Access traffic steering, switching, and splitting (ATSSS) capability inconsistency handling

Abstract

A method in a user equipment (UE) is described. The method includes transmitting a packet data unit (PDU) session establishment request as part of a multi-access (MA) PDU session establishment procedure, and receiving a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying one or more of: rules, network steering functionalities information, and measurement assistance information.

Description

[0001] management of Access Traffic Steering, Switching, and Splitting (ATSSS) features.

[0002] BACKGROUND

[0003] The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and user equipment (UE), as well as communication between network nodes and between UEs. The 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks.

[0004] Excerpt from 3GPP Technical Specification (TS) 23.501 V19.0.0

[0005] The ATSSS feature is an optional feature that may be supported by the UE and the 5G Core (5GC) network.

[0006] The ATSSS feature enables a multi-access Packet Data Unit (PDU) Connectivity Service, which can exchange PDUs between the UE and a data network by simultaneously using one 3GPP access network and one non-3GPP access network and two independent N3 / N9 tunnels between the PSA and RAN / AN. The multi-access PDU Connectivity Service is realized by establishing a Multi- Access PDU (MA PDU) Session, i.e. a PDU Session that may have user-plane resources on two access networks. This assumes both 3GPP access and non-3GPP access are allowed for the Single Network Slice Selection Assistance Information (S-NSSAI) of the PDU Session.

[0007] The UE may request a MA PDU Session when the UE is registered via both 3GPP and non-3GPP accesses, or when the UE is registered via one access only.

[0008] After the establishment of a MA PDU Session, and when there are user-plane resources on both access networks, the UE applies network-provided policy (i.e. ATSSS rules) and considers local conditions (such as network interface availability, signal loss conditions, user preferences, etc.) for deciding how to distribute the uplink traffic across the two access networks. Similarly, the User Plane Function (UPF) anchor of the MA PDU Session applies network-provided policy (i.e. N4 rules) and feedback information received from the UE via the user-plane (such as access network Unavailability or Availability) for deciding how to distribute the downlink traffic across the two N3 / N9 tunnels and the two access networks. When there are user-plane resources on only one access network, the UE applies the ATSSS rules and considers local conditions for triggering the establishment or activation of the user plane resources over another access.

[0009] In the PDU Session Establishment Request that is sent to request a new MA PDU Session, the UE shall provide also its ATSSS capabilities, which indicate the steering functionalities and the steering modes supported in the UE.

[0010] The Session Management Function (SMF) determines the ATSSS capabilities supported for the MA PDU Session based on the ATSSS capabilities provided by the UE and per DNN configuration on SMF. The SMF provides the ATSSS capabilities of the MA PDU Session to the PCF during PDU Session Establishment.

[0011] The Policy and Charging Control (PCC) rules provided by Policy Control Function (PCF) include MA PDU Session Control information. They are used by SMF to derive ATSSS rules for the UE and N4 rules for the UPF.

[0012] The UE receives ATSSS rules from SMF, which indicate how the uplink traffic should be routed across 3GPP access and non-3GPP access. Similarly, the UPF receives N4 rules from SMF, which indicate how the downlink traffic should be routed across 3GPP access and non-3GPP access.

[0013] An MA PDU Session may be established either: a) when it is explicitly requested by an ATSSS-capable UE; or b) when an ATSSS-capable UE requests a single-access PDU Session, but the network decides to establish a MA PDU Session instead.

[0014] ATSSS capabilities supported for the MA PDU Session

[0015] During the PDU Session Establishment or Modification procedure, the SMF determines the ATSSS capabilities supported for the MA PDU Session based on the ATSSS capabilities provided by the UE and per Data Network Name (DNN) configuration on SMF.

[0016] The Unified Data Management (UDM) in the subscription data may indicate if MA PDU session allowed or not by the “atsssAllowed” Information Element (IE).

[0017] If dynamic PCC is to be used for the MA PDU Session, the SMF sends an "MA PDU Request" indication to the PCF in the SM Policy Control Association Create message and the ATSSS Capabilities of the MA PDU session. The SMF provides the currently used Access Type(s) and RAT Type(s) to the PCF. The PCF decides whether the MA PDU session is allowed or not based on operator policy and subscription data.

[0018] Excerpt from 3GPP TS 24.501 V19.0.0, Section 6.4.1.4.1

[0019] If the PDU SESSION ESTABLISHMENT REQUEST message is to establish an MA PDU session and MA PDU session is not allowed due to operator policy and subscription, and the SMF decides to reject the PDU session establishment, the SMF shall include the 5GSM cause value #33 "requested service option not subscribed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0020] Excerpt from 3GPP TS 24.501 V19.0.0, Section 6.1.6.4.3

[0021] If the UE receives the 5G State Machine (5GSM) cause value is #33 "requested service option not subscribed" upon sending PDU SESSION ESTABLISHMENT REQUEST to establish an MA PDU session, the UE shall ignore the Back-off timer value IE and Re-attempt indicator IE provided by the network, if any. The UE shall evaluate User Equipment Route Selection Policy (URSP) rules, if available, as specified in 3GPP TS 24.526 and the UE may send PDU SESSION ESTABLISHMENT REQUEST after evaluating those URSP rules.

[0022] Excerpt from 3GPP TS 24.501 V19.0.0, Section 6.4.1.4.3

[0023] If the UE receives the 5GSM cause value is #33 "requested service option not subscribed" upon sending PDU SESSION ESTABLISHMENT REQUEST to establish an MA PDU session, the UE shall ignore the Back-off timer value IE and Re-attempt indicator IE provided by the network, if any. The UE shall evaluate URSP rules, if available, as specified in 3GPP TS 24.526 and the UE may send PDU SESSION ESTABLISHMENT REQUEST after evaluating those URSP rules.

[0024] However, according to existing 3GPP specifications, when UE indicated ATSSS- ST capability is inconsistent with the SMF supported ATSSS capability (in case there is no common ATSSS capability between the UE and the SMF), or the UE provided ATSSS- ST is not compatible with the network supported ATSSS capability, how SMF handles the PDU Session Establishment request is not described. Inconsistent may refer to the UE and the network not supporting the same ATSSS capability. Not compatible or incompatible may refer to the network not understanding or not supporting the UE indicated ATSSS-ST as the network and UE may use different technologies or be on different releases of 3GPP. In some cases, ATSSS-ST may only be used by the UE to indicate to network, on the network side, an ATSSS capability. Further, the SMF may reject the PDU Session Establishment. However, there is no specific 5GSM Cause which SMF that indicates to the UE that the PDU Session Establishment Reject is due to inconsistent or incompatible ATSSS capabilities between the UE and the network.

[0025] The UE is not aware the network rejects the MA PDU Session Establishment request due to the ATSSS capabilities being inconsistent. The UE may retry to setup new PDU session. However, without any specific reason for this case to reject the PDU Session Establishment request, the reattempt of the PDU Session Establishment from the UE is not optimized. In the worst case, this may result in the end user being without any PDU session, and the end user not being able to access the services provided by the data networks.

[0026] For cases where the UDM subscription or PCF policy do not allow MA PDU Session, the specified 5GSM Cause “#33 "requested service option not subscribed"” is not specific. The UE not being aware that the MA PDU Session Establishment Reject may be due to MA PDU Session not being supported. The UE may reattempt a new PDU Session Establishment based on URSP rules if there are other URSP rules in the UE, without being aware that the MA PDU Session is not subscribed in the network. In the worst case, this may result in the end user being without any PDU Session and not being to access the services provided by the data networks.

[0027] SUMMARY

[0028] Some embodiments advantageously provide methods, systems, and apparatuses for management of Access Traffic Steering, Switching, Splitting (ATSSS) features.

[0029] Some embodiments provide an indicator (i.e., indication), such as “MA PDU session network downgrade to single-access is allowed”, for the UE to indicate to the network that the network may proactively downgrade a requested MA PDU Session type into a single-access PDU Session due to mismatch between UE and network capabilities. The indicator “MA PDU session network downgrade to single-access is allowed” may be included in the “MA PDU session information” IE in the Uplink Non-Access Stratum (NAS) Transport message.

[0030] Some other embodiments provide 5GSM Causes which can be indicated by the network to explicitly indicate to the UE in the PDU Session Establishment Accept and PDU Session Establishment Reject Messages. For example, 5GSM Causes may include “ATSSS capability inconsistent or not supported” and “ATSSS steering mode change due to network capability.” Some embodiments provide an IE (e.g., the Network ATSSS Steering Capability) for the network to include in the PDU Session Establishment Reject and PDU Session Establishment Accept messages. The IE may be used to indicate network supported ATSSS steering mode.

[0031] Some other embodiments provide one or more IES that are applicable to UE triggered PDU Session Modification procedures. Some embodiments provide one or more IEs that are applicable to both 3GPP and non-3GPP access PDU Session Establishment and PDU Session Modification procedures.

[0032] One or more embodiments are beneficial at least because the network can proactively set up a single-access PDU session based on UE support and network policy, e.g., instead of rejecting the MA PDU Session. With a single-access PDU session, the end user can have access provided by data networks even when it is not possible to set up an MA PDU Session. Further, the network may indicate to the UE the specific reasons for an MA PDU Session setup accept or reject, e.g., to make the UE aware of the issue for optimization of UE the consequence handling. In one or more embodiments unnecessary network signaling is reduced or eliminated, and end user experiences and network Key Performance Indicators (KPIs) are improved when compared to existing systems.

[0033] According to one aspect, a method in a user equipment (UE) that has a UE capability is described. The UE is configured to communicate with one or more network nodes using a multi-access packet data unit (MA PDU) session. At least one network node has a network capability. The UE capability and the network capability are associated with Access Traffic Steering, Switching, Splitting (ATSSS). The method includes determining, based on one or both of a UE local configuration and user equipment route selection policy (URSP) rules, a downgrade indication indicating to at least one of the one or more network nodes that a MA PDU session network downgrade to single access is allowed and transmitting the downgrade indication to at least one of the one or more network nodes.

[0034] The downgrade indication can for example indicate to at least one of the one or more network nodes whether an MA PDU session network downgrade to single access is allowed or not. Such indication can be a positive indication (allowed) or a negative indication (not allowed).

[0035] In some embodiments, the downgrade indication is transmitted via an MA PDU Session Information IE, or PCO IE, or 5GSM Capability.

[0036] In some embodiments, the method further includes transmitting an uplink non- access stratum transport message including MA PDU session information. The MA PDU session information includes an information element, and the information element includes the downgrade indication.

[0037] In some other embodiments, the method further includes receiving a first cause indication indicating that an ATSSS capability is inconsistent or not supported.

[0038] In some embodiments, the first cause indication is received in one of a PDU session establishment accept message and a PDU session establishment reject message.

[0039] In some other embodiments, the method further includes performing a single access PDU session establishment based on the first cause indication.

[0040] In some embodiments, the method further includes receiving a second cause indication indicating an ATSSS steering mode change that has occurred due to network capability.

[0041] In some other embodiments, the second cause indication is received in a PDU session establishment accept message.

[0042] In some embodiments, the method further includes continuing with or releasing the MA PDU session based on the second cause indication.

[0043] According to another aspect, a user equipment that has a UE capability is described. The UE is configured to communicate with one or more network nodes using a multi-access packet data unit (MA PDU) session. At least one network node has a network capability. The UE capability and the network capability are associated with Access Traffic Steering, Switching, Splitting (ATSSS). The UE is configured to and / or comprises a radio interface and / or processing circuitry configured to determine, based on one or both of a UE local configuration and user equipment route selection policy (URSP), a downgrade indication indicating to at least one of the one or more network nodes that a MA PDU session network downgrade to single access is allowed and transmit the downgrade indication to at least one of the one or more network nodes.

[0044] The downgrade indication can for example indicate to at least one of the one or more network nodes whether an MA PDU session network downgrade to single access is allowed or not. Such indication can be a positive indication (allowed) or a negative indication (not allowed).

[0045] In some embodiments, the UE is further configured to perform any one of the steps of method in the UE.

[0046] According to one aspect, a method in a first network node in a network is described. The network is configured to support a multi-access packet data unit (MA PDU) session associated with a user equipment (UE). The method includes receiving a downgrade indication indicating that a MA PDU session network downgrade to single access is allowed and determining, based on the downgrade indication, one or both of a first cause indication and a second cause indication. The first cause indication indicates that an Access Traffic Steering, Switching, Splitting, ATSSS, capability is inconsistent or not supported, and the second cause indication indicates an ATSSS steering mode change that has occurred due to network capability. The method further includes transmitting one or both of the first cause indication and the second cause indication.

[0047] The downgrade indication can for example indicate whether an MA PDU session network downgrade to single access is allowed or not. Such indication can be a positive indication (allowed) or a negative indication (not allowed).

[0048] In some embodiments, the downgrade indication is forwarded to the first network node by a second network node, the second network node comprising an access and mobility function (AMF).

[0049] In some other embodiments, the method further includes configuring a single access PDU session in the network based on the downgrade indication.

[0050] In some embodiments, the method further includes rejecting the MA PDU session due to one or more of first network node local policy, an ATSSS capability inconsistency, unified data management (UDM) subscription data, a policy control function (PCF) local policy.

[0051] In some other embodiments, the method further includes transmitting a network ATSSS steering capability indication indicating to the UE a network supported ATSSS steering mode.

[0052] In some embodiments, the first network node includes a session management function (SMF).

[0053] According to another aspect, a first network node in a network is described. The network is configured to support a multi-access packet data unit (MA PDU) session associated with a user equipment (UE). The first network node is configured to and / or comprises a radio interface and / or processing circuitry configured to receive a downgrade indication indicating that a MA PDU session network downgrade to single access is allowed and determine, based on the downgrade indication, one or both of a first cause indication and a second cause indication. The first cause indication indicates that an Access Traffic Steering, Switching, Splitting, ATSSS, capability is inconsistent or not supported, and the second cause indication indicates an ATSSS steering mode change that has occurred due to network capability. The first network node is also configured to transmit one or both of the first cause indication and the second cause indication.

[0054] The downgrade indication can for example indicate whether an MA PDU session network downgrade to single access is allowed or not. Such indication can be a positive indication (allowed) or a negative indication (not allowed).

[0055] In some embodiments, the first network node is further configured to perform any one of the steps of method in the first network node.

[0056] According to another aspect, a method in a UE is described. The method includes transmitting a packet data unit (PDU) session establishment request as part of a multiaccess (MA) PDU session establishment procedure, and receiving a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying one or more of: rules, network steering functionalities information, and measurement assistance information.

[0057] In some embodiments, the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections (MPQUIC) network steering functionalities information.

[0058] In some embodiments, the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

[0059] In some embodiments, the PDU session establishment request is an initial PDU session establishment request, and wherein the method further comprises using the supplemental information in the ATSSS container to generate a subsequent PDU session establishment request that is different from the initial PDU session establishment request.

[0060] In some embodiments, the PDU session establishment request is an initial PDU session establishment request, and wherein the method further comprises using the supplemental information in the ATSSS container to hold off from generating a subsequent PDU session establishment request until at least one criterion is met. In some embodiments, the PDU session establishment request is sent to a network node and the PDU session establishment reject message is received from the network node.

[0061] In some embodiments, the network node is a Session Management Function (SMF).

[0062] According to another aspect, a UE is described. The UE is configured to transmit a packet data unit (PDU) session establishment request as part of a multi-access (MA) PDU session establishment procedure, and receive a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying one or more of: rules, network steering functionalities information, and measurement assistance information.

[0063] In some embodiments, the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections (MPQUIC) network steering functionalities information.

[0064] In some embodiments, the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

[0065] In some embodiments, the PDU session establishment request is an initial PDU session establishment request, and wherein the UE is further configured to use the supplemental information in the ATSSS container to generate a subsequent PDU session establishment request that is different from the initial PDU session establishment request.

[0066] In some embodiments, the PDU session establishment request is an initial PDU session establishment request, and wherein the UE is further configured to use the supplemental information in the ATSSS container to hold off from generating a subsequent PDU session establishment request until at least one criterion is met.

[0067] In some embodiments, the PDU session establishment request is sent to a network node and the PDU session establishment reject message is received from the network node.

[0068] In some embodiments, the network node is a Session Management Function

[0069] (SMF). According to another aspect, a method in a network node is described. The method includes receiving a packet data unit (PDU) session establishment request as part of a multi-access (MA) PDU session establishment procedure, and transmitting a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying at least one of rules, network steering functionalities information, and measurement assistance information.

[0070] In some embodiments, the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections (MPQUIC) network steering functionalities information.

[0071] In some embodiments, the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

[0072] In some embodiments, the PDU session establishment request is received from a UE, and the PDU session establishment reject message is sent to the UE.

[0073] In some embodiments, the network node is a Session Management Function (SMF).

[0074] According to another aspect, a network node is described. The network node is configured to receive a packet data unit (PDU) session establishment request as part of a multi-access (MA), PDU session establishment procedure, and transmit a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying at least one of rules, network steering functionalities information, and measurement assistance information.

[0075] In some embodiments, the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections (MPQUIC) network steering functionalities information. In some embodiments, the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

[0076] In some embodiments, the PDU session establishment request is received from a UE, and the PDU session establishment reject message is sent to the UE.

[0077] In some embodiments, the network node is a Session Management Function (SMF).

[0078] BRIEF DESCRIPTION OF THE DRAWINGS

[0079] A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0080] FIG. 1 is a schematic diagram of an example network architecture illustrating a communication system according to principles disclosed herein;

[0081] FIG. 2 is a block diagram of a network node in communication with a user equipment over a wireless connection according to some embodiments of the present disclosure;

[0082] FIG. 3 is a flowchart of an example process in a user equipment according to some embodiments of the present disclosure;

[0083] FIG. 4 is a flowchart of another example process in a user equipment according to some embodiments of the present disclosure;

[0084] FIG. 5 is a flowchart of an example process in a network node according to some embodiments of the present disclosure;

[0085] FIG. 6 is a flowchart of another example process in a network node according to some embodiments of the present disclosure;

[0086] FIG. 7A-7C shows an example process associated with an ATSSS Capability inconsistency scenario according to some embodiments of the present disclosure;

[0087] FIG. 8 shows an example process where UDM Subscription and PCF policy do not allow a MA PDU session according to some embodiments of the present disclosure; and

[0088] FIG. 9 is a sequence drawing of a UE-requested PDU session establishment procedure. DETAILED DESCRIPTION

[0089] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to management of Access Traffic Steering, Switching, Splitting (ATSSS) features. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0090] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0091] In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

[0092] In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and / or wireless connections.

[0093] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0094] The term “network node” used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multistandard radio (MSR) radio node such as MSR BS, multi-cell / multicast coordination entity (MCE), relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), Access and Mobility Management Function(AMF), SMF, UDM, PCF, etc. The network node may also comprise test equipment. The term “radio node” used herein may be used to also denote a user equipment (UE) such as a wireless device (WD) or a radio network node. In some embodiments, the term “network” is used and may refer to a network node.

[0095] In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The UE herein can be any type of wireless device capable of communicating with a network node or another UE over radio signals, such as a wireless device (WD). The UE may also be a radio communication device, target device, device to device (D2D) UE, machine type UE or UE capable of machine to machine communication (M2M), low-cost and / or low-complexity UE, a sensor equipped with UE, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device etc.

[0096] Also, in some embodiments the generic term “radio network node” is used. It can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell / multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH). Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and / or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

[0097] Note further, that functions described herein as being performed by a user equipment or a network node may be distributed over a plurality of user equipments and / or network nodes. In other words, it is contemplated that the functions of the network node and user equipment described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

[0098] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0099] Referring to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 1 a schematic diagram of a communication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and / or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 (which may comprise one or more other network nodes 16 such as network node 16d) over a wired or wireless connection 20. A first user equipment (UE) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second UE 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of UEs 22a, 22b (collectively referred to as user equipments 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding network node 16. Note that although only two UEs 22 and three network nodes 16 are shown for convenience, the communication system may include many more UEs 22 and network nodes 16.

[0100] Also, it is contemplated that a UE 22 can be in simultaneous communication and / or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a UE 22 can have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, UE 22 can be in communication with an eNB for LTE / E-UTRAN and a gNB for NR / NG-RAN.

[0101] Further, system 10 (and / or any of its components such as network node 16 and UE 22) may support ATSSS functionalities. The ATSSS functionalities may include enabling a multi-access PDU Connectivity Service, e.g., exchange of PDUs between the UE and a data network by simultaneously using network 12 (e.g., 3GPP access network) and network 15 (e.g., a non-3GPP access network). For example, UEs 22 may be configured to communicate with core network 14 and / or one or more other network nodes 16 such as network node 16d) over a wired or wireless connections 17, 19. In some embodiments, network 15 may include one or more features and components of access network 12 and be configured as a non-3GPP access network. Although system 10 is described as supporting ATSSS functionalities, the embodiments are not limited as such, and system 10 may support other functionalities such as multiple access via more than one network (e.g., networks 12, 15).

[0102] A network node 16 is configured to include a node management unit 24 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., network node functions. A user equipment 22 is configured to include a UE management unit 26 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., UE functions.

[0103] Example implementations, in accordance with an embodiment, of the UE 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 2.

[0104] The communication system 10 includes a network node 16 provided in a communication system 10 and includes hardware 28 enabling it to communicate with the UE 22. The hardware 28 may include a radio interface 30 for setting up and maintaining at least a wireless connection 60 with a UE 22 located in a coverage area 18 served by the network node 16. Connection 60 may be configured to use or comprise any of one of connections 17, 19, 20. The radio interface 30 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 30 includes an array of antennas 34 to radiate and receive signal(s) carrying electromagnetic waves. The hardware 28 may also include a communication interface 32 for setting up and maintaining at least a connection with other network nodes 16.

[0105] In the embodiment shown, the hardware 28 of the network node 16 further includes processing circuitry 36. The processing circuitry 36 may include a processor 38 and a memory 40. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 36 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 38 may be configured to access (e.g., write to and / or read from) the memory 40, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0106] Thus, the network node 16 further has software 42 stored internally in, for example, memory 40, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 42 may be executable by the processing circuitry 36. The processing circuitry 36 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by network node 16. Processor 38 corresponds to one or more processors 38 for performing network node 16 functions described herein. The memory 40 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 42 may include instructions that, when executed by the processor 38 and / or processing circuitry 36, causes the processor 38 and / or processing circuitry 36 to perform the processes described herein with respect to network node 16. For example, processing circuitry 36 of the network node 16 may include node management unit 24 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., network node functions. The communication system 10 further includes the UE 22 already referred to. The UE 22 may have hardware 44 that may include a radio interface 46 configured to set up and maintain a wireless connection 60 with a network node 16 serving a coverage area 18 in which the UE 22 is currently located. The radio interface 46 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and / or one or more RF transceivers. The radio interface 46 includes an array of antennas 48 to radiate and receive signal(s) carrying electromagnetic waves.

[0107] The hardware 44 of the UE 22 further includes processing circuitry 50. The processing circuitry 50 may include a processor 52 and memory 54. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 50 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 52 may be configured to access (e.g., write to and / or read from) memory 54, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0108] Thus, the UE 22 may further comprise software 56, which is stored in, for example, memory 54 at the UE 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the UE 22. The software 56 may be executable by the processing circuitry 50. The software 56 may include a client application 58. The client application 58 may be operable to provide a service to a human or non-human user via the UE 22.

[0109] The processing circuitry 50 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by UE 22. The processor 52 corresponds to one or more processors 52 for performing UE 22 functions described herein. The UE 22 includes memory 54 that is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 56 and / or the client application 58 may include instructions that, when executed by the processor 52 and / or processing circuitry 50, causes the processor 52 and / or processing circuitry 50 to perform the processes described herein with respect to UE 22. For example, the processing circuitry 50 of the user equipment 22 may include UE management unit 26 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., UE functions.

[0110] In some embodiments, the inner workings of the network node 16 and UE 22 may be as shown in FIG. 2 and independently, the surrounding network topology may be that of FIG. 1.

[0111] The wireless connection 60 between the UE 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and / or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.

[0112] Although FIGS. 1 and 2 show various “units” such as node management unit 24 and UE management unit 26 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

[0113] FIG. 3 is a flowchart of an example process in a user equipment 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of user equipment 22 such as by one or more of processing circuitry 50 (including the UE management unit 26), processor 52, and / or radio interface 46. UE 22 is configured to determine (Block S100), based on one or both of a UE local configuration and user equipment route selection policy, URSP, rules, a downgrade indication indicating to at least one of the one or more network nodes that a MA PDU session network downgrade to single access is allowed and transmit (Block SI 02) the downgrade indication to at least one of the one or more network nodes.

[0114] The downgrade indication can for example indicate to at least one of the one or more network nodes whether an MA PDU session network downgrade to single access is allowed or not. Such indication can be a positive indication (allowed) or a negative indication (not allo wed). In some embodiments, the downgrade indication is transmitted via an MA PDU Session Information IE, or PCO IE, or 5GSM Capability.

[0115] In some embodiments, the method further includes transmitting an uplink non- access stratum transport message including MA PDU session information. The PDU session information includes an information element, the information element including the downgrade indication.

[0116] In some other embodiments, the method further includes receiving a first cause indication indicating that an ATSSS capability is inconsistent or not supported.

[0117] In some embodiments, the first cause indication is received in one of a PDU session establishment accept message and a PDU session establishment reject message.

[0118] In some other embodiments, the method further includes performing a single access PDU session establishment based on the first cause indication.

[0119] In some embodiments, the method further includes receiving a second cause indication indicating an ATSSS steering mode change that has occurred due to network capability.

[0120] In some other embodiments, the second cause indication is received in a PDU session establishment accept message.

[0121] In some embodiments, the method further includes continuing with or releasing the MA PDU session based on the second cause indication.

[0122] FIG. 4 is a flowchart of another example process in a UE 22 according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of UE 22 such as by one or more of processing circuitry 50 (including the UE management unit 26), processor 52, and / or radio interface 46. UE 22 is configured to transmit (Block S104) a packet data unit (PDU) session establishment request as part of a multi-access (MA) PDU session establishment procedure. UE 22 is further configured to receive (Block S106) a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying one or more of: rules, network steering functionalities information, and measurement assistance information.

[0123] In some embodiments, the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections (MPQUIC) network steering functionalities information.

[0124] In some embodiments, the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

[0125] In some embodiments, the PDU session establishment request is an initial PDU session establishment request, and wherein the method further comprises using the supplemental information in the ATSSS container to generate a subsequent PDU session establishment request that is different from the initial PDU session establishment request.

[0126] In some embodiments, the PDU session establishment request is an initial PDU session establishment request, and wherein the method further comprises using the supplemental information in the ATSSS container to hold off from generating a subsequent PDU session establishment request until at least one criterion is met.

[0127] In some embodiments, the PDU session establishment request is sent to a network node (16) and the PDU session establishment reject message is received from the network node (16).

[0128] In some embodiments, the network node (16) is a Session Management Function (SMF).

[0129] FIG. 5 is a flowchart of an example process in a network node 16 (e.g., a first network node, an SMF. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the node management unit 24), processor 38, and / or radio interface 30. Network node 16 is configured to receive (Block S108) a downgrade indication indicating that a MA PDU session network downgrade to single access is allowed and determine (Block SI 10), based on the downgrade indication, one or both of a first cause indication and a second cause indication. The first cause indication indicates that an Access Traffic Steering, Switching, Splitting, ATSSS, capability is inconsistent or not supported, and the second cause indication indicates an ATSSS steering mode change that has occurred due to network capability. The network node 16 is further configured to transmit (Block SI 12) one or both of the first cause indication and the second cause indication.

[0130] The downgrade indication can for example indicate whether an MA PDU session network downgrade to single access is allowed or not. Such indication can be a positive indication (allowed) or a negative indication (not allowed).

[0131] In some embodiments, the downgrade indication is forwarded to the first network node 16 by a second network node 16, the second network node 16 comprising an access and mobility function (AMF). In some other embodiments, the method further includes configuring a single access PDU session in the network 12, 14, 15 based on the downgrade indication.

[0132] In some embodiments, the method further includes rejecting the MA PDU session due to one or more of first network node local policy, an ATSSS capability inconsistency, unified data management (UDM) subscription data, a policy control function (PCF) local policy.

[0133] In some other embodiments, the method further includes transmitting a network ATSSS steering capability indication indicating to the UE 22 a network supported ATSSS steering mode.

[0134] In some embodiments, the first network node 16 includes a session management function (SMF).

[0135] FIG. 6 is a flowchart of an example process in a network node 16 (e.g., a first network node, an SMF). One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the node management unit 24), processor 38, and / or radio interface 30. Network node 16 is configured to receive (Block SI 14) a packet data unit (PDU) session establishment request as part of a multi-access (MA) PDU session establishment procedure. Network node 16 is further configured to transmit (Block SI 16) a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting (ATSSS) container that includes at least one parameter conveying at least one of rules, network steering functionalities information, and measurement assistance information

[0136] In some embodiments, the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections (MPQUIC) network steering functionalities information.

[0137] In some embodiments, the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

[0138] In some embodiments, the PDU session establishment request is received from a UE (22), and the PDU session establishment reject message is sent to the UE (22). In some embodiments, the network node (16) is a Session Management Function

[0139] (SMF).

[0140] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for management of Access Traffic Steering, Switching, Splitting (ATSSS) features.

[0141] In some embodiments, the term “SMF” refers to a network node 16 that comprises an SMF and / or is configured as an SMF or to perform SMF actions. In some other embodiments, the term “AMF” refers to a network node 16 that comprises an AMF and / or is configured as an AMF or to perform AMF actions. In some embodiments, the term “UDM” refers to a network node 16 that comprises an UDM and / or is configured as an UDM or to perform UDM actions. In some other embodiments, the term “PCF” refers to a network node 16 that comprises a PCF and / or is configured as a PCF or to perform PCF actions.

[0142] Some embodiments provide an indicator (i.e., indication), such as “MA PDU session network downgrade to single-access is allowed”, for the UE 22 to indicate to the network that the network may proactively downgrade a requested MA PDU Session type into a single-access PDU Session due to mismatch between UE 22 and network capabilities. The SMF may determine the mismatch between a UE capability and a network capability. The indicator “MA PDU session network downgrade to single-access is allowed” may be included in the “MA PDU session information” IE in the Uplink Non- Access Stratum (NAS) Transport message. In case the UE ATSSS capability and the SMF ATSSS capability are inconsistent and there is no common ATSSS capability between the UE 22 and the SMF, the SMF may, based on the local policy and the new indicator, set up a single-access PDU Session in the access network where the request is received. That is, instead of a multi-access PDU Session, a “regular” single-access PDU Session is established. In the case the UDM subscription data or PCF local policy does not allow the MA PDU session, the SMF may also, based on the UE indicator and network operator policy, set up a single-access PDU session in the access network where the request is received.

[0143] Some other embodiments provide 5GSM Causes which can be indicated by the network to explicitly indicate to the UE 22 in the PDU Session Establishment Accept and PDU Session Establishment Reject Messages. For example, 5GSM Causes may include “ATSSS capability inconsistent or not supported” and “ATSSS steering mode change due to network capability.” Nonlimiting examples of the 5GSM causes include:

[0144] • “ATSSS capability inconsistent or not supported” o If the UE 22 has indicated “MA PDU session network downgrade to singleaccess is allowed”, the network node 16 comprising the SMF may determine to set up a single-access PDU Session. The network node 16 comprising the SMF may include the 5GSM Cause “ATSSS capability inconsistent or not supported” in the PDU Session Establishment Accept Message, e.g., the 5GSM Cause IE. o In the case the UE 22 has not indicated “MA PDU session network downgrade to single-access is allowed”, or the network node 16 comprising the SMF determines to reject the MA PDU Session setup based on local policy due to ATSSS capability inconsistent or UDM subscription data or PCF local policy, the network node 16 comprising the SMF includes the 5GSM Cause “ATSSS capability inconsistent or not supported” in the PDU Session Establishment Reject message, e.g., the 5GSM Cause IE.

[0145] • “ATSSS steering mode change due to network capability” o For the UE and network ATSSS capability inconsistent scenarios, if network node 16 comprising the SMF and the UE 22 have an implicit minimum requirement the ATSSS-LL be active-standby, the network node 16 comprising the SMF in the PDU Session Establishment Accept may include or indicate the 5GSM Cause “ATSSS steering mode change due to network capability”. When the UE 22 receives the PDU Session Establishment Accept with the Cause, the UE 22, e.g.., based on its capability, decide either to accept the network changed steering mode or to release the PDU Session due to the changed steering mode. o In some embodiments, the alternative indication is applicable only for the scenario that the UE 22 and the network has implicit support of ATSSS-LL active-standby as minimum ATSSS capability.

[0146] Some embodiments provide an IE (e.g., the Network ATSSS Steering Capability) for the network to include in the PDU Session Establishment Reject and PDU Session Establishment Accept messages. The IE may be used to indicate network supported ATSSS steering mode. • For the cases where the ATSSS capability inconsistent between the UE 22 and network node 16 comprising the SMF, the network node 16 comprising the SMF determines to reject the MA PDU Session setup. The network node 16 comprising the SMF may include “network ATSSS steering capability” to indicate to the UE supported ATSSS capability by the network for the UE 22 as a reference in the retry attempt if the UE 22 is able to adjust and fallback its ATSSS capability using network preference.

[0147] • For the cases where the network node 16 comprising the SMF performs one or more actions based on UE indication of “MA PDU session network downgrade to single-access is allowed,” and local policy has downgraded the MA PDU Session to single-access PDU Session, the network node 16 comprising the SMF may include the IE (e.g., in the information or indication). The UE 22 may, based on its capability to decide, either accept the single-access PDU Session, or release the single-access PDU Session and reattempt with MA PDU session setup taking network indicated ATSSS capability into consideration.

[0148] Some other embodiments provide one or more IES that are applicable to UE triggered PDU Session Modification procedures. Some embodiments provide one or more IEs that are applicable to both 3GPP and non-3GPP access PDU Session Establishment and PDU Session Modification procedures.

[0149] In some embodiments, an indication may be included and / or defined in a MA PDU session information component, e.g., 3GPP TS 24.501: 9.11.3.31A MA PDU session information as follows:

[0150] Table 1. - MA PDU session information In some embodiments, a 5GSM cause may be provided, e.g., 3GPP TS 24.501, 5GSM cause as follows:

[0151] Table 2.- 5GSM cause information element (Table 9.11.4.2.1, 3GPP TS 24.501).

[0152] In some other embodiments, an IE for indicating the Network ATSSS steering Capability may be used (Option 1). An example IE related to 3GPP TS 24.501, 8.3.3 PDU Session Establishment Reject is as follows:

[0153] Table 8.3.3.1.1, 3GPP TS 24.501).

[0154] In some embodiments, “Network ATSSS Steering Capability” may be included in the ATSSS container IE (Option 2). An example IE is as follows:

[0155] Table 4. - PDU SESSION ESTABLISHMENT REJECT message content (e.g., e.g., Table 8.3.3.1.1, 3GPP TS 24.501).

[0156] It should be noted that, in some embodiments, the ATSSS container, in addition to including at least one parameter conveying network steering functionalities, also includes supplemental information about the reason for the rejection of the PDU session establishment procedure requested by the UE. This supplemental information includes more information about the reason for the rejection than can be found in the cause indication. Advantageously, this allows the UE to more clearly understand the reason why the PDU session establishment procedure request was rejected, and can use that information to either refrain from sending the same request in the future, or to alter the request, using different parameters.

[0157] In some other embodiments, ATSSS parameter “Network ATSSS Steering Capability” may be defined, e.g., in 3GPP TS 24.193 as follows:

[0158] Table 5.- ATSSS parameter (e.g., Table 6.1.2-1, 3GPP TS 24.193).

[0159] Further, the Network ATSSS Steering Capability may also be defined in 3GPP TS 24.193, 6.1.x. The Network ATSSS Steering Capability may define the ATSSS steering mode supported by the network, which defines the Steering functionality, Steering mode and Steering mode information.

[0160] FIGS. 7A-7C show an example process associated with an ATSSS Capability inconsistency scenario. Although the steps of the example process are described as part of one process, any one of the steps shown in FIGS. 7A-7C may be independent from the example process and may be part of any other process.

[0161] One or more of the following information or indications or information elements (e.g., IES) may be considered new IES that are not included in the existing standards:

[0162] • “MA PDU session network downgrade to single-access is allowed”;

[0163] • maNwDowngradeInd:true;

[0164] • 5GSM Cause: ATSSS capability inconsistent or not supported;

[0165] • 5GSM Cause: Network ATSSS Steering Capability;

[0166] • 5GSM Cause: ATSSS mode change due to network capability;

[0167] FIGS. 7A-7B show Option 1, where the UE 22 and the network do not have implicit minimum ATSSS capability support. The process may include one or more of the following steps:

[0168] Step 1 : UE 22 requests MA PDU Session Establishment with optional new indication: MA PDU Session network downgrade to single-access PDU is allowed, which is included in MA PDU Session Information IE in the Uplink NAS Transport message.

[0169] Step 2a: Network node 16a (e.g., AMF) forwards the UE request of PDU Session Establishment to the network node 16b (e.g., SMF) with new indication maNwDowngradelnd.

[0170] Step 3a: Network node 16b (e.g., SMF) receives the UE ATSSS-ST capability. The UE indicated ATSSS-ST capability is inconsistent or incompatible with the network node 16b (e.g., SMF)’s ATSSS capability. Network node 16b (e.g., SMF) decides based on the UE indication and SMF local policy, to either proceed with a single-access PDU session Establishment or reject the MA PDU Session Establishment.

[0171] When network node 16b (e.g., SMF) decides to proceed with single-access PDU Session Establishment:

[0172] Step 4a: the PDU Session Establishment procedure steps are performed or continued to be performed.

[0173] Step 5: Network node 16b (e.g., SMF) sends NlN2MessageTransfer Request, including N1 SM container: PDU Session Establishment Accept to AMF. The “5GSM Cause: ATSSS capability inconsistent or not supported” is included in the request.

[0174] Step 6: the PDU Session Establishment procedure steps are performed or continued to be performed. The UE 22 receives PDU Session Establishment Accept with single-access PDU Session Type, where the 5GSM Cause indicates that the ATSSS capability is inconsistent or not supported. That is, the UE 22 being aware of a singleaccess PDU Session is set up due to ATSSS capability being inconsistent.

[0175] When network node 16b (e.g., SMF) decides to reject the MA PDU Session Establishment:

[0176] Step 4a: network node 16b (e.g., SMF) responds to the AMF’s SMContextCreateError, where the response includes an N1 container: PDU Session Establishment Reject. The 5GSM Cause “ATSSS Capability inconsistent or not supported” is included. Optionally, the network node 16b (e.g., SMF) can include “Network ATSSS Steering Capability” in the Reject message. Alternatively, step 4 is performed.

[0177] Step 4b: Network node 16b (e.g., SMF) responds to AMF’s SMContextCreateError, where the response includes N1 container: PDU Session Establishment Reject. The 5GSM Cause “ATSSS Capability inconsistent or not supported” is included. Optionally, the network node 16b (e.g., SMF) can include “Network ATSSS Steering Capability” or in ATSSS Container IE in the Reject message.

[0178] Step 5a: MA PDU Session Establishment Reject is forwarded to the UE 22.

[0179] Step 6a: UE 22 may reattempt single-access PDU Session Establishment based on the received 5GSM Cause.

[0180] FIG. 7C shows Option 2, where the UE 22 and the network have implicit minimum ATSSS capability, i.e., ATSSS-LL Active-standby.

[0181] Step 1 : UE 22 sends an MA PDU Session Establishment Request. Step 2b: Network node 16a (e.g., AMF) forwards the UE request to network node 16b (e.g., SMF).

[0182] Step 3b: The UE indicated ATSSS-ST is not consistent or compatible with the SMF ATSSS capability, network node 16b (e.g., SMF) sets up the MA PDU Session with the minimum ATSSS capability, i.e., ATSSS-EE Active-Standby steering functionality.

[0183] Step 4: The MA PDU Session Establishment procedure steps are performed or continue to be performed.

[0184] Step 5b: network node 16b (e.g., SMF) sends to network node 16a (e.g., AMF) the NlN2MessageTransfer Request message including N1 SM container and other information. The N1 SM container includes the ATSSS Container IE (e.g., among other IES). The ATSSS Container IE includes ATSSS Rules indicating ATSSS-EE activestandby steering mode. The 5GSM Cause is included in the N 1 SM container, indicating ATSSS steering Mode change due to network capability.

[0185] Step 6b: the MA PDU session setup procedure steps are performed or continue to be performed.

[0186] Step 7b: the UE 22 receives PDU Session Establishment Accept with ATSSS rules using ATSSS-LL Active-Standby steering mode and the 5GSM Cause. The UE 22 determines (e.g., based on its capability to decide) to continue with the PDU session accepted by the network, or release the MA PDU session.

[0187] FIG. 8 shows an example process where UDM Subscription and PCF policy do not allow a MA PDU Session.

[0188] Step 1 : UE 22 transmits a PDU Session Establishment Request that indicates MA PDU Session network downgrade is allowed.

[0189] Step 2: Network node 16a (e.g., AMF) forwards the request to network node 16b (e.g., SMF), with the indication maNwDowngradelnd set to true, network node 16b (e.g., SMF) retrieves subscription data from network node 16c (e.g., UDM) and receives subscription data from the network node 16c (e.g., UDM). Further, network node 16b (e.g., SMF) sets up policy association to network node 16d (e.g., PCF) and receives response.

[0190] Step 3: UDM subscription data or PCF local policy may not allow MA PDU Session, network node 16b (e.g., SMF) determines, based on the UE indication “MA PDU Session network downgrade to single-access PDU is allowed” and the SMF local policy, whether to downgrade to single-access PDU Session or reject the PDU Session set up. Step 4a: network node 16b (e.g., SMF) determines to set up single-access PDU session, network node 16b (e.g., SMF) sends PDU Session Establishment Accept in the NlN2MessageTransfer Request to network node 16a (e.g., AMF) in the N1 SM container IE. The PDU Session Establishment Accept includes “5GSM Cause: ATSSS capability inconsistent or not supported.”

[0191] Step 4b: network node 16b (e.g., SMF) determines to reject the PDU Session setup, network node 16b (e.g., SMF) sends SMContextCreateError to network node 16a (e.g., AMF), including N1 SM Container IE which includes the PDU Session Establishment Reject message, network node 16b (e.g., SMF) includes, in the PDU Session Establishment Reject, the “5GSM Cause: ATSSS capability inconsistent or not supported.”

[0192] Step 5: Network node 16a (e.g., AMF) forwards the PDU Session Establishment Reject to UE 22.

[0193] Step 6: Based on the received 5GSM Cause, UE 22 may retry to setup singleaccess PDU Session with the DNN.

[0194] Example Standards Implementation

[0195] This section includes specific example details of how one or more embodiments could be implemented within one or more communication standards. Included is an example discussion followed by two example standards contributions. It is to be understood that this section is very specific for exemplary purposes only. Other implementations are possible and are within the scope of the disclosure.

[0196] 1. Introduction

[0197] The ATSSS capability is a combination of ATSSS-LL, MPTCP, and MPQUIC capabilities as defined in 3GPP TS 24.501 clause 9.11.4.1 in the 5GSM capability IE. The 5GSM capability IE is an optional IE which can be included in the PDU SESSION ESTABLISHMENT REQUEST or PDU SESSION MODIFICATION REQUEST message.

[0198] The UE indicates its ATSSS capability in the 5GSM capability IE in the PDU SESSION ESTABLISHMENT REQUEST message or in the PDU SESSION MODIFICATION REQUEST message. As specified in 3GPP TS 23.501, the network, including the SMF and the PCF, based on the local configuration and local policy, decides the ATSSS functionality and steering mode to be used for the MA PDU Session. The SMF conveys the ATSSS steering information to the UE, including ATSSS rules, steering mode, etc., in the PDU SESSION ESTABLISHMENT ACCEPT message or the PDU SESSION MODIFICATION ACCEPT message.

[0199] The ATSSS capability as indicated by the UE and the ATSSS functionality supported by the network may be inconsistent or incompatible. Currently, it is not clearly defined how to handle an event in which the UE and network ATSSS capabilities are incompatible or inconsistent.

[0200] 2. Discussion

[0201] 3GPP TS 24.501 V 19.0.0 defines ATSSS-ST as follows:

[0202] 9.11.4.1.1: 5GSM capability information element 0 0 0 1 ATSSS Low-Layer functionality with any steering mode allowed for ATSSS-LL supported

[0203] 0 0 1 0 MPTCP functionality with any steering mode and ATSSS- LL functionality with only active-standby steering mode supported

[0204] 0 0 1 1 MPTCP functionality with any steering mode and ATSSS- LL functionality with any steering mode allowed for ATSSS-LL supported

[0205] 0 1 0 0 MPQUIC functionality with any steering mode and ATSSS- LL functionality with only active-standby steering mode supported

[0206] 0 1 0 1 MPQUIC functionality with any steering mode and ATSSS- LL functionality with any steering mode allowed for ATSSS-LL supported

[0207] 0 1 1 0 MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode supported

[0208] 0 1 1 1 MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported

[0209] All other values are reserved.

[0210] Transfer of port management information containers (TPMIC) (octet 3, bit 8)

[0211] This bit indicates the 5GSM capability to support transfer of port management information containers

[0212] 0Transfer of port management information containers not supported

[0213] 1Transfer of port management information containers supported

[0214] TS 24.501 Clause 6.4.1.4.1 states:

[0215] If the PDU SESSION ESTABLISHMENT REQUEST message is to establish an MA PDU session and MA PDU session is not allowed due to operator policy and subscription, and the SMF decides to reject the PDU session establishment, the SMF shall include the 5GSM cause value #33 "requested service option not subscribed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT.

[0216] TS 24.501 Clause 6.1.6.4.3 states:

[0217] If the UE receives the 5GSM cause value is #33 "requested service option not subscribed" upon sending PDU SESSION ESTABLISHMENT REQUEST to establish an MA PDU session, the UE shall ignore the Back-off timer value IE and Re-attempt indicator IE provided by the network, if any. The UE shall evaluate URSP rules, if 31 available, as specified in 3GPP TS 24.526 and the UE may send PDU SESSION ESTABLISHMENT REQUEST after evaluating those URSP rules.

[0218] Observation 1: How the network handles the case where the ATSSS capability is inconsistent between the UE and the network is unspecified.

[0219] If the UE and the network (SMF) do not have a mutually supported ATSSS capability, the ATSSS capability is inconsistent. For example, a new steering functionality, MPQUIC-IP, is introduced in Release 19. A UE which is compatible with Release 19.X.0 may in the PDU SESSION ESTABLISHMENT REQUEST include MPQUIC-IP in its ATSSS-ST in the 5GSM capability IE. However, an SMF compatible with an earlier version of the same release may not support MPQUIC-IP. In this case, it is not clearly defined how the SMF handles the MA PDU SESSION ESTABLISHMENT REQUEST.

[0220] The SMF may in this case:

[0221] A) Reject the PDU SESSION ESTABLISHMENT REQUEST message for the MA PDU session with an existing 5GSM Cause. One possible Cause could be #33 "requested service option not subscribed". The UE may re- initiate the PDU session establishment based in URSP rules if there is any;

[0222] B) Create a single-access PDU session without the ATSSS container IE, and without any indication to the UE in the ACCEPT message. The UE may not find a singleaccept PDU session acceptable, which results the UE initiating a PDU session release and reinitiating the MA PDU Session establishment procedure; or

[0223] C) Create an MA PDU session with ATSSS-LL using Active-Standby steering mode based on the assumption that ATSSS-LL with Active-Standby is the mandatory implicit requirement for the UE and the network, which may result in the UE being unable to steer the traffic as expected, or initiate a PDU session release since the assumption may be incorrect.

[0224] This leads to Observation 2.

[0225] Observation 2: Unspecified network handling of the ATSSS capability being inconsistent may result in bad user experience and extra network signaling.

[0226] New ATSSS steering functionalities and steering modes may be introduced in future versions or releases. The new introduced steering functionalities will use the values from the reserved range of the current release. A UE compatible with the latest 3GPP release or a later version may indicate the new introduce steering function, which results in a core network on an earlier release ignoring the entire 5GSM capability IE (due to reserved values being used in the ATSSS-ST field, see 3GPP TS 24.501 clause 7.5.1). The SMF shall proceed to treat the PDU SESSION ESTABLISHMENT REQUEST message without the 5GSM capability IE. How the SMF shall proceed to handle the request message is currently unspecified.

[0227] Observation 3: How the network handles the ATSSS capability incompatible between the UE and the network is not clearly defined in the current release.

[0228] Similarly, the SMF may:

[0229] A) Reject the PDU SESSION ESTABLISHMENT REQUEST message for the MA PDU session with an existing 5GSM Cause. One possible cause could be #33 "requested service option not subscribed". The UE may re- initiate PDU Session Establishment based on URSP rules, if any;

[0230] B) Create a single-access PDU session without the ATSSS container IE, and without any indication to the UE in the accept message. The UE may not find a singleaccess PDU session acceptable, which results in the UE initiating a PDU session release. The UE may re-initiate the PDU session establishment procedure for the MA PDU session; or

[0231] C Create an MA PDU Session with ATSSS-LL using Active-Standby based on the assumption that ATSSS-LL with Active-Standby is the mandatory implicit requirement for the UE and the network, which may result in the UE being unable to steer the traffic as intended, or initiate PDU Session Release since the assumption may be incorrect.

[0232] This leads to Observation 4.

[0233] Observation 4: Unspecified network handling of the ATSSS capability incompatibility may result in bad user experience and extra network signaling.

[0234] The UE may initiate the PDU session modification procedure after inter-system change from SI mode to N1 mode, if the UE is registered in a network supporting the ATSSS. In the PDU session modification request, the UE includes ATSSS-ST in the 5GSM Capability IE. The issues stated in Observation 1 and Observation 3 are applicable to this case as well.

[0235] The SMF in this case, may:

[0236] A) Accept the PDU SESSION MODIFICATION ACCEPT without ATSSS container IE, that indicates to UE a single PDU access PDU session is accepted without any indication to the UE why requested MA PDU session is accepted as a single access PDU Session. The UE may initiate PDU Session release and attempt to setup MA PDU session; or

[0237] B) Reject the MA PDU SESSION MODIFICATION REQUEST with an existing 5GSM Cause; one possible cause could be #33 "requested service option not subscribed". The UE may or may not automatically re-initiate the PDU Session modification depending on whether the network has included a Re-attempt indicator IE and Back-off timer value IE in the REJECT, based on TS 24.501 clause 6.4.2.4.3.

[0238] This leads to Observation 5

[0239] Observation 5: The same issue in Observation 2 to Observation 4 applies to the PDU Session Modification procedure after inter-system change from S 1 mode to N1 mode.

[0240] Proposal- 1: Introduce a new 5GSM cause for the case of the ATSSS capabilities being inconsistent or incompatible between the UE and the network.

[0241] A) If the SMF proceeds with the PDU session establishment or modification procedure with a single-access PDU session, it is not clear whether the UE can accept the MA PDU Session downgrade to a single-access PDU session or not.

[0242] B) If the SMF proceeds with the MA PDU session establishment or modification procedure without receiving the ATSSS-ST capability from UE, the SMF works based on the assumption that both the UE and the network support at minimum implicit ATSSS-LL with Active-Standby steering mode. However, that assumption by the SMF may be incorrect. The network provided ATSSS-LL with Active-Standby rules are then not useable for the UE, and the UE cannot steer user plane traffic as intended.

[0243] With a specific 5GSM Cause to indicate that the ATSSS capabilities are inconsistent or incompatible, the UE can optimize the handling based on the received cause. With the new specific cause, the UE shall accept the network response (either accept or reject), shall not attempt MA PDU session establishment or modification, as the reattempt would fail again. With cause code #33 "requested service option not subscribed", it cannot prevent the UE from reattempting an MA PDU session request if retry conditions are fulfilled.

[0244] Proposal-2: Enable the UE to indicate whether the UE allows the network to downgrade the MA PDU session to a single-access PDU session to proceed when the ATSSS capability is inconsistent or incompatible between the UE and the network.

[0245] For ATSSS / MA PDU sessions, the intention is to offload and distribute user plane traffic to 3GPP and non-3GPP access for better user experience. If ATSSS capabilities being inconsistent or incompatible results in no PDU session being established for the DN, the end user cannot access services provided by the DN. The network can provide better end user experience with proactive continuance with a single-access PDU session based on UE capability and network policy.

[0246] 3. Conclusion:

[0247] In the above clauses the following observations were made:

[0248] Observation 1: How the network handles the case in which the ATSSS capability is inconsistent between the UE and the network is unspecified.

[0249] Observation 2: Unspecified network handling of the ATSSS capability being inconsistent may result in bad user experience and extra network signaling.

[0250] Observation 3: How the network handles the ATSSS capability being incompatible between the UE and the network is currently not clearly defined in the specification. Observation 4: Unspecified network handling of the ATSSS capability incompatibility may result in bad user experience and extra network signaling.

[0251] Observation 5: The same issue as in Observation 2 to Observation 4 applies to the PDU session modification procedure after inter-system change from S 1 mode to N1 mode.

[0252] Based on the above, the following is proposed:

[0253] Proposal- 1: Introduce a new 5GSM cause for the case when the ATSSS capability is inconsistent or incompatible between the UE and the network.

[0254] Proposal-2: Enable the UE to indicate that UE allows the network to downgrade an MA PDU Session to a single-access PDU Session to proceed when the ATSSS capability is inconsistent or incompatible between the UE and the network.

[0255] Example details of Proposal- 1 and Proposal-2 are provided below.

[0256] ProDOsal-1: Specifying cause of rejection due to incompatible ATSSS capabilities (3GPP TS 24.501)

[0257] Reason for change:

[0258] • In the current version of the specification, MA PDU session establishment is built on the assumption that the UE will possess common ATSSS capabilities with the SMF. However, in the event that this is not the case and no common capabilities can be established, it will result in unexpected conditions under which the MA PDU session cannot be established. Given the addition of new MPQUIC steering functionalities in Rel-19, new scenarios in which the situation may occur are added as well. • If the network rejects the (MA) PDU session establishment request, there is currently no precise cause available that will indicate to the UE that the rejection was caused by misaligned ATSSS capabilities. If this was indicated to the UE by the network, the re-attempt would be optimized since the UE would be aware of the cause and thus be able to adjust its parameters accordingly.

[0259] Summary of change:

[0260] • Added text to clauses 6.4.1.4.1 and 6.4.2.4.1, specifying "ATSSS capabilities inconsistent" as a cause, as well as when the SMF may determine to set it, when the PDU session establishment request or PDU session modification request, respectively, is rejected by the network.

[0261] • Added value for cause "ATSSS capabilities inconsistent" to 5GSM cause in the PDU SESSION ESTABLISHMENT REJECT message in clause 9.11.4.2.

[0262] • Added description of cause "ATSSS capabilities inconsistent" to causes listed in B.l.

[0263] Consequences if not approved:

[0264] • In the event that ATSSS capabilities are inconsistent between the UE and the network, if the UE requests an MA PDU session, the UE may be left without PDU connectivity while being unaware of the cause.

[0265] * * * First Change * * * *

[0266] 6.4.1.4.1 General

[0267] If the connectivity with the requested DN is rejected by the network, the SMF shall create a PDU SESSION ESTABLISHMENT REJECT message.

[0268] The SMF shall set the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message to indicate the reason for rejecting the PDU session establishment.

[0269] The 5GSM cause IE typically indicates one of the following SM cause values:

[0270] #8 operator determined barring;

[0271] #26 insufficient resources;

[0272] #27 missing or unknown DNN;

[0273] #28 unknown PDU session type;

[0274] #29 user authentication or authorization failed;

[0275] #31 request rejected, unspecified;

[0276] #32 service option not supported;

[0277] #33 requested service option not subscribed;

[0278] #35 PTI already in use; #38 network failure;

[0279] #39 reactivation requested;

[0280] #46 out of LADN service area;

[0281] #50 PDU session type IPv4 only allowed;

[0282] #51 PDU session type IPv6 only allowed;

[0283] #54 PDU session does not exist;

[0284] #57 : PDU session type IPv4v6 only allowed;

[0285] #58: PDU session type Unstructured only allowed;

[0286] #61: PDU session type Ethernet only allowed;

[0287] #67 insufficient resources for specific slice and DNN;

[0288] #68 not supported SSC mode;

[0289] #69 insufficient resources for specific slice;

[0290] #70 missing or unknown DNN in a slice;

[0291] #82 maximum data rate per UE for user-plane integrity protection is too low;

[0292] #86 UAS services not allowed; [[or]]

[0293] #95 - 111 protocol errors; or

[0294] #xx ATSSS capabilities inconsistent.

[0295] If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "IPv6", and the subscription, the SMF configuration, or both, are limited to IPv4 only for the requested DNN, the SMF shall include the 5GSM cause value #50 "PDU session type IPv4 only allowed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0296] If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "IPv6", and the subscription, the SMF configuration, or both, support none of "IPv4" and "IPv6" PDU session types for the requested DNN, the SMF shall include the 5GSM cause value #28 "unknown PDU session type" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0297] If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "IPv4", and the subscription, the SMF configuration, or both, are limited to IPv6 only for the requested DNN, the SMF shall include the 5GSM cause value #51 "PDU session type IPv6 only allowed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0298] If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "IPv4", and the subscription, the SMF configuration, or both, support none of "IPv4" and "IPv6" PDU session types for the requested DNN, the SMF shall include the 5GSM cause value #28 "unknown PDU session type" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0299] If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "IPv4v6", and the subscription, the SMF configuration, or both, support none of "IPv4v6", "IPv4" and "IPv6" PDU session types for the requested DNN, the SMF shall include the 5GSM cause value #28 "unknown PDU session type" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0300] If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "Unstructured" or "Ethernet", and the subscription, the SMF configuration, or both, do not support the PDU session type for the requested DNN, the SMF shall include the 5GSM cause value #28 "unknown PDU session type" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0301] If the PDU SESSION ESTABLISHMENT REQUEST message is to establish an MA PDU session and includes a PDU session type IE set to "Unstructured", and the SMF configuration does not support the PDU session type, the SMF shall include the 5GSM cause value #28 "unknown PDU session type" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0302] If the PDU SESSION ESTABLISHMENT REQUEST message contains the SSC mode IE indicating an SSC mode not supported by the subscription, the SMF configuration, or both of them, and the SMF decides to rejects the PDU session establishment, the SMF shall include the 5GSM cause value #68 "not supported SSC mode" in the 5GSM cause IE and the SSC modes allowed by SMF in the Allowed SSC mode IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0303] If the PDU SESSION ESTABLISHMENT REQUEST message is to establish an MA PDU session and MA PDU session is not allowed due to operator policy and subscription, and the SMF decides to reject the PDU session establishment, the SMF shall include the 5GSM cause value #33 "requested service option not subscribed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0304] If the PDU SESSION ESTABLISHMENT REQUEST message is to establish an MA PDU session and the SMF determines that the ATSSS capabilities supported by the UE are inconsistent with those supported by the network, and the SMF decides to reject the PDU session establishment, the SMF shall include the 5GSM cause value #xx "ATSSS capabilities inconsistent". If the PDU SESSION ESTABLISHMENT REQUEST message is identified to be for C2 communication and: a) does not include the Service-level-AA container IE with the service-level device ID set to the CAA-level UAV ID; b) does not include the Service-level-AA container IE with the service-level- AA payload and the Service-level-AA payload type; or c) the SMF is informed by the UAS-NF that the UAS service is not allowed, the SMF shall reject the PDU SESSION ESTABLISHMENT REQUEST message by transmitting a PDU SESSION ESTABLISHMENT REJECT message with 5GSM cause IE set to 5GSM cause value #86 "UAS services not allowed".

[0305] In 3GPP access, if the operator's configuration requires user-plane integrity protection for the PDU session and, the maximum data rate per UE for user-plane integrity protection supported by the UE for uplink or the maximum data rate per UE for user-plane integrity protection supported by the UE for downlink, or both, are lower than required by the operator's configuration, the SMF shall include the 5GSM cause value #82 "maximum data rate per UE for user-plane integrity protection is too low" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0306] If the UE requests a PDU session establishment for an LADN when the UE is located outside of the LADN service area, the SMF shall include the 5GSM cause value #46 "out of LADN service area" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0307] If the DN authentication of the UE was performed with the PDU session authentication and authorization procedure and completed unsuccessfully, the SMF shall include the 5GSM cause value #29 "user authentication or authorization failed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message and shall set the EAP message IE of the PDU SESSION ESTABLISHMENT REJECT message to an EAP-failure message as specified in IETF RFC 3748

[0034] , provided by the DN.

[0308] If the DN authentication of the UE was performed with the service-level authentication and authorization procedure and completed unsuccessfully, the SMF shall include the 5GSM cause value #29 "user authentication or authorization failed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message and shall include the service-level- AA response provided by DN in the Service-level-AA container IE of the PDU SESSION ESTABLISHMENT REJECT message. Based on the local policy and user's subscription data, if a PDU session is being established with the request type set to "existing PDU session" and the SMF determines the UE has: a) moved between a tracking area in NB-N1 mode and a tracking area in WB-N1 mode; b) moved between a tracking area in NB-S1 mode and a tracking area in WB-N1 mode; or c) moved between a tracking area in WB-S1 mode and a tracking area in NB-N1 mode, the SMF may reject the PDU SESSION ESTABLISHMENT REQUEST message and: a) include the 5GSM cause value #39 "reactivation requested" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message; or b) include a 5GSM cause value other than #39 "reactivation requested" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0309] NOTE 1 : The included 5GSM cause value is up to the network implementation.

[0310] If the PDU session cannot be established due to resource unavailability in the UPF, the SMF shall include the 5GSM cause value #26 "insufficient resources" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0311] Based on the user's subscription data and the operator policy, if the SMF determines that the UUAA-SM procedure needs to be performed for a UE but the SMF does not receives the service-level device ID set to the CAA-level UAV ID in the Service- level- AA container IE of the PDU SESSION ESTABLISHMENT REQUEST message from the UE, the SMF shall include the 5GSM cause value #86 "UAS services not allowed" in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT REJECT message.

[0312] The network may include a Back-off timer value IE in the PDU SESSION ESTABLISHMENT REJECT message.

[0313] If the 5GSM cause value is #26 "insufficient resources", #67 "insufficient resources for specific slice and DNN", or #69 "insufficient resources for specific slice" and the PDU SESSION ESTABLISHMENT REQUEST message was received from a UE configured for high priority access in selected PLMN or SNPN or the request type provided during the PDU session establishment is set to "initial emergency request" or "existing emergency PDU session", the network shall not include a Back-off timer value IE. If the 5GSM cause value is #29 "user authentication or authorization failed ", the network should include a Back-off timer value IE.

[0314] If the Back-off timer value IE is included and the 5GSM cause value is different from #26 "insufficient resources", #28 "unknown PDU session type", #46 "out of LADN service area", #50 "PDU session type IPv4 only allowed", #51 "PDU session type IPv6 only allowed", #54 "PDU session does not exist", #57 "PDU session type IPv4v6 only allowed", #58 "PDU session type Unstructured only allowed", #61 "PDU session type Ethernet only allowed", #67 "insufficient resources for specific slice and DNN", #68 "not supported SSC mode", and #69 "insufficient resources for specific slice", the network may include the Re-attempt indicator IE to indicate whether the UE is allowed to attempt a PDN connectivity procedure in the PLMN for the same DNN in S 1 mode, whether another attempt in SI mode or in N1 mode is allowed in an equivalent PLMN or whether another attempt in N1 mode is allowed in an equivalent SNPN.

[0315] If the 5GSM cause value is #50 "PDU session type IPv4 only allowed", #51 "PDU session type IPv6 only allowed", #57 "PDU session type IPv4v6 only allowed", #58 "PDU session type Unstructured only allowed", or #61 "PDU session type Ethernet only allowed", the network may include the Re-attempt indicator IE without Back-off timer value IE to indicate whether the UE is allowed to attempt a PDU session establishment procedure in an equivalent PLMN or equivalent SNPN in N1 mode using the same PDU session type for the same DNN (or no DNN, if no DNN was indicated by the UE) and the same S-NSSAI (or no S-NSSAI, if no S-NSSAI was indicated by the UE). The SMF shall send the PDU SESSION ESTABLISHMENT REJECT message. Upon receipt of a PDU SESSION ESTABLISHMENT REJECT message and a PDU session ID, using the NAS transport procedure as specified in subclause 5.4.5, the UE shall stop timer T3580 shall release the allocated PTI value and shall consider that the PDU session was not established.

[0316] If the PDU SESSION ESTABLISHMENT REQUEST message was sent with request type set to "initial emergency request" or "existing emergency PDU session" and the UE receives a PDU SESSION ESTABLISHMENT REJECT message, then the UE may: a) inform the upper layers of the failure of the procedure; or NOTE 2: This can result in the upper layers requesting another emergency call attempt using domain selection as specified in 3GPP TS 23.167 [6]. b) de -register locally, if not de -registered already, attempt initial registration for emergency services.

[0317] If the PDU SESSION ESTABLISHMENT REJECT message includes 5GSM cause #39 "reactivation requested" and the PDU session is being transferred from EPS to 5GS and established with the request type set to "existing PDU session", the UE should reinitiate the UE-requested PDU session establishment procedure as specified in subclause 6.4.1 for: a) the PDU session type associated with the transferred PDU session; b) the SSC mode associated with the transferred PDU session; c) the DNN associated with the transferred PDU session; and d) the S -NS SAI associated with (if available in roaming scenarios) a mapped S- NSSAI if provided in the UE-requested PDU session establishment procedure of the transferred PDU session.

[0318] If the PDU SESSION ESTABLISHMENT REJECT message includes 5GSM cause #86 "UAS services not allowed" and the UE has not included the service-level device ID in the Service-level-AA container IE of the PDU SESSION ESTABLISHMENT REQUEST message and set the value to the CAA-level UAV ID: a) the UE shall not send another PDU SESSION ESTABLISHMENT REQUEST message for UAS services without including the CAA-level UAV ID in the service-level device ID of the Service-level-AA container IE; and b) upon receipt of the request from the upper layers to establish a PDU session for UAS services, the UE shall initiate the UE-requested PDU session establishment procedure by including the service-level device ID in the Service-level-AA container IE of the PDU SESSION ESTABLISHMENT REQUEST message and set the value to the CAA-level UAV ID as specified in subclause 6.4.1.2.

[0319] If the 5GSM cause value is different from #26 "insufficient resources", #28 "unknown PDU session type", #39 "reactivation requested", #46 "out of LADN service area", #50 "PDU session type IPv4 only allowed", #51 "PDU session type IPv6 only allowed", #54 "PDU session does not exist", #57 "PDU session type IPv4v6 only allowed", #58 "PDU session type Unstructured only allowed", #61 "PDU session type Ethernet only allowed", #67 "insufficient resources for specific slice and DNN", #68 "not supported SSC mode", and #69 "insufficient resources for specific slice", #86 "UAS services not allowed", and #33 "requested service option not subscribed" and the PDU SESSION ESTABLISHMENT REQUEST message was received from a UE configured for high priority access in selected PLMN, the network shall not include a Back-off timer value IE.

[0320] * * * Next Change * * * *

[0321] 6.4.2.4.1 General

[0322] Upon receipt of a PDU SESSION MODIFICATION REQUEST message, if the SMF does not accepts the request to modify the PDU session, the SMF shall create a PDU SESSION MODIFICATION REJECT message.

[0323] The SMF shall set the 5GSM cause IE of the PDU SESSION MODIFICATION REJECT message to indicate the reason for rejecting the PDU session modification. The 5GSM cause IE typically indicates one of the following SM cause values: #26 insufficient resources;

[0324] #29 user authentication or authorization failed;

[0325] #31 request rejected, unspecified;

[0326] #32 service option not supported;

[0327] #33 requested service option not subscribed;

[0328] #35 PTI already in use;

[0329] #37 5GS QoS not accepted;

[0330] #43 Invalid PDU session identity;

[0331] #44 Semantic errors in packet filter(s);

[0332] #45 Syntactical error in packet filter(s);

[0333] #46 out of LADN service area;

[0334] #59 unsupported 5QI value;

[0335] #67 insufficient resources for specific slice and DNN;

[0336] #69 insufficient resources for specific slice;

[0337] #83 Semantic error in the QoS operation;

[0338] #84 Syntactical error in the QoS operation; [[or]]

[0339] #95 - 111 protocol errors; or

[0340] #xx ATSSS capabilities inconsistent.

[0341] If the UE requests a PDU session modification for an LADN when the UE is located outside of the LADN service area, the SMF shall include the 5GSM cause value #46 "out of LADN service area" in the 5GSM cause IE of the PDU SESSION MODIFICATION REJECT message.

[0342] If the Extended protocol configuration options IE of the PDU SESSION MODIFICATION REQUEST message indicates 3GPP PS data off UE status and the SMF detects the change of the 3GPP PS data off UE status, the SMF shall not include the 5GSM cause value #26 "insufficient resources", the 5GSM cause value #67 "insufficient resources for specific slice and DNN", the 5GSM cause value #69 "insufficient resources for specific slice" and the 5GSM cause value #46 "out of LADN service area" in the 5GSM cause IE of the PDU SESSION MODIFICATION REJECT message.

[0343] If the UE initiates UE-requested PDU session modification procedure to modify the PDU session transferred from EPS to an MA PDU session with the Request type IE set to "MA PDU request" in the UL NAS TRANSPORT message as specified in 3GPP TS 24.193 [13B] and: a) the SMF determines, based on operator policy and subscription information, that the PDU SESSION MODIFICATION REQUEST message is to be rejected, the SMF shall include the 5GSM cause value #33 "requested service option not subscribed" in the 5GSM cause IE of the PDU SESSION MODIFICATION REJECT message; or b) the SMF determines that the ATSSS capabilities supported by the UE are inconsistent with those supported by the network, and that the PDU SESSION MODIFICATION REQUEST message is to be rejected, the SMF shall include the 5GSM cause value #xx "ATSSS capabilities inconsistent".

[0344] NOTE: If the SMF determines, based on operator policy and subscription information, that the PDU SESSION MODIFICATION REQUEST message is to be accepted as single access PDU session, the ATSSS container IE cannot be included in the PDU SESSION MODIFICATION COMMAND message.

[0345] The network may include a Back-off timer value IE in the PDU SESSION MODIFICATION REJECT message.

[0346] If the 5GSM cause value is #26 "insufficient resources", #67 "insufficient resources for specific slice and DNN", or #69 "insufficient resources for specific slice" and the PDU SESSION MODIFICATION REQUEST message was received from a UE configured for high priority access in selected PLMN or SNPN or the request type provided during the PDU session establishment is set to "initial emergency request" or "existing emergency PDU session", the network shall not include a Back-off timer value IE.

[0347] The SMF shall send the PDU SESSION MODIFICATION REJECT message.

[0348] Upon receipt of a PDU SESSION MODIFICATION REJECT message and a PDU session ID, using the NAS transport procedure as specified in subclause 5.4.5, the UE shall stop timer T3581, release the allocated PTI value, and enter the state PROCEDURE TRANSACTION INACTIVE. If the PDU SESSION MODIFICATION REQUEST message was sent with the Requested MBS container IE included and the MBS operation set to "Join MBS session", and the UE receives a PDU SESSION MODIFICATION REJECT message, then the UE shall consider the requested MBS join as rejected. If the PDU SESSION MODIFICATION REQUEST message was sent with the

[0349] Requested MBS container IE included and the MBS operation set to "Leave MBS session", and the UE receives a PDU SESSION MODIFICATION REJECT message, then the UE shall locally leave the multicast MBS session(s) corresponding to the TMGI(s) in the Requested MBS container IE of the PDU SESSION MODIFICATION REQUEST message.

[0350] * * * Next Change * * * *

[0351] 9.11.4.2 5GSM cause

[0352] The purpose of the 5GSM cause information element is to indicate the reason why a 5GSM request is rejected. The 5GSM cause information element is coded as shown in figure 9.11.4.2.1 and table 9.11.4.2.1.

[0353] The 5GSM cause is a type 3 information element with a length of 2 octets.

[0354] 8 7 6 5 4 3 2 1 octet 1 octet 2

[0355] Figure 9.11.4.2.1: 5GSM cause information element Table 9.11.4.2.1: 5GSM cause information element

[0356] * * * Next Change * * * *

[0357] 1) B.l Causes related to nature of request

[0358] Cause #8 - Operator Determined Barring This 5GSM cause is used by the network to indicate that the requested service was rejected by the SMF due to Operator Determined Barring.

[0359] Cause #26 - Insufficient resources

[0360] This 5GSM cause is used by the UE or by the network to indicate that the requested service cannot be provided due to insufficient resources. Cause #27 - Missing or unknown DNN

[0361] This 5GSM cause is used by the network to indicate that the requested service was rejected by the external DN because the DNN was not included although required or if the DNN could not be resolved.

[0362] Cause #28 - Unknown PDU session type This 5GSM cause is used by the network to indicate that the requested service was rejected by the external DN because the requested PDU session type could not be recognised or is not allowed. Cause #29 - User authentication or authorization failed

[0363] This 5GSM cause is used by the network to indicate that the requested service was rejected by the external DN due to a failed user authentication, revoked by the external DN, or rejected by 5GCN due to a failed user authentication or authorization.

[0364] Cause #31 - Request rejected, unspecified

[0365] This 5GSM cause is used by the network or by the UE to indicate that the requested service or operation or the request for a resource was rejected due to unspecified reasons.

[0366] Cause #32 - Service option not supported

[0367] This 5GSM cause is used by the network when the UE requests a service which is not supported by the PLMN.

[0368] Cause #33 - Requested service option not subscribed

[0369] This 5GSM cause is sent when the UE requests a service option for which it has no subscription.

[0370] Cause #35 - PTI already in use

[0371] This 5GSM cause is used by the network to indicate that the PTI included by the UE is already in use by another active UE requested procedure for this UE.

[0372] Cause #36 - Regular deactivation

[0373] This 5GSM cause is used to indicate a regular UE or network initiated release of PDU session resources.

[0374] Cause #37 - 5GS QoS not accepted

[0375] This 5GSM cause is used by the network if the new 5GS QoS that was indicated in the UE request cannot be accepted.

[0376] Cause #38 - Network failure

[0377] This 5GSM cause is used by the network to indicate that the requested service was rejected due to an error situation in the network.

[0378] Cause #39 - Reactivation requested

[0379] This 5GSM cause is used by the network to request a PDU session reactivation. Cause #41 - Semantic error in the TFT operation

[0380] This 5GSM cause is used by the UE to indicate a semantic error in the TFT operation included in the request.

[0381] Cause #42 - Syntactical error in the TFT operation

[0382] This 5GSM cause is used by the UE to indicate a syntactical error in the TFT operation included in the request. Cause #43 - Invalid PDU session identity

[0383] This 5GSM cause is used by the network or the UE to indicate that the PDU session identity value provided to it is not a valid value or the PDU session identified by the PDU session identity IE in the request or the command is not active.

[0384] Cause #44 - Semantic errors in packet filter(s)

[0385] This 5GSM cause is used by the network or the UE to indicate that the requested service was rejected due to one or more semantic errors in packet filter(s) of the QoS rule included in the request.

[0386] Cause #45 - Syntactical error in packet filter(s)

[0387] This 5GSM cause is used by the network or the UE to indicate that the requested service was rejected due to one or more syntactical errors in packet filter(s) of the QoS rule included in the request.

[0388] Cause #46 - Out of LADN service area

[0389] This 5GSM cause is used by the network to indicate the UE is out of the LADN service area.

[0390] Cause #47 - PTI mismatch

[0391] This 5GSM cause is used by the network or UE to indicate that the PTI provided to it does not match any PTI in use.

[0392] Cause #50 - PDU session type IPv4 only allowed

[0393] This 5GSM cause is used by the network to indicate that only PDU session type IPv4 is allowed for the requested IP connectivity.

[0394] Cause #51 - PDU session type IPv6 only allowed

[0395] This 5GSM cause is used by the network to indicate that only PDU session type IPv6 is allowed for the requested IP connectivity.

[0396] Cause #54 - PDU session does not exist

[0397] This 5GSM cause is used by the network at handover of a PDU session between non-3GPP access and 3GPP access, or at interworking of a PDN connection from non- 3GPP access network connected to EPC or from E-UTRAN connected to EPC to a PDU session, to indicate that the network does not have any information about the requested PDU session.

[0398] Cause #57 - PDU session type IPv4v6 only allowed

[0399] This 5GSM cause is used by the network to indicate that only PDU session types IPv4, IPv6 or IPv4v6 are allowed for the requested IP connectivity.

[0400] Cause #58 - PDU session type Unstructured only allowed This 5GSM cause is used by the network to indicate that only PDU session type Unstructured is allowed for the requested DN connectivity.

[0401] Cause #59 - Unsupported 5QI value

[0402] This 5GSM cause is used by the network if the 5QI indicated in the UE request cannot be supported.

[0403] Cause #61 - PDU session type Ethernet only allowed

[0404] This 5GSM cause is used by the network to indicate that only PDU session type Ethernet is allowed for the requested DN connectivity.

[0405] Cause #67 - Insufficient resources for specific slice and DNN

[0406] This 5GSM cause is by the network to indicate that the requested service cannot be provided due to insufficient resources for specific slice and DNN or maximum group data rate on a 5G VN group identified by a specific slice and DNN has been exceeded.

[0407] Cause #68 - Not supported SSC mode

[0408] This 5GSM cause is used by the network to indicate that the requested SSC mode is not supported.

[0409] Cause #69 - Insufficient resources for specific slice

[0410] This 5GSM cause is used by the network to indicate that the requested service cannot be provided due to insufficient resources for specific slice, maximum number of PDU sessions on a specific slice has been already reached, data rate on a specific slice has been exceeded, or UE-Slice-MBR has been exceeded.

[0411] Cause #70 - Missing or unknown DNN in a slice

[0412] This 5GSM cause is used by the network to indicate that the requested service was rejected by the external DN because the DNN was not included although required or if the DNN could not be resolved, in the slice.

[0413] Cause #81 - Invalid PTI value

[0414] This 5GSM cause is used by the network or UE to indicate that the PTI provided to it is invalid for the specific 5GSM message.

[0415] Cause #82 - Maximum data rate per UE for user-plane integrity protection is too low

[0416] This 5GSM cause is used by the network to indicate that the requested service cannot be provided because the maximum data rate per UE for user-plane integrity protection is too low.

[0417] Cause #83 - Semantic error in the QoS operation

[0418] This 5GSM cause is used by the network or the UE to indicate that the requested service was rejected due to a semantic error in the QoS operation included in the request. Cause #84 - Syntactical error in the QoS operation

[0419] This 5GSM cause is used by the network or the UE to indicate that the requested service was rejected due to a syntactical error in the QoS operation included in the request. Cause #85 - Invalid mapped EPS bearer identity

[0420] This 5GSM cause is used by the network or the UE to indicate that the mapped EPS bearer identity value provided to it is not a valid value or the mapped EPS bearer identified by the mapped EPS bearer identity does not exist.

[0421] Cause #86 - UAS services not allowed

[0422] This 5GSM cause is used by the network to indicate that the requested UAS services are not allowed.

[0423] Cause #xx - ATSSS capabilities inconsistent

[0424] This 5GSM cause is used the network to indicate that the ATSSS the UE are inconsistent with those the network.

[0425] * * * End of Changes * * * * ATSSS MA PDU session network downgrade is allowed (3GPP TS 24.501)

[0426] Reason for change:

[0427] • In the current version of the specification, MA PDU session establishment is built on the assumption that the UE will possess common ATSSS capabilities with the SMF. However, in the event that this is not the case and no common capabilities can be established (e.g. when support for MPQUIC-IP and MPQUIC-E is introduced in Rel-19, if the UE only supports MPTCP and ATSSS-LL with Active Standby and the network only supports MPQUIC-IP), it will result in unexpected conditions under which the MA PDU session cannot be established and the network can either:

[0428] 1) accept the request but as a single-access PDU session, or

[0429] 2) Reject the request.

[0430] • Currently it is not possible for the UE to indicate whether a "downgrade" to a single-access PDU session is acceptable when it has made a request for an MA PDU session. If the above case (1) were to occur, the UE may not find a singleaccess PDU session acceptable, and choose to release the PDU session. This means that the setup of a single-access PDU session was done unnecessarily.

[0431] • If the UE could indicate that a downgrade to a single-access PDU session is not allowed, the network would be aware and handle the MA PDU session request accordingly. • Given the addition of new MPQUIC steering functionalities in Rel-19, new scenarios in which the situation may occur are added as well.

[0432] • In this case, it may be possible to accept the PDU session as a single-access PDU session, providing it is acceptable to the UE, in exchange for PDU connectivity.

[0433] Summary of change:

[0434] • Added text to clause 6.4.1.2, UE requested PDU session establishment procedure, specifying that the UE may indicate to the network whether it is allowed for the network to downgrade a requested MA PDU session to a single-access PDU session.

[0435] • Added text to clause 6.4.1.3, UE requested PDU session establishment procedure accepted by the network, specifying that the SMF may proceed with establishing a single-access PDU session if an MA PDU session was requested by the UE, if the ATSSS capabilities supported by the UE are inconsistent with those supported by the network, if the UE has previously indicated whether it is allowed.

[0436] • Added value indicating "MA PDU session network downgrade is allowed" to the MA PDU session information IE, or alternatively a bit indicating "Downgrade to SA PDU session not allowed" to the 5GSM capability IE.

[0437] Consequences if not approved:

[0438] • In the event that ATSSS capabilities are inconsistent between the UE and the network, if the UE requests an MA PDU session, the UE may be left without PDU connectivity, or it may result in unnecessary signalling.

[0439] * * * First Change * * * *

[0440] 6.4.1.2 UE-requested PDU session establishment procedure initiation

[0441] In order to initiate the UE-requested PDU session establishment procedure, the UE shall create a PDU SESSION ESTABLISHMENT REQUEST message.

[0442] NOTE 0: When IMS voice is available over either 3GPP access or non-3GPP access, the "voice centric" UE in 5GMM-REGISTERED state will receive a request from upper layers to establish the PDU session for IMS signalling, if the conditions for performing an initial registration with IMS indicated in 3GPP TS 24.229

[0014] subclause U.3.1.2 are satisfied.

[0443] If the UE requests to establish a new PDU session, the UE shall allocate a PDU session ID which is not currently being used by another PDU session over either 3GPP access or non-3GPP access. If the N5CW device supporting 3GPP access requests to establish a new PDU session via 3GPP access, the N5CW device supporting 3GPP access shall refrain from allocating "PDU session identity value 15". If the TWIF acting on behalf of the N5CW device requests to establish a new PDU session, the TWIF acting on behalf of the N5CW device shall allocate the "PDU session identity value 15".

[0444] The UE shall allocate a PTI value currently not used and shall set the PTI IE of the PDU SESSION ESTABLISHMENT REQUEST message to the allocated PTI value.

[0445] If the UE is registered for emergency services over the current access, the UE shall not request establishing a non-emergency PDU session over the current access. If the UE is registered for emergency services over the current access it shall not request establishing an emergency PDU session over the non-current access except if the request is for transferring the emergency PDU session to the non-current access. Before transferring an emergency PDU session from non-3GPP access to 3GPP access, or before transferring a PDN connection for emergency bearer services from untrusted non-3GPP access connected to EPC to 3GPP access, the UE shall check whether emergency services are supported in the NG-RAN cell (either an NR cell or an E-UTRA cell) on which the UE is camping.

[0446] NOTE 1: Transfer of an existing emergency PDU session or PDN connection for emergency bearer services between 3GPP access and non-3GPP access is needed e.g. if the UE determines that the current access is no longer available.

[0447] If the UE requests to establish a new emergency PDU session, the UE shall include the PDU session type IE in the PDU SESSION ESTABLISHMENT REQUEST message and shall set the IE to the IP version capability as specified in subclause 6.2.4.2. If the UE requests to establish a new non-emergency PDU session with a DN, the UE shall include the PDU session type IE in the PDU SESSION ESTABLISHMENT REQUEST message and shall set the IE to one of the following values: "IPv4", "IPv6", "IPv4v6", "Ethernet" or "Unstructured" based on the URSP rules or based on UE local configuration (see 3GPP TS 24.526

[0019] ) and based on the IP version capability as specified in subclause 6.2.4.2.

[0448] NOTE 2: When the UE initiates the UE-requested PDU session establishment procedure to transfer an existing non-IP PDN connection in the EPS to the 5GS, the UE can use locally available information associated with the PDN connection to select the PDU session type between "Ethernet" and "Unstructured".

[0449] If the UE requests to establish a new non-emergency PDU session with a DN and the UE requests an SSC mode, the UE shall set the SSC mode IE of the PDU SESSION ESTABLISHMENT REQUEST message to the SSC mode. If the UE requests to establish a PDU session of "IPv4", "IPv6" or "IPv4v6" PDU session type, the UE shall either omit the SSC mode IE or set the SSC mode IE to "SSC mode 1", "SSC mode 2", or "SSC mode 3". If the UE requests to establish a PDU session of "Ethernet" or "Unstructured" PDU session type, the UE shall either omit the SSC mode IE or set the SSC mode IE to "SSC mode 1" or "SSC mode 2". If the UE requests transfer of an existing PDN connection in the EPS to the 5GS or the UE requests transfer of an existing PDN connection in an untrusted non-3GPP access connected to the EPC to the 5GS, the UE shall set the SSC mode IE to "SSC mode 1".

[0450] If the UE requests to establish a new emergency PDU session, the UE shall set the SSC mode IE of the PDU SESSION ESTABLISHMENT REQUEST message to "SSC mode 1".

[0451] A UE supporting PDU connectivity service shall support SSC mode 1 and may support SSC mode 2 and SSC mode 3 as specified in 3GPP TS 23.501 [8].

[0452] If the UE requests to establish a new non-emergency PDU session with a DN, the UE may include the SM PDU DN request container IE with a DN-specific identity of the UE complying with network access identifier (NAI) format as specified in IETF RFC 7542

[0037] ,

[0453] NOTE 3: The UE can avoid including both the SM PDU DN request container IE and the Extended protocol configuration options IE with PAP / CHAP protocol identifiers in the PDU SESSION ESTABLISHMENT REQUEST message. The way to achieve this is implementation dependent.

[0454] If the UE requests to: a) establish a new PDU session; b) perform handover of an existing PDU session from non-3GPP access to 3GPP access; c) transfer an existing PDN connection in the EPS to the 5GS according to subclause 4.8.2.3.1; d) transfer an existing PDN connection in untrusted non-3GPP access connected to the EPC to the 5GS; or e) establish user plane resources over 3GPP access of an MA PDU session established over non-3GPP access only; and the UE at the same time intends to join one or more multicast MBS sessions that is associated to the PDU session, the UE should include the Requested MBS container IE in the PDU SESSION ESTABLISHMENT REQUEST message. In that case, the UE shall set the MBS operation to "Join multicast MBS session" and include the multicast MBS session information(s) and shall set the Type of multicast MBS session ID for each of the multicast MBS session information to either "Temporary Mobile Group Identity (TMGI)" or "Source specific IP multicast address" depending on the type of the multicast MBS session ID available in the UE. Then the remaining values of each of the multicast MBS session information shall be set as following: a) if the Type of multicast MBS session ID is set to "Temporary Mobile Group Identity (TMGI)", the UE shall set the multicast MBS session ID to the TMGI; or b) if the Type of multicast MBS session ID is set to "Source specific IP multicast address for IPv4" or " Source specific IP multicast address for IPv6", the UE shall set the Source IP address information and the Destination IP address information to the corresponding values.

[0455] The UE should not request to join a multicast MBS session for local MBS service if neither current TAI nor CGI of the current cell is part of the MBS service area(s) of the multicast MBS session, if the UE has valid information of the MBS service area(s) of the multicast MBS session.

[0456] NOTE 4: The UE obtains the details of the MBS session ID(s) e.g., TMGI, Source IP address information and Destination IP address information as a pre-configuration in the UE or during the MBS service announcement, which is out of scope of this specification. Pre-configuration can be provided in one or more of the following ways: a) in a UE implementation-specific way (e.g. factory configuration); b) in the USIM (see EFSMBSUECONFIG file in 3GPP TS 31.102

[0022] ); or c) in the UE pre-configuration MO for MBS (see 3GPP TS 24.575 [65).

[0457] The UE should set the RQoS bit to "Reflective QoS supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message if the UE supports reflective QoS and: a) the UE requests to establish a new PDU session of "IPv4", "IPv6", "IPv4v6" or "Ethernet" PDU session type; b) the UE requests to transfer an existing PDN connection in the EPS of "IPv4", "IPv6", "IPv4v6" or "Ethernet" PDN type or of "Non-IP" PDN type mapping to "Ethernet" PDU session type, to the 5GS; or c) the UE requests to transfer an existing PDN connection in an untrusted non-3GPP access connected to the EPC of "IPv4", "IPv6" or "IPv4v6" PDN type to the 5GS. NOTE 5: The determination to not request the usage of reflective QoS by the UE for a PDU session is implementation dependent.

[0458] The UE shall indicate the maximum number of packet filters that can be supported for the PDU session in the Maximum number of supported packet filters IE of the PDU SESSION ESTABLISHMENT REQUEST message if: a) the UE requests to establish a new PDU session of "IPv4", "IPv6", "IPv4v6", or "Ethernet" PDU session type, and the UE can support more than 16 packet filters for this PDU session; b) the UE requests to transfer an existing PDN connection in the EPS of "IPv4", "IPv6", "IPv4v6", or "Ethernet" PDN type or of "Non-IP" PDN type mapping to "Ethernet" PDU session type, to the 5GS and the UE can support more than 16 packet filters for this PDU session; or c) the UE requests to transfer an existing PDN connection in an untrusted non-3GPP access connected to the EPC of "IPv4", "IPv6" or "IPv4v6" PDN type to the 5GS and the UE can support more than 16 packet filters for this PDU session.

[0459] The UE shall include the Integrity protection maximum data rate IE in the PDU SESSION ESTABLISHMENT REQUEST message to indicate the maximum data rate per UE for user-plane integrity protection supported by the UE for uplink and the maximum data rate per UE for user-plane integrity protection supported by the UE for downlink. The UE shall set the MH6-PDU bit to "Multi-homed IPv6 PDU session supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message if the UE supports multi-homed IPv6 PDU session and: a) the UE requests to establish a new PDU session of "IPv6" or "IPv4v6" PDU session type; or. b) the UE requests to transfer an existing PDN connection of "IPv6" or "IPv4v6" PDN type in the EPS or in an untrusted non-3GPP access connected to the EPC to the 5GS.

[0460] The UE shall set the EPT-SI bit to "Ethernet PDN type in SI mode supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message if the UE supports Ethernet PDN type in SI mode and requests "Ethernet" PDU session type. If the UE requests to establish a new PDU session as an always-on PDU session (e.g. because the PDU session is for time synchronization or TSC), the UE shall include the Always-on PDU session requested IE and set the value of the IE to "Always-on PDU session requested" in the PDU SESSION ESTABLISHMENT REQUEST message. NOTE 6: Determining whether a PDU session is for time synchronization or TSC is

[0461] UE implementation dependent.

[0462] If the UE has an emergency PDU session, the UE shall not perform the UE- requested PDU session establishment procedure to establish another emergency PDU session. The UE may perform the UE-requested PDU session establishment procedure to transfer an existing emergency PDU session or an existing PDN connection for emergency services.

[0463] If: a) the UE requests to perform handover of an existing PDU session between 3GPP access and non-3GPP access; b) the UE requests to perform transfer an existing PDN connection in the EPS to the 5GS; or c) the UE requests to perform transfer an existing PDN connection in an untrusted non-3GPP access connected to the EPC to the 5GS; the UE shall: a) set the PDU session ID in the PDU SESSION ESTABLISHMENT REQUEST message and in the UL NAS TRANSPORT message to the stored PDU session ID corresponding to the PDN connection; and b) set the S-NSSAI in the UL NAS TRANSPORT message to the stored S-NSSAI associated with the PDU session ID of a non-emergency PDU session. The UE shall not request to perform handover of an existing non-emergency PDU session:

[0464] 1) between 3GPP access and non-3GPP access if the S-NSSAI is not included in the allowed NSSAI for the target access; or

[0465] 2) from non-3GPP access to 3GPP access: i) if the S-NSSAI is not in the partially allowed NSSAI for 3GPP access; or ii) if the S-NSSAI is in the partially allowed NSSAI for 3GPP access but the TAI where the UE is currently camped on is not in the list of TAs for which the S-NSSAI is supported.

[0466] If the N5CW device supporting 3GPP access requests to perform handover of an existing PDU session from non-3GPP access to 3GPP access, the N5CW device supporting 3GPP access shall set the PDU session ID in the PDU SESSION ESTABLISHMENT REQUEST message and in the UL NAS TRANSPORT message to "PDU session identity value 15". If the UE is registered to a network which supports ATSSS and the UE requests to establish a new PDU session the UE may allow the network to upgrade the requested PDU session to an MA PDU session. In order to allow the network to upgrade the requested PDU session to an MA PDU session, the UE shall set "MA PDU session network upgrade is allowed" in the MA PDU session information IE and shall set the request type to "initial request" in the UL NAS TRANSPORT message. If the UE is registered to a network which does not support ATSSS, the UE shall not perform the procedure to allow the network to upgrade the requested PDU session to an MA PDU session.

[0467] If the UE is registered to a network which supports ATSSS, the UE may request to establish an MA PDU session. If the UE requests to establish an MA PDU session, the UE shall set the request type to "MA PDU request" in the UL NAS TRANSPORT message. If the UE is registered to a network which does not support ATSSS, the UE shall not request to establish an MA PDU session.

[0468] If the UE is registered to a network which supports ATSSS and requests to establish an MA PDU session the UE may allow the network to downgrade the requested MA PDU session to a single-access PDU session. In order to allow the network to downgrade the requested MA PDU session to a single-access PDU session, the UE shall set "MA PDU session network downgrade is allowed" in the MA PDU session information IE and shall set the request type to "initial request" in the UL NAS TRANSPORT message. Alternatively, in order to allow the network to downgrade the requested MA PDU session to a single-access PDU session, the UE shall set "Downgrade to SA PDU session not allowed" (DSANA) in the 5GSM capability IE and shall set the request type to "MA PDU request" in the UL NAS TRANSPORT message.

[0469] When the UE is registered over both 3GPP access and non-3GPP access in the same PLMN and the UE requests to establish a new MA PDU session, the UE may provide an S-NSSAI in the UL NAS TRANSPORT message only if the S-NSSAI is included in the allowed NSSAIs of both accesses.

[0470] NOTE 7: If the UE requested DNN corresponds to an LADN DNN, the AMF does not forward the MA PDU session information IE to the SMF but sends the message back to the UE to inform of the unhandled request (see subclause 5.4.5.2.5).

[0471] If the UE is registered to a network which supports ATSSS and the UE has already an MA PDU session established over one access, the UE may perform the UE-requested PDU session establishment procedure to establish user-plane resources over the other access for the MA PDU session as specified in subclause 4.22 of 3GPP TS 23.502 [9] and the S-NSSAI associated with the MA PDU session is included in the allowed NSSAI of the other access. If the UE establishes user-plane resources over the other access for the MA PDU session, the UE shall: a) set the request type to "MA PDU request" in the UL NAS TRANSPORT message; b) set the PDU session ID to the stored PDU session ID corresponding to the established MA PDU session in the PDU SESSION ESTABLISHMENT REQUEST message and in the UL NAS TRANSPORT message; and c) set the S-NSSAI in the UL NAS TRANSPORT message to the stored S-NSSAI associated with the PDU session ID.

[0472] If the UE requests to establish a new MA PDU session or if the UE requests to establish a new PDU session and the UE allows the network to upgrade the requested PDU session to an MA PDU session: a) if the UE supports ATSSS Low-Layer functionality with any steering mode (i.e., any steering mode allowed for ATSSS Low-Layer functionality) as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "ATSSS Low-Layer functionality with any steering mode allowed for ATSSS-LL supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; NOTE 8: The ATSSS Low-Layer functionality cannot be used together with the redundant steering mode. When the UE indicates that it is capable of supporting the ATSSS Low-Layer functionality with any steering mode, it implies that the UE supports the ATSSS Low-Layer functionality with any steering mode except the redundant steering mode. b) if the UE supports MPTCP functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "MPTCP functionality with any steering mode and ATSSS-LL functionality with only active- standby steering mode supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; c) if the UE supports MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; d) if a performance measurement function in the UE can perform access performance measurements using the QoS flow of the non-default QoS rule as specified in subclause 5.32.5 of 3GPP TS 23.501 [8], the UE shall set the APMQF bit to "Access performance measurements per QoS flow supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; e) if the UE supports MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active- standby steering mode supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; f) if the UE supports MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; g) if the UE supports MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with only activestandby steering mode as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with only activestandby steering mode supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; and h) if the UE supports MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) as specified in subclause 5.32.6 of 3GPP TS 23.501 [8], the UE shall set the ATSSS-ST bits to "MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message.

[0473] Upon receipt of a PDU SESSION ESTABLISHMENT REQUEST message for MA PDU session establishment, the SMF shall check if the 5GSM capability IE in the PDU SESSION ESTABLISHMENT REQUEST message, includes: a) the ATSSS-ST bits set to "MPTCP functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode supported" and: i) if the DNN configuration allows for the MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) but does not allow RTT measurement without using PMF protocol, the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode and ATSSS-LL with only active-standby steering mode, load balancing steering mode or priority based steering mode steering mode in the downlink and MPTCP with any steering mode and ATSSS-LL with only active-standby steering mode in the uplink; ii) if the DNN configuration allows for the MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) and allows RTT measurement without using PMF protocol, the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and MPTCP with any steering mode and ATSSS-LL with only active-standby steering mode in the uplink; or iii) if the DNN configuration allows for the MPTCP functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode, the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode and ATSSS-LL with only active-standby steering mode in the downlink and the uplink; b) the ATSSS-ST bits set to "MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode supported" and: i) if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) but does not allow RTT measurement without using PMF protocol, the SMF shall ensure that the established PDU session has the capability of MPQUIC with any steering mode and ATSSS-LL with only active-standby steering mode, load balancing steering mode or priority based steering mode steering mode in the downlink and MPQUIC with any steering mode and ATSSS-LL with only active-standby steering mode in the uplink; ii) if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) and allows RTT measurement without using PMF protocol, the SMF shall ensure that the established PDU session has the capability of MPQUIC with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and MPQUIC with any steering mode and ATSSS-LL with only active-standby steering mode in the uplink; or iii) if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode, the SMF shall ensure that the established PDU session has the capability of MPQUIC with any steering mode and ATSSS-LL with only active-standby steering mode in the downlink and the uplink; c) the ATSSS-ST bits set to "MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported" and if the DNN configuration allows for the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality), the SMF shall ensure that the established PDU session has the capability of MPQUIC with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and the uplink; d) the ATSSS-ST bits set to "ATSSS Low-Layer functionality with any steering mode allowed for ATSSS-LL supported" and if the DNN configuration allows for the ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality), the SMF shall ensure that the established PDU session has the capability of ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and the uplink; e) the ATSSS-ST bits set to "MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported" and if the DNN configuration allows for the MPTCP functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality), the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and the uplink; f) the ATSSS-ST bits set to "MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode allowed for ATSSS-LL supported" and if the DNN configuration allows for the MPTCP functionality with any steering mode, the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality), the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode , the MPQUIC with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and the uplink; or g) the ATSSS-ST bits set to "MPTCP functionality with any steering mode, MPQUIC functionality with any steering mode and ATSSS-LL functionality with only activestandby steering mode supported" and i) if the DNN configuration allows for the MPTCP functionality with any steering mode, the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) but does not allow RTT measurement without using PMF protocol, the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode, MPQUIC with any steering mode and ATSSS-LL with only active-standby steering mode, load balancing steering mode or priority based steering mode in the downlink and MPTCP with any steering mode, MPQUIC with steering mode and ATSSS-LL with only activestandby steering mode in the uplink; ii) if the DNN configuration allows for the MPTCP functionality with any steering mode, the MPQUIC functionality with any steering mode and ATSSS-LL functionality with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) and allows RTT measurement without using PMF protocol, the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode, MPQUIC with any steering mode and ATSSS-LL with any steering mode (i.e., any steering mode allowed for ATSSS-LL functionality) in the downlink and MPTCP with any steering mode, MPQUIC with steering mode and ATSSS-LL with only active-standby steering mode in the uplink; or iii) if the DNN configuration allows for the MPTCP functionality with any steering mode, the MPQUIC functionality with any steering mode and ATSSS-LL functionality with only active-standby steering mode, the SMF shall ensure that the established PDU session has the capability of MPTCP with any steering mode, MPQUIC with any steering mode and ATSSS-LL with only active-standby steering mode in the downlink and the uplink. If the UE requests to establish a new MA PDU session and the UE supports to establish a PDN connection as the user plane resource of an MA PDU session, the UE shall include the ATSSS request parameter in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message.

[0474] If the UE requests to establish a new MA PDU session and the UE allows the network to downgrade the requested MA PDU session to a single-access PDU session and if the ATSSS functionality supported by the UE is inconsistent with that supported by the network, the network may proceed to set up a single-access PDU session. Alternatively, if the UE requests to establish a new MA PDU session and the UE has not indicated that it does not allow network downgrade to a single-access PDU session and if the ATSSS functionality supported by the UE is inconsistent with that supported by the network, the network may proceed to set up a single-access PDU session.

[0475] If the UE is registered to a network which does not support ATSSS and the UE has already an MA PDU session established over one access, the UE shall not attempt to establish user-plane resources for the MA PDU session over the network which does not support ATSSS as specified in subclause 4.22 of 3GPP TS 23.502 [9].

[0476] If the UE supports 3GPP PS data off, except for the transfer of a PDU session from non-3GPP access to 3GPP access and except for the establishment of user plane resources on the other access for the MA PDU session, the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and include the 3GPP PS data off UE status. The UE behaves as described in subclause 6.2.10.

[0477] If the UE supports Reliable Data Service, the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and include the Reliable Data Service request indicator. The UE behaves as described in subclause 6.2.15.

[0478] If the UE supports DNS over (D)TLS (see 3GPP TS 33.501

[0024] ), the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and include DNS server security information indicator and optionally, if the UE wishes to indicate which security protocol type(s) are supported by the UE, it may include the DNS server security protocol support.

[0479] NOTE 9: Support of DNS over (D)TLS is based on the requirements as specified in

[0480] 3GPP TS 33.501

[0024] , If: a) the PDU session type value of the PDU session type IE is set to "IPv4", "IPv6" or "IPv4v6"; b) the UE indicates "Control plane CIoT 5GS optimization supported" and "IP header compression for control plane CIoT 5GS optimization supported" in the 5GMM capability IE of the REGISTRATION REQUEST message; and c) the network indicates "Control plane CIoT 5GS optimization supported" and "IP header compression for control plane CIoT 5GS optimization supported" in the 5GS network support feature IE of the REGISTRATION ACCEPT message; the UE shall include the IP header compression configuration IE in the PDU SESSION ESTABLISHMENT REQUEST message.

[0481] If: a) the PDU session type value of the PDU session type IE is set to "Ethernet"; b) the UE indicates "Control plane CIoT 5GS optimization supported" and "Ethernet header compression for control plane CIoT 5GS optimization supported" in the 5GMM capability IE of the REGISTRATION REQUEST message; and c) the network indicates "Control plane CIoT 5GS optimization supported" and "Ethernet header compression for control plane CIoT 5GS optimization supported" in the 5GS network support feature IE of the REGISTRATION ACCEPT message; the UE shall include the Ethernet header compression configuration IE in the PDU SESSION ESTABLISHMENT REQUEST message.

[0482] If the UE supports transfer of port management information containers, the UE shall: a) set the TPMIC bit to "Transfer of port management information containers supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message; b) if the UE requests to establish a PDU session of "Ethernet" PDU session type, include the DS-TT Ethernet port MAC address IE in the PDU SESSION ESTABLISHMENT REQUEST message and set its contents to the MAC address of the DS-TT Ethernet port used for the PDU session; c) if the UE-DS-TT residence time is available at the UE, include the UE-DS-TT residence time IE and set its contents to the UE-DS-TT residence time; and d) if a Port management information container is provided by the DS-TT, include the Port management information container IE in the PDU SESSION ESTABLISHMENT REQUEST message. NOTE 10: Only SSC mode 1 is supported for a PDU session which is for time synchronization or TSC.

[0483] If the UE supports secondary DN authentication and authorization over EPC, the UE shall set the SDNAEPC bit to "Secondary DN authentication and authorization over EPC supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message.

[0484] If the UE supporting S 1 mode supports receiving QoS rules with the length of two octets or QoS flow descriptions with the length of two octets via the Extended protocol configuration options IE, the UE shall include the QoS rules with the length of two octets support indicator or the QoS flow descriptions with the length of two octets support indicator, respectively, in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message.

[0485] If the UE supports URSP provisioning in EPS, the UE shall include the URSP provisioning in EPS support indicator in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message.

[0486] If: the UE is operating in single -registration mode; the UE supports local IP address in traffic flow aggregate description and TFT filter in SI mode; and the PDU session Type requested is different from "Unstructured", the UE shall indicate the support of local address in TFT in SI mode in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message.

[0487] If the W-AGF acting on behalf of the FN-RG requests to establish a PDU session of "IPv6" or "IPv4v6" PDU session type, the W-AGF acting on behalf of the FN-RG may include in the PDU SESSION ESTABLISHMENT REQUEST message the Suggested interface identifier IE with the PDU session type value field set to "IPv6" and containing the interface identifier for the IPv6 link local address associated with the PDU session suggested to be allocated to the FN-RG.

[0488] If the UE supports provisioning of ECS configuration information to the EEC in the UE, then the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and shall include the ECS configuration information provisioning support indicator. If the UE supports receiving DNS server addresses in protocol configuration options, the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and in the Extended protocol configuration options IE: a) if the UE requests to establish a PDU session of "IPv4" or "IPv4v6" PDU session type, the UE shall include the DNS server IPv4 address request; and b) if the UE requests to establish a PDU session of "IPv6" or "IPv4v6" PDU session type, the UE shall include the DNS server IPv6 address request.

[0489] If the UE supporting UAS services requests to establish a PDU session for C2 communication, the UE shall include the Service-level-AA container IE in the PDU SESSION ESTABLISHMENT REQUEST message. In the Service-level-AA container IE, the UE shall include: a) the service-level device ID with the value set to the CAA-level UAV ID of the UE; and b) if available, the service-level- AA payload with the value set to the C2 authorization payload and the service-level- AA payload type with the value set to "C2 authorization payload".

[0490] NOTE 11 : The C2 authorization payload in the service-level- AA payload can include one, some or all of the pairing information for C2 communication, an indication of the request for direct C2 communication, pairing information for direct C2 communication, and the UAV flight authorization information.

[0491] If the UE supports the EAS rediscovery, the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and shall include the EAS rediscovery support indication in the Extended protocol configuration options IE.

[0492] If the UE needs to include a PDU session pair ID based on the matching URSP rule or UE local configuration, the UE shall include the PDU session pair ID IE in the PDU SESSION ESTABLISHMENT REQUEST message. If the UE needs to include an RSN based on the matching URSP rule or UE local configuration, the UE shall include the RSN IE in the PDU SESSION ESTABLISHMENT REQUEST message.

[0493] If the UE is not registered for onboarding services in SNPN and needs PVS information, the UE shall include the Extended protocol configuration options IE in the 13

[0494] PDU SESSION ESTABLISHMENT REQUEST message and include the PVS information request in the Extended protocol configuration options IE.

[0495] If the UE supports the EDC, the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and shall include the EDC support indicator in the Extended protocol configuration options IE.

[0496] If the UE supports a "destination MAC address range type" packet filter component and a "source MAC address range type" packet filter component, the UE shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT REQUEST message and shall include the MS support of MAC address range in 5GS indicator in the Extended protocol configuration options IE.

[0497] If the UE supports reporting of URSP rule enforcement and is indicated to send URSP rule enforcement report to network based on the matching URSP rule which contains the URSP rule enforcement report indication set to "URSP rule enforcement report is required", the UE shall include the URSP rule enforcement reports IE in the PDU SESSION ESTABLISHMENT REQUEST message.

[0498] The UE shall transport: a) the PDU SESSION ESTABLISHMENT REQUEST message; b) the PDU session ID of the PDU session being established, being handed over, being transferred, or been established as an MA PDU session; c) if the request type is set to:

[0499] 1) "initial request" or "MA PDU request" and the UE determined to establish a new PDU session or an MA PDU session based on either a URSP rule including one or more S-NSSAIs in the URSP (see subclause 6.2.9) or UE local configuration, according to subclause 4.2.2 of 3GPP TS 24.526

[0019] : i) if the UE is in the HPLMN or the subscribed SNPN, an S-NSSAI in the allowed NSSAI which corresponds to one of the S-NSSAI(s) in the matching URSP rule, if any, or else to the S-NSSAI(s) in the UE local configuration or in the default URSP rule, if any, according to the conditions given in subclause 4.2.2 of 3GPP TS 24.526

[0019] ; ii) if the UE is in a non-subscribed SNPN, the UE determined according to the conditions given in subclause 4.2.2 of 3GPP TS 24.526

[0019] to establish a new PDU session or an MA PDU session based on a URSP rule including one or more S-NSSAIs, and the URSP rule is a part of a non-subscribed SNPN signalled URSP (see

[0500] 3GPP TS 24.526

[0019] ): A) an S-NSSAI in the allowed NSSAI, which is one of the S-NSSAI(s) in the URSP rule; and

[0501] B) a mapped S-NSSAI associated with the S-NSSAI in A); or iii) otherwise:

[0502] A) one of the mapped S-NSSAI(s) which is equal to one of the S-NSSAI(s) in the matching URSP rule, if any, or else to the S-NSSAI(s) in the UE local configuration or in the default URSP rule, if any, according to the conditions given in subclause 4.2.2 of 3GPP TS 24.526

[0019] ; and

[0503] B) the S-NSSAI in the allowed NSSAI associated with the S-NSSAI in A); or la) "initial request" and the UE determined to establish a new PDU session based on the PDU session parameters for 5G ProSe layer-3 UE-to-network relay UE including an S- NSSAI in the UE policies for 5G ProSe UE-to-network relay UE as defined in

[0504] 3GPP TS 24.555 [19F]: i) in case of a non-roaming scenario, an S-NSSAI in the allowed NSSAI which corresponds to the S-NSSAI in the selected PDU session parameters for 5G ProSe layer-3 UE-to-network relay UE, if any; or ii) in case of a roaming scenario:

[0505] A) one of the mapped S-NSSAI(s) which corresponds to the S-NSSAI in the selected PDU session parameters for 5G ProSe layer-3 UE-to-network relay UE, if any; and

[0506] B) the S-NSSAI in the allowed NSSAI associated with the S-NSSAI in A);

[0507] NOTE 12: When the UE is roaming, an AMF compliant with earlier versions of the specification can omit providing to the UE a mapped S-NSSAI for one or more S-NSSAIs in the allowed NSSAI and the UE then locally sets the mapped S-NSSAI as described in subclause 4.6.2.1. lb) "initial request" and the UE has the partially allowed NSSAI and determined to establish a new PDU session based on either a URSP rule including one or more S- NSSAIs in the URSP (see subclause 6.2.9) or UE local configuration, according to subclause 4.2.2 of 3GPP TS 24.526

[0019] : i) if the UE is in the HPLMN or the subscribed SNPN and the current TA is in the list of TAs for which the S-NSSAI is allowed, an S-NSSAI in the partially allowed NSSAI which corresponds to one of the S-NSSAI(s) in the matching URSP rule, if any, or else to the S-NSSAI(s) in the UE local configuration or in the default URSP rule, if any, according to the conditions given in subclause 4.2.2 of 3GPP TS 24.526

[0019] ; ii) if the UE is in the VPLMN or a non-subscribed SNPN, the UE determined according to the conditions given in subclause 4.2.2 of 3GPP TS 24.526

[0019] to establish a new PDU session based on a URSP rule including one or more S-NSSAIs, the URSP rule is a part of a non-subscribed SNPN signalled URSP (see 3GPP TS 24.526

[0019] ) and the current TA is in the list of TAs for which the S-NSSAI is allowed:

[0508] A) an S-NSSAI in the partially allowed NSSAI, which is one of the S-NSSAI(s) in the URSP rule; and

[0509] B) a mapped S-NSSAI associated with the S-NSSAI in A); or

[0510] 2) "existing PDU session", an S-NSSAI, which is an S-NSSAI in the allowed NSSAI associated with the PDU session and (in roaming scenarios) a mapped S-NSSAI, with exception when S-NSSAI is not provided by the network in subclause 6.1.4.2; cl) the alternative S-NSSAI associated with the S-NSSAI to be replaced, if an alternative S-NSSAI for the S-NSSAI or the mapped S-NSSAI exists; d) if the request type is set to:

[0511] 1) "initial request" or "MA PDU request" and the UE determined to establish a new PDU session or an MA PDU session based on either a URSP rule including one or more DNNs in the URSP (see subclause 6.2.9) or UE local configuration, according to subclause 4.2.2 of 3GPP TS 24.526

[0019] , a DNN which corresponds to one of the DNN(s) in the matching URSP rule, if any, or else to the DNN(s) in the UE local configuration or in the default URSP rule, if any, according to the conditions given in subclause 4.2.2 of 3GPP TS 24.526

[0019] ; la) "initial request" and the UE determined to establish a new PDU session based on the PDU session parameters for 5G ProSe layer-3 UE-to-network relay UE including a DNN in the UE policies for 5G ProSe UE-to-network relay UE as defined in 3GPP TS 24.555 [19F] , a DNN which corresponds to the DNN in the selected PDU session parameters for 5G ProSe layer-3 UE-to-network relay UE, if any; or

[0512] 2) "existing PDU session", a DNN which is a DNN associated with the PDU session; e) the request type which is set to:

[0513] 1) "initial request", if the UE is not registered for emergency services and the UE requests to establish a new non-emergency PDU session;

[0514] 2) "existing PDU session", if the UE is not registered for emergency services and the UE requests: i) handover of an existing non-emergency PDU session between 3GPP access and non-3GPP access; ii) transfer of an existing PDN connection for non-emergency bearer services in the EPS to the 5GS; or iii) transfer of an existing PDN connection for non-emergency bearer services in an untrusted non-3GPP access connected to the EPC to the 5GS;

[0515] 3) "initial emergency request", if the UE requests to establish a new emergency PDU session;

[0516] 4) "existing emergency PDU session", if the UE requests: i) handover of an existing emergency PDU session between 3GPP access and non- 3GPP access; ii) transfer of an existing PDN connection for emergency bearer services in the EPS to the 5GS; or iii) transfer of an existing PDN connection for emergency bearer services in an untrusted non-3GPP access connected to the EPC to the 5GS; or

[0517] 5) "MA PDU request", if: i) the UE requests to establish an MA PDU session; ii) the UE requests to establish user plane resources over other access of an MA PDU session established over one access only; or iii) the UE performs inter-system change from SI mode to N1 mode according to subclause 4.8.2.3.1 and requests transfer of a PDN connection which is a user plane resource of an MA PDU session; and f) the old PDU session ID which is the PDU session ID of the existing PDU session, if the UE initiates the UE -requested PDU session establishment procedure upon receiving the PDU SESSION MODIFICATION COMMAND messages with the 5GSM cause IE set to #39 "reactivation requested" ;

[0518] NOTE 13: If the PDU SESSION MODIFICATION COMMAND message included alternative S-NSSAI, the UE includes alternative S-NSSAI in the PDU SESSION ESTABLISHMENT REQUEST message for PDU session re-establishment using the NAS transport procedure as specified in subclause 5.4.5, and the UE shall start timer T3580 (see example in figure 6.4.1.2.1).

[0519] For bullet c) 1), if the matching URSP rule does not have an associated S-NSSAI, or if the UE does not have any matching URSP rule and there is no S-NSSAI in the UE local configuration or in the default URSP rule, the UE shall not provide any S-NSSAI in a PDU session establishment procedure. For bullet c) la), if the selected PDU session parameters for 5G ProSe layer-3 UE- to-network relay UE do not have an associated S-NSSAI, the UE shall not provide any S- NSSAI in a PDU session establishment procedure.

[0520] For bullet d) 1),

[0521] If the matching non-default URSP rule does not have an associated DNN, then the UE shall not provide any DNN in a PDU session establishment procedure;

[0522] If the UE does not have any matching non-default URSP rule, the UE requests a connectivity that requires PAP / CHAP and the UE is configured with the default DNN for the S-NSSAI in the UE local configuration corresponding to the request, then the UE should provide such DNN in a PDU session establishment procedure;

[0523] If the UE does not have any matching non-default URSP rule, the UE requests a connectivity that requires PAP / CHAP, the UE is not configured with the default DNN for the S-NSSAI in the UE local configuration corresponding to the request, and the application provides the DNN, then the UE shall use such DNN in a PDU session establishment procedure;

[0524] If the UE does not have any matching non-default URSP rule, the UE requests a connectivity that does not require PAP / CHAP, the UE is not configured with the DNN for the S-NSSAI in the UE local configuration corresponding to the request, and the application provides the DNN, then the UE shall use such DNN in a PDU session establishment procedure;

[0525] If the UE does not have any matching non-default URSP rule, the UE requests a connectivity that requires PAP / CHAP, the UE is not configured with the default DNN for the S-NSSAI in the UE local configuration corresponding to the request, the application does not provide the DNN and there is no DNN in the default URSP rule, then the UE shall not provide any DNN in a PDU session establishment procedure; or

[0526] If the UE does not have any matching non-default URSP rule, the UE requests a connectivity that does not require PAP / CHAP, the UE is not configured with the DNN for the S-NSSAI in the UE local configuration corresponding to the request, the application does not provide the DNN and there is no DNN in the default URSP rule, then the UE shall not provide any DNN in a PDU session establishment procedure.

[0527] For bullet d) la), if the selected the PDU session parameters for 5G ProSe layer-3 UE-to- network relay UE do not have an associated DNN, the UE shall not provide any DNN in a PDU session establishment procedure. If the request type is set to "initial emergency request" or "existing emergency PDU session" or the UE is registered for onboarding services in SNPN, neither DNN nor S-NSSAI is transported by the UE using the NAS transport procedure as specified in subclause 5.4.5.

[0528] FIG. 9: UE -requested PDU session establishment procedure.

[0529] Upon receipt of a PDU SESSION ESTABLISHMENT REQUEST message, a PDU session ID, optionally an S-NSSAI associated with (in roaming scenarios) a mapped S-NSSAI, optionally a DNN determined by the AMF, optionally a DNN selected by the network (if different from the DNN determined by the AMF), the request type, and optionally an old PDU session ID, the SMF checks whether connectivity with the requested DN can be established. If the requested DNN is not included, the SMF shall use the default DNN.

[0530] If the PDU session being established is a non-emergency PDU session, the request type is not set to "existing PDU session" and the PDU session authentication and authorization by the external DN is required due to local policy, the SMF shall check whether the PDU SESSION ESTABLISHMENT REQUEST message includes the SM PDU DN request container IE or the Service-level- AA container IE.

[0531] If the PDU session being established is a non-emergency PDU session, the request type is not set to "existing PDU session", the SM PDU DN request container IE is included in the PDU SESSION ESTABLISHMENT REQUEST message, the PDU session authentication and authorization by the external DN is required due to local policy and user's subscription data, and: a) the information for the PDU session authentication and authorization by the external DN in the SM PDU DN request container IE is compliant with the local policy and user's subscription data, the SMF shall proceed with the EAP Authentication procedure specified in 3GPP TS 33.501

[0024] and refrain from accepting or rejecting the PDU SESSION ESTABLISHMENT REQUEST message until the EAP Authentication procedure finalizes; or b) the information for the PDU session authentication and authorization by the external DN in the SM PDU DN request container IE is not compliant with the local policy and user's subscription data, the SMF shall consider it as an abnormal case and proceed as specified in subclause 6.4.1.7.

[0532] If the PDU session being established is a non-emergency PDU session, the request type is not set to "existing PDU session", the SM PDU DN request container IE is not included in the PDU SESSION ESTABLISHMENT REQUEST message and the PDU session authentication and authorization by the external DN is required due to local policy and user's subscription data, the SMF shall proceed with the EAP Authentication procedure specified in 3GPP TS 33.501

[0024] and refrain from accepting or rejecting the PDU SESSION ESTABLISHMENT REQUEST message until the EAP Authentication procedure finalizes.

[0533] If the SMF receives the old PDU session ID from the AMF and a PDU session exists for the old PDU session ID, the SMF shall consider that the request for the relocation of SSC mode 3 PDU session anchor with multiple PDU sessions as specified in 3GPP TS 23.502 [9] is accepted by the UE.

[0534] If the SMF receives the onboarding indication from the AMF, the SMF shall consider that the PDU session is established for onboarding services in SNPN. If the UE has set the TPMIC bit to "Transfer of port management information containers supported" in the 5GSM capability IE of the PDU SESSION ESTABLISHMENT REQUEST message and has included a DS-TT Ethernet port MAC address IE (if the PDU session type is "Ethernet"), the Port management information container IE, and, optionally, the UE-DS-TT residence time IE in the PDU SESSION ESTABLISHMENT REQUEST message, the SMF shall operate as specified in 3GPP TS 23.502 [9] subclause 4.3.2.2.L

[0535] If requested by the upper layers, the UE supporting UAS services shall initiate a request to establish a PDU session for UAS services, where the UE: a) shall include the service-level device ID with the value set to the CAA-level UAV ID; b) if provided by the upper layers, shall include the service-level-AA server address, with the value set to the USS address; and c) if provided by the upper layers, shall include: i) the service-level-AA payload type, with the value set to "UUAA payload"; and ii) the service-level-AA payload, with the value set to UUAA payload, in the Service-level-AA container IE of the PDU SESSION ESTABLISHMENT REQUEST message.

[0536] If the PDU session being established is a non-emergency PDU session, the request type is not set to "existing PDU session", the Service-level-AA container IE is included in the PDU SESSION ESTABLISHMENT REQUEST message, and a) the service-level authentication and authorization by the external DN is required due to local policy; b) there is a valid user's subscription information for the requested DNN or for the requested DNN and S-NSSAI; and c) the information for the service-level authentication and authorization by the external DN in the Service-level- AA container IE includes CAA-level UAV ID, then the SMF shall proceed with the UUAA-SM procedure as specified in

[0537] 3GPP TS 23.256 [6AB] and refrain from accepting or rejecting the PDU SESSION ESTABLISHMENT REQUEST message until the service-level authentication and authorization procedure is completed.

[0538] The UE supporting UAS services shall not request a PDU session establishment procedure to the same DNN (or no DNN, if no DNN was indicated by the UE) and the same S-NSSAI (or no S-NSSAI, if no S-NSSAI was indicated by the UE) for which the UE has requested a service level authentication and authorization procedure which is ongoing.

[0539] If the PDU SESSION ESTABLISHMENT REQUEST message includes the PDU session pair ID IE, the RSN IE, or both, the SMF shall operate as specified in subclause 5.33.2 of 3GPP TS 23.501 [8].

[0540] * * * Next Change * * * *

[0541] 2) 6.4.1.3 UE-requested PDU session establishment procedure accepted by the network

[0542] If the connectivity with the requested DN is accepted by the network, the SMF shall create a PDU SESSION ESTABLISHMENT ACCEPT message.

[0543] If the UE requests establishing an emergency PDU session, the network shall not check for service area restrictions or subscription restrictions when processing the PDU SESSION ESTABLISHMENT REQUEST message.

[0544] The SMF shall set the Authorized QoS rules IE of the PDU SESSION ESTABLISHMENT ACCEPT message to the authorized QoS rules of the PDU session and may include the authorized QoS flow descriptions IE of the PDU SESSION ESTABLISHMENT ACCEPT message set to the authorized QoS flow descriptions of the PDU session.

[0545] NOTE 1: This is applicable also if the PDU session establishment procedure was initiated to perform handover of an existing PDU session between 3GPP access and non- 3GPP access, and even if the authorized QoS rules and authorized QoS flow descriptions for source and target access of the handover are the same.

[0546] The SMF shall ensure that the number of the packet filters used in the authorized QoS rules of the PDU Session does not exceed the maximum number of packet filters supported by the UE for the PDU session. If the received request type is "initial emergency request", the SMF shall set the Authorized QoS flow descriptions IE according to the QoS parameters used for establishing emergency services as specified in subclause 5.16.4 of 3GPP TS 23.501 [8].

[0547] SMF shall set the Authorized QoS flow descriptions IE to the authorized QoS flow descriptions of the PDU session, if: a) the Authorized QoS rules IE contains at least one GBR QoS flow; b) the QFI is not the same as the 5QI of the QoS flow identified by the QFI; c) the QoS flow can be mapped to an EPS bearer as specified in subclause 4.11.1 of 3GPP TS 23.502 [9]; or d) the QoS flow is established for the PDU session used for relaying, as specified in subclause 5.6.2.1 of 3GPP TS 23.304 [6EJ.

[0548] NOTE 2: In cases other than above listed cases, it is up to the SMF implementation to include the authorized QoS flow description for the QoS flow in the Authorized QoS flow descriptions IE of the PDU SESSION ESTABLISHMENT ACCEPT message.

[0549] If interworking with EPS is supported for the PDU session, the SMF shall set in the PDU SESSION ESTABLISHMENT ACCEPT message: a) the Mapped EPS bearer contexts IE to the EPS bearer contexts mapped from one or more QoS flows of the PDU session; and b) the EPS bearer identity parameter in the Authorized QoS flow descriptions IE to the EPS bearer identity corresponding to the QoS flow, for each QoS flow which can be transferred to EPS.

[0550] If the "Create new EPS bearer" operation code in the Mapped EPS bearer contexts IE was received, and there is no corresponding Authorized QoS flow descriptions IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall send a PDU SESSION MODIFICATION REQUEST message including a Mapped EPS bearer contexts IE to delete the mapped EPS bearer context. If the EPS bearer identity parameter in the Authorized QoS flow descriptions IE was received, the operation code is "Create new QoS flow description" and there is no corresponding Mapped EPS bearer contexts IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall not diagnose an error, and shall keep storing the association between the QoS flow and the corresponding EPS bearer identity.

[0551] Furthermore, the SMF shall store the association between the QoS flow and the mapped EPS bearer context, for each QoS flow which can be transferred to EPS.

[0552] The SMF shall set the selected SSC mode IE of the PDU SESSION ESTABLISHMENT ACCEPT message to: a) the received SSC mode in the SSC mode IE included in the PDU SESSION ESTABLISHMENT REQUEST message based on one or more of the PDU session type, the subscription and the SMF configuration; b) either the default SSC mode for the data network listed in the subscription or the SSC mode associated with the SMF configuration, if the SSC mode IE is not included in the PDU SESSION ESTABLISHMENT REQUEST message.

[0553] NOTE 3: For bullet b), to avoid issues for UEs not supporting all SSC modes, the network operator can, in the subscription data and local configuration, include at least SSC mode 1 in the allowed SSC modes, and set the default SSC mode to "SSC mode 1" as per 3GPP TS 23.501 [8],

[0554] If the PDU session is an emergency PDU session, the SMF shall set the Selected SSC mode IE of the PDU SESSION ESTABLISHMENT ACCEPT message to "SSC mode 1". If the PDU session is a non-emergency PDU session of "Ethernet" or "Unstructured" PDU session type, the SMF shall set the Selected SSC mode IE to "SSC mode 1" or "SSC mode 2". If the PDU session is a non-emergency PDU session of "IPv4", "IPv6" or "IPv4v6" PDU session type, the SMF shall set the selected SSC mode IE to "SSC mode 1", "SSC mode 2", or "SSC mode 3".

[0555] If the PDU session is a non-emergency PDU session and the UE is not registered for onboarding services in SNPN, the SMF shall set the S-NSSAI IE of the PDU SESSION ESTABLISHMENT ACCEPT message to: a) the S-NSSAI of the PDU session; and b) the mapped S-NSSAI (in roaming scenarios).

[0556] The S-NSSAI or the mapped S-NSSAI (in roaming scenarios) of the PDU session shall be the alternative S-NSSAI if the SMF has received an alternative S-NSSAI from the AMF.

[0557] The SMF shall set the Selected PDU session type IE of the PDU SESSION ESTABLISHMENT ACCEPT message to the selected PDU session type, i.e. the PDU session type of the PDU session. If the PDU SESSION ESTABLISHMENT REQUEST message includes a PDU session type IE set to "IPv4v6", the SMF shall select "IPv4", "IPv6" or "IPv4v6" as the Selected PDU session type. If the subscription, the SMF configuration, or both, are limited to IPv4 only or IPv6 only for the DNN selected by the network, the SMF shall include the 5GSM cause value #50 "PDU session type IPv4 only allowed", or #51 "PDU session type IPv6 only allowed", respectively, in the 5GSM cause IE of the PDU SESSION ESTABLISHMENT ACCEPT message.

[0558] If the selected PDU session type is "IPv4", the SMF shall include the PDU address IE in the PDU SESSION ESTABLISHMENT ACCEPT message and shall set the PDU address IE to an IPv4 address is allocated to the UE in the PDU session.

[0559] If the selected PDU session type is "IPv6", the SMF shall include the PDU address IE in the PDU SESSION ESTABLISHMENT ACCEPT message and shall set the PDU address IE to an interface identifier for the IPv6 link local address allocated to the UE in the PDU session.

[0560] If the selected PDU session type is "IPv4v6", the SMF shall include the PDU address IE in the PDU SESSION ESTABLISHMENT ACCEPT message and shall set the PDU address IE to an IPv4 address and an interface identifier for the IPv6 link local address, allocated to the UE in the PDU session.

[0561] If the selected PDU session type of a PDU session established by the W-AGF acting on behalf of the FN-RG is "IPv4v6" or "IPv6", the SMF shall also indicate the SMF's IPv6 link local address in the PDU address IE of the PDU SESSION ESTABLISHMENT ACCEPT message.

[0562] If the PDU session is a non-emergency PDU session and the UE is not registered for onboarding services in SNPN, the SMF shall set the DNN IE of the PDU SESSION ESTABLISHMENT ACCEPT message to the DNN determined by the AMF of the PDU session.

[0563] The SMF shall set the Session- AMBR IE of the PDU SESSION ESTABLISHMENT ACCEPT message to the Session-AMBR of the PDU session.

[0564] If the selected PDU session type is "IPv4", "IPv6", "IPv4v6" or "Ethernet" and if the PDU SESSION ESTABLISHMENT REQUEST message includes a 5GSM capability IE with the RQoS bit set to "Reflective QoS supported", the SMF shall consider that reflective QoS is supported for QoS flows belonging to this PDU session and may include the RQ timer IE set to an RQ timer value in the PDU SESSION ESTABLISHMENT ACCEPT message. If the selected PDU session type is "IPv4", "IPv6", "IPv4v6" or "Ethernet" and if the PDU SESSION ESTABLISHMENT REQUEST message includes a Maximum number of supported packet filters IE, the SMF shall consider this number as the maximum number of packet filters that can be supported by the UE for this PDU session. Otherwise the SMF considers that the UE supports 16 packet filters for this PDU session.

[0565] The SMF shall consider that the maximum data rate per UE for user-plane integrity protection supported by the UE for uplink and the maximum data rate per UE for userplane integrity protection supported by the UE for downlink are valid for the lifetime of the PDU session.

[0566] If the value of the RQ timer is set to "deactivated" or has a value of zero, the UE considers that RQoS is not applied for this PDU session.

[0567] NOTE 4: If the 5G core network determines that reflective QoS is to be used for a

[0568] QoS flow, the SMF sends reflective QoS indication (RQI) to UPF to activate reflective QoS. If the QoS flow is established over 3GPP access, the SMF also includes reflective QoS Attribute (RQA) in QoS profile of the QoS flow during QoS flow establishment.

[0569] If the selected PDU session type is "IPv6" or "IPv4v6" and if the PDU SESSION ESTABLISHMENT REQUEST message includes a 5GSM capability IE with the MH6- PDU bit set to "Multi-homed IPv6 PDU session supported", the SMF shall consider that this PDU session is supported to use multiple IPv6 prefixes.

[0570] If the selected PDU session type is "Ethernet", the PDU SESSION ESTABLISHMENT REQUEST message includes a 5GSM capability IE with the EPT-SI bit set to "Ethernet PDN type in SI mode supported" and the network supports Ethernet PDN type in SI mode, the SMF shall set the EPT-SI bit of the 5GSM network feature support IE of the PDU SESSION ESTABLISHMENT ACCEPT message to "Ethernet PDN type in SI mode supported".

[0571] If the AMF has indicated to the SMF that the UE supports the non-3GPP access path switching and the SMF supports the non-3GPP access path switching, the SMF shall set the NAPS bit of the 5GSM network feature support IE of the PDU SESSION ESTABLISHMENT ACCEPT message to "non-3GPP access path switching supported".

[0572] If the DN authentication of the UE was performed and completed successfully, the SMF shall set the EAP message IE of the PDU SESSION ESTABLISHMENT ACCEPT message to an EAP-success message as specified in IETF RFC 3748

[0034] , provided by the DN. Based on local policies or configurations in the SMF and the Always-on PDU session requested IE in the PDU SESSION ESTABLISHMENT REQUEST message (if available), if the SMF determines that either: a) the requested PDU session needs to be established as an always-on PDU session (e.g. because the PDU session is for time synchronization or TSC, for URLLC, or for both), the SMF shall include the Always-on PDU session indication IE in the PDU SESSION ESTABLISHMENT ACCEPT message and shall set the value to "Always-on PDU session required" ; or b) the requested PDU session shall not be established as an always-on PDU session and: i) if the UE included the Always-on PDU session requested IE, the SMF shall include the Always-on PDU session indication IE in the PDU SESSION ESTABLISHMENT ACCEPT message and shall set the value to "Always-on PDU session not allowed" ; or ii) if the UE did not include the Always-on PDU session requested IE, the SMF shall not include the Always-on PDU session indication IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0573] If the PDU session is an MA PDU session, the SMF shall include the ATSSS container IE in the PDU SESSION ESTABLISHMENT ACCEPT message. The SMF shall set the content of the ATSSS container IE as specified in 3GPP TS 24.193 [13B] . If the UE requests to establish user plane resources over the second access of an MA PDU session which has already been established over the first access and the parameters associated with ATSSS previously provided to the UE are not to be updated, the "ATSSS container contents" shall not be included in the ATSSS container IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0574] If the PDU session is a single access PDU session containing the MA PDU session information IE with the value set to "MA PDU session network upgrade is allowed" and: a) if the SMF decides to establish a single access PDU session, the SMF shall not include the ATSSS container IE in the PDU SESSION ESTABLISHMENT ACCEPT message; or b) if the SMF decides to establish an MA PDU session, the SMF shall include the

[0575] ATSSS container IE in the PDU SESSION ESTABLISHMENT ACCEPT message, which indicates to the UE that the requested single access PDU session was established as an MA PDU Session. If the PDU session is an MA PDU session containing the MA PDU session information IE with the value set to "MA PDU session network downgrade is allowed" (or "Downgrade to SA PDU session not allowed" (DSANA) is not set in the 5GSM capability IE) and: a) if the SMF decides to establish a single access PDU session, the SMF shall not include the ATSSS container IE in the PDU SESSION ESTABLISHMENT ACCEPT message, which indicates to the UE that the requested MA PDU session was established as a single-access PDU session; or b) if the SMF decides to establish an MA PDU session, the SMF shall include the S container IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0576] If the network decides that the PDU session is only for control plane CIoT 5GS optimization, the SMF shall include the control plane only indication in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0577] If: a) the UE provided the IP header compression configuration IE in the PDU SESSION ESTABLISHMENT REQUEST message; and b) the SMF supports IP header compression for control plane CIoT 5GS optimization; the SMF shall include the IP header compression configuration IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0578] If: a) the UE provided the Ethernet header compression configuration IE in the PDU SESSION ESTABLISHMENT REQUEST message; and b) the SMF supports Ethernet header compression for control plane CIoT 5GS optimization; the SMF shall include the Ethernet header compression configuration IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0579] If the PDU SESSION ESTABLISHMENT REQUEST included the Requested MBS container IE with the MBS operation set to "Join MBS session", the SMF: a) shall include the TMGI for the multicast MBS session IDs that the UE is allowed to join, if any, in the Received MBS container IE, shall set the MBS decision to "MBS join is accepted" for each of those Received MBS information, may include the MBS start time to indicate the time when the multicast MBS session starts and shall include the MBS security container in each of those Received MBS information if security protection is applied for that multicast MBS session and the control plane security procedure is used as specified in annex W.4.1.2 in 3GPP TS 33.501

[0024] , and shall use separate QoS flows dedicated for multicast by including the Authorized QoS flow descriptions IE if no separate QoS flows dedicated for multicast exist or if the SMF wants to establish new QoS flows dedicated for multicast;

[0580] NOTE 5: The network determines whether security protection applies or not for the multicast MBS session as specified in 3GPP TS 33.501

[0024] . b) shall include the TMGI for multicast MBS session IDs that the UE is not allowed to join, if any, in the Received MBS container IE, shall set the MBS decision to "MBS join is rejected" for each of those Received MBS information, shall set the Rejection cause for each of those Received MBS information with the reason of rejection, and if the Rejection cause is set to "multicast MBS session has not started or will not start soon", may include an MBS back-off timer value; and c) may include in the Received MBS container IE the MBS service area for each multicast MBS session and include in it the MBS TAI list, the NR CGI list or both, that identify the service area(s) for the local MBS service

[0581] NOTE 6: For an multicast MBS session that has multiple MBS service areas, the

[0582] MBS service areas are indicated to the UE using MBS service announcement as described in 3GPP TS 23.247

[0053] , which is out of scope of this specification. in the PDU SESSION ESTABLISHMENT ACCEPT message. If the UE has set the Type of multicast MBS session ID to "Source specific IP multicast address" in the Requested multicast MBS container IE for certain MBS session(s) in the PDU SESSION ESTABLISHMENT REQUEST message, the SMF shall include the Source IP address information and Destination IP address information in the Received MBS information together with the TMGI for each of those multicast MBS sessions.

[0583] NOTE 7: Including the Source IP address information and Destination IP address information in the Received MBS information in that case is to allow the UE to perform the mapping between the requested multicast MBS session ID and the provided TMGI. NOTE 8: In SNPN, TMGI is used together with NID to identify an MBS Session.

[0584] If the request type is "existing PDU session", the SMF shall not perform network slice admission control for the PDU session, except for the following cases: a) when EPS counting is not required for the S-NSSAI of the PDU session for network slice admission control and the PDU session is established due to transfer the PDN connection from SI mode to N1 mode in case of inter-system change; or b) handover of an existing PDU session between 3GPP access and non-3GPP access is performed.

[0585] The SMF shall send the PDU SESSION ESTABLISHMENT ACCEPT message.

[0586] Upon receipt of a PDU SESSION ESTABLISHMENT ACCEPT message and a PDU session ID, using the NAS transport procedure as specified in subclause 5.4.5, the UE shall stop timer T3580, shall release the allocated PTI value and shall consider that the PDU session was established.

[0587] If the PDU session establishment procedure was initiated to perform handover of an existing PDU session between 3GPP access and non-3GPP access, then upon receipt of the PDU SESSION ESTABLISHMENT ACCEPT message the UE shall locally delete any authorized QoS rules, authorized QoS flow descriptions, the session-AMBR and the parameters provided in the Protocol configuration options IE when in S 1 mode or the Extended protocol configuration options IE stored for the PDU session before processing the new received authorized QoS rules, authorized QoS flow descriptions, the session- AMBR and the parameters provided in the Extended protocol configuration options IE, if any.

[0588] NOTE 9: For the case of handover from 3GPP access to non-3GPP access, deletion of the QoS flow descriptions implies deletion of the associated EPS bearer identities, if any, and according to subclause 6.1.4.1 also deletion of the associated EPS bearer contexts. Regarding the reverse direction, for PDU sessions via non-3GPP access the network does not allocate associated EPS bearer identities (see 3GPP TS 23.502 [9], subclause 4.11.1.4.1).

[0589] If the PDU session establishment procedure was initiated to perform handover of an existing PDU session from 3GPP access to non-3GPP access and that existing PDU session is associated with one or more multicast MBS sessions, the UE shall locally leave the associated multicast MBS sessions and the SMF shall consider the UE as removed from the associated multicast MBS sessions.

[0590] For an MA PDU session already established on a single access, except for all those MA PDU sessions with a PDN connection established as a user-plane resource, upon receipt of PDU SESSION ESTABLISHMENT ACCEPT message over the other access: a) the UE shall delete the stored authorized QoS rules and the stored session-AMBR; b) if the authorized QoS flow descriptions IE is included in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall delete the stored authorized QoS flow descriptions; and c) if the mapped EPS bearer contexts IE is included in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall delete the stored mapped EPS bearer contexts.

[0591] If the UE supports network slice usage control and: a) a PDU session is successfully established for the on-demand S-NSSAI, the UE shall stop and reset the slice deregistration inactivity timer for the on-demand S-NSSAI over corresponding access type, if running; and b) an MA PDU session is successfully established for the on-demand S-NSSAI, the UE shall stop and reset the slice deregistration inactivity timer for the on-demand S- NSSAI over both 3GPP access and non-3GPP access, if running.

[0592] The UE shall store the authorized QoS rules, and the session- AMBR received in the PDU SESSION ESTABLISHMENT ACCEPT message for the PDU session. The UE shall also store the authorized QoS flow descriptions if it is included in the Authorized QoS flow descriptions IE of the PDU SESSION ESTABLISHMENT ACCEPT message for the PDU session.

[0593] If the number of the authorized QoS rules, the number of the packet filters, or the number of the authorized QoS flow descriptions associated with the PDU session have reached the maximum number supported by the UE upon receipt of a PDU SESSION ESTABLISHMENT ACCEPT message, then the UE may initiate the PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #26 "insufficient resources".

[0594] For a PDU session that is being established with the request type set to "initial request", "initial emergency request" or "MA PDU request", or a PDU session that is being transferred from EPS to 5GS and established with the request type set to "existing PDU session" or "existing emergency PDU session" or a PDU session that is being handed over between non-3GPP access and 3GPP access and established with the request type set to "existing PDU session" or "existing emergency PDU session ", the UE shall verify the authorized QoS rules and the authorized QoS flow descriptions provided in the PDU SESSION ESTABLISHMENT ACCEPT message for different types of errors as follows: a) Semantic errors in QoS operations:

[0595] 1) When the rule operation is "Create new QoS rule", and the DQR bit is set to "the QoS rule is the default QoS rule" when there's already a default QoS rule.

[0596] 2) When the rule operation is "Create new QoS rule", and there is no rule with the DQR bit set to "the QoS rule is the default QoS rule". 3) When the rule operation is "Create new QoS rule" and two or more QoS rules associated with this PDU session would have identical precedence values.

[0597] 4) When the rule operation is an operation other than "Create new QoS rule".

[0598] 5) When the rule operation is "Create new QoS rule", the DQR bit is set to "the QoS rule is not the default QoS rule", and the UE is in NB-N1 mode.

[0599] 6) When the rule operation is "Create new QoS rule" and there is already an existing

[0600] QoS rule with the same QoS rule identifier.

[0601] 7) When the rule operation is "Create new QoS rule", the DQR bit is set to "the QoS rule is not the default QoS rule", and the PDU session type of the PDU session is "Unstructured".

[0602] 8) When the flow description operation is an operation other than "Create new QoS flow description".

[0603] 8a) When the flow description operation is "Create new QoS flow description" and there is already an existing QoS flow description with the same QoS flow identifier.

[0604] 9) When the flow description operation is "Create new QoS flow description", the QFI associated with the QoS flow description is not the same as the QFI of the default QoS rule and the UE is NB-N1 mode.

[0605] 10) When the flow description operation is "Create new QoS flow description", the QFI associated with the QoS flow description is not the same as the QFI of the default QoS rule, and the PDU session type of the PDU session is "Unstructured".

[0606] 11) When the rule operation is "Create new QoS rule" and the DQR bit is set to "the QoS rule is not the default QoS rule" and one match-all packet filter is to be associated with the QoS rule.

[0607] In case 4, case 5, or case 7 if the rule operation is for a non-default QoS rule, the UE shall send a PDU SESSION MODIFICATION REQUEST message to delete the QoS rule with 5GSM cause #83 "semantic error in the QoS operation".

[0608] In case 6, if the existing QoS rule is not the default QoS rule and the DQR bit of the new QoS rule is set to "the QoS rule is not the default QoS rule", the UE shall not diagnose an error, further process the create request and, if it was processed successfully, delete the old QoS rule (i.e. the QoS rule that existed when case 6 was detected). If the existing QoS rule is the default QoS rule or the DQR bit of the new QoS rule is set to "the QoS rule is the default QoS rule", the UE shall initiate a PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #83 "semantic error in the QoS operation". In case 8, case 9, or case 10, the UE shall send a PDU SESSION MODIFICATION REQUEST message to delete the QoS flow description with 5GSM cause #83 "semantic error in the QoS operation".

[0609] In case 8 a, the UE shall not diagnose an error, further process the create request and, if it was processed successfully, delete the old QoS flow description (i.e. the QoS flow description that existed when case 8a was detected).

[0610] Otherwise for all the cases above, the UE shall initiate a PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #83 "semantic error in the QoS operation". b) Syntactical errors in QoS operations:

[0611] 1) When the rule operation is "Create new QoS rule", the QoS rule is a QoS rule of a PDU session of IPv4, IPv6, IPv4v6 or Ethernet PDU session type, and the packet filter list in the QoS rule is empty.

[0612] 2) When the rule operation is "Create new QoS rule", the DQR bit is set to "the QoS rule is the default QoS rule", the PDU session type of the PDU session is "Unstructured", and the packet filter list in the QoS rule is not empty.

[0613] 3) When there are other types of syntactical errors in the coding of the Authorized QoS rules IE or the Authorized QoS flow descriptions IE, such as: a mismatch between the number of packet filters subfield and the number of packet filters in the packet filter list when the rule operation is create new QoS rule", or the number of packet filters subfield is larger than the maximum possible number of packet filters in the packet filter list (i.e., there is no QoS rule precedence subfield included in the QoS rule IE), the QoS Rule Identifier is set to "no QoS rule identifier assigned", or the QoS flow identifier is set to "no QoS flow identifier assigned".

[0614] 4) When, the rule operation is "Create new QoS rule", there is no QoS flow description with a QFI corresponding to the QFI of the resulting QoS rule and the UE determines, by using the QoS rule’s QFI as the 5QI, that there is a resulting QoS rule for a GBR QoS flow (as described in 3GPP TS 23.501 [8] table 5.7.4-1).

[0615] 5) When the flow description operation is "Create new QoS flow description", and the UE determines that there is a QoS flow description of a GBR QoS flow (as described in 3GPP TS 23.501 [8] table 5.7.4-1) which lacks at least one of the mandatory parameters (i.e., GFBR uplink, GFBR downlink, MFBR uplink and MFBR downlink). If the QoS flow description does not include a 5QI, the UE determines this by using the QFI as the 5QI. In case 1 , case 3 or case 4, if the QoS rule is the default QoS rule, the UE shall initiate a PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #84 "syntactical error in the QoS operation". Otherwise, the UE shall send a PDU SESSION MODIFICATION REQUEST message including a requested QoS rule IE, a requested QoS flow description IE or both to delete the QoS rule, the QoS flow description or both with 5GSM cause #84 "syntactical error in the QoS operation".

[0616] In case 2, if the QoS rule is the default QoS rule, the UE shall send a PDU SESSION MODIFICATION REQUEST message including a requested QoS rule IE to delete all the packet filters of the default QoS rule. The UE shall include the 5GSM cause #84 "syntactical error in the QoS operation".

[0617] In case 5, if the default QoS rule is associated with the QoS flow description which lacks at least one of the mandatory parameters, the UE shall initiate a PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #84 "syntactical error in the QoS operation". Otherwise, the UE shall send a PDU SESSION MODIFICATION REQUEST message to delete the QoS flow description which lacks at least one of the mandatory parameters and the associated QoS rule(s), if any, with 5GSM cause #84 "syntactical error in the QoS operation".

[0618] NOTE 10: It is not considered an error if the UE determines that after processing all QoS operations on QoS rules and QoS flow descriptions there is a QoS flow description that is not associated with any QoS rule and the UE is not in NB-N1 mode. c) Semantic errors in packet filters:

[0619] 1) When a packet filter consists of conflicting packet filter components which would render the packet filter ineffective, i.e. no IP packet will ever fit this packet filter. How the UE determines a semantic error in a packet filter is outside the scope of the present document.

[0620] If the QoS rule is the default QoS rule, the UE shall initiate a PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #44 "semantic error in packet filter(s)". Otherwise, the UE shall send a PDU SESSION MODIFICATION REQUEST message to delete the QoS rule with 5GSM cause #44 "semantic error in packet filter(s)". d) Syntactical errors in packet filters:

[0621] 1) When the rule operation is "Create new QoS rule" and two or more packet filters in the resultant QoS rule would have identical packet filter identifiers. 2) When there are other types of syntactical errors in the coding of packet filters, such as the use of a reserved value for a packet filter component identifier.

[0622] If the QoS rule is the default QoS rule, the UE shall initiate a PDU session release procedure by sending a PDU SESSION RELEASE REQUEST message with 5GSM cause #45 "syntactical errors in packet filter(s)". Otherwise, the UE shall send a PDU SESSION MODIFICATION REQUEST message to delete the QoS rule with 5GSM cause #45 "syntactical errors in packet filter(s)".

[0623] If the Always-on PDU session indication IE is included in the PDU SESSION ESTABLISHMENT ACCEPT message and: a) the value of the IE is set to "Always-on PDU session required", the UE shall consider the established PDU session as an always-on PDU session; or b) the value of the IE is set to "Always-on PDU session not allowed", the UE shall not consider the established PDU session as an always-on PDU session.

[0624] The UE shall not consider the established PDU session as an always-on PDU session if the UE does not receive the Always-on PDU session indication IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0625] The UE shall store the mapped EPS bearer contexts, if received in the PDU SESSION ESTABLISHMENT ACCEPT message. Furthermore, the UE shall also store the association between the QoS flow and the mapped EPS bearer context, for each QoS flow which can be transferred to EPS, based on the received EPS bearer identity parameter in Authorized QoS flow descriptions IE and the mapped EPS bearer contexts. The UE shall check each mapped EPS bearer context for different types of errors as follows:

[0626] NOTE 11 : An error detected in a mapped EPS bearer context does not cause the UE to discard the Authorized QoS rules IE and Authorized QoS flow descriptions IE included in the PDU SESSION ESTABLISHMENT ACCEPT, if any. a) Semantic error in the mapped EPS bearer operation:

[0627] 1) When the operation code is an operation code other than "Create new EPS bearer".

[0628] 2) When the operation code is "Create new EPS bearer" and there is already an existing mapped EPS bearer context with the same EPS bearer identity associated with any PDU session.

[0629] 3) When the operation code is "Create new EPS bearer" and the resulting mapped EPS bearer context has invalid mandatory parameters or missing mandatory parameters (e.g., mapped EPS QoS parameters or traffic flow template for a dedicated EPS bearer context). In case 2, if the existing mapped EPS bearer context is associated with the PDU session that is being established, the UE shall not diagnose an error, further process the create request and, if it was process successfully, delete the old EPS bearer context.

[0630] Otherwise, the UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #85 "Invalid mapped EPS bearer identity". b) if the mapped EPS bearer context includes a traffic flow template, the UE shall check the traffic flow template for different types of TFT IE errors as follows:

[0631] 1) Semantic errors in TFT operations:

[0632] 1) When the TFT operation is an operation other than "Create new TFT"

[0633] The UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #41 "semantic error in the TFT operation".

[0634] 2) Syntactical errors in TFT operations: i) When the TFT operation = "Create new TFT" and the packet filter list in the TFT IE is empty. ii) When there are other types of syntactical errors in the coding of the TFT IE, such as a mismatch between the number of packet filters subfield, and the number of packet filters in the packet filter list.

[0635] The UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message with to delete the mapped EPS bearer context 5GSM cause #42 "syntactical error in the TFT operation".

[0636] 3) Semantic errors in packet filters: i) When a packet filter consists of conflicting packet filter components which would render the packet filter ineffective, i.e. no IP packet will ever fit this packet filter. How the UE determines a semantic error in a packet filter is outside the scope of the present document. ii) When the resulting TFT, which is assigned to a dedicated EPS bearer context, does not contain any packet filter which applicable for the uplink direction.

[0637] The UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #44 "semantic errors in packet filter(s)".

[0638] 4) Syntactical errors in packet filters: i) When the TFT operation = "Create new TFT" and two or more packet filters in the resultant TFT would have identical packet filter identifiers. ii) When the TFT operation = "Create new TFT" and two or more packet filters in all TFTs associated with this PDN connection would have identical packet filter precedence values. iii) When there are other types of syntactical errors in the coding of packet filters, such as the use of a reserved value for a packet filter component identifier.

[0639] In case ii, if the old packet filters do not belong to the default EPS bearer context, the UE shall not diagnose an error and shall delete the old packet filters which have identical filter precedence values.

[0640] In case ii, if one or more old packet filters belong to the default EPS bearer context, the UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #45 "syntactical errors in packet filter(s)".

[0641] In cases i and iii the UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #45 "syntactical error in packet filter(s)".

[0642] If the UE detects different errors in the mapped EPS bearer contexts, QoS rules or QoS flow descriptions, the UE may send a single PDU SESSION MODIFICATION REQUEST message to delete the erroneous mapped EPS bearer contexts, QoS rules or QoS flow descriptions. In that case, the UE shall include a single 5GSM cause in the PDU SESSION MODIFICATION REQUEST message.

[0643] NOTE 12: The 5GSM cause to use cannot be different from: #41 "semantic error in the TFT operation", #42 "syntactical error in the TFT operation", #44 "semantic error in packet filter(s)", #45 "syntactical errors in packet filter(s)", #83 "semantic error in the QoS operation", #84 "syntactical error in the QoS operation", and #85 "Invalid mapped EPS bearer identity". The selection of a 5GSM cause is up to the UE implementation.

[0644] If there are mapped EPS bearer context(s) associated with a PDU session, but none of them is associated with the default QoS rule, the UE shall initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context(s) with 5GSM cause #85 "Invalid mapped EPS bearer identity" and shall locally delete the stored EPS bearer identity (EBI) in all the QoS flow descriptions of the PDU session, if any. The UE shall only use the Control plane CIoT 5GS optimization for this PDU session if the Control plane only indication is included in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0645] If the UE requests the PDU session type "IPv4v6" and: a) the UE receives the selected PDU session type set to "IPv4" and does not receive the 5GSM cause value #50 "PDU session type IPv4 only allowed"; or b) the UE receives the selected PDU session type set to "IPv6" and does not receive the 5GSM cause value #51 "PDU session type IPv6 only allowed"; the UE may subsequently request another PDU session for the other IP version using the UE-requested PDU session establishment procedure to the same DNN (or no DNN, if no DNN was indicated by the UE) and the same S-NSSAI associated with (in roaming scenarios) a mapped S-NSSAI (or no S-NSSAI, if no S-NSSAI was indicated by the UE) with a single address PDN type (IPv4 or IPv6) other than the one already activated.

[0646] If the UE requests the PDU session type "IPv4v6", receives the selected PDU session type set to "IPv4" and the 5GSM cause value #50 "PDU session type IPv4 only allowed", the UE shall not subsequently request another PDU session using the UE- requested PDU session establishment procedure to the same DNN (or no DNN, if no DNN was indicated by the UE) and the same S-NSSAI associated with (in roaming scenarios) a mapped S-NSSAI (or no S-NSSAI, if no S-NSSAI was indicated by the UE) to obtain a PDU session type different from the one allowed by the network until any of the following conditions is fulfilled: a) the UE is registered to a new PLMN; b) the UE is switched off; c) the USIM is removed; d) the entry in the "list of subscriber data" for the current SNPN is updated if the UE does not support access to an SNPN using credentials from a credentials holder and equivalent SNPNs; or e) the selected entry of the "list of subscriber data" is updated or USIM is removed for the selected PLMN subscription, if the UE supports access to an SNPN using credentials from a credentials holder, equivalent SNPNs or both.

[0647] If the UE requests the PDU session type "IPv4v6", receives the selected PDU session type set to "IPv6" and the 5GSM cause value #51 "PDU session type IPv6 only allowed", the UE shall not subsequently request another PDU session using the UE- requested PDU session establishment procedure to the same DNN (or no DNN, if no DNN was indicated by the UE) and the same S-NSSAI associated with (in roaming scenarios) a mapped S-NSSAI (or no S-NSSAI, if no S-NSSAI was indicated by the UE) to obtain a PDU session type different from the one allowed by the network until any of the following conditions is fulfilled: a) the UE is registered to a new PLMN; b) the UE is switched off; c) the USIM is removed d) the entry in the "list of subscriber data" for the current SNPN is updated if the UE does not support access to an SNPN using credentials from a credentials holder and equivalent SNPNs; or e) the selected entry of the "list of subscriber data" is updated or USIM is removed for the selected PLMN subscription, if the UE supports access to an SNPN using credentials from a credentials holder, equivalent SNPNs or both.

[0648] NOTE 13: For the 5GSM cause values #50 "PDU session type IPv4 only allowed", and #51 "PDU session type IPv6 only allowed", re-attempt in SI mode for the same DNN (or no DNN, if no DNN was indicated by the UE) is only allowed using the PDU session type(s) indicated by the network.

[0649] If the selected PDU session type of the PDU session is "Unstructured" or "Ethernet", the UE supports inter-system change from N1 mode to SI mode, the UE does not support establishment of a PDN connection for the PDN type set to "non-IP" in SI mode, and the parameters list field of one or more authorized QoS flow descriptions received in the Authorized QoS flow descriptions IE of the PDU SESSION ESTABLISHMENT ACCEPT message contains an EPS bearer identity (EBI), then the UE shall locally remove the EPS bearer identity (EBI) from the parameters list field of such one or more authorized QoS flow descriptions. Additionally the UE shall also initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #85 "Invalid mapped EPS bearer identity".

[0650] If the selected PDU session type of the PDU session is "Ethernet", the UE supports inter-system change from N1 mode to SI mode, the UE does not support establishment of a PDN connection for the PDN type set to "non-IP" in SI mode, the UE, the network or both of them do not support Ethernet PDN type in SI mode, and the parameters list field of one or more authorized QoS flow descriptions received in the Authorized QoS flow descriptions IE of the PDU SESSION ESTABLISHMENT ACCEPT message contains an EPS bearer identity (EBI), then the UE shall locally remove the EPS bearer identity (EBI) from the parameters list field of such one or more authorized QoS flow descriptions. Additionally, the UE shall also initiate a PDU session modification procedure by sending a PDU SESSION MODIFICATION REQUEST message to delete the mapped EPS bearer context with 5GSM cause #85 "Invalid mapped EPS bearer identity".

[0651] For a UE which is registered for disaster roaming services and for a PDU session which is not a PDU session for emergency services: a) if the parameters list field of one or more authorized QoS flow descriptions received in the Authorized QoS flow descriptions IE of the PDU SESSION ESTABLISHMENT ACCEPT message contains an EPS bearer identity (EBI), then the UE shall locally remove the EPS bearer identity (EBI) from the parameters list field of such one or more authorized QoS flow descriptions; and b) the UE shall locally delete the contents of the Mapped EPS bearer contexts IE if it is received in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0652] If the UE receives an IPv4 Link MTU parameter, an Ethernet Frame Payload MTU parameter, an Unstructured Link MTU parameter, or a Non-IP Link MTU parameter in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall pass to the upper layer the received IPv4 link MTU size, the received Ethernet frame payload MTU size, the unstructured link MTU size, or the non-IP link MTU size.

[0653] NOTE 14: The IPv4 link MTU size corresponds to the maximum length of user data packet that can be sent either via the control plane or via N3 interface for a PDU session of the "IPv4" PDU session type.

[0654] NOTE 15: The Ethernet frame payload MTU size corresponds to the maximum length of a pay load of an Ethernet frame that can be sent either via the control plane or via N3 interface for a PDU session of the "Ethernet" PDU session type.

[0655] NOTE 16: The unstructured link MTU size correspond to the maximum length of user data packet that can be sent either via the control plane or via N3 interface for a PDU session of the "Unstructured" PDU session type.

[0656] NOTE 17: A PDU session of "Ethernet" or "Unstructured" PDU session type can be transferred to a PDN connection of "non-IP" PDN type, thus the UE can request the non- IP link MTU parameter in the PDU session establishment procedure. The non-IP link MTU size corresponds to the maximum length of user data that can be sent either in the user data container in the ESM DATA TRANSPORT message or via Sl-U interface as specified in 3GPP TS 24.301

[0015] .

[0657] If the 5G-RG receives an ACS information parameter in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message, the 5G-RG shall pass the ACS URL in the received ACS information parameter to the upper layer.

[0658] If the UE has indicated support for CIoT 5GS optimizations and receives a small data rate control parameters container in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall store the small data rate control parameters value and use the stored small data rate control parameters value as the maximum allowed limit of uplink user data for the PDU session in accordance with 3GPP TS 23.501 [8],

[0659] If the UE has indicated support for CIoT 5GS optimizations and receives an additional small data rate control parameters for exception data container in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall store the additional small data rate control parameters for exception data value and use the stored additional small data rate control parameters for exception data value as the maximum allowed limit of uplink exception data for the PDU session in accordance with 3GPP TS 23.501 [8].

[0660] If the UE has indicated support for CIoT 5GS optimizations and receives an initial small data rate control parameters container or an initial additional small data rate control parameters for exception data container in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall use these parameters for the newly established PDU Session. When the validity period of the initial parameters expire, the parameters received in a small data rate control parameters container or an additional small data rate control parameters for exception data container shall be used.

[0661] If the UE receives a Serving PLMN rate control IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall store the Serving PLMN rate control IE value and use the stored serving PLMN rate control value as the maximum allowed limit of uplink control plane user data for the corresponding PDU session in accordance with 3GPP TS 23.501 [8],

[0662] If the UE receives an APN rate control parameters container or an additional APN rate control for exception data parameters container in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall store these parameters and use them to limit the rate at which it generates uplink user data messages for the PDN connection corresponding to the PDU session if the PDU session is transferred to EPS upon inter-system change from N 1 mode to S 1 mode in accordance with 3GPP TS 24.301

[0015] . The received APN rate control parameters and additional APN rate control for exception data parameters shall replace any previously stored APN rate control parameters and additional APN rate control for exception data parameters, respectively, for this PDN connection.

[0663] If the UE receives an initial APN rate control parameters container or an initial additional APN rate control for exception data parameters container in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall store these parameters in the APN rate control status and use them to limit the rate at which it generates exception data messages for the PDN connection corresponding to the PDU session if the PDU session is transferred to EPS upon intersystem change from N1 mode to SI mode in accordance with 3GPP TS 24.301

[0015] . The received APN rate control status shall replace any previously stored APN rate control status for this PDN connection.

[0664] NOTE 18: In the PDU SESSION ESTABLISHMENT ACCEPT message, the SMF provides either APN rate control parameters container, or initial APN rate control parameters container, in the Extended protocol configuration options IE, but not both. NOTE 19: In the PDU SESSION ESTABLISHMENT ACCEPT message, the SMF provides either additional APN rate control for exception data parameters container, or initial additional APN rate control for exception data parameters container, in the Extended protocol configuration options IE, but not both.

[0665] If the network accepts the use of Reliable Data Service to transfer data for the PDU session, the network shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message and include the Reliable Data Service accepted indicator. The UE behaves as described in subclause 6.2.15.

[0666] If the UE indicates support of DNS over (D)TLS by providing DNS server security information indicator to the network; optionally, the UE indicates which security protocol type(s) are supported by the UE, by providing the DNS server security protocol support to the network; and the network wants to enforce the use of DNS over (D)TLS, the network may include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message and include the DNS server security information with length of two octets. Upon receiving the DNS server security information, the UE shall pass it to the upper layer. The UE shall use this information to send the DNS over (D)TLS (See 3GPP TS 33.501

[0024] ).

[0667] NOTE 20: Support of DNS over (D)TLS is based on the requirements as specified in 3GPP TS 33.501

[0024] and it is implemented based on the operator requirement.

[0668] If the PDU SESSION ESTABLISHMENT REQUEST message includes the Service-level- AA container IE with the service-level device ID set to the CAA-level UAV ID, and the SMF is provided by the UAS-NF the successful UUAA-SM result and the CAA-level UAV ID, the SMF shall store the successful result together with the authorized CAA-level UAV ID and transmit the PDU SESSION ESTABLISHMENT ACCEPT message to the UE, where the PDU SESSION ESTABLISHMENT ACCEPT message shall include the Service-level- AA container IE containing: a) the service-level-AA response, with the SLAR field set to "Service level authentication and authorization was successful" ; b) the service-level device ID with the value set to the CAA-level UAV ID; and c) if a payload is received from the UAS-NF, the service-level-AA payload, with the value set to the payload; d) if a payload type associated with the payload is received from the UAS-NF, the service-level-AA payload type with the values set to the associated payload type.

[0669] NOTE 21 : UAS security information can be included in the UUAA payload by the USS as specified in 3GPP TS 33.256 [24B] .

[0670] If the network accepts the request of the PDU session establishment for C2 communication, the network shall send the PDU SESSION ESTABLISHMENT ACCEPT message including the Service-level-AA container IE containing: a) the service-level-AA response with the value of C2AR field set to the "C2 authorization was successful"; b) if a payload is provided from the UAS-NF, the service-level-AA payload with the value set to the payload; c) if a payload type associated with the payload is provided from the UAS-NF, the service-level-AA payload type with the value set to the payload type; and d) if the CAA-level UAV ID is provided from the UAS-NF, the service-level device

[0671] ID with the value set to the CAA-level UAV ID. NOTE 22: The C2 authorization payload in the service-level- A A payload can include one or both of the C2 session security information, and pairing information for direct C2 communication.

[0672] Upon receipt of the PDU SESSION ESTABLISHMENT ACCEPT message of the PDU session for C2 communication, if the Service-level- AA container IE is included, the UE shall forward the service-level- AA contents of the Service-level- AA container IE to the upper layers.

[0673] The SMF may be configured with one or more PVS IP addresses or PVS names or both associated with the DNN and S-NSSAI used for onboarding services in SNPN, for configuration of SNPN subscription parameters in PLMN via the user plane, or for configuration of a UE via the user plane with credentials for NSSAA or PDU session authentication and authorization procedure. If the PDU session was established for onboarding services in SNPN, or the PVS information request is included in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message establishing a PDU session providing connectivity for configuration of SNPN subscription parameters in PLMN via the user plane, the network may include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message and include the PVS IP address(es) or the PVS name(s) or both associated with the DNN and S-NSSAI of the established PDU session, if available. If the PVS information request is included in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message establishing the PDU session providing connectivity for configuration of a UE via the user plane with credentials for PDU session authentication and authorization procedure, based on the subscribed DNN(s) and S-NSSAI(s) of the UE and the DNN and S-NSSAI of the established PDU session, the network should include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message and include the PVS IP address(es) or the PVS name(s) or both, which are associated with the established PDU session and per subscribed DNN(s) and S-NSSAI(s) of the UE, if available. If the PVS information request is included in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message establishing the PDU session providing connectivity for configuration of a UE via the user plane with credentials for NSSAA, based on the subscribed S-NSSAI(s) of the UE and the S-NSSAI of the established PDU session, the network should include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message and include the PVS IP address(es) or the PVS name(s) or both, which are associated with the established PDU session and per subscribed S-NSSAI(s) of the UE, if available. NOTE 23: If the PVS information request is included in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message establishing a PDU session providing connectivity for configuration of SNPN subscription parameters in SNPN via the user plane by a UE which is not registered for onboarding services in SNPN, the SMF can include the PVS IP address(es) or the PVS name(s) or both, associated with the DNN and S-NSSAI of the established PDU session, if available, in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message.

[0674] NOTE 24: The PVS IP address(es) or the PVS name(s) or both in the SMF can either be locally configured or provided by DCS. The SMF can send the PVS IP address(es) or the PVS name(s) or both that are available in the SMF as the PVS IP address(es) or the PVS name(s) or both to the UE, respectively. If the PDU session was established for onboarding services in SNPN not supporting localized services in SNPN, the PVS IP address(es) or the PVS name(s) or both provided by DCS takes precedence over the PVS IP address(es) or the PVS name(s) or both locally configured, respectively. If the PDU session was established for onboarding services in SNPN supporting localized services in SNPN, the SMF can include both the DCS provided PVS IP address(es) or the PVS name(s) or both associated with the DNN and S-NSSAI of the established PDU session and the locally configured PVS IP address(es) or the PVS name(s) or both associated with the DNN and S-NSSAI of the established PDU session, if available.

[0675] The UE upon receiving one or more PVS IP address(es), if any, one or more the PVS name(s), if any, or both shall pass them to the upper layers.

[0676] NOTE 25: If several PVS IP addresses, several PVS name(s), or one or more PVS IP addresses and one or more PVS name(s) are received, how the UE uses this information is up to UE implementation.

[0677] If the UE indicates support for ECS configuration information provisioning by providing the ECS configuration information provisioning support indicator in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message, then the SMF may include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message with a) at least one of ECS IPv4 Address(es), ECS IPv6 Address(es), and ECS FQDN(s); b) at least one associated ECSP identifier; c) optionally, spatial validity conditions associated with the ECS address; d) optionally, ECS authentication methods associated with the ECS address; and e) optionally, ECS supported PLMNs information list, including the associated ECSP information for which the EDN configuration information can be provided by the ECS.

[0678] The UE upon receiving one or more ECS IPv4 address(es), if any, ECS IPv6 address(es), if any, or ECS FQDN(s), if any, with the associated spatial validity condition, if any, the associated ECS authentication methods, if any, ECS supported PLMNs information list, if any and an ECSP identifier shall pass them to the upper layers.

[0679] NOTE 26: The IP address(es), FQDN(s), or both are associated with the ECSP identifier and replace previously provided ECS configuration information associated with the same ECSP identifier, if any.

[0680] If the SMF needs to provide DNS server address(es) to the UE and the UE has provided the DNS server IPv4 address request, the DNS server IPv6 address request or both of them, in the PDU SESSION ESTABLISHMENT REQUEST message, then the SMF shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message with one or more DNS server IPv4 address(es), one or more DNS server IPv6 address(es) or both of them. If the UE supports receiving DNS server addresses in protocol configuration options and receives one or more DNS server IPv4 address(es), one or more DNS server IPv6 address(es) or both of them, in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message, then the UE shall pass the received DNS server IPv4 address(es), if any, and the received DNS server IPv6 address(es), if any, to upper layers.

[0681] NOTE 27: The received DNS server address(es) replace previously provided DNS server address(es), if any.

[0682] If the PDU SESSION ESTABLISHMENT ACCEPT message includes the Received MBS container IE, for each of the Received MBS information: a) if MBS decision is set to "MBS join is accepted", the UE shall consider that it has successfully joined the multicast MBS session. The UE shall store the received TMGI and shall use it for any further operation on that multicast MBS session. The UE shall store the received MBS service area associated with the received TMGI, if any, and provide the received TMGI to lower layers. The UE may provide the MBS start time if it is included in the Received MBS information to upper layers; or b) if MBS decision is set to "MBS join is rejected", the UE shall consider the requested join as rejected. The UE shall store the received MBS service area associated with the received TMGI, if any. If the received Rejection cause is set to "User is outside of local MBS service area", the UE shall not request to join the same multicast MBS session if neither current TAI nor CGI of the current cell is part of the received MBS service area. If the received Rejection cause is set to "multicast MBS session has not started or will not start soon" and an MBS back-off timer value is included with value that indicates neither zero nor deactivated, the UE shall start a back-off timer T3587 with the value provided in the MBS back-off timer value for the received TMGI, and shall not attempt to join the multicast MBS session with the same TMGI until the expiry of T3587. If the MBS backoff timer value indicates that this timer is deactivated, the UE shall not attempt to join the multicast MBS session with the same TMGI, the Source IP address information of the TMGI, or the Destination IP address information of the TMGI until the UE is switched off, the USIM is removed, or the entry in the "list of subscriber data" for the current SNPN is updated. If the MBS back-off timer value indicates zero, the UE may attempt to join the multicast MBS session with the same TMGI.

[0683] If the PDU session is established for IMS signalling and the UE has requested P- CSCF IPv6 address or P-CSCF IPv4 address, the SMF shall include P-CSCF IP address(es) in the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0684] NOTE 28: The P-CSCF selection functionality is specified in subclause 5.16.3.11 of 3GPP TS 23.501 [8],

[0685] Upon receipt of the PDU SESSION ESTABLISHMENT ACCEPT message, if the UE included the PDU session pair ID in the PDU SESSION ESTABLISHMENT REQUEST message, the UE shall associate the PDU session with the PDU session pair ID. If the UE included the RSN in the PDU SESSION ESTABLISHMENT REQUEST message, the UE shall associate the PDU session with the RSN.

[0686] If the PDU SESSION ESTABLISHMENT ACCEPT message include alternative S-NSSAI, the S-NSSAI for the established PDU session shall be the S-NSSAI to be replaced and the alternative S-NSSAI on the UE side.

[0687] If the UE supports EDC and the network allows the use of EDC, the SMF shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message with the EDC usage allowed indicator. If the UE supports EDC and receives the EDC usage allowed indicator in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall indicate to upper layers that network allows the use of EDC. If the UE supports EDC and the network requires the use of EDC, the SMF shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message with the EDC usage required indicator. If the UE supports EDC and receives the EDC usage required indicator in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall indicate to upper layers that network requires the use of EDC.

[0688] If the PDU SESSION ESTABLISHMENT REQUEST message includes a MS support of MAC address range in 5GS indicator in the Extended protocol configuration options IE, the SMF: a) shall consider that the UE supports a "destination MAC address range type" packet filter component and a "source MAC address range type" packet filter component; and b) if the SMF supports a "destination MAC address range type" packet filter component and a "source MAC address range type" packet filter component and enables the UE to request QoS rules with a "destination MAC address range type" packet filter component and a "source MAC address range type" packet filter component, shall include the Extended protocol configuration options IE in the PDU SESSION ESTABLISHMENT ACCEPT message and shall include the Network support of MAC address range in 5GS indicator in the Extended protocol configuration options IE.

[0689] If the UE receives the 5GSM network feature support IE in the PDU SESSION ESTABLISHMENT ACCEPT message with the non-3GPP access path switching bit set to "non-3GPP access path switching supported" during the PDU session establishment procedure of any PDU session, the UE may include the NSONR bit with value set to "non- 3GPP path switching while using old non-3GPP resources requested" in the Non-3GPP path switching information IE in the REGISTRATION REQUEST message while performing the registration procedure for mobility registration update for non-3GPP access path switching.

[0690] NOTE 29: If the UE is registered to different PLMNs over 3GPP and non-3GPP accesses, the UE uses the capability received over non-3GPP access to determine whether to initiate the registration procedure for mobility registration update for non-3GPP path switching.

[0691] NOTE 30: If the AMF selects an SMF not supporting non-3GPP access path switching, the non-3GPP access path switching can still be performed with the AMF triggering release of the old user plane resources before new user plane resources are established. If the PDU SESSION ESTABLISHMENT ACCEPT message includes a Network support of MAC address range in 5GS indicator in the Extended protocol configuration options IE, the UE shall consider that the network supports a "destination MAC address range type" packet filter component and a "source MAC address range type" packet filter component.

[0692] NOTE 31 : Handling of indication that network allows the use of EDC or that network requires the use of EDC is specified in 3GPP TS 23.548

[0182] .

[0693] If the SMF includes the authorized QoS flow descriptions and the SMF determines to provide the N3QAI to the UE, the SMF shall include the N3QAI IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0694] If the SMF supports URSP provisioning in EPS and the URSP provisioning in EPS support indicator is included in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT REQUEST message, the SMF shall insert the URSP provisioning in EPS support indicator in the Extended protocol configuration options IE of the PDU SESSION ESTABLISHMENT ACCEPT message.

[0695] If the PDU session to be established is a single access PDU session over 3GPP access with IP PDU session type and based on operator policy the SMF determines to provide the protocol description for UL PDU set handling to the UE, the SMF may include the Protocol description IE in the PDU SESSION ESTABLISHMENT ACCEPT message.

[0696] If the Protocol description IE is included in the PDU SESSION ESTABLISHMENT ACCEPT message, the UE shall, for each existing QoS rule, store the associated protocol description included in the Protocol description IE. The UE may use the protocol description information associated with the QoS rule(s) provided by the Protocol description IE to identify PDUs belonging to PDU sets for the uplink direction. NOTE 32: Whether and how to use the protocol description information to identify PDU sets is up to the UE implementation.

[0697] * * * Next Change * * * *

[0698] 3) 9.11.3.31A MA PDU session information

[0699] The purpose of the MA PDU session information information element is to convey the MA-related information for the PDU session.

[0700] The MA PDU session information information element is coded as shown in figure 9.11.3.31 A.1 and table 9.11.3.31A.1.

[0701] The MA PDU session information is a type 1 information element. 8 7 6 5 4 3 2 1

[0702] Figure 9.11.3.31A.1: MA PDU session information information element

[0703] Table 9.11.3.31A.1: MA PDU session information information element

[0704] * * * End of Changes * * * * As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and / or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and / or functionality described herein may be performed by, and / or associated to, a corresponding module, which may be implemented in software and / or firmware and / or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

[0705] Some embodiments are described herein with reference to flowchart illustrations and / or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0706] These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function / act specified in the flowchart and / or block diagram block or blocks.

[0707] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0708] It is to be understood that the functions / acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows. Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0709] Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and / or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

[0710] Abbreviations that may be used in the preceding description include: ATSSS Access Traffic Steering, Switching, Splitting

[0711] ATSSS-LL ATSSS Low-Layer

[0712] It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

1. I l lClaims:

1. A method in a user equipment, UE, (22) comprising: transmitting (S104) a packet data unit, PDU, session establishment request as part of a multi-access, MA, PDU session establishment procedure; and receiving (S106) a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting, ATSSS, container that includes at least one parameter conveying one or more of: rules, network steering functionalities information, and measurement assistance information.

2. The method of Claim 1, wherein the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections, MPQUIC, network steering functionalities information.

3. The method of any one of Claims 1 and 2, wherein the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

4. The method of Claim 3, wherein the PDU session establishment request is an initial PDU session establishment request, and wherein the method further comprises using the supplemental information in the ATSSS container to generate a subsequent PDU session establishment request that is different from the initial PDU session establishment request.

5. The method of Claim 3, wherein the PDU session establishment request is an initial PDU session establishment request, and wherein the method further comprises using the supplemental information in the ATSSS container to hold off from generating a subsequent PDU session establishment request until at least one criterion is met.

6. The method of any one of Claims 1-5, wherein the PDU session establishment request is sent to a network node (16) and the PDU session establishment reject message is received from the network node (16).

7. The method of Claim 6, wherein the network node (16) is a Session Management Function, SMF.

8. A user equipment, UE, (22) configured to communicate with a network node (16), the UE (22) configured to: transmit a packet data unit, PDU, session establishment request as part of a multiaccess, MA, PDU session establishment procedure; and receive a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting, ATSSS, container that includes at least one parameter conveying one or more of: rules, network steering functionalities information, and measurement assistance information.

9. The UE (22) of Claim 8, wherein the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections, MPQUIC, network steering functionalities information.

10. The UE (22) of any one of Claims 8 and 9, wherein the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

11. The UE (22) of Claim 10, wherein the PDU session establishment request is an initial PDU session establishment request, and wherein the UE (22) is further configured to use the supplemental information in the ATSSS container to generate a subsequent PDU session establishment request that is different from the initial PDU session establishment request.

12. The UE (22) of Claim 11, wherein the PDU session establishment request is an initial PDU session establishment request, and wherein the UE (22) is further configured to use the supplemental information in the ATSSS container to hold off from generating a subsequent PDU session establishment request until at least one criterion is met.

13. The UE (22) of any one of Claims 8-12, wherein the PDU session establishment request is sent to a network node (16) and the PDU session establishment reject message is received from the network node (16).

14. The UE (22) of Claim 13, wherein the network node (16) is a Session Management Function, SMF.

15. A method in a network node (16), the method comprising: receiving (SI 14) a packet data unit, PDU, session establishment request as part of a multi-access, MA, PDU session establishment procedure; and transmitting (SI 16) a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting, ATSSS, container that includes at least one parameter conveying at least one of rules, network steering functionalities information, and measurement assistance information.

16. The method of Claim 15, wherein the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections, MPQUIC, network steering functionalities information.

17. The method of any one of Claims 15 and 16, wherein the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

18. The method of any one of Claims 15-17, wherein the PDU session establishment request is received from a user equipment, UE, (22), and the PDU session establishment reject message is sent to the UE (22).

19. The method of any one of Claims 15-18, wherein the network node (16) is a Session Management Function, SMF.

20. A network node (16) configured to communicate with a user equipment, UE, (22), the network node (16) configured to: receive a packet data unit, PDU, session establishment request as part of a multiaccess, MA, PDU session establishment procedure; and transmit a PDU session establishment reject message indicating failure of the MA PDU session establishment procedure, the PDU session establishment reject message comprising an Access Traffic Steering, Switching, Splitting, ATSSS, container that includes at least one parameter conveying at least one of rules, network steering functionalities information, and measurement assistance information.

21. The network node (16) of Claim 20, wherein the at least one parameter conveys the network steering functionalities information, and wherein the network steering functionalities information is Multipath Quick User Datagram Protocol Internet Connections, MPQUIC, network steering functionalities information.

22. The network node (16) of any one of Claims 20 and 21, wherein the PDU session establishment reject message includes a cause indication, the cause indication including information identifying a reason for the rejection of the PDU session establishment procedure, the ATSSS container including supplemental information about the reason for the rejection of the PDU session establishment procedure.

23. The network node (16) of any one of Claims 20-22, wherein the PDU session establishment request is received from a user equipment, UE, (22), and the PDU session establishment reject message is sent to the UE (22).

24. The network node (16) of any one of Claims 20-23, wherein the network node (16) is a Session Management Function, SMF.

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