A communication device capable of performing communication via a second wireless communication system that is different from a first wireless communication system, in a frequency band that is used by the first wireless communication system, the first wireless communication system periodically transmitting a reference signal, the communication device comprising: communication means ; and control means for controlling the communication means, wherein the communication device is a base station device of the second wireless communication system capable of performing communication via the second wireless communication system in the frequency band, and wherein the control means is configured to control the communications means to: transmit, to a base station device of the first wireless communication system, information for operating the base station device in a mode in which the periodical transmission of the reference signal is interrupted for a predetermined period, transmit a predetermined signal of the second wireless communication system while the base station device of the first wireless communication system is operating in the mode, and transmit the information to the base station device of the first wireless communication system, in response to connection to a terminal device capable of performing communication via the second wireless communication system in the frequency band, in a second frequency band that is different from the frequency band, in a state in which communication via the second wireless communication system in the frequency band is not performed. communication means ; and control means for controlling the communication means, wherein the communication device is a base station device of the second wireless communication system capable of performing communication via the second wireless communication system in the frequency band, and wherein the control means is configured to control the communications means to: transmit, to a base station device of the first wireless communication system, information for operating the base station device in a mode in which the periodical transmission of the reference signal is interrupted for a predetermined period, transmit a predetermined signal of the second wireless communication system while the base station device of the first wireless communication system is operating in the mode, and transmit the information to the base station device of the first wireless communication system, in response to connection to a terminal device capable of performing communication via the second wireless communication system in the frequency band, in a second frequency band that is different from the frequency band, in a state in which communication via the second wireless communication system in the frequency band is not performed. transmit, to a base station device of the first wireless communication system, information for operating the base station device in a mode in which the periodical transmission of the reference signal is interrupted for a predetermined period, transmit a predetermined signal of the second wireless communication system while the base station device of the first wireless communication system is operating in the mode, and transmit the information to the base station device of the first wireless communication system, in response to connection to a terminal device capable of performing communication via the second wireless communication system in the frequency band, in a second frequency band that is different from the frequency band, in a state in which communication via the second wireless communication system in the frequency band is not performed. <EOS>