The Research And Implementation Of Wireless Sensor Network Management Platform Based On Software Defined Network

Wireless sensor network(WSN)is a distributed self-organizing network,which is made up by vast wireless sensor nodes.WSN can not only complete the perception and measurement of specified target,but also realize the wireless transmission of sensing data.However,there are some inherent problems in WSN,such as reutilization difficulty,low transmission efficiency and complex network management,which restrict its further development.To this end,this thesis proposes a WSN management platform based on software defined wireless sensor network.The design is elaborated form three aspects,such as the framework of protocol stack,the operation process of network,the software and hardware implementation.In order to realize the management platform based on software defined wireless sensor network(SD-WSN)with embedded technology,this thesis modifies the classical protocol stack of SD-WSN.We redesign the data forwarding layer,the in-network packet processing layer,and the topology discovery layer to reduce the requirement of system computing and storage performance.At the same time,the corresponding network operation process is formulated,which is made up by routing discovery,tasks creating,flow table generation,flow table deployment and task execution,and conforming to the characteristics of centralized management and reconfiguration of software defined technology.Based on the improved protocol stack and network operation process,the devices of SDWSN are designed and implemented,including controller and sensor nodes.The sensor node is based on STM32F407 which is powered by u C/OS-II system.It can execute the tasks of routing discovery,node reconfiguration,and sensor monitoring according to network packets.The controller is based on S5P6818 which is powered by Linux system.The routing protocol and the sensor tasks can be configured by the central controller,and the system can query and configure network resource in real time through the interfaces provided by the controller.Sensor nodes and controller communicate through IEEE 802.15.4 protocol,transmitting control information and sensing data.Finally,the SD-WSN management platform is set up in the laboratory,and the performance of network management and routing transmission are tested.The testing results indicate that the design system can not only acquire sensing data accurately,but also has the capabilities of monitoring network states and reconfiguring nodes in real time.Comparing to distributed self-organizing network,the SD-WSN management platform has better communication reliability and real-time due to centralized management.The design system can communicate normally in the scenarios which the packet interval is not less than 40 milliseconds.