A Kind Of Wireless Sensor Networks For The Heating Network Remote Monitoring

In recent years, with the development of information technology, heating networkremote monitoring system in cities of northern China has been in widespread used, whichestablished the foundation for the overall optimization control of the heating network.Theheating network remote monitoring system used presently has realized data acquisition andcontrol of heating substations,but it can not collect the data of the user end, so it can notsatisfy the further requirements of heating enterprise to the refinement of monitoring data..To resolve the problem of data acquisition of the user end in heating network remotemonitoring system, This thesis researches a wireless sensor network works at433MHz band,which is suitable for the data acquisition of the user end in the heating network remotemonitoring system.The entire monitoring network uses a tree and star hybrid topology, sensor nodes aredeployed at the user end of the heating network，and be responsible for the dataacquisition,it forms a tree network with the sink node. Its hardware mainly includes theSTM32MCU and the nRF905wireless module. As the data transfer device, sink nodes aredeployed in the heating substation, its hardware has the EM310GSM wireless module morethan the sensor node. Sink nodes log on to GPRS network through the EM310GSM module,and form a star network between heating substations. It collects data from the field bus ofheating substations and the wireless sensor network to the internet. According to thecharacteristics of the application environment, sensor nodes use solar power, sink nodes usecity power supply.This study develops a lightweight wireless sensor network protocol, the protocol stacksoftware is designed and implemented based on the μCOS/II embedded operating system, itis divided into the physical layer, the MAC layer, the network layer and the application layer,the lower layer provides service and support to the higher one, so the protocol software hasgood scalability and portability. This work gives the key algorithms of the addressassignment, and the none-slotted CSMA-CA mechanism and the process of formingnetwork and data routing of the wireless sensor network, the frame type of each layer and thepacking and unpacking the frame structure in the sending and receiving process are alsodiscussed in detail. in order to save the electric energy of sensor nodes, the wireless sensor network uses a intermittent working mode, sink nodes control sensor nodes to enter the stateof dormancy by sending a hibernation signal, and sensor nodes uses a self-timed wake mode.At the end of the thesis, it gives the protocol stack software test and the debugging ofhardware, preliminary experiments show that the feasibility of the data acquisition of heatingnetwork user ends based on the wireless sensor network worked in433MHz along with othercommunication means, it makes the collected data from the district heating network remotemonitoring more refined.