Radio station, radio terminal, and method therefor

A secondary radio station comprising:

• at least one transceiver configured to communicate with a radio terminal which performs dual connectivity that uses a first cell on a licensed frequency operated by a master radio station that is associated with a first radio access technology and a second cell on an unlicensed frequency operated by the secondary radio station that is associated with a second radio access technology;
• at least one memory that stores instructions;
• and
• at least one processor configured to execute the instructions to transmit a control message to the master radio station, wherein
• the master radio station transmits to the radio terminal, based on the control message, a notification regarding detection or measurement of a non-serving cell on the unlicensed frequency.

A radio terminal comprising:

• at least one transceiver configured to perform dual connectivity that uses a first cell on a licensed frequency operated by a master radio station that is associated with a first radio access technology and a second cell on an unlicensed frequency operated by a secondary radio station that is associated with a second radio access technology;
• at least one memory that stores instructions;
• and
• at least one processor configured to execute the instructions to:
• receive, from the master radio station, a notification regarding detection or measurement of a non-serving cell on the unlicensed frequency;
• measure, based on the notification, one or more discovery signals transmitted in the non-serving cell;
• and
• report, to the first radio station, a result of the measurement of the one or more discovery signals transmitted in the non-serving cell, wherein
• the notification is transmitted from the master radio station based on a control message that is transmitted from the secondary radio station to the master radio station.

A method performed by a master radio station associated with a first radio access technology, the method comprising:

• providing a radio terminal with dual connectivity that uses a first cell on a licensed frequency operated by the master radio station and a second cell on an unlicensed frequency operated by a secondary radio station that is associated with a second radio access technology;
• receiving a control message from the secondary radio station;
• transmitting to the radio terminal, based on the control message, a notification regarding detection or measurement of a non-serving cell on the unlicensed frequency;
• and
• receiving, from the radio terminal, a result of measurement of one or more discovery signals transmitted in the non-serving cell, wherein
• the detection or the measurement is performed by the radio terminal based on the notification.

A method performed by a secondary radio station associated with a second radio access technology, the method comprising:

• providing the radio terminal with dual connectivity that uses a first cell on a licensed frequency operated by a master radio station that is associated with a first radio access technology and a second cell on an unlicensed frequency operated by the secondary radio station;
• and
• transmitting a control message to the master radio station, wherein
• the master radio station transmits to the radio terminal, based on the control message, a notification regarding detection or measurement of a non-serving cell on the unlicensed frequency.

A method performed by a radio terminal, the method comprising:

• performing dual connectivity that uses a first cell on a licensed frequency operated by a master radio station that is associated with a first radio access technology and a second cell on an unlicensed frequency operated by a secondary radio station that is associated with a second radio access technology;
• receiving, from the master radio station, a notification regarding detection or measurement of a non-serving cell on the unlicensed frequency;
• measuring, based on the notification, one or more discovery signals transmitted in the non-serving cell;
• and
• reporting, to the first radio station, a result of the measurement of the one or more discovery signals transmitted in the non-serving cell, wherein
• the notification is transmitted from the master radio station based on a control message that is transmitted from the secondary radio station to the master radio station.