Optical Network Architecture Design And Its Simulation Verification For Sensor-oriented Applications

Sensor networks usually include sensor nodes,convergence nodes and management nodes.Sensor nodes monitor data and route it to convergence nodes.Data finally arrives at management nodes,with the management node to configure and manage the sensor network.Optical network is a communication network with optical fiber as the transmission link.In this thesis,a kind of sensor network transmitted by optical mediaoptical fiber is proposed,which can realize optical fiber interconnection in sensor network and realize the bidirectional transmission of data from the bottom layer to the central processing layer of the sensor network.In this thesis,a four-layer topology of sensor optical network is designed,which consists of a central processor layer,a processor layer(cluster layer),a pre-processor layer(cluster layer)and an access layer.Firstly,based on the electrically switched sensor network,this thesis uses OPNET to simulate the scheduling strategies of the existing sensor network.The scheduling strategies include traditional scheduling strategy and round-robin scheduling strategy.Simulation and comparison of packet loss rate and end-to-end delay show that the performance of round robin scheduling is better than that of traditional scheduling.Secondly,a small simulation software based on QT platform is developed to simulate the routing and wavelength assignment(Routing and Wavelength Assignment,RWA)strategy of the interconnection network between processor layer and pre-processor layer.The shortest path algorithm and graph coloring theory are used to apply on the routing and wavelength assignment strategy.The simulation results are successfully displayed on interface and can be saved as local files.This thesis will continue to study the architecture design and resource allocation(RWA)algorithm of the large-scale optical network.Torus has many advantages,such as small diameter of network,the same number between input ports and output ports,many routing paths,extensible potential,and so on.In this thesis,a topology design scheme of large-scale optical network based on 2D-Torus architecture is proposed.In optical network,wavelength division multiplexing technology need the existence of ROADM at each node.The method of generating topology is proposed with some specific conditions,and the advantages of the proposed method are verified by the maximum number of hops and the sum of average hops.Routing and wavelength assignment problem(RWA)is one of the most key problems in wavelength division multiplexing(WDM)optical network.This thesis presents a method based on genetic algorithm to solve the RWA problem in large-scale dynamic WDM optical network.Compared with the traditional algorithm,RWA in crossover and mutation is optimized by using a different chromosome coding method,a different population initialization method and a different fitness function.The simulation results show that the genetic algorithm has a lower blocking rate than the traditional algorithm in different scale mesh networks.