A method and system of determining spectral interference are disclosed. In one embodiment, a spectral interference model for a first set of proposed base stations is obtained. The spectral interference model is implemented for the first set of proposed base stations to calculate first modeled spectral interference values, wherein each of the first modeled spectral interference values indicates a spectral interference value for a corresponding one of the first set of proposed base stations. The first set of proposed base stations are updated based on the first modeled spectral interference values to obtain a second set of proposed base stations. First empirical spectral interference values are then obtained for a first proper subset of the second set of proposed base stations. The first empirical spectral interference values are compared with the modeled spectral interference values and the second set of proposed base stations are updated based on the comparison.