A method for PDU session management. The method includes receiving, at an Access and Mobility Management function entity (AMF), a registration request message transmitted by a user equipment (UE), wherein the registration request message comprises a list of PDU sessions to be activated; and, in response to receiving the registration request message, the AMF transmitting to a session management function (SMF) a request message for requesting the SMF to activate UP resources for at least one of the PDU sessions identified in the list of PDU sessions.