Research And Implementation Of The Wireless Sensor Network Platform

The WSN (wireless sensor network) is an ad-hoc network which consist of a large number of randomly scattered tiny sensor-nodes, each of which is equipped with a sensor, data-processing and communication modules. With these tiny sensor-nodes, WSN can monitor and collect ambient information. This paper focused on the research and implementation of TinyOS-based WSN platform. With the careful design of the hardware & software architecture, the WSN platform can adapt to the specific requirements of WSN nodes, such as restricted resource, power-saving, low-cost, ruggedness and high-reliability.Firstly, WSN system is studied as a whole, the illustration of the layered model and the classification of software & hardware functional modules is followed. The necessity of applying multi-hop to WSN networking is also given.Secondly, the software & hardware design and implementation for the two major form-factors of WSN nodes, sensor node and sink node, are provided. The hardware design of a sensor node is given based on AVR MCU and RF transceiver CC2420. And the TinyOS-based software application module is completed after detailed research on the design philosophy and implementation mechanism of a WSN operating system, TinyOS. In the meantime, by porting Linux to WSN nodes, an almost full-fledged sink node is also designed, which can bridge the WSN and the outside network via Internet.Lastly, as a widely-accepted WSN protocol suites, ZigBee and its implementation on sensor nodes are studied. The experimental comparison with the sensor node without WSN operating system indicates that TinyOS-based sensor nodes have advantages of providing reliable performance, better concurrent operation over those without WSN operating system counterparts. At the end of the paper, further research proposals are given.