10G OLT Transceiver Chip XGPON DFB Laser Burst Mode
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Solution Overview
Problem
Existing OLT terminals based on GPON standard have low data rates, which are insufficient to meet current market demands for high-speed and efficient network performance.
Innovation Solution
A 10 G rate OLT terminal transceiver integrated chip is developed using XGPON and DFB laser technology, incorporating a burst mode receiver, continuous mode transmitter, and digital control unit to enhance data rates and signal quality, with features like double-detection for amplitude and frequency, fast recovery modules, and switchable clock data recovery paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If GPON standard is used for OLT terminal, then network efficiency and bandwidth are improved, but data rate is limited to 2.5 Gbps which is insufficient for current market demands
Solution Approach 1:
The transceiver chip implements dynamic rate adaptation by providing both burst mode (2.5 Gbps) and continuous mode (10 Gbps) transmission paths. The system can switch between these modes based on network conditions and service requirements, allowing the same hardware to serve both existing GPON deployments and future 10-Gbps upgrades without requiring separate hardware systems.
Solution Approach 2:
The OLT terminal transceiver is designed with multi-functionality to support multiple operational modes: burst mode for traditional GPON compatibility and continuous mode for 10-Gbps XGPON services. This universal design enables a single device to handle diverse service requirements from 2.5 Gbps to 10 Gbps, eliminating the need for separate devices for different rate requirements.
2Productivity
If 10 Gbps continuous mode transmitter is implemented, then downlink data rate increases from 2.5 Gbps to 10 Gbps, but signal attenuation and interference increase
Solution Approach 1:
The transmitter incorporates automatic optical power control (APC) and automatic temperature control (ATC) feedback mechanisms that continuously monitor signal quality and adjust operating parameters in real-time. This feedback system compensates for signal attenuation by dynamically adjusting launch power and temperature, ensuring stable 10-Gbps transmission despite variations in fiber conditions and environmental temperature.
Solution Approach 2:
The system changes key transmission parameters including optical power levels, modulation depth, and temperature compensation factors to optimize performance at 10 Gbps. By adjusting these parameters dynamically based on detected signal conditions, the system maintains high data rates while compensating for increased signal attenuation that occurs at higher speeds.
3Ease of manufacture
If DFB laser is used instead of EML laser, then cost is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent adopts DFB (distributed feedback) lasers instead of expensive EML (electromagnetic coupling) lasers. DFB lasers are more cost-effective and easier to manufacture with standard semiconductor fabrication processes. While they require precise wavelength control, the overall system design includes temperature tuning mechanisms that compensate for manufacturing variations, making DFB lasers a cost-effective choice for 10-Gbps OLT terminals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly increases downlink data rates from 2.5 Gbps to 10 Gbps, improving download speeds while maintaining compatibility with DFB lasers, which are cost-effective compared to EML lasers, thereby enhancing network performance and reducing costs.
Implementation Method 1
The LDD includes a threshold configuration module to cooperate with the APC (automatic optical power control) and ATC (automatic temperature control) modules to complete the feedback control of the LDD
Implementation Method 2
The continuous LDD (Laser Diode Driver) converts the data flow of the electrical signal into a modulated current to drive the laser to emit light and transmit the optical signal
Implementation Method 3
a burst mode receiver RX, a continuous mode transmitter TX and a digital control unit DIGIITAL
Data Source
AI summary
A 10 G rate OLT terminal transceiver integrated chip based on XGPON and DFB laser includes: a burst mode receiver RX, a continuous mode transmitter TX and a digital control unit DIGIITAL. The burst mode receiver RX amplifies an optical signal from each ONU client into an electrical signal through a burst TIA, processes double-detection for amplitude and frequency of the electrical signal, outputs the signal whose amplitude and waveform pulse width meet the threshold requirements to the host, and uses a fast recovery module to control the timing to meet the XGPON protocol. The continuous mode transmitter TX receives the electrical signal attenuated by the PCB, and selects the bypass BYPASS path or the clock data recovery CDR path according to the degree of attenuation. The digital control unit DIGIITAL is used to provide control signals for the burst mode receiver RX and the continuous mode transmitter TX.