Communication control method and user equipment

1. A communication control method for cell reselection of selecting a serving cell of user equipment by ranking a plurality of cells based on radio quality, the communication control method comprising:

based further on whether a cell is a non-terrestrial cell, the non-terrestrial cell being formed by a radio transceiver of a satellite or an aircraft, determining, by the user equipment, a rank of the cell in the cell reselection.

2. The communication control method according to claim 1 , wherein

the determining includes determining whether the cell is the non-terrestrial cell, depending on whether a time offset is applied to the cell, and

the time offset is time for delaying start timing or expiration timing of a timer used by the user equipment at time of performing communication between the user equipment and the cell.

3. The communication control method according to claim 2 , wherein

the timer is a timer for determining waiting time in which reception of a response message from the cell is to be waited for in a random access procedure for the cell.

4. The communication control method according to claim 2 , wherein

the determining includes determining the rank of the cell to be lower as a value of the time offset is larger.

5. The communication control method according to claim 1 , wherein

the determining includes, when the cell is the non-terrestrial cell, determining the rank of the cell so that the determined rank is lower than when the cell is not the non-terrestrial cell.

6. The communication control method according to claim 1 , wherein

the determining includes, in a case where the user equipment is in a predetermined state and the cell is the non-terrestrial cell, determining the rank of the cell so that the determined rank is higher than when the cell is not the non-terrestrial cell, and

the predetermined state is a state in which a value indicating a movement speed of the user equipment is a first threshold or higher, or a state in which the user equipment is a flying object or an apparatus provided in the flying object and a value indicating altitude of the user equipment is a second threshold or higher.

7. A communication control method for performing handover of user equipment from a source cell to a target cell, the communication control method comprising:

when the target cell is a non-terrestrial cell formed by a radio transceiver of a satellite or an aircraft, receiving, by the user equipment, a time offset to be applied to communication with the non-terrestrial cell from the source cell, wherein

the time offset is time for delaying start timing or expiration timing of a timer used at time of performing communication with the target cell.

8. The communication control method according to claim 7 , wherein

the timer is configured to determine waiting time in which reception of a response message from the target cell is to be waited for in a random access procedure for the target cell.

9. The communication control method according to claim 7 , further comprising:

receiving, by a first base station configured to manage the source cell, information indicating the time offset from a second base station configured to manage the target cell.

10. The communication control method according to claim 7 , further comprising:

transmitting, by a second base station configured to manage the target cell, information indicating the time offset to a core network apparatus; and

receiving, by a first base station configured to manage the source cell, the information indicating the time offset from the core network apparatus.

11. User equipment for performing cell reselection of selecting a serving cell by ranking a plurality of cells based on radio quality, the user equipment comprising:

a processor configured to execute processing of, based further on whether a cell is a non-terrestrial cell, the non-terrestrial cell being formed by a radio transceiver of a satellite or an aircraft, determining a rank of the cell in the cell reselection.