A quantitative fault tolerance evaluation model for topology in wireless sensor networks based on the semi-Markov process

Fault tolerance evaluation has gained increasing importance. In this paper, the semi-Markov process is introduced to describe the fault tolerance of topology in wireless sensor networks. Considering that the changes of topology states leaded by node failure and the changes of topology states leaded by responding to node failure, the topology fault-tolerant state transfer model is established firstly. Then a new fault tolerance evaluation index of topology is proposed based on the property of topology providing network services under different states. The numerical result shows that the topological fault tolerance calculated by the evaluation index and its actual value are consistent, which verifies that the proposed evaluation index can reflect the topological fault tolerance accurately. Moreover, the key factor influencing the topological fault tolerance is also obtained from calculating the sensitivity of parameters in the evaluation index.