ONT Apon System Design Of A Prototype Function Testing System

Today's carriers are racing to meet the broadband-services needs of businesses and home users. The number of people and businesses demanding broadband services is far outstripping the current networks' capabilities. ATM-based passive optical networks (APONs) are emerging as the access technology of choice to meet the needs of today's carriers as well as providing the scalability to meet the bandwidth and services requirements of the future.Since 2001, Nanjing University of Science&Technology has undertaken the Jiangsu Province Hi-Tech Project "Research and Development of Optical Network Terminations (ONTs) in Passive Optical Network System Based on ATM". This paper is the summing-up of the design of examination system of ONTs in APON system. The work done in this paper is described as follows:Firstly, the paper presents an introduction to the layered designing scheme of ONT, defines the meaning and examination methods of functional examination of ONTs, and then brings forward the designing scheme of examination system of ONTs. The examination system comprises an examination board in foreground and software in background.Secondly, the key techniques such as burst-mode receiving, burst-mode synchronizing, scrambling and parallel communictation are discussed. They are bases of design.Thirdly, the design method of the examination board based on FPGA is discussed, and the circuit is provided. Specially discussed is the design of digital circuit in FPGA. The results of functional simulation are provided.At last, the software in background is discussed, and the debugging methods, steps and results of examination system are provided.This project is sponsored by the Jiangsu Province Hi-Tech Funds. The project name is Research and Development of Optical Network Terminations in Passive Optical Network System Based on ATM. The project code is BG2001046.