Distribution Algorithm Communication Network Modeling And Simulation EPON Access Bandwidth Allocation

With the smart grid plans proposed and deepened, research and engineering practice of distribution communication network attract public attention. To adapt to characteristics of distribution network, such as, full-scale, cost-sensitive, harsh environment and diversified business, two levels distribution communication network framework consisted of backbone layer and access layer has been proposed, and developing that backbone layer integrate power dispatching network adopting MSTP or OTN, access layer mainly use EPON. EPON with low cost, high reliability, high bandwidth and flexible networking features is preferred broadband access technology in distribution communication network. However, different from public network EPON technology, in distribution communication network engineering design and equipment selection guide, key technologies research of the Power EPON are relatively backward. Firstly, this paper introduced the entire distribution communication network architecture, facing the challenge and the existing broadband access technologies. On this basis, the feasibility EPON applied in distribution communication network is further analyzed. Secondly, starting from the process field, using OPNET Modeler simulation platform developed the model of EPON, including optical line terminal (OLT), optical network unit (ONU), passive optical splitter (POS) and fiber link with1Gbps, which provided an available experiment platform for studying EPON dynamic bandwidth allocation algorithm (DBA) in distribution communication network, and filled the blank lacking of EPON models in OPNET Modeler. Thirdly, combining the characteristics of distribution communication network and bandwidth and latency requirements of various business, starting with the most basic interleaved polling with adaptive cycle time (IPACT) algorithm, and depending on different authorized windows size arising from distinct authorized service mechanism, this paper improved the mathematical analysis of packets average delay and average polling cycle under three authorization service mechanism, and compared the superiority of three kinds of authorized service mechanism in average packets delay and polling cycle. Fourthly, against long-distance transmission problems caused by hand in hand ring protection network which is used to meet the reliability of distribution communication network, this paper proposed that applying the next generation optical network access technology Long-Reach Passive Optical Network (LR-PON) based on multi-threaded polling to solve increasing packets delay and low bandwidth utilization aroused by long-distance transmission between OLT and ONU, and analyzed packets delay and bandwidth utilization under accessing LR-PON with multi-threaded polling, then proved that LR-PON with multi-threaded polling lowers packets delay and improve network throughput during long-distance transmission.