A wireless communication system, a method, a base station, user equipment and a device. An electronic device for a user equipment in a wireless communication system, wherein the user equipment simultaneously performs wireless data connections with a first base station and a second base station over different carriers, the electronic device including: circuitry configured to, acquire a notification to release the wireless data connection between the user equipment and the first base station from the second base station, if a release triggering node judges that a release condition is satisfied; and release the wireless data connection with the first base station based on the notification, wherein the release triggering node is either the first base station or the second base station.