According to an aspect of the embodiments, a base station device in a wireless communication system including a terminal device and a base station device that is wirelessly connected to the terminal device and transmits signals to the terminal device, the base station device includes, an acquirer which acquires a first version of a signal format corresponding to the terminal device, and a transmitter that transmits, to the terminal device, difference information relating to a signal used for a different purpose from a purpose of a signal of a second version corresponding to the base station device when the first version differs from the second version.