Method and system for managing closed access group feature for user equipment and network

A method for managing a closed access group (CAG) feature by an access and mobility management function (AMF), the method comprising:

• receiving, from a user equipment (UE), a registration request message including first information indicating that the UE does not support the CAG feature, second information on network slice selection assistance information (NSSAI), and third information on a data network name (DNN);
• and
• transmitting, to the UE, a registration reject message including a fifth generation mobility management (5GMM) cause value, wherein the registration request message is rejected due to the UE not supporting the CAG feature, and wherein the UE is allowed to access a 5G system (5GS) via a CAG cell only,
• wherein the CAG feature is used in order to prevent UEs not allowed to access a network from accessing the network, and
• wherein the first information indicating that the UE does not support the CAG feature is a one-bit information provided in a 5GMM capability information element of the registration request message.

A user equipment (UE) for managing a closed access group (CAG) feature, the UE comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to control to:
• transmit, to an access and mobility management function (AMF), a registration request message including first information indicating that the UE does not support the CAG feature, second information on network slice selection assistance information (NSSAI), and third information on a data network name (DNN);
• and
• receiving, from the AMF, a registration reject message including a fifth generation mobility management (5GMM) cause value, wherein the registration request message is rejected due to the UE not supporting the CAG feature, and wherein the UE is allowed to access a 5G system (5GS) via a CAG cell only,
• wherein the CAG feature is used in order to prevent UEs not allowed to access a network from accessing the network, and
• wherein the first information indicating that the UE does not support the CAG feature is a one-bit information provided in a 5GMM capability information element of the registration request message.

An access and mobility management function (AMF) for managing a closed access group (CAG) feature, the AMF comprising:

• a transceiver;
• a controller coupled with the transceiver and configured to control to:
• receive, from a user equipment (UE), a registration request message including first information indicating that the UE does not support the CAG feature, second information on network slice selection assistance information (NSSAI), and third information on a data network name (DNN);
• and
• transmit, to the UE, a registration reject message including a fifth generation mobility management (5GMM) cause value, wherein the registration request message is rejected due to the UE not supporting the CAG feature, and wherein the UE is allowed to access a 5GS (5G system) a CAG cell only,
• wherein the CAG feature is used in order to prevent UEs not allowed to access a network from accessing the network, and
• wherein the first information indicating that the UE does not support the CAG feature is a one-bit information provided in a 5GMM capability information element of the registration request message.