Data Communications Platform Based On Wireless Sensor Networks

With the development of wireless sensor networks(WSN), more and more real-time multimedia applications have been proposed. In order to achieve accurate and fine-grained monitoring on the environment, these applications need to access the rich multimedia information such as audio, video, images and so on. The data transfer mechanism of traditional WSN is not entirely suitable for the transmission of multimedia information, therefore it's necessary to develop a new data transfer mechanism according to the characteristics of multimedia applications.Firstly, this thesis studies the hop-by-hop congestion control mechanism of WSN. It gives a brief introduction to the basic principles of end-to-end congestion control mechanism and hop-by-hop congestion control mechanism, and summarizes the present research situation of hop-by-hop congestion control mechanism in wired network and wireless network. On this basis, learn from the basic idea of hop-by-hop congestion mechanism, a new hop-by-hop congestion control mechanism for wireless multimedia sensor networks named SSHBH is proposed, which implements congestion control by setting simple queue length threshold. Experimental results show that SSHBH responses to network congestion quickly, and achieves high throughput and low latency. Besides, SSHBH can be easily deployed to applications.Next, based on the WSN test bed, a data communications platform which can support the transmission of multimedia information is designed according to the characteristics of wireless line network. With the use of a combination of cross-layer design technology and component technology, the platform reduces the processing overhead of communication and can be easily configured, optimizing the performance of the whole system. SSHBH is integrated into this platform, which can effectively deal with network congestion, eventually ensuring the efficiency of data transmission.Finally, the thesis verifies the performance of data communications platform. An experimental platform for wireless multimedia sensor network is developed firstly according to the conditions of existing hardware in our laboratory. Based on experimental platform, we design and implement a real-time voice capture system of wireless line network by using the data communications platform. Experiments show that this system can capture and transmit real-time voice data effectively, and the voice effect is also satisfactory.