Research On Dba Algorithm In GPON System

Recently, with the growth of Internet and broadband applications, FTTH (Fiber to the Home) becomes 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 Provider) 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 it's key technologies especially. The key technology of GPON includes dynamic bandwidth allocation (DBA), GPON ranging timely adjust, rapid sudden delayed synchronous technology. The dissertation proposed a new dynamic bandwidth allocation (DBA) scheme:based on the all the T-CONT was proposed. It had further supplemented the present correlation research results and had provided an important reference for the next correlation work researcher.This paper first analyzes the working principle of GPON, the function of its parts and key technology from the point of GPON system structure view. Secondly, key conceptions and principles of GPON DBA are studied deep; the basic technology of DBA is introduced. Thirdly, the dissertation analysis of the upstream GPON DBA algorithm at present, a new DBA algorithm based on the all the T-CONT was proposed, elaborated the specific algorithm for improved scheme.Based on Self-similar regression model, the algorithm predicts demand for the next time and modifies the predictive value through the bandwidth request, then take the modified value as the authorized priority for next stage, and use twice dispatching algorithm based on the priority to fill T-CONT on the ONU-side.Finally, the paper proposes a DBA algorithm that is adapt to GPON and builds the GPON model for this algorithm in OPNET modeler and test its performance. The simulation results prove that this algorithm can well support packet delay and Bandwidth utilization specified in ITU-T standard. It is a highly efficient GPON DBA algorithm that can satisfy QOS requirement and guarantee multi-service fairness.