Dynamic Optical Amplifier Gain Control for PON Uplink
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Solution Overview
Problem
In Passive Optical Networks (PON), the increase in single-wavelength modulation rate leads to decreased receiver sensitivity and link power budget, causing issues with uplink signal amplification, as a fixed gain Optical Amplifier (OA) can either over-amplify or under-amplify signals from different Optical Network Units (ONUs), potentially damaging the Optical Line Terminal (OLT) receiver.
Innovation Solution
A method and device where the Optical Amplifier (OA) gain is dynamically adjusted based on a registration signal from the OLT, determining the link attenuation value and adjusting the gain to ensure the uplink optical signal reaches a preset power, preventing damage to the OLT and ensuring adequate bit error rate compliance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed gain Optical Amplifier (OA) is used to amplify uplink optical signals from all ONUs, then the amplification process is simple and device complexity is low, but the receiving power at the OLT varies significantly (up to 20dB difference) causing either over-amplification that damages the OLT receiver or under-amplification that prevents correct reception
Solution Approach 1:
The patent implements dynamic gain adjustment of the Optical Amplifier based on the attenuation characteristics of each ONU. The OA gain is no longer fixed but dynamically adapted to compensate for different link losses, ensuring that uplink signals from all ONUs arrive at the OLT within the acceptable power range. This resolves the contradiction by making the amplification device adaptive rather than static.
Solution Approach 2:
The patent changes the gain parameter of the Optical Amplifier based on the measured attenuation of each ONU's link. By adjusting the OA gain parameter dynamically according to the specific attenuation characteristics, the system ensures reliable reception at the OLT while avoiding over-amplification. This parameter adaptation resolves the contradiction between simple fixed gain and reliable variable gain amplification.
2Reliability
If the OA gain is increased to amplify weak uplink signals from distant ONUs, then signals from distant ONUs can be correctly received, but signals from nearby ONUs are over-amplified and damage the OLT receiver
Solution Approach 1:
The patent applies local quality adjustment by tailoring the OA gain specifically to each ONU's link characteristics. Instead of using a uniform high gain that would over-amplify signals from nearby ONUs, the system adjusts the gain locally for each ONU based on its specific attenuation, ensuring that only the necessary amplification is applied to each signal.
Solution Approach 2:
The patent implements a feedback mechanism where the OLT measures the attenuation of each ONU's link and communicates this information back to control the OA gain. This feedback loop ensures that the OA gain is precisely adjusted to compensate for link loss without over-amplification, resolving the contradiction between adequate amplification for distant ONUs and protection of the OLT receiver from nearby ONU signals.
3Object-affected harmful factors
If the OA gain is decreased to protect the OLT receiver from strong signals, then the OLT receiver is protected from damage, but weak signals from distant ONUs are not amplified enough to be correctly received
Solution Approach 1:
The patent dynamically changes the OA gain parameter based on the specific attenuation of each ONU's link. For ONUs with high attenuation (distant ONUs), the OA gain is increased to ensure adequate signal strength at the OLT. For ONUs with low attenuation (nearby ONUs), the OA gain is decreased to prevent over-amplification and protect the OLT receiver. This parameter adaptation resolves the contradiction.
Solution Approach 2:
The patent makes the OA gain dynamic rather than fixed, allowing it to adapt to the specific requirements of each ONU. The gain is adjusted in real-time based on measured attenuation characteristics, ensuring both receiver protection and adequate signal amplification under different conditions.
Data Source
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AI summary
The present disclosure provides a method and a device for amplifying uplink light of a passive optical network, and a computer-readable storage medium. The passive optical network includes an optical network unit, an optical line terminal, and an optical amplifier provided between the optical network unit and the optical line terminal, and the method include: receiving a registration signal transmitted from the optical line terminal; determining a gain value of the optical amplifier, and performing gain value adjustment on the optical amplifier according to the determined gain value; and completing registration when an uplink optical signal transmitted to the optical line terminal through the optical amplifier reaches preset power.