Signalling in dual connectivity mobile communication networks

A method performed by a target secondary base station in a wireless communication system supporting dual connectivity, the method comprising:

• receiving, from a master base station, a first message for a secondary cell group (SCG) change, the first message including a current SCG configuration associated with a terminal;
• determining whether a full configuration is applied to the SCG change;
• transmitting, to the master base station, a second message as a response to the first message for the SCG change;
• and
• receiving, from the master base station, a third message for completion of a reconfiguration associated with the target secondary base station,
• wherein the second message includes a new SCG configuration associated with the terminal and information indicating that a full configuration is applied to the SCG change, in case that the full configuration is applied to the SCG change.

A method performed by a terminal in a wireless communication system supporting dual connectivity, the method comprising:

• receiving, from a master base station, a first message for a radio resource control (RRC) reconfiguration associated with a secondary cell group (SCG) change, the first message including a new SCG configuration associated with the terminal;
• and
• transmitting, to the master base station, a second message for completion of the RRC reconfiguration associated with the SCG change,
• wherein the new SCG configuration is configured by a target secondary base station;
• and
• wherein a current SCG configuration is released and the new SCG configuration is applied, in case that a full configuration is applied to the SCG change.

A master base station in a wireless communication system supporting dual connectivity, the master base station comprising:

• a transceiver;
• and
• a processor coupled with the transceiver and configured to:
• transmit, to a target secondary base station, a first message for a secondary cell group (SCG) change, the first message including a current SCG configuration associated with a terminal,
• receive, from the target secondary base station, a second message as a response to the first message for the SCG change,
• wherein the second message includes a new SCG configuration associated with the terminal and information indicating that a full configuration is applied to the SCG change,
• transmit, to the terminal, a third message for a radio resource control (RRC) reconfiguration associated with the SCG change, the third message including the new SCG configuration associated with the terminal,
• receive, from the terminal, a fourth message for completion of the RRC reconfiguration associated with the SCG change, and
• transmit, to the target secondary base station, a fifth message for completion of a reconfiguration associated with the target secondary base station.

A target secondary base station in a wireless communication system supporting dual connectivity, the target secondary base station comprising:

• a transceiver;
• and
• a processor coupled with the transceiver and configured to:
• receive, from a master base station, a first message for a secondary cell group (SCG) change, the first message including a current SCG configuration associated with a terminal,
• determine whether a full configuration is applied to the SCG change,
• transmit, to the master base station, a second message as a response to the first message for the SCG change, and
• receive, from the master base station, a third message for completion of a reconfiguration associated with the target secondary base station,
• wherein the second message includes a new SCG configuration associated with the terminal and information indicating that a full configuration is applied to the SCG change, in case that the full configuration is applied to the SCG change.

A terminal in a wireless communication system supporting dual connectivity, the terminal comprising:

• a transceiver;
• and
• a processor coupled with the transceiver and configured to:
• receive, from a master base station, a first message for a radio resource control (RRC) reconfiguration associated with a secondary cell group (SCG) change, the first message including a new SCG configuration associated with the terminal, and
• transmit, to the master base station, a second message for completion of the RRC reconfiguration associated with the SCG change,
• wherein the new SCG configuration is configured by a target secondary base station;
• and
• wherein a current SCG configuration is released and the new SCG configuration is applied, in case that a full configuration is applied to the SCG change.