| With the birth of computer in the1940s, the emergence of applications such as databases and multimedia technologies in the1960s and the rise of Internet in the1990s, information technologies have been gradually integrated into all fields of our society and are playing a significant roll. Today, the emergence of wireless sensor networks(WSNs) may lead information technology to leap once again thus taking a step forward to narrow the distance of the human and physical world. As an important branch of WSNs, wireless multimedia sensor networks (WMSNs) combine the WSNs technology and multimedia technology. While WMSNs helps people to obtain abundant information such as images, audio and video, it also calls higher requirements correspondingly for research. The paper selects two significant aspects of WMSNs, acquisition and transmission of multimedia data, to research and implement. The work can make a contribution to making WMSNs more practical.First of all, the prospects for development and research status at home and broad of WSNs and WMSNs are introduced. Secondly, the framework of system located in by the subjects in our study and establishment of devleopment platform are given. Then the research and implement of some key technologies of WMSNs are elaborated deeply, including the acquisition module and transmission module. The work on acquisition module consists of the modification of the kernel source, the realization of OV3640control module, the optimization of some parameters of H.264video encoder and the implement of acquisition of audio data and video data. The work on transimission module includes the implements of the LT FEC, the statistics module of channel packet loss rate based on Gilbert model and the real-time feedback mechanism of optimal package length. At last, the detailed system tests on the results of the work above are done, and the test results indicate that the acquisition module and transmission module are able to meet the requirement of the paper. |
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