Communication system

A base station for taking part in a procedure for adding a cell as a secondary cell, the base station comprising:

• a memory storing instructions;
• and
• one or more processors configured to execute the instructions to:
• receive, as part of the procedure for adding the cell as the secondary cell, from a user equipment (UE) connected to the base station, a measurement report which includes a Closed Subscriber Group Identity (CSG ID), wherein the CSG ID included in the measurement report is the CSG ID of a potential candidate cell for dual connectivity in which the UE will communicate via both a primary cell of the base station and the secondary cell when the candidate cell has been added as the secondary cell;
• request, as part of the procedure for adding the cell as the secondary cell, a Mobility Management Entity (MME) to verify a membership status of the UE for the CSG ID, wherein the request includes the CSG ID of the candidate cell;
• and
• receive, as part of the procedure for adding the cell as the secondary cell, from the MME, a response which includes a CSG membership status information element providing a result of CSG membership verification performed at the MME.

A method performed by a base station, as part of a procedure for adding a cell as a secondary cell, the method comprising:

• receiving, as part of the procedure for adding the cell as the secondary cell, from a user equipment (UE) connected to the base station, a measurement report which includes a Closed Subscriber Group Identity (CSG ID), wherein the CSG ID included in the measurement report is the CSG ID of a potential candidate cell for dual connectivity in which the UE will communicate via both a primary cell of the base station and the secondary cell, when the candidate cell has been added as the secondary cell;
• requesting, as part of the procedure for adding the cell as the secondary cell, a Mobility Management Entity (MME) to verify a membership status of the UE for the CSG ID, wherein the request includes the CSG ID of the candidate cell;
• and
• receiving, as part of the procedure for adding the cell as the secondary cell, from the MME, a response which includes a CSG membership status information element providing a result of CSG membership verification performed at the MME.

A user equipment (UE) for taking part in a procedure for adding a cell as a secondary cell, the UE comprising:

• a memory storing instructions;
• and
• one or more processors configured to execute the instructions to:
• detect, as part of the procedure for adding the cell as the secondary cell and when the UE is connected to a base station, a potential candidate cell for dual connectivity in which the UE will communicate via both a primary cell of the base station and the secondary cell when the candidate cell has been added as the secondary cell;
• read system information in the candidate cell, the system information comprising a Closed Subscriber Group Identity (CSG ID);
• and
• transmitting, to the base station, a measurement report which includes the CSG ID.

A method, performed by a user equipment (UE), as part of a procedure for adding a cell as a secondary cell, the method comprising:

• detecting, as part of the procedure for adding the cell as the secondary cell and when the UE is connected to a base station, a potential candidate cell for dual connectivity in which the UE will communicate via both a primary cell of the base station and the secondary cell when the candidate cell has been added as the secondary cell;
• reading system information in the candidate cell, the system information comprising a Closed Subscriber Group Identity (CSG ID);
• and
• transmitting, to the base station, a measurement report which includes the CSG ID.