The Key Technology Research And Preliminary Design Of IOT Cloud Gateway

The forest environment monitoring has important ecological significance, socialsignificance and economic significance. With the rapid development of the Internet of Thingsand cloud computing, you can use advance technology such as wireless sensor to realize thedynamic monitoring of the forest environment. The dynamic forest environment informationcan be used as the technical support and data decision service for the forest fire prevention, theecological environment monitoring and the precision forestry. This paper focuses on the keytechnology research of the forestry cloud gateway and designs the cloud gatewaypreliminarily.My main work is as follows:1、The wireless sensor network technology research in the forest environmentBased on the wireless sensor network technology, the sensor network deploymentcovering strategies and the sensor network topology organization, the paper proposes a schemeto build wireless sensor network in the woodland, the shrub land and the sparse land. In thewoodland and the sparse land, due to the land surface is only block by the tree, the paperadopts the lozenge network coverage strategy and hierarchical network topology structure toreduce the unnecessary wireless communication link between sensor nodes. In the shrub land,according to the dense land surface vegetation, the paper adopts the equilateral triangle griddeployment strategy and the Mesh topology structure to build multiple routing paths betweensensor nodes and improve the robustness. The ZigBee simulation test shows that the woodlandnetwork packet loss rate is an average of0.0567and the delay between nodes is an average of0.0233s；The shrub land network packet loss rate is an average of0.1034and the delaybetween nodes is an average of0.0444s; the sparse land network packet loss rate is an averageof0.0524and the delay between nodes is an average of0.0234s when the network throughputis reached0.0037Mbit/s. This method can meet the needs of the forest resource monitoring.2、Forestry cloud gateway design According to the forest sensor network and the technology of cloud service, this paperdesigns the forestry cloud gateway based on ARM11. The forest cloud gateway lower connectswireless sensor devices and manages the subnet sensor devices, so that the forest cloudgateway can collect and transfer the forest data. According to the complex diversity of forestenvironment, the forest cloud gateway is designed to support a variety of sensor devices toshield the heterogeneity of the sensor devices. The forest cloud gateway supports ZigBeesensor device, bluetooth sensor device and WLAN sensor device. At the same time, based onthe unified time list, the forest cloud gateway adopts different forest data collection algorithmsadjust to the different forest sensor network. Due to the forestland and the sparse land, thesensor node chooses the LEACH algorithm to produce cluster head and the Prim algorithm totransfer data in the form of multiple hops; for the shrub land network, the sensor node choosesthe GRID algorithm. In the data transmission, according to the different forest networkcoverage situation, the cloud gateway is designed to support multiple data transmissionmethods to shield heterogeneity of the cloud platform. This cloud gateway supports threetransmission module:3G transmission, digital radio transmission and satellite transmission.The forest cloud gateway upper connects the cloud platform and provide the access interface tothe cloud platform. Through the cloud platform, the users can manager the forest cloudgateway and submit the acquisition forest data task. This forest cloud gateway provides threeaccess method including Web Server mode, SSH method and the short message mode.3、The satellite data transmission method research based on the forest cloud gatewayIntegrating Digi M10satellite transmission module, the forest cloud gateway realizes theforest sensor data transmission under no public Internet coverage. The system can actively andpassively read data from sensor network device via RS232and RJ45interface, divide data tosmall blocks, and then compress these blocks respectively, to adapt the maximum datatransferring limit of the modem. Finally compressed data will be transferred to central databasevia satellite network. Test result shows that data transferring speed is about31.27Byte/s, andsystem can successfully transfer data to central database when keep data reading duration time from sensor network device to100s indicating that this method is applicable for datatransferring in remote forest area.In summary, the paper provides a solution based on the Internet of things technology forthe forest environment and provides a new way to promote the informatization, automation andintelligent for our forest environment monitoring.