The Research Of Movement Control Strategy Based On Node Coverage For Multi-tier Mobile Sensor Network

As a new type of information acquisition and processing technology, MobileWireless Sensor Network (MWSN) has incomparable superiority over static wirelesssensor networks. This type of sensor network has found wide application in variousfields such as military defense, urban management, environment observation, healthcare, household and business etc. The introduction of mobile nodes extends thenetwork applications, but also brings more technical challenges. Node mobility maylead to dynamic network topology and frequent communication interruption, which isprone to great impact on the effectiveness of data collection and transmission.Adopting multi-tier structure to improve the performance of MWSN is a generallyaccepted method in the current research areas. Study movement control strategy ofmulti-tier WSN to ensure the effective transmission of network information, is ofgreat significance.Based on multi-tier mobile sensor network architecture, we propose a movementcontrol strategy on the basis of node coverage. Different from partition controlstrategy, our policy focus on overall situation, and offer a new train of thought forstudying movement control strategy. The main work is as follows:(1) Partition communication sets for S nodes: S (sensor) nodes deployedrandomly in the monitoring area. Based on the nodes’ distribution information,divides all S nodes into several communication circles, whose radius is S nodes’communication range. Consider the centers as the optimal location for data collection.Therefore, when F (fusion) nodes traverse those centers, S nodes in thosecommunication circles can transmit all the sensed data to F nodes in a single-hop way.Namely, F nodes achieve the covering purpose and receive information.(2) Proposing Virtual Attractive Force (VFA) model: Assume F nodes and Snodes, which are the centers of communication circles, exert forces upon each other.The model constructs VFA between them to provide a basis for F nodes’ optimalmoving route.(3) Planning optimal route for F nodes: Generate F nodes ordered list of movingdestinations Based on VFA model. Every F node traverses the destinations in itsordered list, and stay for a while after its arrival to receive network information. The Fnodes make joint efforts to collect information, which can balance energy consumption and prolong network lifetime.Finally, we simulate with MM-WSN (Multi-tier Mobile Wireless SensorNetwork) software platform, to validate efficiency of the strategy. Simulation resultsshow that the strategy can not only decrease negative impact of network instabilityand high data loss rate caused by node mobility, but also low mobile nodes’ energyconsumption and extend network life cycle.