Patent ID: 11228997

Abstract:
A method of handling multi-access (MA) Protocol data unit (PDU) session under inter-system change is proposed. An MA PDU session uses one 3GPP access network or one non-3GPP access network at a time, or simultaneously one 3GPP access network and one non-3GPP access network. The UE and network can support Access Traffic Steering Switching and Splitting (ATSSS) functionalities to distribute traffic over 3GPP access and non-3GPP access for the established MA PDU session. Upon intersystem change from 5GS to EPS over the 3GPP access, if interworking with EPS is not supported, the MA PDU session is maintained in 5GS over the non-3GPP access type. Data traffic over of the MA PDU session over the 3GPP access type is transferred to the non-3GPP access type.