A technique is offered which is adapted for optimization computations and which makes it possible to carry out an estimation of the state of propagation of radio waves quickly and accurately during a search for the locations of wireless stations. During the optimization computations, sending points and receiving points are set using a parameter search technique. Propagation paths are computed using a far-field approximation technique for Maxwell's equations. A propagation path leading to a local area where the accuracy is low with the far-field approximation technique is extracted from the computed paths. The state of scattering previously calculated using a numerical analysis technique for Maxwell's equations is reflected in the extracted path to modify the propagation path. The communication characteristics of the modified path are evaluated. The steps S101-S105 are performed repeatedly a given number of times. A sending point and a receiving point producing optimum communication characteristics are output.