BASE STATION, WIRELESS COMMUNICATION SYSTEM AND METHOD

摘要

An aspect of the present invention relates to a base station, which comprises: a signal transmitting/receiving unit that communicates wireless signals with a user apparatus; a cell managing unit that manages a primary cell and one or more secondary cells to be allocated to the user apparatus so as to communicate the wireless signals; and a validity determining unit that determines whether feedback information received from the user apparatus is valid. When the cell managing unit determines that a secondary cell having been set in the user apparatus has been activated in response to an event that the cell managing unit instructs the user apparatus to cause the secondary cell to transition to the active state, the cell managing unit monitors feedback information from the secondary cell. If feedback information having been regarded, by the validity determining unit, as valid is not received within a predetermined time interval, the cell managing unit determines that the secondary cell is in the inactive state.