This paper studies perception layer scheduling problem for Internet of Things. In particular, it conducts research and analysis to real solution classification of three-dimensional space four-anchor node localization problem.. By employing inequality proving theory and the corresponding inequality proving analysis software DISCOVERER, the classification result of specific four-anchor localization is derived. The mathematical description of location problem is given at first and the nonlinear equations arising from traditional method are transformed into polynomial equations with inequality constraints. Inequality proving theory and tools are then used to explore the solution classification with some parameters fixed to give the complete distribution of solutions in this case. The solution classification criterion has important guiding role in practical applications and also can improve the performance of node layout and precise information perception.