The Research And Implementation Of QoS Model Of GPON System

With the development of Internet, the demand of bandwidth is increasing rapidly and service access tends to be more diversified. As to the GPON system, which plays an important role in Access Network, it needs to provide higher QoS performance to face that challenges. This thesis aims to study and design the QoS model of GPON system and improve the QoS performance, to support multi-user and multi-service access more effectively.The QoS Model of GPON system of my practice unit is studied and an improved QoS Model of GPON system is designed. The main contributions are as following.(1) As to scheduling link of QoS Model, two scheduling modes:service-hierarchy and service-flat are designed, which bring the ability of scheduling based on service to the GPON system. Therefore, the adaptability of GPON system to different deployment scenarios is improved, especially to group user deployment scenario.(2) As to the packet marking link of QoS Model, an improved packets marking scheme called Pbit-Weighted TrTCM (PW-TrTCM) is designed. Comparing to TrTCM, PW-TrTCM can realize differential marking for the packets with different priorities and make the result of packet marking in favour of high-priority packets. Therefore, better QoS guarantee can be provided for high-priority packets. Meanwhile, PW-TrTCM can avoid unnecessary packets loss caused by pre-making based on Pbit.The improved QoS Model has been implemented and verified based on the software architecture of the practice unit. So far, it has been adopted and deployed by many Broadband Network Providers, include Hunan Unicom, Singapore Telecommunications, etc.