Research On Data Collection In Wireless Sensor Networks Based On Mobile Nodes

As the foundation of Internet of things, wireless sensor networks (WSNs), contact theobjective world with the virtual information world closely. The applications of WSNs are basedon the data collection, i.e., the sensor nodes collect information which are within the range ofcommunication and transmit the information to the base station with the proper route protocols inlow data delay and long network life. But the limitation of energy and cache space of nodesaround the base station, as well as the multi-hop transmission instability will seriously interferethe performance of traditional data collection protocols. Hence, designing effective data collectionprotocols with optimal performance has a very important significance.In this thesis, we mainly analyze the architecture and corresponding characteristics of WSNsand focus on the application mode and transmission mode, then propose a data collection protocolbased on mobile nodes. This thesis made following contributions:(1)We design a data collection mechanism by using mobile base station. Firstly, we putforward a new clustering algorithm-Time High-Overflow-Based Dominating (THD), and thesensor network is divided into several clusters based on sample rate and cache of nodes in thenetwork. Secondly, we describe the temporary caching mechanism (TCM) to further resolve thebuffer overflow problem. Finally, in order to design the optimal path of the mobile base stations,Dominating-Based Minimum Weighted Sum (DMWS) protocol is proposed.(2)After researching current data collection protocols based on a mobile station, we find theyhave many drawbacks in flexibility and real-time.So,we propose a new protocol based on multiplemobile nodes. Firstly, the base station assigns multiple mobile nodes to each subnet when thewhole network is divided. Then, we design a optimal route for each mobile node with CombineSkip-Or-Substitute(CS) algorithm. Finally, we propose a Mobile-nodes Collaboration(MC)algorithm to transmit data to station.We verify the effectiveness with the traditional data collection protocols, The algorithm inthis thesis shortens the moving distance of the mobile base station, extends the network life cycle,reduces the energy consumption of the network, and has the shorter delay of the data.