A communication method, including: sending a response signal including terminal information to a portable terminal upon receiving an identification information request; accepting periodically a connection request from the portable terminal during a period not shorter than a second period and three-fold period not longer than the second period, for each period not shorter than the third period and not longer than three-fold period of the third period; establishing a wireless link with the portable terminal upon receiving the connection request; and controlling an execution apparatus for executing a predetermined operation after the link connection establishment unit has established the wireless link.