When the presence of an RF ID tag is detected by a contactless reader/writer, an information processing terminal causes a contactless reader/writer to set a state flag in the RF ID tag to a first state which indicates that a wireless LAN communication unit of the mobile telephone is in an inactive state, and sends presence information indicating the presence of the mobile telephone to the information processing apparatus. When the state flag in the RF ID tag is set to the first state, the mobile telephone disables the wireless LAN communication unit. The information processing apparatus receives the presence information and stores the received presence information in a database. When the information processing apparatus receives a request for terminating an incoming IP telephone call on the mobile telephone, it searches the database and sends, to the information processing terminal, information indicating the incoming call, and also transfers, to the wireless LAN access point, an IP packet signaling the incoming call. When the information processing terminal receives the incoming call information from the information processing apparatus, it causes the contactless reader/writer to set the state flag in the RF ID tag to a second state which indicates that the wireless LAN communication unit of the mobile telephone is in an active state. When the state flag in the RF ID tag is set to the second state, the mobile telephone enables the wireless LAN communication unit.