The present invention relates to an apparatus and method for triggering change of a Radio Resource Control (RRC) state for a user equipment operating in a cellular network. According to the method a Radio Link Control (RLC) buffer threshold associated with a Radio Link Control buffer is set to an initial value upon the user equipment entering a CELL_FACH RRC state. The RLC buffer threshold is decreased as a function of time. A RRC state change for the user equipment between the CELL_FACH RRC state and a CELL_DCH RRC state is triggered according to a predetermined rule based on a current size of the RLC buffer and the RLC buffer threshold. The method facilitates achieving a desired RRC state transition behavior for some types of users.