COMMUNICATION DEVICE, MOBILE COMMUNICATION DEVICE, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD

摘要

A communications apparatus (100) includes an identifying unit (110), and obtaining unit (130), and an announcing unit (140). The identifying unit (110) identifies positions where wireless communication with a mobile communications apparatus is possible, the positions being included in a coverage area of the communications apparatus (100). The obtaining unit (130) obtains from a database (120) that is inaccessible to the mobile communications apparatus, frequency information (131) that indicates frequencies that can be used for the wireless communication at the positions identified by the identifying unit (110). The announcing unit (140) announces in the coverage area and by a radio signal (142), correspondence information (141) that is based on the frequency information (131) obtained by the obtaining unit (130) and that correlates the positions and the frequencies that can be used.