Wdm-pon Access Methods, And Dba Algorithm

WDM-PON using wavelength division multiplexing technology provides a higher bandwidth to access Internet. It achieves a truly super broadband symmetric access network. WDM-PON has inherited all the advantages of PON avoiding some of the PON's technical problems, for example the ONU ranging. It also has obvious advantages in system upgrading and network management. As technology advances, the cost of WDM optical components, especially the passive optical components decrease, WDM-PON access network technology will be the development of a predictable trend, and may be the ultimate solution for access networks.It is necessary to do research in the way that WDM-PON access backbone network. The network connections of the two different access networks have been analysed. Then using the OPNET network model, the two access methods have been simulated respectively. In the conditions that the internal data in different proportions and different network load, three kinds of data on the two networks have been simulated and compared respectively. Simulation results show that the second access method could reduce the network data delay better and improve network performance.Dynamic wavelength and slot allocation algorithm in WDM-PON is also one of the most popular researches, and now there is no standard algorithm. Therefore from analysis of a more classic dynamic wavelength slot allocation algorithm, a new algorithm has been put forward. The new algorithm provides alterable defalt bandwidth for each ONU at the beginning of each period. Then using the OPNET network model, the two algorithms have been simulated and compared. Simulation results show that the new algorithm could reduce the network data delay and couldn't degrad the network bandwidth utilization. Each ONU shared bandwidth fairnly in the new algorithm.