The communication system according to the present invention includes: a mobile device 300 connectable to an LTE system and a 3G system; and an RNC 210 configured to control mobility of the mobile device 300 between the LTE system and the 3G system. When the mobile device sends the RNC 210 a request for connection to the 3G system instead of the LTE system because the LTE system imposes access restriction to restrict communication performed by the mobile device 300, the mobile device 300 incorporates mobility information in the request for connection, the mobility information indicating that the mobile device hands over from the LTE system. In addition, when acquiring the mobility information from the mobile device 300, the RNC 210 restrains the mobile device 300 from handing over to the LTE system.