PON Standby OLT Ranging for Reduced Service Interruption
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Solution Overview
Problem
Current PON systems experience long service interruptions due to the time-consuming process of measuring distance parameters between a standby optical line terminal (OLT) and optical network units (ONUs) after a link failure, leading to excessive service downtime.
Innovation Solution
The standby OLT measures distance parameters between itself and each ONU using a secondary management channel while the primary OLT continues data transmission, allowing seamless switching to the standby OLT without interrupting service data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the standby OLT measures distance parameters after switching to it, then measurement accuracy is ensured, but service interruption time becomes excessively long
Solution Approach 1:
The patent applies preliminary action by having the standby OLT measure distance parameters to ONUs before a link failure occurs. The standby OLT continuously maintains distance parameter information through periodic measurements or pre-established databases, so that when switching is needed, the measurement is already complete and accurate data is immediately available, eliminating the time delay associated with post-switching measurements.
Solution Approach 2:
The patent implements dynamics by making the distance parameter measurement process adaptive and flexible. The system can dynamically adjust measurement frequency based on network conditions, switch between different measurement methods (time-of-flight, signal strength), and update distance parameters in real-time without disrupting service, allowing the measurement system to respond efficiently to changing conditions.
2Speed
If the standby OLT performs ranging before switching, then service switching speed is improved, but system complexity increases
Solution Approach 1:
The patent applies universality by designing the standby OLT to perform multiple functions: it serves as both a backup transmission path and an active measurement node. The same hardware and software resources at the standby OLT are used for both maintaining distance parameter databases and performing actual service transmission, eliminating the need for separate dedicated measurement equipment and reducing overall system complexity.
Solution Approach 2:
The standby OLT performs self-service by autonomously maintaining its own distance parameter database through independent measurements and updates. It can automatically detect link failures, initiate measurements, and update its database without external intervention, reducing the need for complex centralized control mechanisms and simplifying the overall system architecture.
3Measurement precision
If the primary OLT stops sending downlink optical signals for ranging, then ranging accuracy is improved, but service data transmission is interrupted
Solution Approach 1:
The patent applies segmentation by separating the management channel functions from the service data transmission functions. The downlink optical signal is divided into distinct segments: one for management/ranging purposes and another for service data transmission. This allows the ranging function to operate independently without interrupting service data flow, as each can use different time slots, frequencies, or code divisions.
Solution Approach 2:
The patent introduces an intermediary mechanism where the standby OLT acts as a mediator for distance parameter measurements. Instead of the primary OLT directly interrupting service transmission to perform ranging, the standby OLT performs measurements through alternative paths or using pre-established connections, serving as an intermediary that enables accurate ranging without disrupting the primary service data transmission path.
Data Source
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AI summary
This application pertains to the communications field, and discloses a method and an apparatus applied to a PON system, a system, and a storage medium. The PON system includes a primary OLT, a standby OLT, and at least one ONU. The primary OLT performs window open ranging on the at least one ONU over a first management channel, and the primary OLT performs service data transmission with any ONU over a first service channel. The method includes: The standby OLT determines that the primary OLT stops sending a downlink optical signal over the first management channel. The standby OLT sends a ranging request to a first ONU over a second management channel, where the first ONU is one of the at least one ONU, and the second management channel is a channel between the standby OLT and the at least one ONU. The standby OLT obtains a distance parameter between the first ONU and the standby OLT based on a ranging response received from the first ONU over the second management channel. In this application, service interruption duration can be reduced.