A method of changing a radio access configuration between a terminal and a network. The network performs the steps of: initiating a new configuration that is related to an old configuration for the same terminal; informing the terminal to apply the second configuration; and determining when the terminal uses the second configuration based on the reception of a radio signal from the terminal. The terminal performs the steps of: receiving information to apply a new configuration; transmitting, to the network, a radio signal indicating a change in configuration; and changing from an old configuration to the new configuration at a predetermined time after transmitting the radio signal.