing upstream signal transmission infrastructure and built-in signal processing capabilities of the OLT. The OLT naturally receives and processes upstream signals from all ONUs, and the detection of LOS and FEC error information leverages existing error correction and signal monitoring functions already present in the system
Solution Approach 2:
The OLT performs multiple functions simultaneously: it manages bandwidth allocation for all ONUs, monitors upstream signals for detection purposes, processes FEC error correction, and transmits control instructions. This multi-functionality allows rogue ONU detection to be integrated into existing operations without requiring separate dedicated monitoring equipment
3Loss of time
If deactivated ONU is switched to operation mode using preset ONU setting information, then recovery time is reduced, but risk of incorrect configuration increases
Solution Approach 1:
ONU setting information including configuration parameters and identification data is stored in advance in the OLT's memory before the ONU becomes rogue. When recovery is needed, the OLT retrieves these pre-stored settings and rapidly reconfigures the ONU, eliminating the need for time-consuming detection and configuration processes while maintaining accuracy through use of previously verified settings
Data Source
AI summary
A rogue ONU detection and recovery method in a PON network includes steps of: monitoring upstream signals transmitted from a plurality of ONUs to an OLT to acquire LOS signal information and FEC error information; sensing an operation of the rogue ONU in the PON network on the basis of the LOS signal information and the FEC error information; and deactivating at least one of the plurality of ONUs and recovering the rogue ONU to a normal ONU according to whether or not the operation of the rogue ONU is released.