A communications apparatus includes a processor configured to identify positions where wireless communication with a mobile communications apparatus is possible, the positions being included in a coverage area of the communications apparatus; and obtain from a database that is inaccessible to the mobile communications apparatus, frequency information that indicates frequencies that can be used for the wireless communication at the identified positions; and an announcing unit configured to announce in the coverage area and by a radio signal, correspondence information that is based on the frequency information obtained by the obtaining unit and that correlates the positions and the frequencies that can be used.