Research On Key Technologies Of Wireless Multimedia Sensor Networks Node

As a special application of the traditional wireless sensor networks (WSNs), the wireless multimedia sensor networks (WMSNs) has deeply changed the communication between human and nature, and extended human's visual field to any physical space .Right now, WMSNs is being paid wide attention by military, industry and academe because of the applicable worth in national defence, environment, medical, family, exploring outer space, and so on.Supported by the National Science Foundation of PR China"Image compression algorithm and its multi-nodes cooperative transmission strategy for wireless multimedia sensor networks"(Grant No. 60872151), this dissertation concentrates its attention on the key technology of wireless multimedia sensor networks node.The main contents and contributions of this dissertation are as follows:1. The development of multimedia sensor node in and abroad is discussed in detail. The feature, disadvantage and open research issues of the WMSNs are introduced.2. Design the multimedia sensor node based on DSP. This node, which adopts the architecture of CPLD and DSP, has the advantages of strong data processing capability, good parallel performance and easy update characteristic. It is designed with ping-pong data interface, which ensure the data transmissionthe real time. We choose the nRF24E1 which supports Zigbee technique to complete the node's data wireless communication.3. A multi-node cooperation distributed image compression algorithm based on EBC of JPEG2000 in the cluster-based Wireless Multimedia Sensor Networks is proposed. In this algorithm,the image is partitioned into several tiles (blocks) in EBC coding of the flow of JPEG2000, and then each block is sent to a group of nodes. Simulation results show that this multi-node cooperation distributed algorithm can prolong the lifetime of the WMSNs compared with"centralized"compression algorithm under a specific image quality requirement.4. The topology structure of the wireless multimedia sensor networks based Zigbee technique in Wireless Multimedia Sensor Networks is discussed, and the Zigbee wireless communication protocol and its advantage in monitor field are summarized. Compared the features between Zigbee and other three wireless techniques, we propose a method of network consisting based on Zigbee technique.The multimedia sensor node designed in this paper has been used in the structure of the WSNs now.