Research On Mission Reliability Of Transmission For Wireless Sensor Network

The characteristics of the wireless sensor network leads to unstable network transmission reliability.The existing wireless sensor network reliability guarantee mechanism often starts from the heuristic design around individual parameters and needs to be continuously patched after the actual deployment.This is due to the fact that the network design did not fully consider the reliability requirements at the beginning.At present,the research on the basic reliability of network has established a more rigorous theoretical basis and technical system.However,the research on the task reliability of wireless sensor network has not recognized mature theoretical and technical methods.Therefore,it has theoretical and practical value to study the task reliability of wireless sensor network tasks.From the perspective of the task reliability of wireless sensor networks,this dissertation constructs an overall optimized reliability solution that adapts to the characteristics of wireless sensor networks.This scheme is general and is not limited to specific network topologies and network protocols.Moreover,the scheme can dynamically adjust according to network changes,so that the reliable transmission of wireless sensor network is tightly coupled from design to task assignment.The main research work and contributions of this dissertation are as follows:1)For the problem that the topological information of wireless sensor networks is difficult to obtain,we study the strategy that it is not limited by the specific routing protocol assumptions,and can dynamically and efficiently infer the routing topology of a wireless sensor network.A routing topology inference method RTI based on packet tracking hybrid local detection is proposed to reconstruct the routing topology from the source node to the sink node.RTI can adapt to dynamic networks and can reconstruct a topology of general directed acyclic graph with good adaptability.We choose the topological distance and reconstruction time to evaluate the correctness and effectiveness of RTI,and compare it with iPath and PathZip.The simulation results show that RTI can maintain good reconfiguration in dynamic and packet loss environments,providing a global routing view for wireless sensor networks,and maintaining the computational complexity of polynomial levels.2)Research on reliability assessment of wireless sensor network tasks.This dissertation analyzes the characteristics of wireless sensor network transmission in multi-source background,defines the transmission reliability of wireless sensor network,and establishes the mission profile and the fault criteria of wireless sensor network transmission.From the perspective of task reliability,we consider the case of downstream and upstream networks and establish the reliability assessment model of the transmission.The on-demand evaluation model is implemented,and the evaluation framework can be dynamically updated according to the network conditions.Based on this framework,we evaluated the transmission reliability for typical cluster and mesh wireless sensor networks.Compared with the 2-end reliability,the theoretical values of task reliability evaluated with task identification are closer to the simulated values,thus verifying the validity and accuracy of the evaluation framework.Accurate evaluation of transmission reliability for wireless sensor network can better optimize the design of reliable transmission mechanism,reduce the energy consumption of network transmission and multipath routing,and reduce the delays caused by transmission,therefore,the evaluation framework has important application value.3)Aiming at the problem of reliable and efficient centralized task allocation strategy for transmission in wireless sensor networks,from the perspective of global optimization,the problem of wireless sensor network task allocation for transmission with minimum energy consumption under the constraint of reliability and task deadline is transformed into nonlinear mixed integer programming problem.And through the event-driven dynamic adjustment the strategy of task allocation for transmission,a reliable and energy efficient task allocation of transmission based on a centralized approach,RETAT-C is proposed.Based on the global routing view,sink acquires global network state information and uses it as the basis for global optimization in RETAT-C.According to the transmission reliability requirements and the task deadline constraints,RETAT-C uses the transmission reliability assessment model to evaluate the transmission reliability from the source nodes to sink in the network,and select the task allocation strategy of transmission in wireless sensor network with the lowest energy consumption under the constraint of reliability requirement and task deadline.Since RETAT-C performs task allocation from the perspective of global optimization and the reliability evaluation result based on task granularity,the simulation results show that compared with IWSN which allocates the task through counting the packet loss rate of frequency,RETAT-C has obvious advantages in both the success rate and the energy consumption of task allocation for transmission.4)Aiming at the reliable and efficient distributed task allocation problem in wireless sensor networks,two distributed task allocations of transmission in hierarchical and planar topology are researched.Two distributed task allocation of transmission strategies in wireless sensor networks under the constraints of reliability and task deadline are proposed,which are RETAT-Cluster(Reliable and Energy Efficient Task Allocation of Transmission Based on Cluster)and RETAT-Multi-sink(Reliable and Energy Efficient Task Allocation of Transmission Based on Multi-sink),respectively.In the RETAT-Cluster strategy,the sink assigns reliability to all cluster heads according to the reliability requirements of the application,and the cluster head performs local task allocation of transmission according to the assigned phase target reliability constraints.Simulation results show that RETAT-Cluster reduces the communication cost and latency of task allocation of transmission compared to centralized task allocation of transmission.The global view of the RETAT-Multi-sink is obtained by fetching local views from multiple sink nodes.This method reduces the delay for obtaining global views.In addition,multiple sinks have a consistent global view for global optimization.The way to respond to local task allocation requirements,and without the need to communicate with remote nodes,overcomes the disadvantages of centralized task allocation in large-scale sensor networks with large communication overhead and large delay,and has better scalability.This strategy can solve the task allocation of transmission in large-scale wireless sensor networks reliably and efficiently.