The Design Of MAC And Interoperability Protocol And Gateway Cloud Server Module In Wireless Sensor Networks

Development of low power wireless micro-sensor, wireless analog and digital electronic technologies and RF technology make applications of a variety of wireless sensor network become more and more widely. In practical applications, the wireless sensor network nodes are typically deployed in areas which are remote, hazardous or difficult to reach. Moreover, nodes are typically powered by batteries. So the demand for the low power and long distance wireless sensor networks is becoming more and more urgent. Many wireless sensor network models can not get the trade-off between low power consumption and long distance transmission. Some sensor network nodes can reach a good level in terms of low power consumption, but can not reach an ideal transmission distance. Some other sensor network nodes can achieve good transmission distance, but waste too much on the performance and power consumption. So the design of increasing the transmission distance on the basis of low power consumption in WSNs is important for practical applications.This thesis combines the low power and long distance wireless sensor network practical application projects. In order to achieve the maximum transmission distance on the basis of the lower power consumption, a low power and long distance wireless sensor network system is designed. The model of the system is analyzed in this thesis, and the system model consists of three parts. The first part is the node part which includes Client hardware modules and the terminal APP. The second part is the gateway module, which includes ARM board, Server hardware modules and the terminal APP. The third part is the cloud server module, which includes cloud server internal process modules and the terminal APP.In order to achieve the long distance transmission on the basis of lower power consumption, the ZigBee protocol is studied. The protocol stack architecture on the basis of the ZigBee protocol which fits for the system is designed. This protocol architecture includes the physical layer, the MAC layer and the application layer. The underlying software of the system runs on this software architecture platform. At the same time, the MAC layer protocol which fits for the system has been designed, and it is achieved by the custom state machine transitions which based on the TDMA. The implementation of the long distance transmission is achieved by the tail-biting convolutional codes. The wireless transceiver of the data frame is achieved by the use of multi-rate. The sync word of the data frame uses a kind of transmission or reception rate, while the effective information of the data frame uses another kind of rate to send or receive. As a result, it can improve the performance and the transmission distance of system.At the same time, to meet the practical project presentation demand, the system increases the phone APP, gateways, servers and other cloud modules. These include the design of interoperable protocols between the APP and the connected modules, and interface module and functional design in gateway and cloud server.The APP is designed as a tool which assists the running of the system and can also communicate with the connected modules and display the parameter information of the related modules. It can be achieved by the interoperability protocol between the APP and the connected modules. As a centralized module, gateway module can process the information from the nodes. Parameter information of gateway and nodes can be stored in the cloud server to provide a remote access for users.