Time Delay Under Limited Wsan Mobile Path Planning And The Distributed Data Distribution

How to balance the energy consumption and data collection delay has become a primary problem for mobile wireless sensor and actuator network. Aiming at the in-efficiency energy utilization issue brought by the unbalanced workload distribution and high communication overhead under deadline constraint for the network, this thesis focuses on improving energy efficiency by developing a path planning scheme for controlled mobile actuator and a data dissemination protocol for uncontrolled actuator. The main works are as follows:In order to solve the unbalanced energy consumption problem for moving path planning of controlled mobile actuator, we propose a dynamic in-degree priority path planning algorithm, which optimizes the network energy utility under time constraint. Based on the energy and location of sensor nodes, the algorithm firstly constructs a dynamic shortest path tree connected all the nodes in network. Then, the high in-degree node has more possibility to be chosen as rendezvous, which will buffer locally aggregated data and upload the data to the mobile actuators with delay constraints when them arrive. In contrast to existing rendezvous selection approaches, we dynamic change the rendezvous node to avoid it’s death caused by heavy load. Then, the moving path of mobile actuator is determined by solving the traveling salesman problem. Moreover, a multi-actuators partition approach is proposed to balance the energy consumption.A distributed delay-sensitive data dissemination strategy is presented to reduce the increasing severe delay caused by high communication overhead during data dissemination to mobile actuators. Based on the geographical location and the transmission radius of sensor nodes, a virtual grid is established, and nodes in the same grid dynamically select the head node based on the residual energy and position. To reduce the communication overhead during the transmission, the head node manages the dissemination tree for mobile actuators’join and leaving distributively. Joint the workload and location information of sensor nodes, a delay-sensitive data dissemination tree is designed to guarantee the real-time requirement and reduce data transmission delay.Finally, performance evaluations of the proposed path planning algorithm and dissemination protocol are taken under OMNET++and MIXIM simulation. The performances of rendezvous node distribution, network energy consumption and packet success delivery ratio etc. for data transmission are analyzed, and the results show the reasonability of our approaches proposed in this thesis.