# US 11,909,828 B2 · Device and method for handling always-on PDU session in wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,828 B2 - Document ID: US11909828B2 - Status: Granted - Kind: B2 - Application number: 17/766,525 - Filed: 2020-09-29 - Published: 2023-02-09 - Granted: 2024-02-20 - Earliest claimed: 2019-10-04 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Kisuk Kweon; Kyungjoo Suh; Youngkyo Baek - Web page: https://patentgrep.com/patent/US11909828B2 ## CPC - H04L 67/14: Session management (for real-time applications in data packet communications networks H04L65/1066) - H04L 67/142: Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms - H04W 76/11: Allocation or use of connection identifiers - H04W 76/20: Manipulation of established connections - H04W 80/10: adapted for {application} session management, e.g. SIP [Session Initiation Protocol] {(connection management H04W76/00; arrangements for session management H04L67/14)} - H04W 8/06: Registration at serving network Location Register, VLR or user mobility server - H04W 60/00: Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration - H04W 60/04: using triggered events - H04W 84/042: {Public Land Mobile systems, e.g. cellular systems} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Disclosed is a 5th generation (5G) or pre-5G communication system for supporting a data transmission rate higher than that of a 4th generation (4G) communication system such as long term evolution (LTE). According to various embodiments of the disclosure, provided is a method for operating an access and mobility management function (AMF) in a wireless communication system, comprising the steps of: receiving, from user equipment (UE), a service request including a list of protocol data unit (PDU) sessions to be activated, or a message about a mobility registration update; checking, on the basis of UE context information about the UE, whether identifiers (IDs) of all of always-on PDU sessions are included in the list of PDU sessions to be activated; and, when an omitted always-on PDU session is checked from the list of the PDU sessions to be activated, transmitting, to a session management function (SMF), a Nsmf_PDUSession_UpdateSMContext request message for requesting user plane activation of the omitted always-on PDU session. ## Claims ### Claim 1 A method performed by an access and mobility management function (AMF) in a wireless communication system, the method comprising: receiving, from a user equipment (UE), a first message including a list of protocol data unit (PDU) sessions to be activated; identifying, based on UE context information of the UE, whether identifiers (IDs) of all of always-on protocol data unit (PDU) sessions are included in the list of PDU sessions to be activated; and in case that at least one always-on PDU session omitted from the list of the PDU sessions to be activated is identified, transmitting, to a session management function (SMF), a second message including information for requesting user plane activation of the at least one always-on PDU session. ### Claim 2 (depends on 1) The method of claim 1, wherein the second message further includes the list of the PDU sessions to be activated and a list of the at least one always-on PDU sessions. ### Claim 3 (depends on 1) The method of claim 1, further comprising transmitting, to the SMF, information on a connection management-connected (CM-connected) state notification of the UE; and performing a user plane activation procedure for the at least one always-on PDU session. ### Claim 4 (depends on 3) The method of claim 3, wherein the user plane activation procedure is selectively performed based on local policy information or configuration information. ### Claim 5 (depends on 3) The method of claim 3, wherein the user plane activation procedure is selectively performed based on a communication of the SMF and the UE related to the at least one always-on PDU session. ### Claim 6 A method performed by a session management function (SMF) in a wireless communication system, the method comprising: receiving, from an access and mobility management function (AMF), a second message including information for requesting user plane activation of at least one always-on protocol data unit (PDU) session, which is omitted from a list of PDU sessions to be activated of a user equipment (UE) included in a first message transmitted from the UE to the AMF; receiving, from the AMF, information on a connection management-connected (CM-connected) state notification of the UE; and identifying whether the at least one always-on PDU session has been omitted from the list of PDU sessions to be activated. ### Claim 7 (depends on 6) The method of claim 6, wherein the second message further includes the list of the PDU sessions to be activated and a list of the at least one always-on PDU sessions. ### Claim 8 (depends on 6) The method of claim 6, further comprising determining whether to perform a user plane activation procedure for the at least one always-on PDU session; and performing a user plane activation procedure for the at least one always-on PDU session. ### Claim 9 (depends on 8) The method of claim 8, wherein whether to perform the user plane activation procedure for the at least one always-on PDU session is selectively determined based on local policy information or configuration information. ### Claim 10 (depends on 8) The method of claim 8, wherein whether to perform the user plane activation procedure for the at least one always-on PDU session is selectively performed based on a communication of the SMF and the UE related to the at least one always-on PDU session. ### Claim 11 An access and mobility management function (AMF) in a wireless communication system, the AMF comprising: a transceiver; and at least one processor coupled with the transceiver, wherein the at least one processor is configured to: receive, from a user equipment (UE), a first message including a list of protocol data unit (PDU) sessions to be activated; identify, based on UE context information of the UE, whether identifiers (IDs) of all of always-on protocol data unit (PDU) sessions are included in the list of PDU sessions to be activated; and in case that at least one always-on PDU session omitted from the list of the PDU sessions to be activated is identified, transmit, to a session management function (SMF), a second message including information for requesting user plane activation of the at least one always-on PDU session. ### Claim 12 (depends on 11) The apparatus AMF of claim 11, wherein the second message further includes the list of the PDU sessions to be activated and a list of the at least one always-on PDU sessions. ### Claim 13 (depends on 11) The AMF of claim 11, wherein the at least one processor is further configured to: transmit, to the SMF, information on a connection management-connected (CM-connected) state notification of the UE; and perform a user plane activation procedure for the at least one always-on PDU session. ### Claim 14 (depends on 13) The AMF of claim 13, wherein the user plane activation procedure is selectively performed based on local policy information or configuration information. ### Claim 15 (depends on 13) The AMF of claim 13, wherein the user plane activation procedure is selectively performed based on communication of the SMF and the UE related to the at least one always-on PDU session.