OEO Ranging Packet Timing for PON Delay Jitter Control
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Solution Overview
Problem
In passive optical network (PON) systems, delay jitters accumulate due to optical-electrical-optical converters (OEOs) causing large delays and instability in signal transmission, leading to data loss and interference.
Innovation Solution
Implement a method where OEOs delay sending ranging packets based on jitter elimination parameters to determine equalization delays, allowing for dejitter processing on upstream data to eliminate delay jitters and improve transmission performance and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If OEOs are deployed to lengthen transmission distance, then transmission distance is improved, but delay jitter accumulates causing large delays and instability
Solution Approach 1:
The patent applies preliminary action by having the first OEO delay the ranging packet before it reaches the OLT. This advance delay compensates for the cumulative delay jitter that will occur during subsequent transmission, ensuring that the packet arrives at the correct time despite the unstable OEO processing. The OLT calculates the equalization delay based on this pre-delayed ranging packet, allowing downstream OEOs to compensate for their own delay jitters in advance.
2Reliability
If delay jitter is eliminated through dejitter processing, then signal transmission stability is improved, but transmission time is increased
Solution Approach 1:
The patent performs dejitter processing in advance by delaying the ranging packet before the OLT receives it. This allows the system to calculate the correct equalization delay beforehand, so that when actual data transmission occurs, the compensation can be applied efficiently without requiring extensive real-time processing. The OLT uses the pre-calculated equalization delay to adjust downstream timing, reducing the need for complex real-time adjustments.
3Measurement precision
If equalization delay is calculated based on receiving time, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent simplifies the measurement process by using a pre-delayed ranging packet that arrives at the OLT at a known, controlled time. The OLT calculates the equalization delay based on the difference between the expected arrival time (after applying the first OEO's delay) and the actual arrival time. This preliminary timing adjustment provides a clean, precise measurement without requiring complex real-time analysis of multiple delay components, reducing the computational burden on the OLT.
Data Source
AI summary
Embodiments of this application disclose a communication processing method. The method includes: A first optical-electrical-optical converter OEO receives a ranging packet of an optical network unit ONU at a first moment. The first OEO sends the ranging packet to a next-level OEO of the first OEO or an optical line termination OLT after a delay of M bits or a delay of first duration from the first moment based on a jitter elimination parameter of the first OEO, where the OLT is connected to the ONU through N levels of OEOs, the first OEO is one of the N levels of OEOs, M is an integer greater than or equal to 1, and N is an integer greater than or equal to 1.