Abstract: A connection management method includes: checking if a specific message is received from a 3rd Generation Partnership Project (3GPP) network over a non-3GPP connection; and in response to receiving the specific message, starting a user equipment (UE) initiated procedure for release of the non-3GPP connection.

Abstract: A method of access domain preference selection for mobile originating short message service (MO SMS) using Attention (AT) command in EPS/5GS is provided. A new AT command is defined to specify the preferred access domain for UE to use for MO SMS over NAS messages when the UE supports non-3GPP access (e.g., in 5GS) and 3GPP access (e.g., in EPS/5GS). The set AT command (+CADSMS=[<access domain preference>]) is provided for the purpose of specify the access preference that the UE will use to send MO SMS over NAS message, the read AT command (+CADSMS?) returns the currently selected access preference, and a test AT command (+CADSMS=?) returns the supported access preference as a compound value.

Abstract: A connection recovery method for recovering a connection between a communications apparatus and a data network includes: receiving a first message indicating a non-3GPP access from the 3GPP network device in a CM-IDLE state in the non-3GPP access network; transmitting a second message to the 3GPP network device via 5GMM protocol over 3GPP control plane to establish the user plane resources for the non-3GPP PDU session; receiving a third message indicating that the user plane resources cannot be reestablished; and transmitting to the 3GPP network device a service request message via the 5GMM protocol over the 3GPP Internet PDU session of 3GPP user plane to reestablish the user plane resources, or a PDU session establishment request message via 5GSM protocol over the 3GPP control plane to handover the non-3GPP PDU session from the non-3GPP access network to the 3GPP access network in response to the third message.

Abstract: Various solutions for transmitting user data under congestion control with respect to user equipment and network apparatus in wireless communications are described. An apparatus may establish a control plane connection to transmit user data. The apparatus may determine whether a back-off timer is running. The apparatus may establish a user plane connection when the back-off timer is running. The apparatus may transmit the user data via the user plane connection.

Abstract: A connection recovery method for recovering a connection between a communications apparatus and a data network includes: receiving a first message indicating a non-3GPP access from the 3GPP network device in a CM-IDLE state in the non-3GPP access network; transmitting a second message to the 3GPP network device via 5GMM protocol over 3GPP control plane to establish the user plane resources for the non-3GPP PDU session; receiving a third message indicating that the user plane resources cannot be reestablished; and transmitting to the 3GPP network device a service request message via the 5GMM protocol over the 3GPP Internet PDU session of 3GPP user plane to reestablish the user plane resources, or a PDU session establishment request message via 5GSM protocol over the 3GPP control plane to handover the non-3GPP PDU session from the non-3GPP access network to the 3GPP access network in response to the third message.

Abstract: Various solutions for transmitting user data under congestion control with respect to user equipment and network apparatus in wireless communications are described. An apparatus may establish a control plane connection to transmit user data. The apparatus may determine whether a back-off timer is running. The apparatus may establish a user plane connection when the back-off timer is running. The apparatus may transmit the user data via the user plane connection.