Gpon System, Dynamic Bandwidth Allocation Algorithm For The Simulation Study

Recently, with the growth of Internet and broadband applications, FTTH(Fibre to the Home) become the objective of access networks and is accepted as a kind of excellent integrated solution for access network. Among kinds of optical access network techniques, GPON supports multi-speed rates, full-services QOS, robust network, high efficiency and other advantages, and considers the suggestions of SPs(service providers) at the same time. GPON is regarded as one of the best choices for broadband access network in the future. So it is very important to research GPON and its key technologies especially.The dissertation includes technique background of GPON, protocol summary, function architectures of OLT and ONU, DBA(dynamic band allocation)algorithm and so on. Based on the comprehension of protocols of ITU-T G.984 and the analysis of many research results, we gives a solution of the architecture design for OLT and ONU in GPON system. Then based the research of DBA, the dissertation describes a DBA algorithm that is adapt to GPON and builds the model for this algorithm in OPNET and test its performance.The first chapter FOREWORD introduces the history of PON network, necessity of GPON, analysis of marketing and the features of GPON products. The second chapter explains GPON protocols and network configuration, and then describes the function architecture and frame format of GTC. The third chapter introduces the function architecture of OLT and ONU, and then describes the functions and architectures of the key modules.The fourth chapter shows the information about DBA in GPON protocols at first. Then the chapter explains the function principle of DBA, its signals and format, and the several work modes in DBA. Based the past research results, the fifth chapter proposes a DBA algorithm that is adapt to GPON and builds the model for this algorithm in OPNET and test its performance. The simulation results show this algorithm can satisfy the full service QOS requirements of GPON.