When a user inputs necessary details on a user's decision screen and transmits the inputted details (Step S3), an acceptance server 12 reads an address list from an address DB 21 and then transmits the address list to the user (Step S4). When the user selects an address from the address list and transmits the selected address, an area decision server 13 retrieves and reads a map of the surrounding of the selected address from a map DB 23 and transmits the map to the user (Step S6). The user then inputs the numbers of stories of a building where the user desires to utilize the wireless communication service and the direction of an antenna based on the map of the surrounding, and transmits those inputted particulars (Step S7). The area decision server 13 reads base station information from a base station DB 24 and calculates the transmission characteristic between two points, namely the antenna and the base station, to decide whether communication between the two points is executable or not. If it is decided that the communication is executable, the sign-up application is accepted.