.10 G-dynamic Of Epon Bandwidth Allocation Algorithm Implementation And Verification

EFM (Ethernet in the First Mile) is established in 2000, and 1G EPON standard was released in October 2005. In order to improve the transmission rate and optimizing the performance of the system, 10G EPON standards is issued in September 2009.But the key technologies of EPON--DBA is not explicitly specified in both the two standards. It is significant to research on the scheme of DBA.Based on compatible with the 1G EPON, the dynamic bandwidth allocation algorithm of 10G EPON is implemented in this dissertation. The main specifications to be completed are as follows: Firstly, support fix bandwidth,ensure bandwidth,BEB bandwidth and the configuration of them. Secondly, for the priority of ONU, the allocations of BEB bandwidth are firstly in high-priority ONU, then in low-priority ONU. Thirdly, sustain the fair bandwidth allocation of the ONU with same priority. Fourthly, the configurable minimum bandwidth is 512kbps and the precision of allocation is no more than 256kbps.Fifthly, support 256 ONU and two queue sets and eight queues for each ONU. Sixthly, ONU can be discovered automatically.The technical route in this dissertation is three steps as follows: the algorithm analysis,the implementation of logic and verification. Based on the bandwidth allocation scheme of GPON and the differences between EPON and GPON, the improvement of the original algorithm is discμssed in the dissertation. The support on TDM is increased in fix bandwidth allocation. The token bucket policing is adopted to allow the accumulation of ensure bandwidth. Two rounds allocation mechanism isμsed to improve the utilization of bandwidth in BEB bandwidth. The time slot overlapping between different ONU is allowed and the issued bandwidth can be permitted to be more than total configurable bandwidth. Based on the research and improvement on the dynamic bandwidth allocation scheme, the design architecture of DBA is presented. DBA is divided into four modules: CPU interface module,Collect report module,Bandwidth calculate module and Bandwidth send module. Then the design and implement of each sub-module are completed. For the verification of DBA, test points are extracted and test cases are developed. Based on the VMM verification architecture, the development of IT verification environment is finished in the dissertation. Running the test case and debugging are the last work.Ultimately, all the specification of 10G EPON CTC requires are implemented in this dissertation. 1K LLIDs can be sμstained in this dissertation, and the configuration granularity of bandwidth and the precision of bandwidth allocation both are 128kbps.The improved algorithm in the dissertation is to improve the utilization of bandwidth, but less consideration with data latency and packet loss rate. Due to the high bur-sty of data services in the network, the research on scheduling mechanism and prediction algorithm of flow will be the later work.