Design And Realization Of A Wireless Sensor Networks Gateway Based On Embedded System

A wireless sensor networks gateway design and realization scheme based on embedded system is demonstrated in this dissertation. This scheme focuses on the development of wireless sensor networks, combining the features of wire and wireless communication network and embedded system technology, aiming at the oneness of the wireless sensor networks gateway data transmission method presently and has been put into practice on the remote data transmission of wireless sensor networks.The new gateway adopts 32-bit low power ARM7TDMI-based micro controller S3C44B0X as the kernel of hardware platform. Its peripheral circuits mainly include the storage system, serial communication interface, Ethernet interface, clock system and other circuit systems, and provide serial-port extension unit and standard interface unit to be used for further linkage of other data transmission method. In this gateway, the uClinux embedded operating system is selected to supervise each hardware and serve as the software platform. The application software of the gateway is written in C language and is based on Linux's multi-thread mechanism. The functions of the gateway include real time collecting, processing and storing of aggregation node data in wireless sensor networks through serial-port communication, utilizing Ethenet and wireless communication network as carriers in transferring data information to transmit data of the sensor network to remote terminals, while enclosing the data in short message which is sent to mobile terminals at preset timing.The design and completion of this gateway not only has good extensibility, but also has compensated for the limitation of single data transmission method for present gateways and realized integration of wired and wireless data transmission methord. Further, the efficiency of operating the gateway is improved by supervision of embedded operating system and realization of multi-thread programming. Having considered the actual environment in which the wireless sensor networks is disposed, the gateway realizes a separate data transmission module, which enables the gateway to freely select either of the Ethernet and the wireless communication network to make data communication with remote terminals or mobile terminals. This scheme will not only ensure the flexibility, real-time characteristic, reliability and adaptability of data and alarm information transmission, but also enhance the extensibility of functions and transplantability of the gateway. Therefore, it puts forward a valuable blueprint of multi-network connection method for future remote monitoring system.