Research On Channel Assignment Scheme For Wireless Sensor Networks Based On Static Topology

With the rapid development of information technology, human society ismoving forward from industrialization to informatization. As an important meansfor human obtaining information from natural world, the importance of wirelesssensor networks is becoming increasingly prominent. It combines data acquisition,data processing and wireless communications in one system. And its application inmilitary and civil field is very promising with its low price and good adaptation toharsh environment. In actual application, the sensor nodes are often deployed veryintensive, which leads to a serious communication interference between nodes anddeteriorates the network performance. Therefore, the application of multi-channeltechnology in WSN, is becoming a hot research direction of WSN’s MAC layer.For the general wireless networks, there have been very mature multi-channelassignment schemes. But the unique features of sensor nodes, such as only one RFinterface, limited energy, limited computing power, make these mature schemes notapplicable for WSN. So we need design an assignment scheme for WSN with lowenergy consumption and less complex algorithm.Through researching the problem of channel assignment in wireless sensornetwork, this thesis proposed a channel assignment scheme based on the locationinformation of sensor nodes. Faced with the WSN which has static topology, thisscheme divides the whole area of WSN into a series of grids and uses the locationinformation of sensor nodes to determine which grid they are located in. The gridsare taken as the criteria when assigning channels the nodes. Then, the entire networkis divided into several subnets with overlapping regions but isolated spectrum. Next,aiming to minimize the interference in the network, we obtained a reasonable size ofthe grid through theoretical deduction. Then, we verified by simulation that thenumber of blocked nodes caused by conflict can reach the minimum value when thenetwork is divided and assigned channels using certain grid size.According to the scheme put forward in this paper, a complete channelassignment model has been designed. Besides, the channel assignment processduring the network initialization and the channel switching process during therunning time of network have been expounded in details. Then we verified theimprovement of the indicators like throughput and end-to-end delay by simulationafter using the proposed channel assignment model.In addition, while working on the theories guiding the project, this paperestablished the test platform of ubiquitous network based on the resource allocation to validate the result of theoretical research. Finally, we completed the realizationand validation of the proposed channel resources assignment model on theembedded nodes on the platform.