Study On ONT Channel Layer In Apon System Design Of Hardware Circuit

ONT in APON system is an intelligent wide band network terminal appliance, which can make the optical fiber come to house. It's a multimedia equipment located in home and can distribute different bandwidth applications such as vidio, voice, data to all kinds of terminal in home such as TV, telephone, computer and so on. It has the function like set-top-box, but its capacity and quality of service are better than set-top-box existing.This paper originated from the high-tech project of Jiangsu province and its CODE is BG2001046.The paper introduced the functional block schematic of realizing the whole ONT in APON based on the network model of B-ISDN and bring forward path layer system design according to the protocol. It adopt the framework of DSP+FPGA, select FirStreamTM155G chip to accomplish the function of ATM layer and AAL layer and FPGA to fulfill the function of timing cooperation between DSP and FirStreamTM155G, and using Digital Signal Process technology to make a interface with top layer. Finally, we analyzed the problem of signal integrity in high speed circuit design and make a simulation using the signal integrity analyze software -Bordsim, and finished the connectivity debugging.