Further, in an embodiment of the present invention, the expression, radio (wireless) parameters are “configured (set)” may mean that a predetermined value is pre-configured, or may mean that a radio parameter indicated by the base station apparatus 10 or the user apparatus 20 is configured.

FIG. 1 is a drawing illustrating a configuration example of a network architecture according to an embodiment of the present invention. As illustrated in FIG. 1, a radio network architecture in an embodiment of the present invention includes 4G-CU, 4G-RU (Remote Unit, Remote Radio Station), EPC (Evolved Packet Core), etc., on the LTE-Advanced side. The radio network architecture in an embodiment of the present invention includes 5G-CU, 5G-DU, etc., on the 5G side.

As illustrated in FIG. 1, the 4G-CU includes layers of RRC (Radio Resource Control), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and L1 (layer 1, PHY layer, or physical layer), and is connected to the 4G-RU via CPRI (Common Public Radio Interface). A network node including the 4G-CU and the 4G-RU is referred to as eNB.