Researches On Role-based Middleware In Wireless Sensor Network

The era of Internet of things (IOT) will bring us a reform frominformationalization to intelligentization. When IOT is connected with internet andmobile communication network, we can have an omnibearing awareness of each otheranywhere, anytime. Our life will experience an overt change from "feeling" into"awareness". Wireless sensor network (WSN), as a key technology of IOT and themain form of data collection, has become more and more important in nowadaysscientific development. A large number of self-organizing tiny sensor nodes randomlydeployed in sensing area of WSN, due to great amount, it is difficult to withdraw thenodes and re-compile the application. Taking to meet the QoS, energy consumption,real-time and heterogeneity performance requirements as a given, how to exploitwireless sensor network applications easily and proactively becomes a practicalrequirement of the development of WSN.Middleware can mask the underlying detailsof the WSN, and reduce the burden of building applications using cross-layertechnology to provide a unified standard service to application layer. In this thesis,the middleware technology of wireless sensor network will be researched for themulti-application requirements.Firstly, the thesis introduces the function and principle of the middleware forwireless sensor network and deeply studies various problems of it. Each node inapplication-driven wireless sensor network always plays on a special role andshoulders several responsibilities. According to the diversity and difference of therole played by nodes in WSN, the role mapping framework model in WSN wasproposed. A role-based middleware for wireless sensor network (RobMSN) wasdesigned based on that model. From the view of the formal semantics andspecifications of the middleware, the role mapping specifications solve the problem ofsemantic conflicts in role mapping abstract, making the role mapping context fullyreflected in the role specifications of middleware. Applications will be mapped as thespecific roles of node which played in the wireless sensor network using RobMSN, itcan be cross-platformed and implemented dynamic application services.Secondly，the excessive overhead during the broadcast of data packet belongs tothe large-capacity role is a squandering of energy. By analyzing the broadcasting priceas well as the forwarding cost, using application service requirement and enviromental context knowledge, we introduced a priced-based role broadcastalgorithm in WSN. Based on the network status and service requirement parametersand properties, we discussed the design of forwarding cost and introduced a pricefunction on the facet of price variation. The effect of forwarding data size and theperformance of energy consumption is measured by forwarding price. Simulation ismade to evaluate the performance of the algorithm on the aspects of forwarding rate,arrival rate as well as energy consumption.Finally, on Agilla mobile plateform, we realized the role-based middleware andverified RobMSN middleware. For RobMSN middleware, it can greatly ease theburden of construction of application program, simplify the role mapping process.Nodes can adjust its role adaptively accoding to the network status and applicationtype.