| Recent years, with the development of popularization and broadband Internet application, FTTH is widely considered as a kind of ideal integrated access solutions with the ultimate goal of access network development. In all kinds of optical access technology, because of variety of rate, full service's Qos guarantee, powerful survivability, high efficiency, and other unique advantage, and fully consider the opinions of the operators, GPON technology thinks over opinions of operating agencies and it is considered to be the best choice of the broadband access in the future. Therefore, the research on GPON technology, especially the study of key technology of GPON has very important position.Dynamic bandwidth allocation (DBA) technology is one of the key technology of GPON system. In the whole system, effective dynamic bandwidth allocation can change GPON system every optical network unit of uplink used bandwidth ONU adapted to user rate in real-time, make all kinds of changes to improve the system bandwidth utilization. The thesis is based on high bandwidth utilization and QoS equity support, report type (NSR) DBA insufficiency from existing DBA strategy analysis of the existing status, wavelet analysis into GPON service forecast is designed based on wavelet multiresolution analysis of dynamic bandwidth GPON match scheme. GPON system presents from the similarity and uplink business multiple points sex, raise the frame of predict model, through wavelet model can achieve flow monitoring accurately. According to the monitoring of bandwidth requirements, using weight priority bandwidth allocation mechanism for ONU transmission container the bandwidth required for a reasonable distribution. Then, to solve DBA defects of status report (SR), improve DBA algorithm of put forward the ONU server new business and compensation, put business forecast correction module into ONU end join waiting time, to compensate defects of when OLT received bandwidth request frame can't reaction condition of moments of caching authorized, thereby to reduce the transmission delay and improve business leisure time buttress utilization.On the scheme designed basis, OPNET simulation platform is introduced in thesis, in accordance with the principle of GPON network, establishes the simulation model, this model has uplink frame, and the frame, descending radio data frame for piece-wise restructuring, and other functions. And the average delay mainly from business characteristics and bandwidth utilization two respects inspect the scheme of business QoS guarantee. The simulation results are analyzed to verify the two sets of the effectiveness of the proposed scheme and feasibility. |
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