Adaptive reliability-based splitting algorithms for ordered sequential detection in WSNs

We consider a distributed detection problem in a large, single-hop, wireless sensor network. Because of limited collection time and bandwidth, the fusion center (FC) is not able to collect the local observations from all sensor nodes. A distributed detection scheme with a selection strategy and a capability to operate in a finite bandwidth is required. We propose an ordered sequential detection scheme which jointly integrates a reliability-based splitting algorithm, an ordered-transmission strategy, and a sequential probability ratio test (SPRT). The proposed scheme allows the FC to collect the local observations in descending order of their reliabilities by using a reliability-based splitting algorithm. As it receives successfully transmitted observations, the FC sequentially decides whether to make a global decision or to continue collecting more local observations. The numerical results show that the proposed scheme significantly outperforms a conventional SPRT scheme. The improvement increases as the number of sensor nodes in the network increases.