GPON Downlink Synchronization Domain FEC for Header Bit Errors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high bit error rate of the frame header in Gigabit-capable passive optical networks (GPON) systems, particularly in 10 G GPON, leads to asynchronous states in optical network terminals, disrupting downlink data transmission and compromising system reliability.
Innovation Solution
Implementing forward error correction (FEC) encoding using the Reed Solomon code RS (255, 239) on the synchronization domain of downlink frames, which includes a physical synchronization (Psync) and identifier (Ident) domain, and incorporating a 16-byte FEC check domain to correct errors and maintain frame synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the downlink rate is increased from 2.5 Gbps to 10 Gbps in 10 G GPON, then the transmission speed is improved, but the bit error rate of the frame header is greatly increased
Solution Approach 1:
The patent applies forward error correction (FEC) encoding to the Psync and Ident domains before transmission. This preliminary encoding process prepares the synchronization data with error correction capabilities in advance, allowing the receiver to detect and correct bit errors that occur during high-speed transmission, thus resolving the contradiction between increased transmission rate and increased bit error rate
Solution Approach 2:
The patent converts the harmful effect of high bit error rates into a benefit by using FEC encoding. The encoding process adds redundancy bits that enable the system to not only tolerate but actually correct errors, transforming the potential harm of high-speed transmission errors into a demonstration of robust error correction capability that maintains reliability at 10 Gbps
2Reliability
If FEC encoding is carried out on the synchronization domain, then the reliability of frame synchronization is improved, but the device complexity is increased
Solution Approach 1:
The patent applies FEC encoding selectively only to the synchronization domain (Psync and Ident fields) rather than the entire frame. This localized approach provides error protection where it is most critical for frame synchronization while avoiding the unnecessary complexity of encoding the entire data payload, thus improving synchronization reliability without proportionally increasing overall device complexity
Solution Approach 2:
The patent implements partial FEC encoding by applying error correction only to the critical synchronization portion of the frame (8 bytes of Psync and Ident domains) rather than the complete frame structure. This partial action provides sufficient error protection for synchronization purposes while keeping the encoding complexity manageable and avoiding excessive processing overhead
Data Source
AI summary
Disclosed in the present invention are a method and apparatus for processing downlink frame synchronization in a Gigabit-capable passive optical network (GPON) system, wherein the method comprises: carrying out forward error correction (FEC) encoding on data in a synchronization domain of a downlink frame of the GPON system, wherein the synchronization domain includes a physical synchronization (Psync) domain and an identifier (Ident) domain; filling the FEC encoded data into an FEC check domain provided in the downlink frame; and sending the downlink frame. By virtue of the present invention, the effect of improving the reliability of GPON downlink frame synchronization is achieved.