Radio terminal, radio station, and method thereof
A radio terminal ( 3 ) operates to perform a predetermined process regarding a first cell (Cell # 2 ) on an unlicensed frequency (F 2 ) based on a predetermined relationship between a frame timing of a first serving cell (Cell # 1 ) using a licensed frequency (F 1 ) and a frame timing of the first cell (Cell # 2 ) using the unlicensed frequency (F 2 ). This contributes, for example, to enabling a radio terminal to differentiate among two or more cells when these cells use the same cell identifier.
1. A radio terminal comprising:
a memory; and
at least one processor coupled to the memory and configured to:
perform carrier aggregation using a primary cell operating in licensed frequency and a secondary cell operating in shared spectrum, the primary cell and the secondary cell being served by at least one radio station;
receive, from the at least one radio station, an offset value that is indicated by a number of subframes; and
perform Received Signal Strength Indicator (RSSI) measurements on the shared spectrum, based on the offset value and a timing of a first symbol in a subframe of the primary cell.
2. The radio terminal according to claim 1 , wherein the timing of the first symbol in the subframe of the primary cell is aligned with a timing of a first symbol in a subframe of the secondary cell.
3. The radio terminal according to claim 1 , wherein a difference between the timing of the first symbol in the subframe of the primary cell and a timing of a first symbol in a subframe of the secondary cell is within the offset value.
4. The radio terminal according to claim 1 , wherein the at least one processor is configured to receive the offset value from a base station of the primary cell or another base station of a serving cell which is different from the primary cell.
5. A radio station comprising:
a memory; and
at least one processor coupled to the memory and configured to:
provide carrier aggregation using a primary cell operating in licensed frequency and a secondary cell operating in shared spectrum to a radio terminal, one or both of the primary cell and the secondary cell being served by the radio station;
transmit, to the radio terminal, an offset value that is indicated by a number of subframes; and
receive, from the radio terminal, a result of Received Signal Strength Indicator (RSSI) measurements on the shared spectrum, wherein
the RSSI measurements is performed by the radio terminal based on the offset value and a timing of a first symbol in a subframe of the primary cell.
6. A method performed by a radio terminal comprising:
performing carrier aggregation using a primary cell operating in licensed frequency and a secondary cell operating in shared spectrum, the primary cell and the secondary cell being served by at least one radio station;
receiving, from the at least one radio station, an offset value that is indicated by a number of subframes; and
performing Received Signal Strength Indicator (RSSI) measurements on the shared spectrum, based on the offset value and a timing of a first symbol in a subframe of the primary cell.