Research On Homology Theory Based Coverage Optimization Control Algorithm In Wireless Sensor Networks

Coverage is a fundamental problem in wireless sensor networks(WSNs),which greatly affects the quality of service(Qo S)that the networks can provide.Therefore,coverage optimization control has been widely concerned by scholars at home and abroad.Traditional coverage optimization control algorithms usually need to use the precise location information of nodes or the distance information between nodes,but it is costly to obtain the information above.In this thesis,a distributed coverage optimization algorithm is proposed by using the connectivity information between nodes for scenarios where the location information of nodes and distance information between nodes are unknown.Based on this,an efficient k-coverage optimization algorithm is proposed for k-coverage scenarios with higher monitoring requirements.And the performance of the proposed algorithms is analyzed by simulations.The main contributions of the thesis are as follows.(1)A coverage optimization algorithm based on connectivity information between nodes is proposed.Firstly,WSN is modeled as the corresponding Rips complex.Then,a redundancy decision algorithm based on complex expansion(CE)is proposed.Redundant nodes and edges in the Rips complex are determined and deleted in a distributed manner through cyclic iteration without changing the homology of Rips complex,thus simplifying the Rips complex as much as possible and obtaining the minimum independent set of nodes that completely covers the field of interest(Fo I)in the corresponding WSN.Finally,the proposed algorithm is analyzed and compared with a centralized reduction algorithm for simplicial complex by simulation.The results show that the performance for reducing Rips complex of the proposed algorithm is similar to that of the centralized algorithm,but the computational complexity is lower.(2)As for the k-coverage scenarios of Fo I,a k-coverage optimization algorithm based on the connectivity information between nodes is proposed.Firstly,WSN is modeled as the corresponding Rips complex.Then,based on the aforementioned algorithm,a coverage degree decrement algorithm and a k-round cyclic calling mechanism are proposed.In each round,the1-coverage optimization algorithm and the coverage degree decrement algorithm are called in turn.After k rounds of calls,k minimal subsets of independent coverage nodes are obtained to realize k-coverage optimization of the Fo I.Finally,the performance of the proposed algorithm is compared with that of a centralized k-coverage optimization algorithm through simulation analysis.The results show that the performance of the proposed algorithm is similar to that of the centralized algorithm,but the complexity is lower.