Research On Upstream Dynamic Andwidth Allocation Algorithm Of Passive Optical Network

Under the rapid development of information and communication technologies in modern society, copper access networks are no longer to meet people's growing demand for broadband access and deploying optical access networks become more and more imperative. Futhermore, because PON have several intrinsic advantages, it is the inevitable choice of optical access network. Upstream multiple access control mechanism along with relevant bandwidth allocation algorithm at MAC layer occupy a very important position in PON technologies and play a key role in deciding PON performance as well as realizing multi-service access support. At the base of introducing PON technologies, this thesis focuses on the research of upstream multiple access control mechanism and relevant bandwidth allocation algorithm of PON MAC that can support multi-service access and provide Qos guarantees. The main work and study are as follows.This thesis gives an in-depth introduction and analysis of EPON technology standards and principles, especially the multipoint control sublayer and multipoint control protocol. It focuses on the study of EPON upstream dynamic bandwidth allocation algorithm and proposes a integreated enhanced EPON upstream DBA algorithm based on hybrid bandwidth allocation, namely IEHG-DBA. IEHG dynamic bandwidth algorithm utilizes hybrid GAR/GBR bandwidth allocation method, realizes Qos guarantees for differentiated services and optimizes for EF services. Morevoer, this algorithm can flexiblly adjust bandwidth allocation ratio between AF and BE services by set relevant weights. Furthermore, IEHG-DBA improves the overall performance by utilizing iterative excessive bandwidth allocation, optimally arranging polling order and predicting upcoming AF service packets while generating status reports of AF service. At last, his thesis gives the compter simulation results and analyzes these results, verifying the effetiveness and superiority of the proposed algorithm.This thesis gives an in-depth introduction and analysis of GPON technology standards and principles, especially the GTC layer upstream DBA mechanisms. After that this thesis studies the GPON upstream DBA algotithm and proposes a fair and iterative upstream DBA algorithm based on cyclic polling following the ITU-T standards. The proposed algorithm has the following advantages: 1) based on cyclic polling, easy to implement; 2) guarantees fairness,fairly make dynamic bandwidth allocation; 3) dynamic bandwidth allocation is iterative and increase network bandwidth utilization. This thesis also gives the method of how to modeling GPON upstream DBA mechanisms using OPNET Modeler and then analyzes and verifies the proposed algorithm through computer simulation.SUCCESS-HPON is a next generation TDM/WDM hybrid PON technologies proposed by Stanford University, which has lower network costs, is compatible with legacy TDM-PON and can upgrade from TDM-PON smoothly. This thesis introduces the architecture and principles of SUCCESS-HPON, focuses on the study of MAC protocol and scheduling algorithm of SUCCESS-HPON and proposes a new MAC scheduling algorithm which can not only realize efficient utilization of DWDM tunable devices and wavelength resources, but can provide fairness and Qos guarantees. Futhermore, this algorithm can be easily revised to realize better Qos control and support.