A radio terminal (3) operates to perform a predetermined process regarding a first cell (Cell #2) on an unlicensed frequency (F2) based on a predetermined relationship between a frame timing of a first serving cell (Cell #1) using a licensed frequency (F1) and a frame timing of the first cell (Cell #2) using the unlicensed frequency (F2). This contributes, for example, to enabling a radio terminal to differentiate among two or more cells when these cells use the same cell identifier.