Apparatus, method and computer program

Abstract

The present disclosure relates to an apparatus, a method and a computer program. There is provided an apparatus comprising means for: receiving, from a network, information indicating a first allowed network slice; establishing a first protocol data unit (PDU) session with the network using the first allowed network slice; receiving a trigger from the network for replacing the first network slice with a second allowed network slice; for the PDU session, triggering to replace the first network slice with the second network slice; receiving update information indicating a second allowed network slice and at least one third allowed network slice from the network; mapping each of the alternative second allowed network slice and the at least one alternative third allowed network slice to the first network slice based on the update information; and triggering, for the PDU session, replacement of the second allowed network slice with one of the at least one third allowed network slice based on receiving the update information.

Description

Technical Field

[0001] Various embodiments of this disclosure generally relate to methods, apparatus and computer programs, and particularly, but not limited to, provisionally available network slices and network slice replacements. Background Technology

[0002] A communication system can be viewed as a facility that enables communication between two or more communication devices, or provides communication devices with network access. Mobile or wireless communication networks are an example of communication networks. Communication devices may be served by application servers.

[0003] Mobile or wireless communication networks can operate according to multiple standards, such as those provided by 3GPP (3rd Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of mobile or wireless communication networks operating according to 3GPP standards are often referred to as 4G (fourth generation) networks, 5G (fifth generation) networks, 5G Advanced networks, and 6G networks. Summary of the Invention

[0004] Some embodiments of this disclosure will be described with reference to certain aspects. These aspects are not intended to indicate key or essential features of the various exemplary embodiments of this disclosure, nor are they intended to limit its scope. Other features, aspects, and elements will be readily understood by those skilled in the art in light of this disclosure. For example, it should be understood that other aspects can be provided by combination of any two or more aspects described herein.

[0005] In a first aspect, a method is provided, the method comprising: receiving from a network information indicating a first permitted network slice; establishing a first Protocol Data Unit (PDU) session with the network using the first permitted network slice; receiving from the network a trigger for replacing the first network slice with a second permitted network slice; triggering the replacement of the first network slice with the second network slice for the PDU session; receiving from the network update information indicating the second permitted network slice and at least one third permitted network slice; mapping each of the replaced second permitted network slice and at least one replaced third permitted network slice to the first network slice based on the update information; and triggering, for the PDU session, to replace the second permitted network slice with one of the at least one third permitted network slice based on the received update information.

[0006] The first allowed network slice can be a temporarily allowed network slice.

[0007] The second and third permitted network slices can be alternative network slices.

[0008] The method may include: receiving the information and updating the information from network functions.

[0009] Network functions can be at least one of access and mobility functions or session management functions.

[0010] This method may include receiving update information in a user equipment configuration update message.

[0011] The method may include receiving update information in a protocol data unit session modification message.

[0012] The method may include receiving update information via non-access stratum signaling.

[0013] The method may include providing the network with information indicating support for network slice replacement using temporarily available network slice replacement.

[0014] The method may include: after receiving update information indicating at least one third allowed network slice, removing a second allowed network slice from the memory of the device.

[0015] In a second aspect, a method is provided, the method comprising: providing information to a user equipment indicating a first allowed network slice; establishing a first protocol data unit (PDU) session with the user equipment using the first allowed network slice; triggering the replacement of the first allowed network slice with a second network slice for the PDU session; determining that the second allowed network slice has become unavailable; and providing the user equipment with: update information indicating the second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and at least one third allowed network slice to the first network slice.

[0016] The first allowed network slice can be a temporarily allowed network slice.

[0017] The second and third permitted network slices can be alternative network slices.

[0018] This method can be implemented at the access and mobility functions.

[0019] This method may include providing update information in the user equipment configuration update message.

[0020] The method may include receiving update information via non-access stratum signaling.

[0021] The method may include receiving information indicating support for network slice replacement using temporarily available network slice replacement.

[0022] Determining that a second allowed network slice has become unavailable may include: determining that the second allowed network slice is congested, or that the availability period for the second allowed network slice has expired.

[0023] The method may include: determining an indication to provide at least one third permitted network slice based on load information received from network data and analysis functions.

[0024] In a third aspect, a method is provided, the method comprising: at a device, for a PDU session, triggering the replacement of a first allowed network slice with a second allowed network slice; receiving from an access management function an indication to replace the second allowed network slice with at least one third network slice; and providing to a user equipment: update information indicating the second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and at least one third allowed network slice to the first network slice.

[0025] This method may include providing update information in the protocol data unit session modification message.

[0026] The second and third permitted network slices can be alternative network slices.

[0027] In a fourth aspect, a method is provided, the method comprising: receiving from a network information indicating a first permitted network slice; establishing a first protocol data unit (PDU) session using the first permitted network slice; receiving from the network a trigger for replacing the first network slice with a second permitted network slice; triggering the replacement of the first network slice with the second network slice for a PDU session; receiving from the network update information indicating at least one third permitted network slice; mapping the at least one third permitted network slice to the first network slice based on the update information; and triggering the replacement of the second permitted network slice with one of the at least one third permitted network slices.

[0028] The first allowed network slice can be a temporarily allowed network slice.

[0029] The second and third permitted network slices can be alternative network slices.

[0030] The method may include: receiving the information and updating the information from network functions.

[0031] Network functions can be at least one of access and mobility functions or session management functions.

[0032] This method may include receiving update information in a user equipment configuration update message.

[0033] The method may include receiving update information in a protocol data unit session modification message.

[0034] The method may include providing the network with information indicating support for network slice replacement using temporarily available network slice replacement.

[0035] The method may include: after receiving update information indicating at least one third allowed network slice, removing a second allowed network slice from the memory of the device.

[0036] In a fifth aspect, a method is provided, the method comprising: providing information to a user equipment indicating a first allowed network slice; establishing a first protocol data unit (PDU) session with the user equipment using the first allowed network slice; triggering the replacement of the first allowed network slice with a second network slice for the PDU session; determining that the second allowed network slice becomes unavailable; and providing the user equipment with update information indicating at least one third allowed network slice, and information for mapping at least one third allowed network slice to the first network slice.

[0037] The first allowed network slice can be a temporarily allowed network slice.

[0038] The second and third permitted network slices can be alternative network slices.

[0039] This method can be implemented at the access and mobility functions.

[0040] This method may include providing update information in a user equipment configuration update message.

[0041] The method may include receiving information from the user equipment indicating support for network slice replacement using a temporarily available network slice replacement.

[0042] Determining that a second allowed network slice becomes unavailable includes: determining that the second allowed network slice is congested, or that the availability period for the second allowed network slice has expired or is about to expire.

[0043] The method may include: determining an indication to provide at least one third permitted network slice based on load information received from network data and analysis functions.

[0044] In a sixth aspect, a method is provided at a session management function, the method comprising: for a PDU session, triggering the replacement of a first allowed network slice with a second allowed network slice; receiving from an access management function an indication to replace the second allowed network slice with at least one third network slice; and providing to a user equipment update information indicating at least one third allowed network slice, and information for mapping at least one third allowed network slice to the first network slice.

[0045] This method may include providing update information in the protocol data unit session modification message.

[0046] The second and third permitted network slices can be alternative network slices.

[0047] In a seventh aspect, a method is provided, the method comprising: receiving from a network information indicating a first permitted network slice; establishing a first protocol data unit (PDU) session using the first permitted network slice; receiving from the network additional information indicating: a second permitted network slice, an availability period for the second permitted network slice, at least one third permitted network slice, and an availability period for each of the at least one third permitted network slice; mapping the second permitted network slice and each of the at least one third permitted network slice to the first network slice based on the additional information; receiving information for triggering the replacement of the first permitted network slice with the second permitted network slice; replacing the first permitted network slice with the second permitted network slice for a PDU session; determining, based on the received availability period for the second permitted network slice, that the second network slice has become unavailable; and, based on the determination, triggering, for the PDU session, the replacement of the second network slice with at least one third permitted network slice.

[0048] The method may include: establishing a second protocol data unit session using at least one third permitted network slice when the availability period for the second permitted network slice has expired.

[0049] The method may include: providing the network with an indication of when at least one third permitted network slice will be used to establish a second protocol data unit session.

[0050] The method may include: receiving the information and updating the information from network functions.

[0051] Network functions can be at least one of access and mobility functions or session management functions.

[0052] This method may include receiving update information in a user equipment configuration update message.

[0053] The method may include receiving update information in a protocol data unit session modification message.

[0054] The method may include providing the network with information indicating support for network slice replacement using temporarily available network slice replacement.

[0055] The second and third permitted network slices can be alternative network slices.

[0056] In an eighth aspect, a method is provided, the method comprising: providing information to a user equipment indicating a first permitted network slice; establishing a first protocol data unit session with the user equipment using the first permitted network slice; providing the user equipment with additional information, and information for mapping each of a second permitted network slice and at least one third permitted network slice to the first network slice, the additional information indicating: the second permitted network slice, an availability period for the second permitted network slice, at least one third permitted network slice, and an availability period for each of the at least one third permitted network slice; triggering the replacement of the first permitted network slice with the second permitted network slice; and receiving from the user equipment a request to replace the second permitted network slice with at least one third permitted network slice.

[0057] This method can be implemented at the access and mobility functions.

[0058] This method may include providing update information in a user equipment configuration update message.

[0059] The method may include receiving information from the user equipment indicating support for network slice replacement using a temporarily available network slice replacement.

[0060] The method may include determining an indication to provide at least one third permitted network slice based on load information received from network data and analytics functions.

[0061] The second and third permitted network slices can be alternative network slices.

[0062] In a ninth aspect, a method is provided at a session management function, the method comprising: providing information to a user equipment indicating a first allowed network slice; establishing a first Protocol Data Unit (PDU) session with the user equipment using the first allowed network slice; providing the user equipment with additional information and information for mapping each of a second allowed network slice and at least one third allowed network slice to the first network slice, the additional information indicating: the second allowed network slice, an availability period for the second allowed network slice, at least one third allowed network slice, and an availability period for each of the at least one third allowed network slice; triggering the replacement of the first allowed network slice with the second allowed network slice; and receiving from the user equipment a request to establish a PDU session using at least one third allowed network slice.

[0063] This method may include providing additional information in the protocol data unit session modification message.

[0064] The second and third permitted network slices can be alternative network slices.

[0065] In a tenth aspect, an apparatus is provided that includes components for performing the method according to any one of the first to ninth aspects.

[0066] In an eleventh aspect, an apparatus is provided, the apparatus comprising at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to perform at least one method according to any one of the first to ninth aspects.

[0067] In a twelfth aspect, a non-transitory computer-readable medium comprising instructions is provided, wherein when executed by at least one processor of a device, the instructions cause the device to perform a method according to any one of the first to ninth aspects.

[0068] Some embodiments of this disclosure are defined in the dependent claims.

[0069] Many different aspects have been described above. As previously stated, it should be understood that other aspects may be provided by any combination of two or more of the above (or other aspects in this disclosure).

[0070] Various other aspects are also described in the following detailed description and claims. Attached Figure Description

[0071] Some embodiments will be described by way of non-limiting and illustrative examples only with reference to the accompanying drawings, in which:

[0072] Figure 1 An example of a communication network to which the examples disclosed herein can be applied is shown;

[0073] Figure 2 An example format of S-NSSAI is shown;

[0074] Figure 3 An example format alternative to NSSAIIE is shown;

[0075] Figure 4 An example mapping format between the S-NSSAI to be replaced and the alternative S-NSSAI is shown;

[0076] Figure 5 A flowchart of the example method is shown;

[0077] Figure 6 A flowchart of the example method is shown;

[0078] Figure 7 A flowchart of the example method is shown;

[0079] Figure 8 An example format for the extended alternative NSSAIIE is shown;

[0080] Figure 9 An example signaling flow is shown;

[0081] Figure 10 A flowchart of the example method is shown;

[0082] Figure 11 A flowchart of the example method is shown;

[0083] Figure 12 A flowchart of the example method is shown;

[0084] Figure 13 An example format of the alternative NSSAIIE with enhanced mapping is shown;

[0085] Figure 14 A flowchart of the example method is shown;

[0086] Figure 15 A flowchart of the example method is shown;

[0087] Figure 16 A flowchart of the example method is shown;

[0088] Figure 17 An example format for the extended alternative NSSAIIE is shown; and

[0089] Figure 18 An example of the device is shown.

[0090] Figure 19 The process of modifying a PDU session for a network request is shown.

[0091] Figure 20 The encoding of the alternative NSSAI information element is shown.

[0092] Figure 21 The encoding of the alternative NSSAI information element is shown. Detailed Implementation

[0093] The following embodiments are provided by way of non-limiting and illustrative example. Although the specification may refer to "a," "an," or "some" embodiments in several places in the text, this does not necessarily mean that every reference refers to the same embodiment or that a particular feature applies only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is intended that such a feature, structure, or characteristic may be applied in conjunction with other embodiments (whether explicitly described or not).

[0094] It should be understood that although the terms "first," "second," etc., may be used in this document to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0095] For the purposes of this disclosure, the phrases "at least one of A or B", "at least one of A and B", and "A and / or B" refer to (A), (B), or (A and B). For the purposes of this disclosure, the phrases "A, B, and / or C" refer to (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0096] As used herein, the term “or” means non-exclusive “or” unless otherwise stated (e.g., “otherwise” or “or in alternatives”).

[0097] As used herein, unless explicitly stated otherwise, performing a feature, step, or function in response to A does not mean that the feature, step, or function is performed immediately after A occurs, because one or more intermediate features, steps, or functions may be performed (at least partially) between the occurrence of the feature, step, or function and A. Similarly, performing a feature, step, or function based on A does not mean that the feature, step, or function is performed solely based on A, because the feature, step, or function may be based on one or more other features, steps, or functions besides A.

[0098] The embodiments described herein can be implemented in communication networks such as any of the following radio access technologies (RATs): Global Microwave Access Interoperability (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunications System based on Basic Wideband Code Division Multiple Access (W-CDMA) (UMTS, 3G), High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Advanced LTE and Enhanced LTE (eLTE), 5G (also known as NR), or any future RAT, such as 6G. Furthermore, communication within the communication network can utilize any suitable wireless communication technology, including but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Multiplexing (OFDM), and / or Discrete Fourier Transform Spread Spectrum OFDM (DFT-s-OFDM).

[0099] As used herein, the terms "network device" or "network node" refer to a node in a communication network through which user equipment can access the network and / or which is configured to control radio communications and manage radio resources within the cell. A network node or network device may be referred to as a base station (BS), access point (AP), or access node. Depending on the technology used, a network device may be, for example, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), an NRNB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Header Terminal (RH), a Remote Radio Header Terminal (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low-power node, a non-terrestrial network (NTN), or non-terrestrial network equipment such as satellite network equipment, low Earth orbit (LEO) satellites and geostationary orbit (GEO) satellites, or aircraft network equipment.

[0100] Furthermore, regarding the splitting of the radio access network (RAN), network equipment can refer to a centralized unit (CU) and / or a distributed unit (DU) of a base station. The interface between the CU and the DU may be referred to as the F1 interface in NR. In a split RAN architecture, node operations can be performed at least partially in a central / centralized unit (CU) (e.g., a server, host, or node) coupled to DU operations (e.g., a radio headend / node). A CU can control one or more DUs to at least act as a transmit / receive (Tx / Rx) node. In some embodiments, a DU may include, for example, a radio link control (RLC), media access control (MAC) layer, and physical (PHY) layer, while a CU may include layers above the RLC layer, such as the packet data convergence protocol (PDCP) layer, radio resource control (RRC), and internet protocol (IP) layer. Other functional splitting is also possible. In practice, any processing task can be performed in a CU or a DU, and the boundary of responsibility transfer between the CU and the DU may depend on the applied implementation.

[0101] The term "terminal device" refers to any terminal device that can be configured to perform wireless communication. For example, a terminal device may be referred to as a communication device, user equipment (UE), subscriber station (SS), or mobile station (MS). Terminal devices can include: mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, USB dongles, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote operating rooms), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc.

[0102] As used herein, the term "resource" can refer to radio resources in the time domain, frequency domain, spatial domain, and / or code domain. Some examples of resources may include, for example, physical resource blocks (PRBs), radio frames, subframes, time slots, subbands, frequency regions, subcarriers, beams, etc. The terms "transmit" and / or "receive" can refer to wireless transmission and / or reception via a radio propagation channel on a radio resource.

[0103] Figure 1 The illustration shows an example of a communication network to which the examples disclosed herein can be applied. The communication network, or cellular communication network, may include a network node 110 configured to provide one or more cells (such as cell 100) and a network node 112 configured to provide one or more other cells (such as cell 102). For example, each cell may be a macrocell, microcell, femtocell, or picocell. A cell may define the coverage area or service area of ​​a corresponding access node.

[0104] Network nodes (110, 112) can be configured to provide radio access to a communication network to user equipment (UE) 120 (one or more UEs). Radio access may include downlink (DL) communication from network nodes (110, 112) to UE 120, and uplink (UL) communication from UE 120 to network nodes (110, 112). Examples of uplink channels may include a physical uplink control channel (PUCCH) for transmitting control information, and a physical uplink shared channel (PUSCH) for transmitting data to the network. Examples of downlink channels may include a physical downlink control channel (PDCCH) for transmitting control information, and a physical downlink shared channel (PDSCH) for transmitting data to the user equipment.

[0105] Multiple UEs (120, 122) can exist in the system. Each of the multiple UEs can be served by the same or different network nodes (110, 112). UEs can be configured with dual connectivity (DC), where a UE (e.g., UE 120) can be connected to multiple network nodes (110, 112). UEs (120, 122) can communicate with each other when a device-to-device (D2D) communication interface is established between them via a so-called sidechain (SL). For example, this D2D communication can be referred to as machine-to-machine, peer-to-peer (P2P) communication, or vehicle-to-vehicle (V2V) communication.

[0106] In a communication network with multiple network nodes, these nodes can connect to each other via interfaces. For example, the LTE specification refers to this interface as the X2 interface. The interface between an LTE node and a 5G node, or between two 5G nodes, can be called the Xn interface.

[0107] Network nodes 110 and 112 can also connect to the core network 116 of the communication network via another interface. The LTE specification designates the core network as an Evolved Packet Core (EPC), and the core network can include multiple entities (e.g., Mobility Management Entity (MME) and gateway nodes). The MME can handle the mobility of terminal devices in a tracking area covering multiple cells and handle signaling connections between the terminal devices and the core network. Gateway nodes can handle data routing within the core network and data routing to / from terminal devices. The 5G specification designates the core network as a 5G Core (5GC). For example, the 5GC can include Access and Mobility Management Functions (AMF) and User Plane Functions / Gateways (UPF), among other functions. The AMF can handle the termination of Non-Access Stratum (NAS) signaling, NAS encryption and integrity protection, registration management, connection management, mobility management, access authentication and authorization, and security context management. For example, UPF nodes can support packet routing and forwarding, packet inspection, and Quality of Service (QoS) processing.

[0108] Network slicing is a 5G feature that allows different services to be supported using the same underlying mobile network infrastructure. The service requirements of a network slice can differ, such as Ultra Reliable Low Latency Communication (URLLC) and Enhanced Mobile Broadband (eMBB); or the tenants providing these services can also differ.

[0109] Network slices are uniquely identified via S-NSSAI (Single Network Slice Selection Auxiliary Information). Current 3GPP specifications allow UEs to connect simultaneously and be served by a maximum of eight slices, each corresponding to one of eight network slices, i.e., eight S-NSSAIs. On the other hand, each cell can support dozens or even hundreds of slices; for example, in the current specification, a Tracking Area (TA) can support up to 1024 network slices, which can be further expanded with an additional 65535 slices.

[0110] Figure 2 An example format for S-NSSAI is shown. S-NSSAI can include both the Slice Service Type (SST) and Slice Differentiator (SD) fields, which have a total length of 32 bits, or it can include only the SST field portion, in which case the length of S-NSSAI is only 8 bits.

[0111] The SST field can have standard and non-standard values. Values ​​from 0 to 127 belong to the standardized SST range. For example, an SST value of 1 indicates that the slice is suitable for 5G eMBB, an SST value of 2 indicates that the slice is suitable for URLLC, and so on. SD is defined by the operator.

[0112] When S-NSSAI becomes unavailable or congested, the concept of network slice replacement can be used to replace S-NSSAI with an alternative S-NSSAI.

[0113] Network fragment replacement can be triggered under the following conditions:

[0114] If the NSSF detects that S-NSSAI has become unavailable or congested (e.g., based on the analysis output of the Orchestration and Management Entity (OAM) or Network Data and Analysis Function (NWDAF), the NSSF sends a network slice availability notification for S-NSSAI to the AMF. This notification may include an alternative S-NSSAI, which the AMF can use to replace the original S-NSSAI. When S-NSSAI becomes available again, the Network Slice Selection Function (NSSF) notifies the AMF.

[0115] If the Policy and Charging Function (PCF) detects that S-NSSAI becomes unavailable or congested for the UE (e.g., based on OAM or NWDAF analysis output), the PCF sends an access and mobility-related policy notification to the AMF. This notification may include an alternative S-NSSAI, which the AMF can use to replace the original S-NSSAI. When S-NSSAI becomes available to the UE again, the PCF notifies the AMF.

[0116] When the S-NSSAI becomes unavailable or congested (and when it becomes available again), the OAM sends a notification to the AMF and provides the AMF with an alternative S-NSSAI.

[0117] Depending on the UE's connection status, the AMF can provide alternative S-NSSAIs (if not already included) for the S-NSSAI in Allow NSSAI and Configure NSSAI, and provide the UE with a mapping between (multiple) S-NSSAIs to (multiple) alternative S-NSSAIs in the UE Configuration Update message or Registration Accept message.

[0118] For example, if the UE has not yet received the mapping from S-NSSAI to the alternative S-NSSAI by allowing NSSAI, the UE only provides S-NSSAI in the Protocol Data Unit (PDU) session establishment message. If the AMF determines that the requested S-NSSAI will be replaced by the alternative S-NSSAI, and if the UE supports network slice replacement, the AMF performs a UE configuration update procedure to reconfigure the alternative S-NSSAI to the UE. The AMF continues the PDU session establishment procedure using the alternative S-NSSAI, and selects the SMF that subscribes to data using the replaced S-NSSAI, and selects a suitable SMF that can support both network slice replacement and the alternative S-NSSAI. The AMF provides both the alternative S-NSSAI and the original S-NSSAI to the SMF in the Nsmf_PDUSession_CreateSMContext service operation.

[0119] Figure 3 This shows an example format for an NSSAI Information Element (IE). Figure 4 An example mapping format between the S-NSSAI to be replaced and the alternative S-NSSAI is shown. For example... Figure 4 As shown, the replaced S-NSSAI has an alternative S-NSSAI that can be used as a replacement in the process.

[0120] Network slices can be available to a UE or UE group only for a specific amount of time, either pre-configured via OAM or known via subscription information.

[0121] Based on information received from the NSSF or Unified Data Management (UDM), the AMF can indicate the validity period of one or more S-NSSAIs in the configuration NSSAIs provided to the UE in the registration acceptance or UE configuration update message.

[0122] If the validity time indicator S-NSSAI is unavailable, the UE should not include the S-NSSAI in the requested NSSAI. If the S-NSSAI is already part of an allowed or partially allowed NSSAI, the UE should remove the S-NSSAI from its locally stored list of allowed or partially allowed NSSAIs, and the UE should locally release any PDU sessions associated with the S-NSSAI. From the UE's perspective, the UE receives the time constraints of the slice in the form of S-NSSAI time validity information. Time validity can be provided for up to 16 S-NSSAIs. For each S-NSSAI, validity can have one or more time windows, where each time window is associated with the start and end times of validity.

[0123] If an invalid S-NSSAI (validity time indicating that S-NSSAI is unavailable) is included in allowed NSSAI or partially allowed NSSAI, the AMF removes the S-NSSAI locally and requests the SMF to release the PDU session associated with the S-NSSAI (if any).

[0124] Currently, the mapping between the replaced slice and the substitute slice for slice replacement features only includes a one-to-one mapping, meaning that only one substitute slice is mapped to the substitute slice during the process. The possibility of triggering network slice replacement when the replaced slice is congested is considered; however, there is currently no defined operation when the substitute slice (i.e., the slice used as a replacement) becomes unavailable during the operation.

[0125] In the following text, the term "replaced slice" refers to the slice initially used by the UE before it became congested or under maintenance at the core network. The terms "original slice" and "replaced slice" are used interchangeably.

[0126] The term "alternate slice" refers to a slice used to replace a slice originally used by the UE before the original slice becomes congested or is maintained at the core network. The terms "alternate slice" and "replacement slice" are used interchangeably.

[0127] Three cases were considered (S1, S2, S3), where T rep = Replacement period of the replaced slice / congestion time, and T alt =Time availability of alternative slices:

[0128] •S1: The replacement period of the replaced slice and the substitution slice have the same duration:

[0129] T rep =T alt

[0130] •S2: The replacement period of the replaced slice is shorter than the duration of the replacement slice: T rep <T alt ,

[0131] •S3: The replacement period of the replaced slice is longer than the duration of the replacement slice: T rep >T alt .

[0132] Both S1 and S2 are supported by using the procedures in the current specification as described above.

[0133] However, since there is currently no supported behavior, S3 needs to modify / add to the specification.

[0134] Due to congestion of the alternative slice itself or based on some other time constraint, the time availability of the alternative slice may be shorter than the time required to use it as a replacement, i.e., T. rep >T alt In this scenario, the availability of an alternative slice for the UE will cease before the expected availability of the replacement slice, leaving the UE without a usable slice during the network slicing process.

[0135] For T rep Based on the maintenance of the replaced slice, AMF can know T rep T alt Long, and choose to satisfy T alt ≥T rep Required alternative slice (if such an alternative slice can be found).

[0136] However, for T rep Given the congestion situation, this problem is not easy to solve because PCF / NSSF / OAM does not know how long the replaced S-NSSAI will remain congested.

[0137] Before using an alternative slice as a replacement slice, the network may not know the availability T at a specific time. alt For example, if the replacement slice itself becomes congested during the network slice replacement operation, it can be difficult to estimate the time required for the replacement (T). rep For example, if the replacement is triggered due to congestion rather than just maintenance.

[0138] Currently, there is no procedure to handle what happens when the alternative slice that the UE was updated to operate on during the replacement of the original slice becomes unavailable.

[0139] In other words, the network and UE behaviors are not specified if the duration of the alternative slice is longer than the duration of the replacement slice, and the UE is unable to access either slice after the duration of the alternative slice expires.

[0140] Figure 5 A flowchart of an example method is shown. This method can be executed at a device. The device may include the UE or be included in the UE.

[0141] At 501, the method includes: receiving information from the network indicating that a first network slice is permitted.

[0142] At 502, the method includes: establishing a first Protocol Data Unit (PDU) session with the network using a first permitted network slice.

[0143] At 503, the method includes: receiving from the network a trigger for replacing a first network slice with a second permitted network slice.

[0144] At 504, the method includes: for a PDU session, triggering the replacement of the first network slice with the second network slice.

[0145] At 505, the method includes: receiving updated mapping information from the network indicating a second permitted network slice and at least one third permitted network slice.

[0146] At 506, the method includes: mapping each of the alternative second allowed network slice and at least one alternative third allowed network slice to a first network slice based on updated mapping information.

[0147] At 507, the method includes: based on the reception, for a PDU session, triggering the replacement of a second allowed network slice with a third allowed network slice from at least one third allowed network slice.

[0148] refer to Figure 5 The method may include receiving and updating information from network functions. The network function may be at least one of access and mobility functions or session management functions.

[0149] Figure 6 A flowchart of an example method is shown. This method can be executed at a device. The device may include or be included in a network node. The network node may be or implement network functions such as AMF or SMF.

[0150] At 601, the method includes: providing information to the user equipment indicating a first permitted network slice.

[0151] At 602, the method includes: establishing a first protocol data unit session with a user equipment using a first permitted network slice.

[0152] At 603, the method includes: for a PDU session, triggering the replacement of the first allowed network slice with a second network slice.

[0153] At 604, the method includes: determining that a second allowed network slice becomes unavailable.

[0154] At 605, the method includes: providing to the user equipment: update information indicating a second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and at least one third allowed network slice to a first network slice.

[0155] Reference Figure 6 In the method described, determining that the second allowed network slice has become unavailable may include: determining that the second allowed network slice is congested, or that the availability period for the second allowed network slice has expired.

[0156] Figure 7 A flowchart of an example method is shown. This method can be executed at a device. The device may include or be included in a network node. The network node may be or implement SMF.

[0157] At 701, the method includes: for a PDU session, triggering the replacement of the first allowed network slice with a second allowed network slice.

[0158] At 702, the method includes: receiving from the access management function an indication to replace a second permitted network slice with at least one third network slice.

[0159] At 703, the method includes: providing the user equipment with: update information indicating a second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and at least one third allowed network slice to a first network slice.

[0160] The first allowed slice can be a temporary allowed slice. The second and third allowed network slices can be alternative network slices.

[0161] For example, refer to Figures 5 to 7 The method may involve creating an Extended Alternate NSSAI IE, wherein more than one alternative slice is mapped to the UE's replaced slice. An Extended Alternate NSSAI IE is an example indicating updated information for a second allowed network slice and at least one third allowed network slice. Figure 8 An example format for an extended alternative S-NSSAIIE is shown. In this figure, for simplicity, there are two alternative S-NSSAIs (1 and 2), and only one S-NSSAI is to be replaced; however, typically, more slices can be included as alternative S-NSSAIs. Upon receiving update information indicating at least one third allowed network slice, the UE can remove the second allowed network slice from the device's memory.

[0162] In this new extended alternative NSSAI IE, the maximum number of alternative slices mapped to an S-NSSAI to be replaced can be limited to N, for example, 8 slices, and the total number of alternative slices for all slices to be replaced can also be considered finite.

[0163] The UE will receive more than one alternative slice in the update information (e.g., extended NSSAIIE). When the first alternative slice is further replaced, the more than one alternative slice needs to be replaced with a second alternative slice contained in the IE, and potentially subsequently replaced with a third alternative slice, a fourth alternative slice, and so on.

[0164] If an extended alternative NSSAI IE is received, the UE can ignore the previous alternative NSSAI IE (Rel-18) and trigger SSC mode 3 upon receiving a new extended alternative NSSAI IE (i.e., establishing a new PDU session using alternative S-NSSAI_2 before releasing the PDU session with alternative S-NSSAI_1). This is an example of triggering a process to replace a second allowed network slice with one of at least three allowed network slices for a PDU session based on received update information. This will enable seamless handover of alternative S-NSSAIs similar to the traditional case of network slice replacement.

[0165] Updates to replace NSSAI IE can be triggered using the UE configuration update process or the registration process.

[0166] refer to Figure 5 The described method may include Protocol Data Unit (PDU) session modification messages. In the example, the PDU session modification command is extended to enable seamless PDU session modification between several alternative slices mapped to the same replaced slice.

[0167] refer to Figure 5 The described method may include receiving update information (e.g., from SMF) in a UE configuration update message. In the example, the extension of the UE configuration update includes additional alternative slices that the UE can use during network slice replacement.

[0168] Update information can be received via NAS signaling, such as during the registration process.

[0169] It may be necessary to change the alternative S-NSSAIIE to allow multiple alternative S-NSSAIs in different entries to be mapped to the same replaced S-NSSAI.

[0170] This also requires changes to determine which entry to use, or at least clarification on whether multiple alternative slices can be mapped to the same replaced slice.

[0171] The network can provide the UE with an indication of at least one third permitted network slice. Network slices can be created (automatically) for capacity enhancement / congestion management. The trigger for creating a new slice can be due to slice usage / load conditions reported by NWDAF. This indication can be based on load information received from network data and analytics functions.

[0172] The UE can provide the network with the following information: indicating support for network slice replacement using temporarily available network slice replacement.

[0173] Figure 9 An example signaling flow between the UE, RAN node, and CN (AMF, SMF, and UPF) is shown.

[0174] In step 1, the UE registers with the network and requests slice 1 for use. The UE also indicates to the network that it supports the features of network slice replacement and temporarily available network slices. This is an example of providing the network with information indicating support for network slice replacement using temporarily available network slices.

[0175] In step 2, the AMF provides the UE with a list of allowed NSSAIs containing slice 1. This is an example of the process of providing information to the user equipment indicating the first allowed network slice.

[0176] In step 3, the UE establishes a PDU session with the network that has slice 1.

[0177] In steps 4 and 5, after a period of time, slice 1 becomes congested or unavailable at the core network and AMF. This is determined based on internal configuration or via communication with other core network NFs, such as the NSSF or PCF, to identify a new replacement slice for the UE's original slice 1. The AMF provides the UE with a new allowed NSSAI, which includes slice 1 and slice 2, where slice 2 is the alternative S-NSSAI for the replaced slice 1. In this case, slice 2 is a temporarily available S-NSSAI because the AMF cannot find any other suitable S-NSSAI to replace slice 1, for example, considering slice service level agreements (SLAs). This is an example of triggering the replacement of the first network slice with a second allowed network slice and, for a PDU session, triggering the process of replacing the first network slice with a second allowed network slice.

[0178] In step 6, after a period of time, the AMF detects that slice 2 of the UE's replaced slice 1 will become unavailable, for example, due to expiration or becoming unavailable, but slice 1 is still congested and therefore still needs to be replaced to maintain service to the UE. This is an example of the process for determining the second allowed network slice to become unavailable.

[0179] In step 7, the AMF triggers a UE configuration update command to the UE via NAS signaling. This NAS signaling indicates a new extended replacement NSSAIIE, which includes the UE's original slice (i.e., slice 1) and additional replacement S-NSSAI. This is an example of a process from the network providing update information indicating a second allowed network slice and at least one third allowed network slice.

[0180] In step 8, in this example, the AMF provides the UE with a PDU session modification command via NAS signaling. This NAS signaling indicates a new extended alternative S-NSSAI, which includes the UE's original slice (i.e., slice 1) and additional alternative S-NSSAIs. This is an example of a process from the network providing update information indicating a second allowed network slice and at least one third allowed network slice. In this example scenario, slice 2 is the first alternative S-NSSAI, and slice 3 is the second alternative S-NSSAI. The AMF updates the UE's allowed NSSAIs, which now include slices 2 and 3. The AMF can also provide the UE with an indication to enable SSC mode 3 for PDU session establishment, thereby achieving PDU session continuity.

[0181] In step 9, the UE establishes a PDU session using the new allowed NSSAI list and the new mapping information between the original slice 1 and the second alternative slice 3. This is an example of a process that maps each of the alternative second allowed network slice and at least one alternative third allowed network slice to the first network slice based on the update information, and triggers the replacement of the second allowed network slice with one of the at least one third allowed network slice for the PDU session based on the received update information.

[0182] Figures 10 to 15 Examples of embodiments are provided, in which the encoding of the extended alternative to NSSAI differs from that of the reference. Figures 5 to 8 The aforementioned encoding.

[0183] In one option, after the first alternative slice, which has already been used to replace the original slice of the UE, is no longer available, for example, because the alternative slice is a temporary slice or because of congestion exceeding T. alt Then you can update the replacement NSSAI IE to remove the T alt The previous replacement for S-NSSAI, and added new network slice replacements for the replaced S-NSSAI.

[0184] If the alternative slice is unavailable and the AMF determines that the S-NSSAI that has been replaced is not yet available, the AMF provides the UE with an updated alternative NSSAI during the UE configuration update process or during registration, which does not include the unavailable alternative S-NSSAI.

[0185] These additions have the advantage of "cleaning / flashing" alternative NSSAI (i.e., removing unavailable alternative S-NSSAI), which is currently only updated when the replaced S-NSSAI becomes available again.

[0186] Figure 10 A flowchart of an example method is shown, in which a previously replaced S-NSSAI is removed and a new network slice replacement is added for the replaced S-NSSAI. This method can be performed at a device. The device may include or be included in a UE.

[0187] At 1001, the method includes: receiving information from the network indicating a first permitted network slice.

[0188] At 1002, the method includes: establishing a first protocol data unit session using a first permitted network slice.

[0189] At 1003, the method includes: receiving from the network a trigger for replacing a first network slice with a second permitted network slice.

[0190] At 1004, the method includes: for a PDU session, triggering the replacement of the first network slice with the second network slice.

[0191] At 1005, the method includes: receiving update information from the network indicating at least one third permitted network slice.

[0192] At 1006, the method includes: mapping at least one third allowed network slice to a first network slice based on update information.

[0193] At 1007, the method includes: triggering the replacement of a second allowed network slice with a third allowed network slice from at least one third allowed network slice.

[0194] Figure 11 A flowchart of an example method is shown. This method can be executed at a device. The device may include or be included in a network node. The network node may be or implement network functions such as AMF or SMF.

[0195] At 1101, the method includes: providing information to the user equipment indicating a first permitted network slice.

[0196] At 1102, the method includes: establishing a first protocol data unit session with a user equipment using a first permitted network slice.

[0197] At 1103, the method includes: for a PDU session, triggering the replacement of the first allowed network slice with a second network slice.

[0198] At 1104, the method includes: determining that a second allowed network slice becomes unavailable.

[0199] At 1105, the method includes: providing the user equipment with update information indicating at least one third allowed network slice, and information for mapping at least one third allowed network slice to a first network slice.

[0200] Figure 12 A flowchart of an example method is shown. This method can be executed at a device. The device may include or be included in a network node. The network node may be or implement SMF.

[0201] At 1201, the method includes: for a PDU session, triggering the replacement of the first allowed network slice with a second allowed network slice.

[0202] At 1202, the method includes: receiving from the access management function an indication to replace the second permitted network slice with at least one third network slice.

[0203] At 1203, the method includes: providing the user equipment with update information indicating at least one third allowed network slice, and information for mapping at least one third allowed network slice to a first network slice.

[0204] Figure 13 References are shown Figures 10 to 12 The example format described is for mapping between the S-NSSAI to be replaced and the alternative S-NSSAI.

[0205] The time validity of each alternative S-NSSAI can be included in the alternative S-NSSAI IE sent to the UE. In this way, the UE can make automatic decisions and switch to the next alternative S-NSSAI without requiring update information from the network.

[0206] Figure 14 A flowchart of an example method is shown, in which the validity period (or time validity) is included in the update information. This method can be performed at a device. The device may include the UE, or be included within the UE.

[0207] At 1401, the method includes: receiving information from the network indicating a first permitted network slice.

[0208] At 1402, the method includes: establishing a first protocol data unit session using a first permitted network slice.

[0209] At 1403, the method includes receiving additional information from the network, the additional information indicating: a second allowed network slice, an availability period for the second allowed network slice, at least one third allowed network slice, and an availability period for each of the at least one third allowed network slice.

[0210] At 1404, the method includes: mapping each of the second allowed network slice and at least one third allowed network slice to the first network slice based on additional information.

[0211] At 1405, the method includes: receiving information for triggering the replacement of a first allowed network slice with a second allowed network slice.

[0212] At 1406, the method includes: for a PDU session, replacing the first allowed network slice with a second allowed network slice.

[0213] At 1407, the method includes: determining that a second network slice becomes unavailable based on the received availability time period for the second permitted network slice.

[0214] At 1408, the method includes: based on the determination, for a PDU session, triggering the replacement of the second network slice with at least one third permitted network slice.

[0215] Figure 15 A flowchart of an example method is shown. This method can be executed at a device. The device may include, or be included in, a network node. The network node may be, or implement network functions such as AMF or SMF.

[0216] At 1501, the method includes: providing information to the user equipment indicating a first permitted network slice.

[0217] At 1502, the method includes: establishing a first protocol data unit session with a user equipment using a first permitted network slice.

[0218] At 1503, the method includes: providing additional information to the user equipment, and information for mapping each of the second allowed network slice and at least one third allowed network slice to the first network slice, the additional information indicating: the second allowed network slice, the availability period for the second allowed network slice, at least one third allowed network slice, and the availability period for each of the at least one third allowed network slice.

[0219] At 1504, the method includes: triggering the replacement of the first allowed network slice with the second allowed network slice.

[0220] At 1505, the method includes: receiving from the user equipment a request to replace a second allowed network slice with at least one third allowed network slice.

[0221] Figure 16 A flowchart of an example method is shown.

[0222] At 1601, the method includes: providing information to the user equipment indicating a first permitted network slice.

[0223] At 1602, the method includes: establishing a first protocol data unit session with a user equipment using a first permitted network slice.

[0224] At 1603, the method includes: providing additional information to the user equipment, and information for mapping each of the second allowed network slice and at least one third allowed network slice to the first network slice, the additional information indicating: the second allowed network slice, the availability time period for the second allowed network slice, at least one third allowed network slice, and the availability time period for each of the at least one third allowed network slice.

[0225] At 1604, the method includes: triggering the replacement of the first allowed network slice with the second allowed network slice.

[0226] At 1605, the method includes: receiving from the user equipment a request to establish a PDU session using at least one third permitted network slice.

[0227] Validity period (also known as availability period) can be included in the alternative NSSAIIE as... Figure 8 and Figure 13 An extension of the example format shown.

[0228] When the timer expires, the UE can use a specific slice based on that timer and select the next slice. This is an example of determining that the second allowed network slice becomes unavailable based on the received availability period for the second allowed network slice, and based on that determination, triggering a process for the PDU session to replace the second network slice with at least one third allowed network slice.

[0229] In some cases, the network may know in advance when a slice is available (e.g., events, matches, game sessions). Timing can be retrieved / updated from application features as an option.

[0230] The UE can provide the network with an indication of the time when at least one third permitted network slice will be used to establish a second Protocol Data Unit (PDU) session. For example, the UE can signal the time required for the requested slice to be used. In this example, the timing for each slice is provided by the network, and the UE can signal which slice to use based on the remaining time. (Reference) Figures 14 to 16 The described method can be described as being based on UE behavior, where the UE selects an alternative slice to be used.

[0231] Synchronization between the UE and the AMF is required to align the alternative slices used (e.g., if the SMF indicates support for two slices, the UE can use a UE-triggered PDU session modification procedure to update from one alternative slice to the other).

[0232] Figure 17 An example format for an extended alternative NSSAI IE is shown, which includes a mapping between the replaced slice and multiple alternative slices, as well as their corresponding time availability timers.

[0233] The above methods can provide a solution to problems during network slice replacement, where the replacement slice (i.e., the slice the network uses as a replacement for the original replaced slice) becomes unavailable, for example, due to timeout or congestion, while the original replaced slice remains unavailable / thus maintaining seamless operation of the UE's PDU session when switching between different slices. The specification defines standard (currently missing) procedures / behaviors for both the network and the UE when the replacement slice is unavailable.

[0234] Update the list of alternative slices (multiple) by replacing unavailable alternative slices with available alternative slices.

[0235] Figure 18 A block diagram of apparatus 10 is shown by way of example. For example, apparatus 10 includes at least one processor 12 and at least one memory 14 storing instructions 15, which, when executed by the at least one processor, cause apparatus 10 to perform at least one or more methods (or portions thereof) disclosed herein, as well as any embodiment (or corresponding portions thereof). In one example, at least one memory and instructions (e.g., computer program code, software) are configured, together with at least one processor, to cause apparatus 10 to perform one or more methods (or portions thereof) disclosed herein, as well as any embodiment (or corresponding portions thereof).

[0236] The processor 12 may include, or be configured as, one or more circuit systems configured to perform various stages of the method according to the embodiments described herein.

[0237] As used herein, the term "circuit system" can refer to one or more or all of the following: (a) a purely hardware circuit implementation, such as an implementation solely in analog and / or digital circuit systems; and (b) a combination of hardware circuitry and software, such as, where applicable: (i) a combination of (multiple) analog and / or digital hardware circuitry with software / firmware; and (ii) any portion of (multiple) hardware processors (including (multiple) digital signal processors), software, and (multiple) memories having software, which work together to enable a device (such as a user equipment) to perform various functions; and (c) (multiple) hardware circuitry or (multiple) processors, such as (multiple) microprocessors or portions thereof, which require software (e.g., firmware) operation, but may be absent when the software is not required to operate. This definition of circuit system applies to all uses of the term herein, including in any claim. As another example, as used herein, the term circuit system also covers implementations of hardware circuitry or processors (or multiple processors) or portions thereof and their accompanying software and / or firmware. For example, if applicable to a particular claim element, the term "circuit system" also covers baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0238] The memory 14 can be implemented using any suitable data storage technology. The memory may include a database for storing data. For example, the memory 14 may be at least partially located outside the device 10, but accessible by the device 10.

[0239] Instruction 15 may be included in a computer-readable medium or a non-transitory computer-readable medium. As used herein, the term non-transitory refers to a limitation on the medium itself (i.e., tangible rather than tactile), rather than a limitation on the persistence of data storage (e.g., random access memory (RAM) versus read-only memory (ROM).

[0240] For example, device 10 is a terminal device such as a UE. As another example, the device is included in such a terminal device, for example, as a chipset configured to control the terminal device. Device 10 can be made or configured to at least perform... Figure 5 , Figure 10 ,or Figure 14 The methods and / or methods of any one or more embodiments described herein, or include components for performing these methods.

[0241] As another example, device 10 is a network entity. In another embodiment, the device is included in such a network entity, for example, a chipset configured to control the network entity. Device 10 can be caused or configured to at least perform Figure 6 , Figure 7 , Figure 11 , Figure 12 , Figure 15 ,or Figure 16 The methods and / or methods of any one or more embodiments described herein, or include components for performing these methods.

[0242] The device may include one or more entities of any protocol layer, such as a MAC entity, RRC entity, RLC entity, PDCP entity, or PHY entity. In some embodiments, the entity is configured to at least perform Figure 6 , Figure 7 , Figure 11 , Figure 12 , Figure 15 ,or Figure 16 The methods and / or the methods of any one or more embodiments described herein.

[0243] Device 10 includes a radio interface 16. Radio interface 16 can provide communication capabilities to device 10. Radio interface 16 may include a receiver configured to receive information according to at least one cellular or non-cellular standard. Radio interface 16 may include a transmitter configured to transmit information according to at least one cellular or non-cellular standard. Receivers may include more than one receiver. Transmitters may include more than one transmitter. Radio interface 16 may include a transceiver configured to receive and transmit information according to at least one cellular or non-cellular standard. Transceivers may include more than one transceiver.

[0244] Device 10 may include a user interface 18, which includes at least one of the following: for example, a keypad, a microphone, a touch display, a monitor, a speaker, etc. User interface 18 can be used to control the device by a user. User interface 18 may be external to device 10. For example, device 10 may be connected to another device, such as a computer, via a wireless or wired connection, and device 10 may be controlled by a user via the computer.

[0245] In one embodiment, at least some of the processes described herein may be performed by an apparatus comprising components for performing at least some of the processes described above. Components for performing the method steps disclosed herein may include software and / or hardware components of apparatus 10. For example, at least one processor 12, memory 14, and computer program code form components for performing one or more methods (or portions thereof) disclosed herein, as well as corresponding portions thereof, of any embodiment. As used herein, the term “component” shall be interpreted in the singular as a single element or in the plural as a combination of single elements. Thus, the term “component for [performing A, B, C]” shall be interpreted to encompass an apparatus in which only one component is used to perform A, B, and C, or in which separate components are used to perform A, B, and C, or in which partially or completely overlapping components are used to perform A, B, and C. Furthermore, the terms "component for performing A, component for performing B, component for performing C" should be interpreted as covering an apparatus in which only one component is used to perform A, B and C, or in which there are separate components for performing A, B and C, or in which there are partially or completely overlapping components for performing A, B and C.

[0246] Although this disclosure has been described above with reference to the accompanying drawings and non-limiting and illustrative examples, it will be apparent that the scope of this disclosure is not limited thereto, and that it can be modified in many different ways. As technology advances, those skilled in the art will understand how this disclosure can be further implemented and / or modified in various ways. Furthermore, it will be apparent to those skilled in the art that the embodiments described herein can, but need not, be combined with other embodiments described herein in various ways.

[0247] Below is an example of an implementation:

[0248]

[0249]

[0250]

[0251] ***Change Begins***

[0252] 4.6.2.7 Network Slice Replacement Based on Mobility Management

[0253] Support for network slice replacement by the UE or network is optional. If the UE and network support network slice replacement, and the AMF determines that the S-NSSAI included in the NSSAI needs to be replaced with an alternative S-NSSAI, then the AMF provides the UE with the following during the general UE configuration update process or registration process:

[0254] a) Allow alternatives to S-NSSAI in NSSAI (if not already included);

[0255] b) Configure the alternative S-NSSAI in NSSAI (if it is not already included);

[0256] c) Alternative S-NSSAI in NSAG information (if not already included and the UE supports NSAG); and

[0257] d) Replacement S-NSSAI, which includes mapping information between the S-NSSAI to be replaced and the corresponding replacement S-NSSAI.

[0258] as follows

[0259] a) For non-roaming UEs, the AMF provides the UE with mapping information between the S-NSSAI included in the NSSAI and the alternative S-NSSAI; or

[0260] Note 1: In non-roaming scenarios, the alternative S-NSSAI need not be part of (multiple) subscribed S-NSSAIs in the UE subscription.

[0261] b) For roaming UEs:

[0262] 1) If an S-NSSAI included in the permitted NSSAI needs to be replaced (i.e., the S-NSSAI to be replaced is a part of the VPLMN S-NSSAI), the AMF provides the UE with mapping information between the S-NSSAI included in the permitted NSSAI and the replacement S-NSSAI; and

[0263] 2) If an S-NSSAI included in (multiple) mappings of NSSAI needs to be replaced (i.e., the S-NSSAI to be replaced is a part of the HPLMN S-NSSAI), the AMF provides the UE with mapping information between the S-NSSAI to be replaced and the replacement S-NSSAI.

[0264] Note 1A: In roaming scenarios, the S-NSSAI that serves as a substitute for the HPLMN S-NSSAI portion need not be a portion of the (multiple) subscribed S-NSSAIs in the UE subscription.

[0265] Note 2: The AMF local policy determines when to provide the UE with the mapping information between the S-NSSAI to be replaced and the alternative S-NSSAI. This can be when the alternative S-NSSAI is available and no PDU session has been established with the S-NSSAI to be replaced, or when the UE has established the first PDU session associated with the S-NSSAI to be replaced.

[0266] If the requested NSSAI contains multiple alternative S-NSSAIs as alternatives to multiple unsubscribed S-NSSAIs, the AMF should verify the multiple alternative S-NSSAIs based on the stored alternative NSSAIs.

[0267] If the alternative S-NSSAI is subject to NSSAA, then the alternative S-NSSAI provided by the AMF should be a portion of the subscribed S-NSSAI(s) in the UE's subscription. The AMF should perform an NSSAA procedure for such an alternative S-NSSAI, and after the NSSAA procedure for the alternative S-NSSAI is successfully completed, perform network slice replacement as described above.

[0268] If a reNSSAA process is underway for the S-NSSAI to be replaced, the AMF should continue the reNSSAA process and, after the reNSSAA process for the S-NSSAI to be replaced is successfully completed, perform network slice replacement as described above.

[0269] Note 2A: When configuring an alternative S-NSSAI, the maximum number of S-NSSAIs defined in Section 4.6.2.2 for allowing and configuring NSSAIs applies.

[0270] If the AMF determines that the replaced S-NSSAI is available again, the AMF will provide the UE with the updated replacement S-NSSAI during the UE configuration update process or registration process, excluding the replaced S-NSSAI and its corresponding replacement S-NSSAI.

[0271] If all(multiple) of the replaced S-NSSAIs become available again, the AMF provides the replacement NSSAIs with a length set to 0 during the UE configuration update process or registration process.

[0272] Note 3: If both the S-NSSAI to be replaced and the replacement S-NSSAI have S-NSSAI location validity information, then the NS-AoS of the replacement S-NSSAI is the same as or greater than that of the S-NSSAI to be replaced.

[0273] If the UE is located in a cell outside the NS-AoS of the replaced S-NSSAI but within the NS-AoS of the replacement S-NSSAI, the AMF provides an updated allowed NSSAI and partially allowed NSSAI during the UE configuration update process or registration process, but does not include the replaced S-NSSAI in the allowed NSSAI and partially allowed NSSAI (if included).

[0274] If the alternative S-NSSAI is not part of (multiple) subscribed S-NSSAI, and:

[0275] a) The replaced S-NSSAI is removed from the NSSAI-enabled or partially NSSAI-enabled systems; or

[0276] b) The replaced S-NSSAI is available again.

[0277] The AMF should provide the UE with an updated NSSAI (allowed or partially allowed) during the UE configuration update or registration process, excluding the replacement S-NSSAI. For case a), the AMF may also provide the UE with an updated configuration NSSAI during the UE configuration update or registration process, excluding the replacement S-NSSAI. For case b), the AMF should also provide the UE with an updated configuration NSSAI during the UE configuration update or registration process, excluding the replacement S-NSSAI.

[0278] Based on the SMF local configuration, if the replaced S-NSSAI is subject to NSAC, or the substitute S-NSSAI is subject to NSAC, or both, then the SMF can perform NSAC on the replaced S-NSSAI or the substitute S-NSSAI or both.

[0279] If the AMF determines that the current alternative S-NSSAI for network slice replacement is unavailable, and the S-NSSAI to be replaced still needs to be replaced, the AMF provides the UE with (multiple) updated alternative S-NSSAIs during UE configuration or registration.

[0280] ***Next Change***

[0281] 4.6.3.4 Session Management-Based Network Slice Replacement

[0282] if:

[0283] a) UE and network support network slice replacement;

[0284] b) The UE is provided with mapping information between the S-NSSAI to be replaced and the replacement S-NSSAI; and

[0285] c) The UE decides to establish a new PDU session with the S-NSSAI to be replaced.

[0286] During PDU session establishment, the UE provides both the S-NSSAI to be replaced and the alternative S-NSSAI. If timer T3584 or timer T3585 for the S-NSSAI to be replaced is running, the UE should not stop the timer during PDU session establishment. If the SMF receives both the S-NSSAI to be replaced and the alternative S-NSSAI during PDU session establishment, the SMF continues to use the alternative S-NSSAI for the PDU session establishment process. If the PDU session establishment request is accepted, the SMF includes the alternative S-NSSAI in the PDU session establishment acceptance message. On the UE side, the S-NSSAI for the established PDU session consists of both the S-NSSAI to be replaced and the alternative S-NSSAI.

[0287] If the UE is provided with a mapping from VPLMN S-NSSAI to VPLMN Substitute S-NSSAI, the UE provides both VPLMN Substitute S-NSSAI and VPLMN S-NSSAI during PDU session establishment. The AMF sends both VPLMN Substitute S-NSSAI and VPLMN S-NSSAI to the SMF. If the UE is provided with a mapping from HPLMN S-NSSAI to HPLMN Substitute S-NSSAI, the UE provides both HPLMN Substitute S-NSSAI and HPLMN S-NSSAI during PDU session establishment. The AMF sends both HPLMN Substitute S-NSSAI and HPLMN S-NSSAI to the SMF.

[0288] If the SMF receives an alternative S-NSSAI for an existing PDU session from the AMF, and:

[0289] a) If the SMF decides to retain the existing PDU session (i.e., the SMF can provide services for both the replacement S-NSSAI and the S-NSSAI to be replaced), the SMF sends the replacement S-NSSAI to the UE during the network-requested PDU session modification process; or

[0290] b) If the SMF decides to reactivate an existing PDU session, and:

[0291] 1) If the SSC mode of the PDU session is SSC mode 3, the SMF initiates a PDU session modification procedure to trigger a PDU session reactivation performed by the UE; or

[0292] 2) If the SSC mode of the PDU session is SSC mode 1 or SSC mode 2, the SMF initiates the PDU session release procedure to trigger the PDU session reactivation performed by the UE, and the UE provides both the S-NSSAI to be replaced and the alternative S-NSSAI during the PDU session establishment process.

[0293] When the replaced S-NSSAI becomes available again, if the SMF receives the replaced S-NSSAI for an existing PDU session from the AMF, and:

[0294] a) If the SMF decides to retain the existing PDU session (i.e., the SMF can serve the replaced S-NSSAI), the SMF sends the replaced S-NSSAI to the UE during the network-requested PDU session modification process; or

[0295] b) If the SMF decides to reactivate an existing PDU session, and:

[0296] 1) If the SSC mode of the PDU session is SSC mode 3, the SMF sends the replaced S-NSSAI to the UE during the PDU session modification process to trigger the PDU session reactivation initiated by the UE; or

[0297] 2) If the SSC mode of the PDU session is SSC mode 1 or SSC mode 2, the SMF sends the replaced S-NSSAI to the UE during the PDU session release process to trigger the PDU session reactivation performed by the UE; and the UE provides the replaced S-NSSAI during the PDU establishment process.

[0298] If timer T3584 or timer T3585 used for the replaced S-NSSAI is running, and the replaced S-NSSAI in the alternative NSSAI is available, and the AMF provides the UE with updated NSSAI permission and NSSAI configuration, then the UE should stop the timer.

[0299] When the alternative S-NSSAI becomes unavailable during network slice replacement, if the SMF receives an additional alternative S-NSSAI for an existing PDU session from the AMF, and:

[0300] a) If the SMF decides to retain the existing PDU session (i.e., the SMF can serve the additional alternative S-NSSAI), the SMF sends the additional alternative S-NSSAI to the UE during the network-requested PDU session modification process; or

[0301] b) If the SMF decides to reactivate an existing PDU session, and:

[0302] 1) If the SSC mode of the PDU session is SSC mode 3, the SMF sends an additional alternative S-NSSAI to the UE during the PDU session modification process to trigger the PDU session reactivation performed by the UE.

[0303] ***Next Change***

[0304] 5.4.4.2 Network-Initiated General UE Configuration Update Process

[0305] AMF should initiate the general UE configuration update process by sending a "configuration update command" message to the UE.

[0306] AMF should be in the "Configuration Update Command" message:

[0307] a) Includes one or more of the following parameters: 5G-GUTI, TAI list, allowed NSSAI (which may include multiple mapped S-NSSAIs), LADN information, extended LADN information, service area list, MICO indication, NITZ information, configured NSSAI (which may include multiple mapped S-NSSAIs), NSSRG information, S-NSSAI location validity information, S-NSSAI time validity information, rejected S-NSSAI IE or extended rejected NSSAI IE, and network slice subscription. Change indication, operator-defined access category definition, SMS indication, "CAG information list", UE radio capability ID, 5GS registration result, UE radio capability ID deletion indication, truncated 5G-S-TMSI configuration, T3447 value, "List of (multiple) PLMNs to be used under disaster conditions", disaster roaming waiting range, disaster return waiting range, PEIPS auxiliary information, priority indicator, NSAG information, alternative NSSAI, partially allowed NSSAI, partially denied NSSAI, on-demand NSSAI, feature authorization indication or maximum time offset of discontinuous coverage;

[0308] b) Includes a configuration update instruction for IE, where the registration request bit is set to "Request Registration"; or

[0309] c) includes a combination of both a) and b).

[0310] If the UE is registering or being registered for the bootstrapping service in the SNPN, the SNPN should not offer the UE the option to configure NSSAI, allow NSSAI, or deny NSSAI.

[0311] If the UE supports Extended Deny NSSAI, then (multiple) Deny S-NSSAIs should be included in Extended Deny NSSAIIE. Otherwise, (multiple) Deny S-NSSAIs should be included in Deny NSSAIIE.

[0312] In roaming scenarios, if the extended rejection NSSAIIE is included in the Configuration Update Command message, then AMF should provide (multiple) mappings S-NSSAI for the rejection NSSAI.

[0313] If an acknowledgment is requested from the UE, the AMF should indicate "Request Acknowledgment" in the acknowledgment bit of the Configuration Update Instruction IE in the Configuration Update Command message, and should start timer T3555. Acknowledgment should be requested for all parameters except those including only NITZ information.

[0314] In order to initiate parameter renegotiation between the UE and the network, the AMF should indicate "Request Registration" in the registration request bit of the configuration update instruction IE in the "Configuration Update Command" message.

[0315] Note 1: By indicating "Request Registration" in the registration request bit of the Configuration Update Instruction IE in the "Configuration Update Command" message sent to the UE, the AMF can initiate a general UE configuration update procedure to update the emergency number list, expand the emergency number list, or both.

[0316] If the reconfiguration of the AMF that allows new NSSAI information or supports S-NSSAI requires AMF relocation, the AMF should indicate "Request Registration" in the registration request bit of the Configuration Update Instruction IE and include the NSSAI-enabled IE in the Configuration Update Command message.

[0317] If the AMF includes a new allowed NSSAI in the "Configuration Update Command" message, and the subscription information includes NSSRG information, then the S-NSSAI of the allowed NSSAI should be associated with at least one public NSSRG value. If the network has pending NSSAIs, then the S-NSSAI in both the pending NSSAIs and the allowed NSSAIs should be associated with at least one public NSSRG value.

[0318] If the AMF includes a new part that allows NSSAI, and the new part that allows NSSAI requires the AMF to relocate, then the AMF should indicate "Request Registration" in the registration request bit of the Configuration Update Instruction IE, and include the part that allows NSSAI in the Configuration Update Command message.

[0319] If the AMF includes a new configuration NSSAI in the "Configuration Update Command" message, and the new configuration NSSAI requires AMF relocation as specified in 3GPPTS 23.501[8], then the AMF should indicate "Request Registration" in the registration request bit of the configuration update instruction IE in that message.

[0320] If the AMF includes the new configuration NSSAI in the "Configuration Update Command" message, the subscription information includes NSSRG information, and the UE has already set the NSSRG bit in the 5GMM capability IE of the "Registration Request" message to:

[0321] a) If "NSSRG is supported", then AMF should include NSSRG information in the "Configuration Update Command" message; or

[0322] b) “NSSRG not supported”, then the configuration NSSAI should include one or more S-NSSAIs, each S-NSSAI being associated with all (multiple) NSRG values ​​of the default S-NSSAI, or the configuration NSSAI should include all subscribed S-NSSAIs based on instructions received from the UDM, as specified in 3GPP TS 23.501[8], even if these S-NSSAIs do not share any public NSRG values.

[0323] If the AMF needs to update the NSSRG information, and the UE sets the NSSRG bit in the 5GMM capability IE of the "Registration Request" message to "Support NSSRG", then the AMF should include the new NSSRG information in the "Configuration Update Command" message.

[0324] If the AMF includes new NSSRG information in the "Configuration Update Command" message, and the AMF determines based on the new NSSRG information that the UE needs to provide a new request for NSSAI because there is no common NSSRG value for all S-NSSAIs that allow NSSAI, then the "Configuration Update Command" message should indicate "Re-request Registration" in the registration request bit of the Configuration Update Instruction IE.

[0325] If the UE supports S-NSSAI time validity information and the AMF needs to update the S-NSSAI information, the AMF should include the new S-NSSAI validity information in the "Configuration Update Command" message.

[0326] If the AMF needs to update the S-NSSAI location validity information to the UE, and the UE sets the SLVI bit in the 5GMM capability IE of the "Registration Request" message to "Support S-NSSAI location validity information", then the AMF should include the new S-NSSAI location validity information in the "Configuration Update Command" message.

[0327] If the "Configuration Update Command" message is initiated solely due to changes that allow NSSAI and these changes require the UE to initiate a registration process, but the AMF is unable to determine the UE's NSSAI permission in accordance with 3GPP TS 23.501[8], then the "Configuration Update Command" message should indicate "Request Registration" in the Registration Request bit of the Configuration Update Indicator IE and should not contain any other parameters.

[0328] If the slice deregistration inactivity timer has expired, the UE does not support network slice usage control, and the AMF removes on-demand S-NSSAI from the allowed NSSAIs for the corresponding access type, then the AMF should include the new allowed NSSAIs in the "Configuration Update Command" message.

[0329] if:

[0330] -AMF needs to enforce a change to the restrictions on using enhanced coverage or using CE mode B, as described in section 5.3.18; or

[0331] -AMF has decided to notify UEs in 5GMM-CONNECTED mode and registered for disaster roaming services that the disaster conditions no longer apply;

[0332] Note 1A: The AMF triggering of the general UE configuration update process to notify UEs that the disaster conditions are no longer applicable only applies to UEs that are already in 5GMM-CONNECTED mode.

[0333] AMF should indicate "Request Registration" in the registration request bit of the configuration update instruction IE, and indicate "No need to release N1 NAS signaling connection" in the signaling connection maintenance request bit of the additional configuration instruction IE in the "Configuration Update Command" message.

[0334] If the network slice-specific authentication and authorization process for S-NSSAI is completed as follows:

[0335] a) If successful, the AMF shall include the S-NSSAI in the permitted NSSAIs on the same access as the requested S-NSSAI, or in the partially permitted NSSAIs on 3GPP access; or

[0336] b) If the failure occurs, the AMF should include the S-NSSAI in the rejected NSSAIs for failed or revoked NSSAIs on 3GPP access or non-3GPP access, with the reason for rejection being "S-NSSAI is unavailable due to failure or revocation of network slice-specific authentication and authorization".

[0337] If the current authorization for S-NSSAI in the access type that allows NSSAI is revoked, then the AMF should:

[0338] a) Provide the UE with new permission for NSSAI, excluding S-NSSAI whose authorization has been revoked; and

[0339] b) Provide a new rejection NSSAI for failed or revoked NSSAI, including S-NSSAI in the rejection NSSAI for revoked authorization, with the rejection reason being "S-NSSAI is unavailable due to failure or revocation of network slice-specific authentication and authorization".

[0340] Allowing NSSAI, partially allowing NSSAI, and denying NSSAI should be included in the Configuration Update Command message to reflect the results of the process subject to network slice-specific authentication and authorization constraints.

[0341] Note 2: If multiple S-NSSAIs are subject to network slice-specific authentication and authorization, this is implementation-specific if the AMF informs the UE of the results of these procedures in one or more "Configuration Update Command" messages.

[0342] If the AMF includes a network slice indication IE in the "Configuration Update Command" message, and the network slice subscription change indication is set to "Change network slice subscription", and requires the UE to initiate a registration process for allowing NSSAI changes, but the AMF cannot determine the UE's NSSAI permission in accordance with 3GPP TS 23.501[8], then the "Configuration Update Command" message should additionally indicate "Request Registration" in the registration request bit of the configuration update indication IE, and should not include allowing NSSAI.

[0343] If EAC mode is activated for S-NSSAI, the AMF should perform NSAC on the NSAC-bound S-NSSAI before including such S-NSSAI in the "Allow NSSAI" field of the "Configuration Update Command" message. If EAC mode is deactivated for S-NSSAI, the AMF should perform NSAC on the NSAC-bound S-NSSAI after including such S-NSSAI in the "Allow NSSAI" field of the "Configuration Update Command" message.

[0344] If the UE supports extended rejection of NSSAI, and the AMF determines that one or more S-NSSAIs have reached the maximum number of UEs specified in Section 4.6.2.5 within the allowed NSSAIs, then the AMF should include a rejection NSSAI containing one or more S-NSSAIs in the extended rejection NSSAI IE of the Configuration Update Command message, with the rejection reason being "S-NSSAI unavailable due to reaching the maximum number of UEs." Furthermore, the AMF may include a backoff timer value in the extended rejection NSSAI IE of the Configuration Update Command message for each S-NSSAI, with the rejection reason being "S-NSSAI unavailable due to reaching the maximum number of UEs." To avoid a large number of UEs simultaneously initiating postponement requests, the network should select a backoff timer value for each S-NSSAI of the notified UEs, ensuring asynchronous timeouts.

[0345] If the UE does not indicate support for extended rejected NSSAIs, and the maximum number of UEs has been reached, the AMF should include rejected NSSAIs containing one or more S-NSSAIs in the rejected NSSAI IE, with the reason "S-NSSAI is not available in the current registration area," and should not include these S-NSSAIs in the allowed NSSAIs in the "Configuration Update Command" message. Furthermore, the AMF can start a local implementation-specific timer for each rejected S-NSSAI for the UE based on network policy, and when the local implementation-specific timer expires, the AMF can remove the rejected S-NSSAI from the rejected NSSAIs and update it to the UE by initiating a general UE configuration update procedure.

[0346] Note 3: Based on network policy, AMF may include (multiple) S-NSSAIs that have reached the maximum number of UEs in the rejection of NSSAIs, and the reason for rejection is not "S-NSSAI is not available in the current registration area".

[0347] If the UE sets the NSAG bit in the 5GMM capability IE of the "Registration Request" message to "Support NSAG", the AMF can include the NSAG information IE in the "Configuration Update Command" message. Up to four NSAG entries are allowed to be associated with the TAI list in the NSAG information IE.

[0348] Note 3A: How AMF selects NSAG entries to include in the NSAG information IE depends on the specific implementation, such as considering NSAG priority and the current registered region.

[0349] Note 3B: If the NSAG of a PLMN and its equivalent PLMN(s) have different associations with S-NSSAI, then the AMF includes a list of TAIs for the NSAG entries in the NSAG information IE.

[0350] If the UE supports network slice replacement, and the AMF determines that it needs to provide the UE with mapping information between the S-NSSAI to be replaced and the alternative S-NSSAI, then the AMF should include the alternative NSSAIIE or extended alternative NSSAIIE, the allowed NSSAIIE (including the alternative S-NSSAI, if not included in the currently allowed NSSAIs), and the configured NSSAIIE (including the alternative S-NSSAI, if not included in the currently configured NSSAIs) in the "Configuration Update Command" message. If the AMF determines that the S-NSSAI to be replaced is available, then the AMF should provide the updated alternative NSSAI in the alternative NSSAI IE in the "Configuration Update Command" message, but excluding the replaced S-NSSAI and its corresponding alternative S-NSSAI. If the AMF determines that the alternative S-NSSAI is unavailable, but the S-NSSAI to be replaced still needs to be replaced, then the AMF should provide the updated list of alternative NSSAIs included in the extended alternative NSSAI IE in the "Configuration Update Command". If the AMF determines that all(multiple) replaced S-NSSAIs are available, the AMF should provide the Replacement NSSAI IE with the length of the Replacement NSSAI content set to 0 in the Configuration Update Command message. If the AMF determines that the replaced S-NSSAI is not supported due to the UE moving outside the NS-AoS of the S-NSSAI, and the Replacement S-NSSAI is available, the AMF should provide the updated Allowed NSSAI and Partially Allowed NSSAI (if available) in the Configuration Update Command message, excluding the Replacement S-NSSAI (if included) in the Allowed NSSAI and Partially Allowed NSSAI.

[0351] If the UE supports partial network slicing, and the AMF needs to update the partial allow NSSAI, partial deny NSSAI, or both, then the AMF should include the partial allow NSSAIIE, partial deny NSSAIIE, or both in the "Configuration Update Command" message.

[0352] If the UE supports network slice usage control and the AMF needs to update the on-demand NSSAI, the AMF should include the on-demand NSSAIIE in the "Configuration Update Command" message.

[0353] If the AMF needs to update the LADN information, the AMF should include the LADN information in the LADN information IE of the "Configuration Update Command" message.

[0354] If the UE supports LADN for each DNN and S-NSSAI, and the AMF needs to update the extended LADN information, then the AMF should include the extended LADN information in the extended LADN information IE of the "Configuration Update Command" message.

[0355] if:

[0356] -UE does not support LADN for per-DNN and S-NSSAI;

[0357] -UE only applies to a single S-NSSAI subscription to LADN DNN; and

[0358] -AMF only has extended LADN information;

[0359] AMF can decide to provide the LADN service area as LADN information for the LADN DNN that extends LADN information, and include the LADN information in the LADN information IE of the "Configuration Update Command" message.

[0360] Note 3C: If the LADN service area is configured based on DNN and S-NSSAI, in order to provide services to UEs that do not support LADN for each DNN and S-NSSAI, it is recommended that the LADN DNN be served by only a single S-NSSAI.

[0361] Note 3D: If the UE subscribes to multiple S-NSSAI LADN DNNs, the AMF can treat it as if no extended LADN information is available.

[0362] Note 3E: If applicable, the AMF partially allows independent allocation of LADN service areas and TAI lists associated with S-NSSAI within NSSAI.

[0363] If the UE does not support LADN for per-DNN and S-NSSAI, and the AMF has neither LADN information nor extended LADN information, then the AMF should not provide any LADN information to the UE.

[0364] If the AMF needs to update the "CAG Information List", the AMF should include the CAG Information List IE or the extended CAG Information List IE in the "Configuration Update Command" message.

[0365] Note 4: If the UE supports an extended CAG information list, the CAG information list can be included in the CAG information list IE or the extended CAG information list IE.

[0366] If the UE does not support the extended CAG information list, then the CAG information list should not be included in the extended CAG information list IE.

[0367] If the AMF needs to update the "CAG information list", the UE has an emergency PDU session, and the AMF can determine that the UE is in a state of emergency.

[0368] a) In a CAG cell, and based on the current PLMN's "Allowed CAG List" in the updated "CAG Information List," none of the (multiple) CAG-IDs supported by the CAG cell are authorized; or

[0369] b) In non-CAG cells, the current PLMN entry in the updated "CAG Information List" includes "Indication that the UE is only allowed to access 5GS via CAG cells";

[0370] AMF can instruct SMF to perform a local release of the following items:

[0371] a) All non-emergency single-access PDU sessions associated with 3GPP access;

[0372] b) All MA PDU sessions that have not established PDN connections as user plane resources and have not established user plane resources on non-3GPP access; and

[0373] c) 3GPP access user plane resources for all these MA PDU sessions, and user plane resources established on both accesses.

[0374] The AMF should not instruct the SMF to release an emergency PDU session. If the AMF instructs the SMF to perform a local release of the following:

[0375] a) All single-access non-urgent PDU sessions associated with 3GPP access;

[0376] b) All MA PDU sessions that have not established PDN connections as user plane resources and have not established user plane resources on non-3GPP access; and

[0377] c) 3GPP access user plane resources for all these MA PDU sessions, and user plane resources established on both accesses;

[0378] The network should behave as if the UE registered for emergency services via 3GPP access, and should set the emergency registration bit of the 5GS registration result IE in the "Configuration Update Command" message to "Register for Emergency Services".

[0379] If the AMF is initiating a general UE configuration update procedure to indicate to a UE that has registered for disaster roaming services and has an ongoing emergency PDU session that the UE has registered for emergency services, as described in Section 4.24, then the AMF shall set the emergency registration bit of the 5GS registration result IE in the Configuration Update Command message to "Register for emergency services".

[0380] If AMF:

[0381] - Update the "CAG Information List" to remove one or more CAG-IDs authorized based on the permitted CAG list of the service PLMN or equivalent PLMN; or

[0382] - Update the "CAG Information List" to set an "Instruction that UE is only allowed to access 5GS via CAG cell" for the serving PLMN or an equivalent PLMN that was not previously configured.

[0383] After the configuration update process is completed, if the UE does not have an emergency PDU session, the AMF should initiate the release of the N1 NAS signaling connection in accordance with Clause 5.3.1.3.

[0384] If the AMF needs to use the control plane CIoT 5GS optimization to update the truncated 5G-S-TMSI configuration of the UE in NB-N1 mode, the AMF should include the truncated 5G-S-TMSI configuration IE in the "Configuration Update Command" message.

[0385] If the AMF includes a UE radio capability ID deletion indication IE in the configuration update command message, the AMF should indicate "Request registration" in the registration request bit of the configuration update indication IE.

[0386] If the AMF needs to redirect the UE to the EPC, as described in Section 4.8.4A.2, the AMF shall indicate “Request Registration” in the Registration Request bit of the Configuration Update Instruction IE and “No Need to Release N1 NAS Signaling Connection” in the Signaling Connection Maintenance Request bit of the Additional Configuration Instruction IE in the Configuration Update Command message.

[0387] If the UE is not in NB-N1 mode and the UE supports RACS, the AMF can include the UE Radio Capability ID IE or the UE Radio Capability ID Deletion Instruction IE in the Configuration Update Command message.

[0388] Within the established 5GMM context, the network can send zero, one, or more "configuration update command" messages to the UE. If more than one "configuration update command" message is sent, these messages do not need to have the same content.

[0389] After receiving the results of the UUAA-MM procedure from the UAS-NF, the AMF should include:

[0390] a) Service Level AA response, where the SLAR field is set to:

[0391] 1) If AMF detects that the UUAA-MM process is successful, then "Service Level Authentication and Authorization Has Been Successful"; or

[0392] 2) If AMF detects that the UUAA-MM process has failed, then "Service Level Authentication and Authorization failed or Service Level Authorization was revoked";

[0393] b) If the CAA-level UAV ID is provided by the UAS-NF, then the value of the Service Level Device ID is set to the CAA-level UAVID; and

[0394] c) If the payload is received from the UAS-NF, then in the Service Level AA container IE of the "Configuration Update Command" message:

[0395] 1) Service level AA payload, whose value is set to payload; and

[0396] 2) If the payload type associated with the payload is received, the service level AA payload type is set to the payload type; and

[0397] 3) If the payload type associated with the payload is a C2 authorized payload, then based on the authorization result received from the UAS-NF, the Service Level AA response is given, where the C2AR field is set to "C2 authorization successful" or "C2 authorization unsuccessful or C2 authorization revoked";

[0398] Note 5: According to 3GPP TS 33.256[24B], the USS may include UAS security information in the UUAA payload.

[0399] Note 5A: Service Level AA payloads associated with payload type “C2 Authorized Payload” may include: pairing information for direct C2 communication, or security information as specified in TS 33.256[24B], or both.

[0400] Note 6: If the AMF receives an HTTP code set to “4xx” or “5xx” as specified in 3GPP TS 29.500[20AA], or if the AMF detects a UUAA-MM fault as specified in 3GPP TS 29.256[221B], the AMF considers the UUAA-MM process to have failed.

[0401] If the AMF needs to deliver a UUAA revocation notification received from the UAS-NF to the UE, the AMF should include a Service Level AA response in the Service Level AA container IE of the Configuration Update Command message, where SLAR is set to "Service Level Authentication and Authorization Failed or Service Level Authorization Revoked".

[0402] If the UE supports UAS service and the UAS service becomes enabled for the UE (e.g., because over-the-air subscription becomes part of the UE subscription data retrieved from the UDM), the AMF can include a service level AA service status indication in the service level AA container IE of the "Configuration Update Command" message, where the UAS field is set to "Enable UAS service".

[0403] If the UE supports MINT, the AMF can be included in the list of PLMNs to be used in the disaster condition IE in the "Configuration Update Command" message.

[0404] If the UE supports MINT, the AMF can include the disaster roaming wait range IE in the "Configuration Update Command" message.

[0405] If the UE supports MINT, the AMF can include the disaster return wait range IE in the "Configuration Update Command" message.

[0406] Note 7: AMF can determine the contents of the "List of PLMNs to be used under disaster conditions", the value of the disaster roaming wait range, and the value of the disaster return wait range based on the local network configuration.

[0407] If the UE supports discontinuous coverage, the AMF can include the maximum time offset (IE) for discontinuous coverage in the "Configuration Update Command" message.

[0408] If the UE supports and the network supports and accepts the use of PEIPS assistance information, and the AMF needs to update the PEIPS assistance information, the AMF can include the PEIPS assistance message in the updated PEIPS assistance information IE of the "Configuration Update Command" message.

[0409] If the AMF needs to notify the UE whether the use of Access Identifier 1 is valid or no longer valid, then

[0410] 1) If the UE supports MPS indicator updates via the UE configuration update procedure, then AMF:

[0411] a) The UE is notified by setting the MPS indicator bit of the priority indicator IE in the "Configuration Update Command" message to either "Access Identifier 1 Valid" or "Access Identifier 2 Invalid". Based on operator policy, the AMF sets the MPS indicator bit in the "Configuration Update Command" message based on the MPS priority information in the user subscription context obtained from the UDM; or...

[0412] b) In the "Configuration Update Command" message, the configuration update instruction for IE should indicate "Request Registration" in the registration request bit; or

[0413] 2) If the UE supports MCS indicator updates via the UE configuration update procedure, then AMF:

[0414] a) The UE is notified by setting the MCS indicator bit of the priority indicator IE in the "Configuration Update Command" message to either "Access Identifier 2 Valid" or "Access Identifier 1 Invalid". Based on operator policy, the AMF sets the MCS indicator bit in the "Configuration Update Command" message based on the MCS priority information in the user subscription context obtained from the UDM; or...

[0415] b) In the "Configuration Update Command" message, the configuration update instruction for IE should indicate "Request Registration" in the registration request bit; or

[0416] 3) Otherwise, the AMF should indicate "Request Registration" in the registration request bit of the configuration update instruction IE in the "Configuration Update Command" message.

[0417] If the UE sets the reconnection to network due to RAN timing state change in the 5GMM capability IE of the "Registration Request" message to "Support reconnection to network due to RAN timing state change", then the AMF can include the RAN timing IE in the "Configuration Update Command" message, where the RecReq bit is set to "Request reconnection".

[0418] When a UE performs MBSR operation, and its MBSR authorization status changes to unauthorized MBSR operation based on UE subscription and local policy, and the UE is allowed to operate as a UE, the AMF should include a Feature Authorization Indicator (IE) in the Configuration Update Command message and should set the MBSRAI field to "Unauthorized as MBSR operation but allowed as UE operation". The AMF may also request the SMF to release the PDU session to provide OAM access in the serving PLMN (see 3GPP TS 23.501 [8]). When a UE that was not allowed to perform MBSR operation becomes allowed to perform MBSR operation based on UE subscription and local policy, the AMF should include a Feature Authorization Indicator (IE) in the Configuration Update Command message and set the MBSRAI field to "Authorized as MBSR operation".

[0419] ***Next Change***

[0420] 5.4.4.3 General UE configuration updates accepted by the UE

[0421] Upon receiving a "Configuration Update Command" message, if timer T3346 is running, the UE should stop timer T3346 and update the appropriate information stored in the UE with its contents.

[0422] If "Request Confirmation" is indicated in the confirmation bit of the configuration update instruction IE in the "Configuration Update Command" message, the UE should send a "Configuration Update Complete" message.

[0423] If the UE receives a new 5G-GUTI in a "Configuration Update Command" message, the UE should consider the new 5G-GUTI valid, the old 5G-GUTI invalid, stop timer T3519 (if running), and delete any stored SUCIs; otherwise, the UE should consider the old 5G-GUTI valid. If the "Configuration Update Command" message is sent via a non-3GPP access, and the UE is in the 5GMM-REGISTERED state in both the 3GPP access and non-3GPP access within the same PLMN, the UE should provide the 5G-GUTI to the lower layer of the 3GPP access.

[0424] If the UE receives a new TAI list in the "Configuration Update Command" message, the UE should consider the new TAI list valid and the old TAI list invalid; otherwise, the UE should consider the old TAI list valid. If the registered area contains TAIs belonging to different PLMNs, these PLMNs are equivalent PLMNs, and...

[0425] a) If the UE has already stored the allowed NSSAI for the current registered region, then the UE shall store the allowed NSSAI for the current registered region in each allowed NSSAI associated with each PLMN in the registered region;

[0426] b) If the UE has already stored the rejection NSSAI for the current registered region, then the UE should store the rejection NSSAI for the current registered region in each rejection NSSAI associated with each PLMN in the registered region;

[0427] c) If the UE has already stored the rejection NSSAI for a failed or revoked NSSAA, then the UE shall store the rejection NSSAI for the failed or revoked NSSAA in each rejection NSSAI associated with each PLMN in the registered area;

[0428] d) If the UE has already stored the maximum number of UE rejection NSSAIs reached, then the UE shall store the maximum number of UE rejection NSSAIs reached in each rejection NSSAI associated with each PLMN in the registration area; and

[0429] e) If the UE has already stored pending NSSAIs, then the UE shall store the pending NSSAIs in each pending NSSAI associated with each PLMN in the registered area.

[0430] If the UE receives a new truncated 5G-S-TMSI configuration in the "Configuration Update Command" message, the UE should consider the new truncated 5G-S-TMSI configuration to be valid and the old truncated 5G-S-TMSI configuration to be invalid; otherwise, the UE should consider the old truncated 5G-S-TMSI configuration to be valid.

[0431] If the UE receives a new service area list in the "Configuration Update Command" message, the UE should consider the new service area list to be valid and the old service area list to be invalid; otherwise, the UE should consider the old service area list (if any) to be valid.

[0432] If the UE receives new NITZ information in the "Configuration Update Command" message, the UE should consider the new NITZ information to be valid and the old NITZ information to be invalid; otherwise, the UE should consider the old NITZ information to be valid.

[0433] If the UE receives LADN information IE in the "Configuration Update Command" message, the UE should consider the old LADN information invalid and the new LADN information (if any) valid; otherwise, the UE should consider the old LADN information valid.

[0434] If the UE receives extended LADN information IE in the "Configuration Update Command" message, the UE should consider the old extended LADN message invalid and the new extended LADN information valid (if any); otherwise, the UE should consider the old extended LADN information valid.

[0435] If the UE receives a new allowed NSSAI for the associated access type in the "Configuration Update Command" message, the UE shall consider the new allowed NSSAI for the associated access type to be valid and store the allowed NSSAI for the associated access type in accordance with the provisions of Section 4.6.2.2, while the old allowed NSSAI for the associated access type shall be invalid; otherwise, the UE shall consider the old allowed NSSAI for the associated access type to be valid.

[0436] If the UE receives a new configuration NSSAI in a "Configuration Update Command" message, the UE should consider the new configuration NSSAI for the registered PLMN or SNPN to be valid, while the old configuration NSSAI for the registered PLMN or SNP should be invalid; otherwise, the UE should consider the old configuration NSSAI for the registered PLMN or SNPN to be valid. The UE should store the new configuration NSSAI in accordance with section 4.6.2.2. Furthermore, if the "Configuration Update Command" message includes:

[0437] a) If the UE receives a new configuration NSSAI in a "Configuration Update Command" message but does not have an NSSRG information IE, the UE shall store the contents of the NSSRG information IE in accordance with section 4.6.2.2.

[0438] Note 1: When the UE receives the NSSRG information IE, the UE can provide the NSSRG information to the lower layers in order to perform NSAG-aware cell reselection.

[0439] b) If the UE receives the S-NSSAI location validity information IE, then the UE shall store the contents of the S-NSSAI location validity information IE in accordance with section 4.6.2.2. If the UE receives a new configuration NSSAI in a "Configuration Update Command" message but does not have the S-NSSAI location validity information IE, then the UE shall delete any stored S-NSSAI location validity information (if any) in accordance with section 4.6.2.2.

[0440] c) If the S-NSSAI time validity information IE is received, the UE shall store the contents of the S-NSSAI time validity information IE in accordance with Section 4.6.2.2. If the UE receives a new configuration NSSAI in a "Configuration Update Command" message but does not have the S-NSSAI time validity information IE, the UE shall delete any stored S-NSSAI validity information (if any) in accordance with Section 4.6.2.2; or

[0441] d) For on-demand NSSAI IEs, the UE shall store the contents of the on-demand NSSAI IE as specified in Section 4.6.2.2. If the UE receives a new configuration NSSAI IE in a Configuration Update Command message but does not have an on-demand NSSAI IE, the UE shall delete any stored on-demand NSSAIs as specified in Section 4.6.2.2. If the S-NSSAI deleted from the on-demand NSSAI is running, the UE shall stop the slice deregistration inactive timer.

[0442] If the "Configuration Update Command" message contains a partial allow for NSSAI IE, the UE shall store the partially allowable NSSAI IE content in accordance with Section 4.6.2.2. If the "Configuration Update Command" message contains a partial deny for NSSAI IE, the UE shall store the partially deny for NSSAI IE content in accordance with Section 4.6.2.2.

[0443] If the UE receives a network slice instruction (IE) in the "Configuration Update Command" message and the network slice subscription change instruction is set to "Change Network Slice Subscription", the UE shall delete the network slice information of each PLMN or SNMN other than the current PLMN or SNPN in accordance with the provisions of Section 4.6.2.2, and remove all tracking areas from the "5GS Prohibited Roaming Tracking Areas" list, which were added due to the rejection of S-NSSAI because "S-NSSAI is not available in the current registered area".

[0444] If the UE receives an operator-defined access category definition (IE) in a configuration update command message, and the IE contains one or more operator-defined access category definitions, then the UE should delete all operator-defined access category definitions stored for the RPLMN and store the received operator-defined access category definitions for the RPLMN. If the UE receives an operator-defined access category definition (IE) in a configuration update command message, and the IE does not contain any operator-defined access category definitions, then the UE should delete any operator-defined access category definitions stored for the RPLMN. If the configuration update command message does not contain an operator-defined access category definition (IE), then the UE should not delete any operator-defined access category definitions stored for the RPLMN.

[0445] If the UE receives an SMS indication IE in the "Configuration Update Command" message, where the SMS availability indication is set to:

[0446] a) If "SMS on NAS is unavailable," the UE should consider that the network does not allow SMS on the NAS; and

[0447] b) “SMS on NAS is available” means that after the general UE configuration update process is completed, the UE can request to use SMS on NAS by performing the registration process of mobility and periodic registration update as required by Section 5.5.1.3.

[0448] If the UE receives a CAG information list IE or an extended CAG information list IE in a "Configuration Update Command" message, the UE should:

[0449] a) When received in HPLMN or EHPLMN, replace the “CAG information list” stored in the UE with the received CAG information list IE or extended CAG information list IE;

[0450] Note 2: When the UE receives the CAG information list IE or extended CAG information list IE from the HPLMN derived from the IMSI in the PLMN code, the EHPLMN list exists and is not empty, and the HPLMN does not exist in the EHPLMN list. The UE behaves as if it received the CAG information list IE or extended CAG information list in the VPLMN.

[0451] b) When the UE receives a CAG information list IE or extended CAG information list IE in a serving PLMN other than HPLMN or EHPLMN, replace the serving VPLMN entry of the "CAG information list" stored in the UE with the received serving VPLM entry of the CAG information list IE or extended CAG information list IE; or

[0452] Note 3: When the UE receives a CAG information list IE or an extended CAG information list IE in a serving PLMN other than HPLMN or EHPLMN, PLMN entries other than serving VPLMN (if any) in the received CAG information list IE are ignored.

[0453] c) When the UE receives a CAG information list IE or an extended CAG information list IE in a serving PLMN other than HPLMN or EHPLMN, and the CAG information list IE or the extended ACG information list IE does not contain a serving VPLMN entry, remove the serving VPLMN entry from the "CAG information list" stored in the UE.

[0454] The UE shall store the received “CAG information list” in the CAG information list IE or the extended CAG information list IE in accordance with the provisions of Annex C.

[0455] If the received "CAG information list" includes an entry containing the current PLMN identifier, and the UE sets the CAG bit in the 5GMM capability IE of the "Registration Request" message to "Support CAG", then the UE should operate as follows.

[0456] a) If the UE receives a "Configuration Update Command" message via a CAG cell, based on the "Allowed CAG List" of the current PLMN entry in the received "CAG Information List," none of the CAG-IDs supported by the current CAG cell have been authorized, and:

[0457] 1) If the current PLMN entry in the received “CAG information list” does not include “indication that the UE is only allowed to access 5GS via CAG cell”, then the UE should enter the 5GMM-REGISTERED.LIMITED-SERVICE state and should search for a suitable cell using the updated “CAG information list” according to 3GPP TS 38.304

[28] or 3GPP TS 36.304[25C]; or

[0458] 2) The entries for the current PLMN in the received "CAG information list" include "Instruction that the UE is only allowed to access 5GS via CAG cell", and:

[0459] i) If one or more CAG-IDs are authorized based on the "Allowed CAG List" of the current PLMN entry in the received "CAG Information List", the UE shall enter the 5GMM-REGISTERED.LIMITED-SERVICE state and shall search for a suitable cell using the updated "CAG Information List" in accordance with 3GPP TS 38.304

[28] ; or

[0460] ii) If no CAG-ID is authorized in the "Allowed CAG List" based on the current PLMN entry in the received "CAG Information List", and:

[0461] A) If the UE does not have an emergency PDU session, the UE should enter the 5GMM-REGISTERED.PLMN-SEARCH state and should use the updated "CAG information list" to apply the PLMN selection procedure defined in 3GPP TS 23.122[5]; or

[0462] B) If the UE has an emergency PDU session, the UE should perform local release of all PDU sessions associated with 3GPP access, excluding the emergency PDU session, and enter the 5GMM-REGISTERED.LIMITED-SERVICE state; or

[0463] b) If the UE receives a "Configuration Update Command" message via a non-CAG cell, and the current PLMN entry in the received "CAG Information List" includes an indication that the UE is only allowed to access 5GS via a CAG cell, and:

[0464] 1) If one or more CAG-IDs are authorized according to the current PLMN's "Allowed CAG List" in the received "CAG Information List", the UE should enter the 5GMM-REGISTERED.LIMITED-SERVICE state and should search for a suitable cell using the updated "CAG Information List" according to 3GPP TS38.304

[28] ; or

[0465] 2) If no CAG-ID is authorized in the "Allowed CAG List" based on the current PLMN entry in the received "CAG Information List", and:

[0466] i) If the UE does not have an emergency PDU session, the UE should enter the 5GMM-REGISTERED.PLMN-SEARCH state and should use the updated "CAG information list" to apply the PLMN selection procedure defined in 3GPP TS 23.122[5]; or

[0467] ii) If the UE has an emergency PDU session, the UE shall perform local release of all PDU sessions associated with 3GPP access except for the emergency PDU session and enter the 5GMM-REGISTERED.LIMITED-SERVICE state.

[0468] If the received CAG information list does not include an entry containing the current PLMN identifier, and the UE receives a configuration update command message via the CAG cell, the UE should enter the 5GMM-REGISTERED.LIMITED-SERVICE state and should use the updated CAG information list to search for a suitable cell according to 3GPP TS 38.304

[28] or 3GPP TS 36.304[25C].

[0469] If the "Configuration Update Command" message indicates "Request Registration" in the Registration Request bit of the Configuration Update Instruction IE, and:

[0470] a) It does not contain other parameters, or contains at least one of the following parameters: new NSSAI allowed, new partially allowed NSSAI, new configured NSSAI, new NSSRG information, or network slice subscription change indication, and:

[0471] 1) If an emergency PDU session exists, the UE should release the existing N1 NAS signaling connection after the general UE configuration update process is completed and the emergency PDU session is released. Furthermore, the UE should:

[0472] i) If any(multiple) Tsor-cm timers are running and have stopped, attempt to acquire service on a higher priority PLMN (see 3GPP TS 23.122[5]); or

[0473] ii) In all other cases, the registration process for mobility and periodic registration updates shall be initiated in accordance with Section 5.5.1.3; or

[0474] 2) If the emergency PDU session does not exist, the UE should wait until the general UE configuration update process is completed and the existing N1NAS signaling connection is released:

[0475] i) If any(multiple) Tsor-cm timers are running and have stopped, attempt to acquire service on a higher priority PLMN (see 3GPP TS 23.122[5]); or

[0476] ii) In all other cases, the registration process for mobility and periodic registration updates shall be initiated in accordance with Section 5.5.1.3;

[0477] b) Including MICO indications, but excluding indications for new NSSAI permission, new NSSAI configuration, new NSSRG information, or network slice subscription change, the UE shall, after the completion of the general UE configuration update process, initiate the periodic registration process for mobility and registration updates in accordance with Section 5.5.1.3 to renegotiate the MICO mode with the network.

[0478] c) Includes additional configuration instructions for IE, and:

[0479] 1) "No need to release N1 NAS signaling connection" is indicated in the signaling connection maintenance request bit of the additional configuration instruction IE; and

[0480] 2) The "Configuration Update Command" message does not include instructions for new NSSAI permissions, new NSSAI configurations, new NSSRG information, or network slice subscription changes.

[0481] The UE shall, after the completion of the general UE configuration update process, initiate the registration process for mobility and periodic registration updates in accordance with the provisions of Section 5.5.1.3; or

[0482] d) Includes a UE radio function ID deletion instruction IE that is set to "Request network-assigned UE radio capability ID deletion", and:

[0483] 1) The UE is not in NB-N1 mode;

[0484] 2) Excludes new NSSAI permissions, new NSSAI configurations, new NSSRG information, or network slice subscription change instructions; and

[0485] 3) The UE sets the RACS bit in the 5GMM capability IE of the "Registration Request" message to "Support RACS".

[0486] After the general UE configuration update process is completed, the UE shall initiate the registration process for mobility and periodic registration updates in accordance with the provisions of Section 5.5.1.3.

[0487] A UE that receives a rejection NSSAI in a "Configuration Update Command" message will take the following actions based on the rejection reasons in (multiple) S-NSSAI rejections:

[0488] "S-NSSAI is not available in the current PLMN or SNPN".

[0489] The UE shall add (multiple) Reject S-NSSAIs to the Reject NSSAIs of the current PLMN or SNPN in accordance with Clause 4.6.2.2, and shall not attempt to use (multiple) S-NSSAIs in the current PLMN or SNPN on any access until the UE is shut down, the UICC containing the USIM is removed, the Subscriber Data List entry with the SNPN identifier of the current SNPN is updated, or (multiple) Reject S-NSSAIs are removed in accordance with Clause 4.6.2.2.

[0490] "S-NSSAI is not available in the current registered region"

[0491] The UE shall add (multiple) Reject S-NSSAIs to the Reject NSSAIs for the current registered area in accordance with Section 4.6.2.2, and shall not attempt to use (multiple) S-NSSAIs in the current registered area on the current access until the UE is turned off, the UE moves out of the current registered area, the UICC containing the USIM is removed, the Subscriber Data List entry with the SNPN identifier of the current SNPN is updated, or (multiple) Reject S-NSSAIs are removed in accordance with Section 4.6.2.2.

[0492] S-NSSAI is unavailable due to network slice-specific authentication and authorization failures or revocations.

[0493] The UE shall add (multiple) Reject S-NSSAIs to the Reject NSSAIs of a failed or revoked NSSAA in accordance with Clause 4.6.2.2, and shall not attempt to use (multiple) S-NSSAIs in any access of the current PLMN or SNPN until the UE is shut down, the UICC containing the USIM is removed, the Subscriber Data List entry with the SNPN identifier of the current SNPN is updated, or (multiple) Reject S-NSSAIs are removed in accordance with Clauses 4.6.1 and 4.6.2.2.

[0494] S-NSSAI is unavailable due to reaching the maximum number of UEs.

[0495] Unless the backoff timer value received with the S-NSSAI is zero, the UE shall add (multiple) reject S-NSSAIs to the reject NSSAIs to reach the maximum number of UEs specified in Section 4.6.2.2, and shall not attempt to use (multiple) S-NSSAIs in the current PLMN or SNPN on any access until the UE is shut down, the UICC containing the USIM is removed, the Subscriber Data List entry with the SNPN identifier of the current SNPN is updated, or (multiple) reject S-NSSAIs are removed as described in Sections 4.6.1 and 4.6.2.2.

[0496] Note 4: If the backoff timer value received with S-NSSAI in the rejection of NSSAI is zero in accordance with Section 10.5.7.4a of 3GPP TS 24.008

[12] , the UE will not regard S-NSSAI as a rejection of S-NSSAI.

[0497] If one or more S-NSSAIs are rejected due to "S-NSSAI unavailable due to reaching maximum number of UEs", then the UE behavior for each S-NSSAI will be as follows:

[0498] a) Stop the timer T3526 associated with S-NSSAI (if it is running);

[0499] b) Start timer T3526 using the following:

[0500] 1) If the backoff timer value is received along with an S-NSSAI that is neither zero nor deactivated, then return the backoff timer value received along with the S-NSSAI; or

[0501] 2) If no backoff timer value is received along with S-NSSAI, then return the implementation-specific backoff timer value; and

[0502] c) When the timer T3526 associated with S-NSSAI expires, remove S-NSSAI from the rejected NSSAIs to reach the maximum number of UEs.

[0503] If the UE receives NSAG information IE in the "Configuration Update Command" message, the UE shall store the NSAG information in accordance with the provisions of Section 4.6.2.2.

[0504] If the UE receives an alternative NSSAI IE in a "Configuration Update Command" message, the UE shall store the alternative NSSAI in accordance with Section 4.6.2.2.

[0505] If the UE receives the extended alternative NSSAIIE in the "Configuration Update Command" message, the UE shall store the alternative NSSAI in accordance with the provisions of Section 4.6.2.2.

[0506] If the UE receives an on-demand NSSAI IE in a "Configuration Update Command" message, the UE shall store the on-demand NSSAI in accordance with Section 4.6.2.2.

[0507] If the UE receives the T3447 value IE in the "Configuration Update Command" message and indicates "Support Service Interval Control" in the "Registration Request," the UE should replace the stored T3447 value with the received value in the T3447 value IE. If the received T3447 value is neither zero nor deactivated, it should be used with timer T3447 on the next startup. If the received T3447 value is zero or deactivated, the UE should stop timer T3447 (if it is running).

[0508] If the UE is not in NB-N1 mode, the UE will set the RACS bit in the 5GMM capability IE of the "Registration Request" message to "Support RACS", and the "Configuration Update Command" message will include:

[0509] a) A UE Radio Capability ID Deletion Instruction (IE) set to "Request network-assigned UE Radio Capability ID deletion" requires the UE to delete any network-assigned UE Radio Capability IDs associated with an RPLMN or RSNPN. Furthermore, if the UE supports accessing the SNPN using a certificate from a certificate holder, an equivalent SNPN, or both, the UE should delete the selected entry in the "Subscriber Data List" stored at the UE or the selected PLMN subscription; or

[0510] b) The UE shall store the UE radio capability ID IE in accordance with the provisions of Annex C.

[0511] If the UE is not currently registered for emergency services, and the emergency registration bit of the 5GS registration result IE in the "Configuration Update Command" message is set to "Register for Emergency Services", then the UE should consider itself to have registered for emergency services and should release all non-emergency PDU sessions locally (if any).

[0512] If the UE receives a "Configuration Update Command" message from the Service Level AA container IE, the UE passes it to the upper layer.

[0513] Note 5: The Service Level AA container IE may include a Service Level AA payload of type “C2 Authorized Payload”, which includes pairing information for direct C2 communication, or security information as specified in TS 33.256[24B], or both.

[0514] If the "Configuration Update Command" message includes a Service Level AA response in the Service Level AA container IE and the SLAR field is set to "Service Level Authentication and Authorization Failed or Service Level Authorization Revoked", then the UE should forward the Service Level AA response to the upper layer, and the UUAA authorization data is deleted in accordance with 3GPP TS 33.256[24B].

[0515] If the UE receives a list of PLMNs to be used in the disaster condition IE in the "Configuration Update Command" message, and the UE supports MINT, then the UE should delete the "List of (Multiple) PLMNs to be used in the disaster condition" and the PLMN ID of the RPLMN (if any) stored in the ME, and may store the "List of (Multiple) PLMNs to be used in the disaster condition" included in the list of PLMNs to be used in the disaster condition IE together with the PLMN ID of the RPLMN in the ME.

[0516] If the UE receives the disaster roaming wait range IE in the "Configuration Update Command" message, and the UE supports MINT, then the UE should delete the disaster roaming wait distance (if any) stored in the ME, and store the disaster roaming wait distance included in the disaster roaming wait range IE in the ME.

[0517] If the UE receives a disaster return waiting area IE in the "Configuration Update Command" message, and the UE supports MINT, then the UE should delete the disaster roaming waiting area (if any) stored in the ME, and store the disaster roaming waiting area included in the disaster roaming waiting area IE in the ME.

[0518] If the UE receives the discontinuous coverage maximum time offset (IE) in the configuration update command message, the UE should replace any previously received discontinuous coverage maximum time offset values ​​on the same satellite NG-RAN RAT type and PLMN with the most recently received timer value.

[0519] If the UE receives the updated PEIPS assistance information IE in the "Configuration Update Command" message, and the UE supports NR paging subgroups, then the UE should use the PEIPS assistance information included in the updated PEIPS assistance information IE.

[0520] If the UE receives a "Configuration Update Command" message, the MPS indicator bit in the priority indicator IE is set to "Access Identifier 1 is valid":

[0521] -Accessed via 3GPP; or

[0522] -If the UE is registered to the same PLMN or SNPN via 3GPP access and non-3GPP access, then it will be via non-3GPP access;

[0523] The UE shall act as a UE with Access Identifier 1 configured for MPS, as described in Section 4.5.2, in all NG-RANs of the registered PLMN and its equivalent PLMN, or in the case of SNPN, as described in Section 4.52A, in all NG-RANs of the registered SNPN and its equivalent SNPN.

[0524] If the UE receives a "Configuration Update Command" message, the MPS indicator bit in the priority indicator IE is set to "Access Identifier 1 is valid":

[0525] - Via non-3GPP access; or

[0526] -If the UE is registered to the same PLMN or SNPN via 3GPP access and non-3GPP access, then access is via 3GPP.

[0527] The UE shall act as a UE with an access identifier 1 configured for MPS, as described in Section 4.5.2, in non-3GPP access with a registered PLMN or its equivalent PLMN, or in the case of an SNPN, as described in Section 4.52A, in non-3GPP access with a registered SNPN or its equivalent SNPN.

[0528] The MPS indicator bit in IE is valid in the priority indicator provided in the "Configuration Update Command" message:

[0529] - In all NG-RANs where a PLMN and its equivalent PLMN are registered, or in the case of an SNPN in all NG-RANs where an SNPN and its equivalent SNPN are registered, until:

[0530] - The UE receives a "Registration Acceptance" message where the MPS indicator bit is set to "Access Identifier 1 Invalid", or the UE receives a "Configuration Update Command" message where the MPS indicator bit of the priority indicator IE is set to "Access Identifier 1 Invalid":

[0531] -Accessed via 3GPP; or

[0532] - If the UE registers to the same PLMN or SNPN via 3GPP access and non-3GPP access, then it will be via non-3GPP access; or

[0533] - The UE selects a non-equivalent PLMN (or, in the case of an SNPN, a non-equivalent SNPN); or

[0534] - In non-3GPP access where a PLMN or its equivalent is registered, or in the case of an SNPN in non-3GPP access where an SNPN or its equivalent is registered, until:

[0535] - The UE receives a "Registration Acceptance" message, in which the MPS indicator bit is set to "Access Identifier 1 Invalid", or the UE receives a "Configuration Update Command" message, in which the MPS indicator bit of the priority indicator IE is set to "Access Identifier 1 Invalid":

[0536] - Via non-3GPP access; or

[0537] - If the UE registers to the same PLMN or SNPN via 3GPP access and non-3GPP access, then it will access via 3GPP; or

[0538] - The UE selects a non-equivalent PLMN (or, in the case of an SNPN, a non-equivalent SNPN).

[0539] Access identifier 1 is only applicable when the UE is in N1 mode.

[0540] If the UE receives a "Configuration Update Command" message, the MCS indicator bit in the priority indicator IE is set to "Access Identifier 2 is valid":

[0541] -Accessed via 3GPP; or

[0542] -If the UE is registered to the same PLMN or SNPN via 3GPP access and non-3GPP access, then it will be via non-3GPP access;

[0543] The UE shall act as a UE with Access Identifier 2 configured for the MCS, as described in Section 4.5.2, in all NG-RANs of the registered PLMN and its equivalent PLMN, or in the case of the SNPN, as described in Section 4.52A, in all NG-RANs of the registered SNPN and its equivalent SNPN.

[0544] If the UE receives a "Configuration Update Command" message, the MCS indicator bit in the priority indicator IE is set to "Access Identifier 2 is valid":

[0545] - Via non-3GPP access; or

[0546] -If the UE is registered to the same PLMN or SNPN via 3GPP access and non-3GPP access, then access is via 3GPP.

[0547] The UE shall act as a UE with an access identifier 2 configured for the MCS, as described in Section 4.5.2, in non-3GPP access with a registered PLMN or its equivalent PLMN, or in the case of an SNPN, as described in Section 4.5.2A, in non-3GPP access with a registered SNPN or its equivalent SNPN.

[0548] The priority indicator provided in the "Configuration Update Command" message has the MCS indicator bit valid in IE:

[0549] - In all NG-RANs where a PLMN and its equivalent PLMN are registered, or in the case of an SNPN in all NG-RANs where an SNPN and its equivalent SNPN are registered, until:

[0550] - The UE receives a "Registration Acceptance" message, in which the MCS indicator bit is set to "Access Identifier 2 Invalid", or the UE receives a "Configuration Update Command" message, in which the MCS indicator bit of the priority indicator IE is set to "Access Identifier 2 Invalid":

[0551] -Accessed via 3GPP; or

[0552] - If the UE registers to the same PLMN or SNPN via 3GPP access and non-3GPP access, then it will be via non-3GPP access; or

[0553] - The UE selects a non-equivalent PLMN (or, in the case of an SNPN, a non-equivalent SNPN); or

[0554] - In non-3GPP access where a PLMN or its equivalent is registered, or in the case of an SNPN in non-3GPP access where an SNPN or its equivalent is registered, until:

[0555] - The UE receives a "Registration Acceptance" message, in which the MCS indicator bit is set to "Access Identifier 2 Invalid", or the UE receives a "Configuration Update Command" message, in which the MCS indicator bit of the priority indicator IE is set to "Access Identifier 2 Invalid":

[0556] - Via non-3GPP access; or

[0557] - If the UE registers to the same PLMN or SNPN via 3GPP access and non-3GPP access, then it will access via 3GPP; or

[0558] - The UE selects a non-equivalent PLMN (or, in the case of an SNPN, a non-equivalent SNPN).

[0559] Access identifier 2 is only applicable when the UE is in N1 mode.

[0560] If a UE that supports UAS service is not currently registered for UAS service, and the "Configuration Update Command" message includes a Service Level AA service status indication in the Service Level AA container IE, where the UAS field is set to "Enable UAS service", then the UE will pass the Service Level AA service status indication to the upper layer.

[0561] If a UE that supports reconnecting to the network due to a change in RAN timing synchronization status receives a RAN timing synchronization IE in a Configuration Update Command message, where the RecReq bit is set to "Request Reconnection", then the UE shall operate in accordance with the provisions of Sections 5.3.1.4, 5.5.1.3.2 and 5.6.1.1.

[0562] If the UE performing the MBSR operation receives the MBSRAI field of the Feature Authorization Indicator (IE) in the Configuration Update Command message, the UE NAS layer notifies the lower layer of the MBSR authorization status.

[0563] ***Next Change***

[0564] 6.3.2 PDU Session Modification Process for Network Requests

[0565] 6.3.2.1 Overview

[0566] The purpose of the network-requested PDU session modification process is to enable the network to modify the PDU session, renegotiate the header compression configuration associated with the PDU session, convey the port management information container, trigger EAS rediscovery, provide an updated DNS server address due to a newly selected local DNS server or a newly selected EASDF, provide updated ECS configuration information, remove a joined UE from one or more multicast MBS sessions associated with the PDU session, update ATSSS parameters (e.g., ATSSS rules), update the security information of the MBS service area or the multicast MBS session to which the UE has joined, or notify the UAS service of the service level AA process or the result of C2 authorization.

[0567] 6.3.2.2 Initiation of PDU Session Modification Procedure for Network Requests

[0568] In order to initiate a PDU session modification process for a network request, the SMF should create a "PDU session modification command" message.

[0569] If the authorized QoS rules of a PDU session are modified or marked for synchronization with the UE, the SMF should set the authorized QoS principle IE of the "PDU Session Modification Command" message to the authorized QoS rules of the PDU session. The SMF should ensure that the number of 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 possible, the SMF can bind service data flows for which the UE has requested service isolation to a dedicated QoS flow for the PDU session. Otherwise, the SMF can bind service data flows to an existing QoS flow. The SMF should use only one dedicated QoS flow for service isolation. If the UE has requested service isolation for multiple service data flows with different QoS treatments, the SMF should bind all these service data flows to a single QoS flow. If the SMF allows service isolation for service data flows in QoS rules, the SMF should create new authorized QoS rules for these service data flows and should remove the packet filters corresponding to these service data services from other authorized QoS rules.

[0570] If the authorized QoS flow description of the PDU session is modified or marked as synchronized with the UE, the SMF should set the authorized QoS flow description IE of the "PDU session modification command" message to the authenticated QoS flow description of the PDU session.

[0571] If the SMF creates a new authorized QoS rule for a new QoS flow, the SMF should include the authorized QoS flow description for that QoS flow in the authorized QoS flow description IE of the "PDU Session Modification Command" message, if:

[0572] a) Newly created authorized QoS rules are used for new GBR QoS flows;

[0573] b) The QFI of the new QoS flow is different from the 5QI of the QoS flow identified by the QFI;

[0574] c) The new QoS flow can be mapped to the EPS bearer specified in Clause 4.11.1 of 3GPP TS 23.502[9]; or

[0575] d) Establish a new QoS flow for a PDU session used for relaying, as specified in Clause 5.6.2.1 of 3GPP TS 23.304[6E].

[0576] Note 0: In cases other than those described above, the SMF implementation decides whether to include the authorized QoS flow description for the new QoS flow for the new authorized QoS rule in the authorized QoS flow description of the PDU session modification command message.

[0577] If the session AMBR of the PDU session is modified, the SMF should set the selected session AMBR IE of the "PDU session modification command" message to the session AMBR of the PDU session.

[0578] If interoperability between the PDU session and EPS is supported, and the mapped EPS bearer context of the PDU session is modified, the SMF should set the mapped EPS bearer context IE of the "PDU Session Modification Command" message to the mapped EPS bearer context of the PDU session. If the association between the QoS flow and the mapped EPS bearer context changes, the SMF should set the EPS bearer identifier parameter in the authorized QoS flow description IE of the "PDU Session Modification Command" message to the new EPS bearer identifier associated with the QoS flow.

[0579] Note 0A: SMF can include multiple mapped EPS bearer context fields with the same EPS bearer identifier in the mapped EPS bearer context IE of the "PDU Session Modification Command" message. For example, if it is necessary to modify the group filter, the modification requires more than one TFT opcode, or it is necessary to modify the mapped service flow template, the modification exceeds the maximum size of the TFTIE.

[0580] If the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure, and the "PDU session modification request" message includes a 5GSM capability IE, then the SMF should:

[0581] a) If the RQoS bit is set to:

[0582] 1) "Supports reflection QoS" means the UE is considered to support reflection QoS for this PDU session; or

[0583] 2) If "Reflection QoS is not supported", then it is assumed that the UE does not support reflection QoS for this PDU session; and;

[0584] b) If the MH6-PDU bit is set to:

[0585] 1) "Supports multi-homed IPv6 PDU sessions" means that the PDU session supports the use of multiple IPv6 prefixes; or

[0586] 2) “Multi-homed IPv6 PDU sessions are not supported” means that the PDU session does not support the use of multiple IPv6 prefixes.

[0587] If the SMF believes that the QoS flow belonging to the PDU session supports reflective QoS, the SMF may include the RQ timer IE set to the RQ timer value in the PDU session modification command message.

[0588] If it is necessary to deliver the port management information container (see 3GPP TS 23.501[8] and 3GPP TS 23.502[9]), and the UE sets the TPMIC bit in the 5GSM capability IE to “Support Transport Port Management Information Container”, then the SMF should include the port management information container IE in the “PDU Session Modification Command” message.

[0589] For PDN connections established in S1 mode, when changing systems from S1 mode to N1 mode, if the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure, and the UE-requested PDU session modification procedure has not yet been successfully executed, then the PDU session type is "IPv4", "IPv6", "IPv4v6", or "Ethernet", and the "PDU session modification request" message includes the maximum supported packet filter number (IE). The SMF should consider this number as the maximum number of packet filters that the UE can support for this PDU session. Otherwise, the SMF assumes that the UE supports 16 packet filters for this PDU session.

[0590] For PDN connections established in S1 mode, when the system changes from S1 mode to N1 mode, if the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure, and the UE-requested PDU session modification procedure has not yet been successfully executed, then the SMF should consider that the maximum data rate of each UE supported by the UE for uplink user plane integrity protection and the maximum data rate of each UE supported by the UE for downlink user plane integrity protection are valid during the lifetime of the PDU session.

[0591] For PDN connections established in S1 mode, during system transitions from S1 mode to N1 mode, if the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure, and the UE-requested PDU session modification procedure has not yet been successfully executed, and the SMF determines the PDU session request IE based on the local policy or configuration in the SMF and the normally open PDU session request IE in the "PDU session modification request" message (if available):

[0592] a) The requested PDU session must be a normally open PDU session. The SMF should include a normally open PDU session indication IE in the "PDU Session Modification Command" message, and should set that value to "Require normally open PDU session"; or

[0593] b) The requested PDU session should not be an always-open PDU session, and:

[0594] 1) If the UE includes a Persistently Open PDU Session Request IE, the SMF should include a Persistently Open PDU Session Indicator IE in the "PDU Session Modification Command" message and set its value to "Disallow Persistently Open PDU Sessions"; or

[0595] 2) If the UE does not include a normally open PDU session request IE, then the SMF should not include a normally open PDU session indication IE in the PDU session modification command message.

[0596] For a PDN connection established in S1 mode, when changing from S1 mode to N1 mode between systems, if the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure, the UE-requested PDU session modification procedure has not yet been successfully executed, the UE supports EDC, and the network allows the use of EDC, then the SMF should include the Extended Protocol Configuration Option (IE) with an EDC usage permission indicator in the "PDU Session Modification Command" message.

[0597] For PDN connections established in S1 mode, when changing between systems from S1 mode to N1 mode, if the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure, the UE-requested PDU session modification procedure has not yet been successfully executed, the UE supports EDC, and the network needs to use EDC, then the SMF should include the Extended Protocol Configuration Option (IE) with an EDC usage requirement indicator in the "PDU Session Modification Command" message.

[0598] If a QoS flow for a URLLC is created in a PDU session, and the SMF does not provide a normally open PDU session indicator IE with the value set to "Need a normally open PDU session" during the UE-requested PDU session establishment process or the network-requested PDU session modification process of the PDU session, then the SMF should include the normally open PDU session indicator IE in the "PDU session modification command" message and should set the value to "Need a normally open PDU session".

[0599] For PDN connections, when changing between systems from S1 mode to N1 mode, if the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure, and the UE-requested PDU session modification procedure has not yet been successfully executed, then the PDU session is a single-access PDU session on 3GPP access with IP PDU session type. The SMF can decide to provide a protocol description associated with the PDU session and can include the protocol description IE in the "PDU session modification command" message.

[0600] If the RQ timer value is set to "deactivate" or zero, the UE considers that RQoS is not applied to the PDU session and removes (if any) derived QoS rules associated with the PDU session.

[0601] If the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure, the SMF should set the PTI IE of the "PDU session modification command" message to the PTI of the "PDU session modification request" message received as part of the UE-requested PDU session modification procedure.

[0602] If the network-requested PDU session modification procedure is triggered by a UE-requested PDU session modification procedure, and the UE has included the requested MBS container IE in the "PDU Session Modification Request" message, where the MBS operation is set to "Join Multicast MBS Session", then SMF:

[0603] a) The received MBS container IE shall include the TMGI (if any) of the multicast MBS session ID to which the UE is allowed to join, and the MBS decision for each of these received MBS messages shall be set to “Accept MBS Joining”, which may include the MBS start time for indicating the time when the multicast MBS session begins, and if security protection is applied to the multicast MBS and the control plane security process is used in accordance with Annex W.4.1.2 of 3GPP TS 33.501

[24] , the MBS security container shall be included in each received MBS message, and if there is no separate QoS stream dedicated to multicast, or if the SMF wants to establish a new QoS stream for multicast, a separate QoS stream dedicated to multicast shall be used by including the authorized QoS stream description IE;

[0604] Note 1: The network determines whether security protections apply to multicast MBS sessions as specified in 3GPP TS 33.501

[24] .

[0605] b) The received MBS container IE should include the TMGI (if any) of the multicast MBS session ID to which the UE was refused to join, the MBS decision for each of these received MBS messages should be set to "Refuse to join MBS," and a rejection reason should be set for each of these received MBS messages. If the rejection reason is set to "Multicast MBS session has not started or will not start soon," an MBS fallback timer value may be included; and

[0606] c) The MBS service area for each multicast MBS session may be included in the received MBS container IE, and this includes an MBS TAI list, an NR CGI list, or both of these, which identify the service area(s) of the local MBS service.

[0607] Note 2: For multicast MBS sessions with multiple MBS service areas, the MBS service area is indicated to the UE using MBS service announcements as described in 3GPP TS 23.247

[53] , which is not within the scope of this specification.

[0608] In the "PDU Session Modification Command" message, if the UE sets the type of the multicast MBS session ID in the requested MBS container IE for a certain multicast MBS session in the "PDU Session Modification Request" message to "Source Specific IP Multicast Address", then the SMF should include the source IP address information and destination IP address information, as well as the TMGI of each of these multicast MBS sessions, in the received MBS information.

[0609] Note 3: In this case, including source IP address information and destination IP address information in the received MBS information is to allow the UE to perform the mapping between the requested multicast MBS session ID and the provided TMGI.

[0610] Note 4: In SNPN, TMGI is used together with NID to identify MBS sessions.

[0611] if:

[0612] a) The SMF wants to remove a joined UE from one or more multicast MBS sessions; or

[0613] b) The network-requested PDU session modification process is triggered by the UE-requested PDU session modification process, and the UE has included the requested MBS container IE in the "PDU session modification request" message, where the MBS operation is set to "leave multicast MBS session".

[0614] The SMF should include the multicast MBS session ID from which the UE was removed (if any) in the received MBS container IE in the PDU session modification command message, and should set the MBS decision for each of these received MBS messages to "Remove UE from multicast MBS session". The SMF may include the updated MBS service area (if any) in each received MBS message. The SMF can remove QoS flows associated with multicast by including the authorized QoS flow description IE in the PDU session modification command message. If the UE is removed from a multicast MBS session due to MBS session release, the SMF should set the rejection reason to "Multicast MBS session release". The SMF should include: a rejection reason (if any) for each received MBS message, and set its value, as well as the reason for removing the UE from the corresponding multicast MBS session.

[0615] Note 5: Based on operator policies, such as after a locally configured time period, when a UE moves outside all (or more) MBS service areas of a multicast MBS session, the SMF is allowed to trigger the removal of the joined UE from the multicast MBS session.

[0616] If the SMF wants to update the MBS security information of a multicast MBS session that the UE has joined, the SMF should include the corresponding multicast MBS session ID and MBS security container in the MBS container IE received in the "PDU Session Modification Command" message, and should set the MBS decision in the received MBS information to "MBS Security Information Update".

[0617] If the SMF wants to update the MBS service area of ​​a multicast MBS session that the UE has joined, the SMF should include the corresponding multicast MBS session ID and the updated MBS service area in the MBS container IE received in the "PDU Session Modification Command" message, and set the MBS decision in the received MBS information to "MBS Service Area Update".

[0618] Note 6: As described in 3GPP TS 23.247

[53] , it is also permissible to use MBS service announcements to update the MBS service area of ​​a multicast MBS session to the UE, which is not within the scope of this specification.

[0619] If the network needs to update the ATSSS parameters (see 3GPP TS 24.193[13B] Section 5.2.4), the SMF shall include the ATSSS container IE and the ATSSS parameters update in the PDU Session Modification Command message.

[0620] If the PDU session modification procedure requested by the network is not triggered by the PDU session modification procedure requested by the UE, the SMF should set the PTI IE of the "PDU session modification command" message to "unassigned procedure transaction identifier".

[0621] If the SSC mode selected for the PDU session is “SSC mode 3”, and the SMF requests to relocate the SSC mode 3 PDU session anchor using multiple PDU sessions in accordance with 3GPP TS 23.502[9], then the SMF should include 5GSM reason #39 “reactivation request” in the “PDU session modification command” message, and may include the PDU session address lifetime parameter in the extended protocol configuration option IE of the “PDU session modification command” message. If the SSC mode selected for the PDU session is “SSC mode 3”, then the S-NSSAI or mapped S-NSSAI associated with the PDU session needs to be replaced, and the SMF determines that the PDU session needs to be re-established on the replacement S-NSSAI, then the SMF should include the replacement S-NSSAI IE and 5GSM reason #39 “reactivation request” in the “PDU session modification command” message. If the SSC mode selected for the PDU session is "SSC Mode 3", then the replaced S-NSSAI is available, and the SMF determines that the PDU session needs to be re-established on the replaced S-NSSAI. The SMF should include 5GSM reason #39 "Request Reactivation" and include the replaced S-NSSAI in the "PDU Session Modification Command" message.

[0622] Note 7: If the AMF requests the SMF to release the PDU session due to the change of the network slice instance of the PDU session, the SMF can also initiate the relocation of the anchor of the SSC mode 3PDU session with multiple PDU sessions, such as Section 5.15.5.3 of 3GPP TS 23.501[8].

[0623] The SMF should send a "PDU Session Modification Command" message, and the SMF should start timer T3591 (see [link]). Figure 19 (Example in the text).

[0624] Note 8: If the SMF requests to relocate an SSC mode 3PDU session anchor with multiple PDU sessions, as specified in 3GPP TS23.502[9], a relocation request indication indicating whether the SMF should be reassigned or reused is provided to the AMF.

[0625] If Control Plane CIoT 5GS optimization is enabled for PDU sessions, and the IP header compression configuration IE is included in a PDU session establishment request message or a PDU session modification request message, and SMF supports Control Plane CIoT 5GS optimization and IP header compression for use with Control Plane CIoT 5GS optimization, then SMF can include the IP header compression configuration IE in a PDU session modification command message to renegotiate the IP header compression configuration associated with the PDU session.

[0626] If Control Plane CIoT 5GS optimization is enabled for PDU sessions, and the Ethernet header compression configuration IE is included in the "PDU Session Establishment Request" message or the "PDU Session Modification Request" message, and the SMF supports Control Plane CIoT 5GS optimization and Ethernet header compression for use with Control Plane CIoT 5GS optimization, then the SMF can include the Ethernet header compression configuration IE in the "PDU Session Modification Command" message to reconfigure the Ethernet header compression configuration associated with the PDU session.

[0627] If the network request for PDU session modification is associated with a C2 authorization process, the SMF should send a "PDU session modification command" message via a Service Level AA container IE, which includes:

[0628] a) Service Level AA response, where the value of the C2AR field is set to "C2 authorization successful";

[0629] b) If the payload is provided from the UAS-NF, then the service level AA payload, whose value is set to the payload; and

[0630] c) If the payload type associated with the payload is provided from UAS-NF, then the service level AA payload type, whose value is set to the payload type; and

[0631] d) If the CAA-level UAV ID is provided from the UAS-NF, then the service level device ID is set to the CAA-level UAV ID.

[0632] Note 9: The C2 licensed payload in the Service Level AA payload may include one, some, or all of the following: pairing information for C2 communication and pairing information for direct C2 communication.

[0633] Note 9A: The C2 authorization payload in the service level AA payload may include: security information for C2 sessions as specified in TS 33.256[24B].

[0634] If the Service Level AA procedure for establishing a PDU session for the UAS service is triggered for re-authentication purposes, and the UAS-NF provides a successful UUAA-SM result to the SMF, then the SMF should send a "PDU Session Modification Command" message to the UE. This "PDU Session Modification Command" message should include a Service Level AA container IE, which contains:

[0635] a) In a Service Level AA response, the value of the SLAR field is set to "Service Level Authentication and Authorization Successful";

[0636] b) If the CAA-level UAV ID is received from the UAS-NF, then the Service Level Device ID is set to the CAA-level UAV ID;

[0637] c) If a payload is received from the UAS-NF, the service level AA payload, whose value is set to the payload; and

[0638] d) If a payload type associated with a payload is received, the service level AA payload type is set to the payload type.

[0639] If the SMF needs to provide the UE with new ECS configuration information, and the UE indicates support for ECS configuration in the "PDU Session Establishment Request" message or in S1 mode, the SMF can include the Extended Protocol Configuration Option (IE) in the "PDU Session Modification Command" message, where:

[0640] a) at least one of (multiple) ECS IPv4 addresses, (multiple) ECS IPv6 addresses, and (multiple) ECS FQDNs;

[0641] b) At least one associated ECSP identifier;

[0642] c) Optionally, space validity conditions associated with ECS addresses; and

[0643] d) Optionally, an ECS authentication method associated with an ECS address.

[0644] Note 10: (Multiple) IP addresses, (multiple) FQDNs, or both are associated with an ECSP identifier, and replace the previously provided ECS configuration information associated with the same ECSP identifier (if any).

[0645] If the SMF needs to provide the UE with (multiple) DNS server addresses, and the UE provides a DNS server IPv4 address request, a DNS server IPv6 address request, or both in a PDU session establishment request message or a PDU session modification request message, then the SMF should include an extended protocol configuration option IE in the PDU session modification command message, which includes one or more DNS server IPv4 addresses, one or more DNS server IPv6 addresses, or both.

[0646] If the SMF needs to trigger EAS rediscovery, and the UE indicates support for EAS rediscovery in the "PDU Session Establishment Request" or "PDU Session Modification Request" message, then the SMF should include the extended protocol configuration option IE in the "PDU Session Modification Command" message:

[0647] a) Has an EAS rediscovery indication, but no indication has an impact; or

[0648] b) Has the following:

[0649] 1) If the UE supports EAS rediscovery indications with the affected EAS IPv4 address range, then there are one or more EAS rediscovery indications with the affected EAS IPv4 address range.

[0650] 2) If the UE supports EAS rediscovery indications with the affected EAS IPv6 address range, then there are one or more EAS rediscovery indications with the affected EAS IPv6 address range.

[0651] 3) If the UE supports EAS rediscovery indications with (multiple) affected EAS FQDNs, then it supports one or more EAS rediscovery indications with affected EAS FQDNs; or

[0652] 4) Any combination of the above items.

[0653] When the UE has requested a P-CSCF IPv6 address or a P-CSCF IPv4 address, and the SMF provides (multiple) P-CSCF addresses during the PDU session establishment process, if the network-requested PDU session modification process is triggered to restore the P-CSCF, the SMF shall include (multiple) P-CSCF IP addresses in the Extended Protocol Configuration Options (IE) of the PDU Session Modification Command message as specified in Section 5.8.2.2 of 3GPP TS 23.380

[54] .

[0654] If the S-NSSAI or its mapping S-NSSAI for a PDU session needs to be replaced, and the SMF determines that the PDU session needs to be retained, the SMF should include the replacement S-NSSAI in the PDU session modification command message. If the replacement S-NSSAI is available, and the SMF determines that the PDU session needs to be retained, the SMF includes the replacement S-NSSAI in the PDU session modification command message.

[0655] If the S-NSSAI or its mapping S-NSSAI for a PDU session needs to be replaced, and the SMF determines that the PDU session needs to be retained, the SMF should include the extended replacement S-NSSAIIE in the PDU session modification command message. If the replacement S-NSSAI is available, and the SMF determines that the PDU session needs to be retained, the SMF includes the replacement S-NSSAI in the PDU session modification command message.

[0656] If the SMF includes an authorized QoS flow description and the SMF determines that N3QAI should be provided to the UE, then the SMF should include the N3QAI IE in the PDU Session Modification Command message.

[0657] If the PDU session is a single-access PDU session with IP PDU session type established through 3GPP access, and the SMF determines to provide the UE with a protocol description for UL PDU set processing based on operator policy, the SMF can include the protocol description IE in the "PDU session modification command" message.

[0658] ***Next Change***

[0659] 6.3.2.3 PDU Session Modification Process for Network Requests Received by the UE

[0660] Upon receiving a "PDU Session Modification Command" message, if the UE provided a DNN during PDU session establishment, then if timer T3396 is running for the DNN provided by the UE, the UE should stop timer T3396. If the UE did not provide a DNN during PDU session establishment, and the request type is different from "Initial Emergency Request" and "Existing Emergency PDU Session," then the UE should stop timer T3396 associated with no DNN (if it is running). If a "PDU Session Modification Command" message for an emergency PDU session is received, the UE should not stop timer T3396 associated with no DNN (if it is running). In SNPN, timers T3396 to be stopped include:

[0661] b) Timer T3396 (if running), which is applied to all equivalent SNPNs associated with the RSNPN or equivalent SNPN, and associated with the selected entry in the "Subscriber Data List" or the selected PLMN subscription; and

[0662] a) Timer T3396 (if running) is applied to register the SNPN, which is associated with the RSNPN, and if the UE supports accessing the SNPN using a certificate from a certificate holder, the registered SNPN is associated with an entry selected in the Subscriber Data List or the selected PLMN subscription.

[0663] Upon receiving the "PDU Session Modification Command" message, if the UE provided S-NSSAI and DNN during PDU session establishment, and if timer T3584 is running for the [S-NSSAI, DNN] combination provided by the UE, the UE should stop timer T3584. If the UE provided DNN but not S-NSSAI during PDU session establishment, and if it is running for the same [no S-NSSAI, DNN] combination provided by the UE, the UE should stop timer T3584. If the UE provided S-NSSAI but not DNN during PDU session establishment, and if timer T3584 is running for the same [S-NSSAI, no DNN] combination provided by the UE, the UE should stop timer T3584. If the UE provided neither DNN nor S-NSSAI during PDU session establishment, and if it is running for the same [no S-NSSAI, no DNN] combination provided by the UE, the UE should stop timer T3584. The timer T3584 to be stopped includes:

[0664] a) In PLMN:

[0665] 1) Timer T3584 (if running), which is applied to all PLMNs; and

[0666] 2) Timer T3584 (if running), which is used to register the PLMN; or

[0667] b) In SNPN:

[0668] 1) Timer T3584 (if running), which is applied to all equivalent SNPNs and associated with the RSNPN or equivalent SNPN, and associated with the selected entry in the "Subscriber Data List" or the selected PLMN subscription; and

[0669] 2) Timer T3584 (if running) is applied to the registered SNPN associated with the RSNPN, and if the UE supports accessing the SNPN using a certificate from a certificate holder, it is applied to the equivalent SNPN associated with an entry in the "Subscriber Data List" or the selected PLMN subscription, or both.

[0670] Upon receiving the "PDU Session Modification Command" message, if the UE provided S-NSSAI during PDU session establishment, and if timer T3585 is running for S-NSSAI of the PDU session, the UE should stop timer T3585. If the UE did not provide S-NSSAI during PDU session establishment, and the request type is different from "Initial Emergency Request" and "Existing Emergency PDU Session," the UE should stop timer T3585 (if it is running) that is not associated with S-NSSAI. Timers T3585 to be stopped include:

[0671] a) In PLMN:

[0672] 1) Timer T3585 (if running), which is applied to all PLMNs and access points that receive "PDU session modification commands";

[0673] 2) Timer T3585 (if running), which is applied to all PLMNs, as well as both 3GPP access types and non-3GPP access types;

[0674] 3) Timer T3585 (if running), which is used for PLMN registration and receiving "PDU session modification commands" upon access; and

[0675] 4) Timer T3585 (if running), which is used to register the PLMN and both 3GPP access type and non-3GPP access type; or

[0676] b) In SNPN:

[0677] 1) Timer T3585 (if running) is applied to all equivalent SNPNs and accesses that receive “PDU Session Authentication Command” messages, associated with RSNPN or equivalent SNPN, and associated with the selected entry in the “Subscriber Data List” or the selected PLMN subscription.

[0678] 2) Timer T3585 (if running) is applied to all equivalent SNPNs, as well as both 3GPP access types and non-3GPP access types, associated with RSNPN or equivalent SNPN, and associated with the selected entry in the "Subscriber Data List" or the selected PLMN subscription.

[0679] 3) Timer T3585 (if running), applied to access for registering the SNPN and receiving the "PDU Session Authentication Command" message, associated with the RSNPN, and if the UE supports accessing the SNPN using a certificate from a certificate holder, applied to the equivalent SNPN or both, associated with the selected entry in the "Subscriber Data List" or the selected PLMN subscription; and

[0680] 4) Timer T3585 (if running) is applied to register the PLMN, as well as to both 3GPP access types and non-3GPP access types, associated with the RSNPN, and if the UE supports accessing the SNPN using a certificate from a certificate holder, it is applied to the equivalent SNPN or both, associated with the selected entry in the "Subscriber Data List" or the selected PLMN subscription.

[0681] If a "PDU session modification command" message for an emergency PDU session is received, the UE should not stop timer T3585 (if it is running) that is not associated with S-NSSAI.

[0682] Note 1: After receiving the "PDU Session Modification Command" message for the PDU session, if the UE provided a DNN (or no DNN) and S-NSSAI (or no S-NSSAI) when the PDU session was established, then timer T3396 associated with the DNN (or no DNN, if the UE did not provide a DNN) is running, and timer T3584 associated with the DNN (or no DNN, if the UE did not provide a DNN) and S-NSSAI (or no S-NSSAI, if the UE did not provide an S-NSSAI) of the PDU session is running, then the UE stops both timer T3396 and timer T3584.

[0683] Note 2: After receiving the "PDU Session Modification Command" message for the PDU session, if the UE provided a DNN (or no DNN) and S-NSSAI (or no S-NSSAI) when the PDU session was established, then timer T3585 associated with the S-NSSAI (or no S-NSSAI if the UE did not provide S-NSSAI) of the PDU session is running, and timer T3584 associated with the DNN (or no DNN if the user equipment did not provide DNN) and S-NSSAI (or no S-NSSAI if the UE did not provide S-NSSAI) of the PDU session is running, then the UE stops both timer T3585 and timer T3584.

[0684] If the "PDU Session Modification Command" message includes an authorized QoS rule IE, the UE should process the QoS rules sequentially, starting with the first QoS rule.

[0685] If the PDU session modification command message includes an authorized QoS rule IE, and the rule opcode of one or more QoS rules is set to "Delete existing QoS rule", then the UE should delete the protocol description associated with the QoS rule (if any).

[0686] If the "PDU Session Modification Command" message includes a mapped EPS bearer context (IE), the UE should process the mapped EPS bearer contexts sequentially, starting with the first mapped EPS bearer context.

[0687] If the "PDU Session Modification Command" message includes an Authorized QoS Flow Description (IE), the UE should process the QoS Flow Descriptions sequentially, starting with the first QoS Flow Description.

[0688] The UE should replace the stored authorized QoS rules, authorized QoS flow descriptions, and session AMBR of the PDU session with (multiple) received values ​​(if any) in the "PDU session modification command" message.

[0689] If the "PDU Session Modification Command" message includes a mapped EPS bearer context (IE), the UE should check for different types of errors in each mapped EPS bearer context, as follows:

[0690] Note 3: Errors detected in the mapped EPS bearer context will not cause the UE to discard the authorized QoS rule IE and authorized QoS flow description IE (if any) included in the "PDU Session Modification Command" message.

[0691] a) Semantic errors in EPS mapping operations:

[0692] 1) Opcode = "Create new EPS bearer", and an existing mapped EPS bearer context with the same EPS bearer identifier already exists and is associated with any PDU session.

[0693] 2) Opcode = "Delete existing EPS bearer", and there is no existing mapped EPS bearer context with the same EPS bearer identifier associated with the PDU session being modified.

[0694] 3) The opcode is “Modify existing EPS bearer” and there is no existing mapped EPS bearer context with the same EPS bearer identifier associated with the PDU session being modified.

[0695] 4) The opcode is “Create a new EPS bearer” or “Modify an existing EPS bearer”, and the resulting mapped EPS bearer context has invalid or missing mandatory parameters (e.g., mapped EPS QoS parameters or service templates for a dedicated EPS bearer context).

[0696] In Case 1, if the existing mapped EPS bearer context is associated with the PDU session being modified, the UE should not diagnose the error, proceed with the creation request, and delete the old EPS bearer context if the processing is successful.

[0697] In scenario 2, the UE should not diagnose the error, process the deletion request further, and if the processing is successful, assume that the mapped EPS bearer context has been successfully deleted.

[0698] Otherwise, after sending "PDU session modification complete" for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU session modification request" message to delete the mapped EPS bearer context with 5GSM reason #85 "Invalid mapped EPS bearer identifier".

[0699] b) If the mapped EPS bearer context includes a service flow template, the UE should check whether the service flow template has different types of TFTIE errors as follows:

[0700] 1) Semantic errors in TFT operation:

[0701] i) When an existing TFT exists in the EPS bearer context, the TFT operation is "Create new TFT".

[0702] ii) When the TFT operation is not a "Create New TFT" operation and there is no TFT in the EPS bearer context.

[0703] iii) TFT operation = "Remove group filter from existing TFT", at which point the TFT will be empty.

[0704] iv) TFT Operation = "Delete Existing TFT", for dedicated EPS bearer context.

[0705] In scenario iv, after sending "PDU session modification complete" for an ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU session modification request" message to remove the mapped EPS bearer context with 5GSM reason #41 "semantic error in TFT operation".

[0706] In other cases, the UE should not diagnose errors and perform the following actions to resolve inconsistencies:

[0707] In case i, the UE should further process the new activation request to create a new TFT, and if the processing is successful, delete the old TFT.

[0708] In case ii, the UE should:

[0709] - Process new requests, and if the TFT operation is "Delete existing TFT" or "Remove group filter from existing TFT", and if no errors are detected according to items 2, 3 and 4, then the TFT is considered to have been successfully deleted;

[0710] - If the TFT operation is "Add a group filter in an existing TFT" or "Replace a group filter in an existing TFT", the new request will be treated as an activation request.

[0711] In case iii, if the packet filter belongs to a dedicated EPS bearer context, the UE should process the new deletion request, and if no error is detected according to items 2, 3 and 4, after sending "PDU session modification complete" for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU session modification request" message to delete the mapped EPS bearer context with 5GSM reason #41 "semantic error in TFT operation".

[0712] In case iii, if the group filter belongs to the default EPS bearer context, the UE should process the new deletion request, and if no errors are detected according to items 2, 3 and 4, the existing TFT is deleted. This corresponds to using a matching group filter for the default EPS bearer context.

[0713] 2) Syntax errors in TFT operation:

[0714] i) When the TFT operation = "Create a new TFT", "Add a group filter in an existing TFT", "Replace the group filter in an existing TFT", or "Delete a group filter from an existing TFT", and the group filter list in TFTIE is empty.

[0715] ii) TFT Operation = "Delete Existing TFT" or "No TFT Operation", where the group filter list in TFT IE is not empty.

[0716] iii) When the original TFT does not contain the group filter to be replaced, the TFT operation is "Replace the group filter in the existing TFT".

[0717] iv) When the group filter to be deleted does not exist in the original TFT, TFT operation = "Delete group filter from existing TFT".

[0718] v) Invalid.

[0719] vi) When other types of syntax errors exist in the encoding of TFT IE, such as the number of subfields of the group filter not matching the number of group filters in the group filter list.

[0720] In case iii, the UE should not diagnose the error, process the replacement request further, and if no error is detected according to items 3 and 4, the received packet filter should be included in the existing TFT.

[0721] In case iv, the UE should not diagnose the error, process the deletion request further, and if no error is detected according to items 3 and 4, the corresponding group filter is considered to have been successfully deleted.

[0722] Otherwise, after sending "PDU session modification complete" for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU session modification request" message to delete the mapped EPS bearer context with 5GSM reason #42 "syntax error in TFT operation".

[0723] Note 3a: Implementations that strictly adhere to the list of group filter defined in section 10.5.6.12 of 3GPP TS 24.008

[12] may fail to detect case 2)ii).

[0724] 3) Semantic errors in group filters:

[0725] i) When a packet filter consists of conflicting packet filter components, this will render the packet filter ineffective, meaning no IP packets will fit into this packet filter. How the UE determines semantic errors in a packet filter is beyond the scope of this document.

[0726] ii) When the resulting TFT assigned to a dedicated EPS bearer context does not contain any packet filters applicable to the uplink direction from the packet filters created according to the network request.

[0727] After sending "PDU session modification complete" for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU session modification request" message to remove the mapped EPS bearer context with 5GSM reason #44 "(multiple) semantic errors in packet filters".

[0728] 4) Syntax errors in grouping filters:

[0729] i) When the TFT operation is "Create a new TFT", "Add a group filter to an existing TFT", or "Replace a group filter in an existing TFT", two or more group filters in the resulting TFT will have the same group filter identifier.

[0730] ii) When the TFT operation is "Create a new TFT", "Add a group filter to an existing TFT", or "Replace a group filter in an existing TFT", two or more group filters in all TFTs associated with the PDN connection will have the same group filter priority value.

[0731] iii) When other types of syntax errors exist in the encoding of the group filter, such as using reserved values ​​for the group filter component identifier.

[0732] In scenario i, if the new request contains two or more packet filters with the same packet filter identifier, after sending a "PDU session modification complete" message for the ongoing PDU session modification process, the UE should initiate a PDU session modification process by sending a "PDU session modification request" message to remove the mapped EPS bearer context with 5GSM reason #45 "Syntax error in packet filter". Otherwise, the UE should not diagnose the error, process the new request further, and if processing is successful, remove the old packet filter with the same packet filter identifier.

[0733] In case ii, if the old group filter does not belong to the default EPS bearer context, the UE should not diagnose the error, but should process the new request further, and if the processing is successful, the old group filter with the same filter priority value should be deleted.

[0734] In case ii, if one or more old packet filters belong to the default EPS bearer context, after sending “PDU session modification complete” for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a “PDU session modification request” message to remove the mapped EPS bearer context with 5GSM reason #45 “(multiple) packet filters syntax error”.

[0735] Otherwise, after sending "PDU session modification complete" for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU session modification request" message to remove the mapped EPS bearer context with 5GSM reason #45 "Syntax error in packet filter".

[0736] If a new EPS bearer identifier parameter, which can be transmitted to the EPS, is received in the Authorized QoS Flow Description IE, the UE should update the association between the QoS flow and the mapped EPS bearer context based on the new EPS bearer identifier and the mapped EPS bearer context. If the "Delete Existing EPS Bearer" opcode is received in the mapped EPS bearer context IE, the UE should discard the association between the QoS flow and the corresponding mapped EPS bearer context and delete the corresponding mapped EPS bearer context.

[0737] if:

[0738] a) The UE detects different errors in the EPS bearer context mapping as described above, which requires sending a "PDU Session Modification Request" message to remove the erroneous EPS bearer context mapping; and

[0739] b) Optionally, if the UE detects an error in a QoS rule and needs to delete at least one QoS rule described in Clause 6.3.2.4, it needs to send a "PDU Session Modification Request" message to delete the erroneous QoS rule;

[0740] After sending a "PDU session modification complete" message for an ongoing PDU session modification process, the UE can send a single "PDU session modification request" message to remove the erroneous mapped EPS bearer context and, optionally, the erroneous QoS rule. The UE should include the 5GSM reason IE in the "PDU session modification request" message.

[0741] Note 4: The reason for using 5GSM cannot be different from: #41 "Semantic error in TFT operation", #42 "Syntax error in TFT operation", #44 "Semantic error in (multiple) packet filters", #45 "Syntax error in (multiple) packet filters", #83 "Semantic error in QoS operation", #84 "Syntax error in QoS operation", or #85 "Invalid mapped EPS bearer identifier". The choice of 5GSM reason depends on the UE implementation.

[0742] After receiving the "PDU session modification command" message and the PDU session ID, the NAS transmission procedure specified in Clause 5.4.5 is used. If the UE accepts the "PDU session modification command" message, the UE considers the PDU session to have been modified, and the UE should create a "PDU session modification complete" message.

[0743] If the "PDU Session Modification Command" message contains a PTI value allocated during the PDU session modification process requested by the UE, the UE should stop timer T3581. The UE should ensure that the PTI value allocated to this process is not immediately released.

[0744] Note 5: The method used to achieve this depends on the implementation. For example, the UE can ensure that the PTI value assigned to the procedure is not released for a period of time equal to or greater than the default value of timer T3591.

[0745] When the PTI value is not released, the UE will treat any received PDU session modification command message with the same PTI value as a network retransmission (see Section 7.3.1).

[0746] If the SSC mode selected for the PDU session is "SSC Mode 3", and the "PDU Session Modification Command" message includes 5GSM reason #39 "Request Reactivation", the UE can provide the PDU session address lifetime to the upper layer (if received in the PDU session address lifetime parameter of the Extended Protocol Configuration Option IE in the "PDU Session Modification Command" message). After the network-requested PDU session modification process is completed:

[0747] a) If the PDU session is an MA PDU session:

[0748] 1) Established through both 3GPP and non-3GPP access, and:

[0749] - The UE registers within the same PLMN via both 3GPP access and non-3GPP access:

[0750] - The UE shall, upon receiving the "PDU session modification command" message, re-initiate the PDU session establishment procedure requested by the UE as specified in Article 6.4.1; or

[0751] - The UE registers in different PLMNs through both 3GPP access and non-3GPP access:

[0752] The UE shall re-initiate the PDU session establishment procedure requested by the UE as specified in Section 6.4.1 on both access points. The UE shall re-initiate the PDU session establishment procedure requested by the UE through the access point that first receives the "PDU session modification command" message; or

[0753] 2) Established through a single access point only:

[0754] - The UE shall re-initiate the PDU session establishment procedure requested by the UE in section 6.4.1 by establishing access to user plane resources; or

[0755] b) If the PDU session is a single-access PDU session:

[0756] - The UE shall re-initiate the PDU session establishment procedure requested by the UE as specified in Section 6.4.1 through the access associated with the PDU session; and

[0757] For a re-initiated UE request to establish a PDU session, the UE should set a new PDU session ID that is different from the PDU session ID associated with the current PDU session, and should:

[0758] a) Set the PDU session type to the PDU session type associated with the current PDU session;

[0759] b) Set the SSC mode to the SSC mode associated with the current PDU session;

[0760] c) Set the DNN to the DNN associated with the current PDU session;

[0761] d) Set S-NSSAI to:

[0762] 1) If provided during the PDU session establishment process requested by the UE in the current PDU session, then the S-NSSAI associated with the mapped S-NSSAI (if available in roaming scenarios); or

[0763] 2) If the UE receives an alternative S-NSSAI IE or an extended alternative S-NSSAI IE in a "PDU Session Modification Command" message, then the S-NSSAI received in the PDU session establishment accept message of the existing PDU session will be used; and

[0764] e) If received in the alternative S-NSSAI IE or extended alternative S-NSSAI of the PDU session modification command message, the alternative S-NSSAI associated with the mapped S-NSSAI (if available in roaming scenarios).

[0765] If the UE has indicated support for CIoT 5GS optimization and receives a small data rate control parameter container in the Extended Protocol Configuration Option IE of the PDU Session Modification Command message, the UE should store the small data rate control parameter value and use the stored small data rate control parameter value as the maximum allowed limit for uplink user data in the PDU session in accordance with 3GPP TS23.501[8]. If the UE has a previously stored small data rate control parameter value for the PDU session, the UE should replace the stored small data rate control parameter value of the PDU session with the received small data rate control parameter value in the Extended Protocol Configuration Option IE of the PDU Session Modification Command message.

[0766] If the UE has indicated support for CIoT 5GS optimization and has received a container of additional small data rate control parameters for anomalous data in the Extended Protocol Configuration Option IE of the PDU Session Modification Command message, the UE shall store the additional small data rate control parameters for anomalous data values ​​and use the stored additional small data rate control parameters for anomalous data as the maximum allowable limit for uplink anomalous data in the PDU session in accordance with 3GPP TS 23.501 [8]. If the UE has previously stored additional small data rate control parameters for anomalous data values ​​for the PDU session, the UE shall replace the stored additional small data rate control parameters for anomalous data values ​​for the PDU session with the received additional small data rate control parameters for anomalous data values ​​in the Extended Protocol Configuration Option IE of the PDU Session Modification Command message.

[0767] The UE should include the PDU session ID of the old PDU session that is about to be released in the old PDU session IDIE of the "UL NAS Transmission Message" that transmits the "PDU Session Establishment Request Message".

[0768] Note 6: The UE should maintain the PDU session, which includes the 5GSM reason #39 "Request Reactivation" "PDU Session Modification Command" message received before the PDU session address lifetime value is indicated or before receiving an indication from the upper layer (e.g., the old PDU session is no longer needed).

[0769] If the selected PDU session type is "Unstructured," the UE supports inter-system changes from N1 mode to S1 mode, the UE does not support establishing PDN connections for PDN types set to "Non-IP" in S1 mode, and one or more authorized QoS flow description parameter list fields received in the "PDU Session Modification Command" message contain the EPS Bearer Identifier (EBI), then the UE should remove the EPS Bearer Identifier (EBI) locally from the parameter list fields of such one or more authorized QoS flow descriptions. After sending a "PDU Session Modification Complete" message for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU Session Modification Request" message to delete the mapped EPS bearer context with 5GSM reason #85 "Invalid Mapped EPS Bearer Identifier."

[0770] If the selected PDU session type is "Ethernet", the UE supports inter-system changes from N1 mode to S1 mode, the UE does not support establishing PDN connections for PDN types set to "Non-IP" in S1 mode, the UE, the network, or both do not support the Ethernet PDN type in S1 mode, and one or more authorized QoS flows received in the authorized QoS flow description IE of the "PDU Session Modification Command" message contain an EPS bearer identifier (EBI), then the UE should remove the EPS bearer identifier (EBI) from the parameter list field of the one or more authorized QoS flow descriptions locally. After sending a "PDU Session Modification Complete" message for the ongoing PDU session modification process, the UE should initiate the PDU session modification process by sending a "PDU Session Modification Request" message to delete the mapped EPS bearer context with 5GSM reason #85 "Invalid Mapped EPS Bearer Identifier".

[0771] For UEs that have already registered for disaster roaming services and non-emergency service PDU sessions:

[0772] a) If one or more authorized QoS flow description parameter list fields received in the authorized QoS flow description IE of the PDU session modification command message contain the EPS bearer identifier (EBI), then the UE should remove the EPS bearer identifier (EBI) from the parameter list fields of the one or more authorized QoS flow descriptions locally; and

[0773] b) If the UE receives the mapped EPS bearer context IE in the PDU session modification command message, the UE should delete its content locally.

[0774] If the "PDU Session Modification Command" message includes a normally open PDU session indicator for IE, and:

[0775] a) If the IE value is set to "Requires always-on PDU session", then the UE should treat the established PDU session as a always-on PDU session; or

[0776] b) If the value of IE is set to "Disallow always-on PDU sessions", then the UE should not treat the established PDU session as a always-on PDU session.

[0777] If the UE does not receive a normally open PDU session indication in the "PDU session modification command" message:

[0778] a) If, for a PDN connection established in S1 mode, the network-requested PDU session modification procedure is triggered by the UE-requested PDU session modification procedure when the system changes from S1 mode to N1 mode, then the UE should not treat the modified PDU session as a normally open PDU session; or

[0779] b) Otherwise:

[0780] 1) If the UE has already received a Persistent PDU Session Indicator (IE) for this PDU session, with its value set to "Persistent PDU Session Required", then the UE should treat the PDU session as a persistent PDU session; or

[0781] 2) Otherwise, the UE should not treat the PDU session as an always-on PDU session.

[0782] If the PDU session modification command message contains a port management information container (IE), the UE should forward the contents of the port management information container (IE) to the DS-TT (see 3GPP TS 23.501[8] and 3GPP TS 23.502[9]).

[0783] If the UE receives the Serving PLMN Rate Control IE in the PDU Session Modification Command message, the UE shall store the Serving PLMN Rate Control IE value, replace any existing value, and use the stored Serving PLMN Rate Control value as the maximum allowable limit for uplink control plane user data for the corresponding PDU session in accordance with 3GPP TS 23.501[8].

[0784] If the "PDU Session Modification Command" message includes the received MBS container IE, then for each received MBS message in the received MBS information:

[0785] a) If the MBS decision is set to "Accept MBS Join", the UE should consider itself to have successfully joined the multicast MBS session. The UE should store the received TMGI and use it for any further operations on that multicast MBS session. The UE should store the received MBS service area (if any) associated with the received TMGI and provide the received TMGI to the lower layers. If the MBS start time is included in the received MBS information, the UE can provide the MBS start time to the upper layers;

[0786] (b) If the MBS decision is set to "Deny MBS Join," the UE should consider the requested join to be rejected. The UE should store the received MBS service area (if any) associated with the received TMGI. If the received rejection reason is set to "User outside the local MBS service area," the UE should not request to join the same multicast MBS session if neither the current TAI nor CGI of the current cell is part of the received MBS service area. If the received rejection reason is set to "Multicast MBS session has not started or will not start soon," and the MBS backoff timer value includes a value that is neither zero nor deactivated, the UE should start backoff timer T3587 using the value provided for the received TMGI in the MBS backoff timer, and should not attempt to join the multicast MBS session using the same TMGI, the source IP address information of the TMGI, or the destination IP address information of the TMGI before T3587 expires. If the MBS fallback timer value indicates that the timer is deactivated, the UE should not attempt to join a multicast MBS session using the same TMGI until the UE is powered off, the USIM is removed, or the entry in the current SNPN's "Subscriber Data List" is updated. If the MBS fallback timer value indicates zero, the UE may attempt to join an MBS session using the same TMGI.

[0787] c) If the MBS decision is set to "Remove UE from multicast MBS session", the UE should consider that it has successfully left the multicast MBS session, and if the received rejection reason is set to "Multicast MBS session release", the UE should consider that the multicast MBS session has been released. Then, the UE should instruct the lower layer to delete the stored TMGI;

[0788] d) If the MBS decision is set to "MBS service area update", the UE should store the received MBS service area associated with the received TMGI and replace the current MBS service area with the received area.

[0789] e) If the MBS decision is set to "MBS security information update", the UE should replace the current MBS security information with the MBS security information received in the MBS security container associated with the received TMGI.

[0790] If the UE indicates support for ECS configuration information configuration in the "Session Establishment Request" message or in S1 mode, then when the extended protocol configuration option IE is received in the "PDU Session Modification Command" message...

[0791] a) One or more ECS IPv4 addresses, ECS IPv6 addresses, and ECS FQDNs;

[0792] b) One or more related ECSP identifiers;

[0793] c) Optionally, space validity conditions associated with ECS addresses; and

[0794] d) Optionally, the ECS authentication method associated with the ECS address, after which...

[0795] Then the UE should pass them to the upper layer.

[0796] If the UE supports receiving DNS server addresses in the protocol configuration options and receives one or more DNS server IPv4 addresses, one or more DNS server IPv6 addresses, or both in the extended protocol configuration option IE of the PDU session modification command message, then the UE should pass the received DNS server IPv4 addresses (if any) and the received DNS server IPv6 addresses (if any) to the upper layer.

[0797] Note 7: The received DNS server addresses will replace the previously provided DNS server addresses (if any).

[0798] If the UE supports EAS rediscovery and receives it in the Extended Protocol Configuration Options (IE) of the "PDU Session Modification Command" message:

[0799] a) The EAS rediscovers the instruction without any effect; or

[0800] b) The following content:

[0801] 1) If the UE supports it, there are one or more EAS rediscovery indications for the affected EAS IPv4 address range;

[0802] 2) If the UE supports it, there are one or more EAS rediscovery indications with the affected EAS IPv6 address range;

[0803] 3) If the UE supports it, then it has one or more EAS rediscovery indications for the affected EAS FQDN; or

[0804] 4) Any combination of the above items;

[0805] The UE should then pass the EAS rediscovery instruction and(multiple) received affected EAS IPv4 address ranges (if supported and included),(multiple) received EAS IPv6 address ranges (if supported and included), and(multiple) received EAS FQDNs (if supported and included) to the upper layer.

[0806] Note 8: According to 3GPP TS 23.548[10A], the upper layer processes the EAS rediscovery indication, and(multiple) affected EAS IPv4 address ranges (if any),(multiple) affected EAS IPv6 address ranges (if any), and(multiple) received EAS FQDNs (if any).

[0807] Upon receiving the "PDU Session Modification Command" message, if the network-requested PDU session modification process is triggered by the UE-requested PDU session modification process, including the Service Level AA container IE, then the UE should forward the Service Level AA content of the Service Level AA container IE to the upper layer.

[0808] If the UE supports EDC and receives an EDC usage allow indicator in the Extended Protocol Configuration Options (IE) of the PDU Session Modification Command message, the UE should instruct the upper layer network to allow the use of EDC.

[0809] If the UE supports EDC and receives an EDC usage requirement indicator in the Extended Protocol Configuration Options (IE) of the PDU Session Modification Command message, the UE should indicate to the upper layer that the network needs to use EDC.

[0810] Note 9: 3GPP TS 23.548

[182] specifies the handling of instructions on whether a network allows the use of EDC or requires the use of EDC.

[0811] If the alternative S-NSSAIIE is included in the "PDU Session Modification Command" message, the UE should replace the S-NSSAI or mapped S-NSSAI associated with the PDU session according to the alternative S-NSSAIIE. On the UE side, the S-NSSAI for the established PDU session should be the S-NSSAI to be replaced and the alternative S-NSSAI.

[0812] If the extended alternative S-NSSAIIE is included in the "PDU Session Modification Command" message, the UE should replace the S-NSSAI or mapped S-NSSAI associated with the PDU session according to the extended alternative S-NSSAIIE. On the UE side, the S-NSSAI for the established PDU session should be the S-NSSAI to be replaced and the alternative S-NSSAI.

[0813] If the Protocol Description IE is included in the PDU Session Modification Command message for existing QoS rules,

[0814] a) For a protocol description field whose length value is set to 1 for an associated QoS rule, the UE should delete any previously stored protocol descriptions of the QoS rule indicated by the QRI field of the protocol description field; and

[0815] b) For protocol description fields with a length value greater than 1 in the associated QoS rule, if there is no stored protocol description, the UE should store the relevant protocol description, or if there is a stored protocol description in the QoS rule, replace any previously stored protocol description with the new received protocol description.

[0816] The UE can use it to identify PDUs belonging to the PDU set in the uplink direction.

[0817] Note 10: Whether and how to use protocol descriptions to identify PDU sets depends on the UE implementation.

[0818] The UE shall use the NAS transmission procedure specified in Clause 5.4.5 to transmit the “PDU session modification complete” message and the PDU session ID.

[0819] After sending the "PDU session modification complete" message, if the "Create new EPS bearer" opcode in the mapped EPS bearer context IE is received in the "PDU session modification command" message, and the "PDU session modification command" message has neither a corresponding authorized QoS flow description IE nor an existing QoS flow description corresponding to the EPS bearer identifier included in the mapped EPS bearer context, then the UE should send a "PDU session modification request" message including the mapped EPS bearer context IE to delete the mapped EPS bearer context.

[0820] After sending the “PDU session modification complete” message, if there are multiple mapped EPS bearer contexts for the PDU session being modified, but none of them are associated with the default QoS rule, the UE should delete the multiple mapped EPS bearer contexts locally and delete the EPS bearer identifier (EBI) (if any) stored in all QoS flow descriptions of the PDU session locally.

[0821] If a port management information container (see 3GPP TS 23.501[8] and 3GPP TS 23.502[9]) is required to be delivered, the UE should include the port management information container IE in the PDU session modification complete message.

[0822] Upon receiving the “PDU session modification complete” message, the SMF should stop timer T3591 and treat the PDU session as modified. If the SSC mode selected for the PDU session is “SSC mode 3” and the “PDU session modification command” message includes 5GSM reason #39 “reactivation request”, the SMF should start timer T3593. If the PDU session address lifetime value is sent to the UE in the “PDU session modification command” message, timer T3593 should start with the same value; otherwise, the default value should be used. If the “PDU session modification complete” message contains a port management information container (IE), the SMF should process the contents of the IE in accordance with the provisions of 3GPP TS23.501[8] and 3GPP TS 23.502[9].

[0823] ***Next Change***

[0824] 8.2.19 Configuration Update Command

[0825] 8.2.19.1 Message Definition

[0826] The AMF sends a "configuration update command" message to the UE. See Table 8.2.19.1.1.

[0827] Message type: Configuration update command

[0828] Meaning: Dual

[0829] Direction: Network to UE

[0830] Table 8.2.19.1.1: Content of the "Configuration Update Command" message

[0831]

[0832]

[0833]

[0834]

[0835] ***Next Change***

[0836] Version 8.2.19.x is an extended replacement for NSSAI.

[0837] The network may include this IE to provide the UE with several alternative NSSAIs when the alternative slice currently used for network slice replacement is unavailable.

[0838] ***Next Change***

[0839] 8.3.9 PDU Session Modification Command

[0840] 8.3.9.1 Message Definition

[0841] The “PDU Session Modification Command” message is sent by the SMF to the UE to indicate the modification of the PDU session. See Table 8.3.9.1.1.

[0842] Message type: PDU session modification command

[0843] Meaning: Dual

[0844] Direction: Network to UE

[0845] Table 8.3.9.1.1: Content of the "PDU Session Modification Command" message

[0846]

[0847]

[0848] Note: For networks conforming to version 15.2.1 or earlier of this specification, the IEI value of this message can be sent to the mapped EPS bearer context IE with a value of "7F".

[0849] ***Next Change***

[0850] Version 8.3.9.x is an extended replacement for NSSAI.

[0851] The network may include this IE to provide the UE with several alternative NSSAIs when the alternative slice currently used for network slice replacement is unavailable.

[0852] ***Next Change***

[0853] Version 9.11.3.x is an extension that replaces NSSAIIE.

[0854] The purpose of expanding the alternative NSSAI information element is to identify a list of mapping information between the S-NSSAI to be replaced and the alternative S-NSSAI.

[0855] The encoding of the alternative NSSAI information element is as follows: Figure 20 , Figure 21 As shown in Table 9.11.3.x.1.

[0856] The alternative to NSSAI is a type 4 information element with a minimum length of 2 octets and a maximum length of 146 octets.

[0857] Table 9.11.3.x.1: Alternative NSSAI Information Elements

[0858]

[0859] ***End of (multiple) changes***

Claims

1. An apparatus for communication, the apparatus comprising at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to perform at least the following: Receive information from the network indicating that the first network slice is permitted; Establish a first Protocol Data Unit (PDU) session with the network using the first allowed network slice; Receive a trigger from the network for replacing the first network slice with a second allowed network slice; For the PDU session, the replacement of the first network slice with the second network slice is triggered; Receive update information from the network indicating the second allowed network slice and at least one third allowed network slice; Based on the updated information, each of the alternative second allowed network slice and at least one alternative third allowed network slice is mapped to the first network slice; as well as Based on the received update information, for the PDU session, the second allowed network slice is replaced with one of the at least one third allowed network slices.

2. The apparatus of claim 1, wherein the first permitted network slice is a temporary permitted network slice.

3. The apparatus according to claim 1 or 2, wherein the second allowed network slice and the third allowed network slice are alternative network slices.

4. The apparatus according to any one of claims 1 to 3, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: Receive the information and the update information from the network function.

5. The apparatus of claim 4, wherein the network function is at least one of access and mobility function or session management function.

6. The apparatus of claim 4 or 5, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The update information is received in the user equipment configuration update message.

7. The apparatus according to any one of claims 4 to 6, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The update information is received in the protocol data unit session modification message.

8. The apparatus according to any one of claims 1 to 7, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The update information is received via non-access stratum signaling.

9. The apparatus according to any one of claims 1 to 8, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: Provide the network with the following information: indicate support for network slice replacement using temporarily available network slice replacement.

10. The apparatus according to any one of claims 1 to 9, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: After receiving the update information indicating the at least one third allowed network slice, the second allowed network slice is removed from the device's memory.

11. An apparatus for communication, the apparatus comprising at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to perform at least: Provide the user equipment with information indicating the first permitted network slice; Establish a first protocol data unit session with the user equipment using the first allowed network slice; For the PDU session, the first allowed network slice is replaced with the second network slice; Determine that the second allowed network slice becomes unavailable; as well as Provide the user equipment with: update information indicating the second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and the at least one third allowed network slice to the first network slice.

12. The apparatus of claim 11, wherein the first permitted network slice is a temporary permitted network slice.

13. The apparatus of claim 11 or 12, wherein the second allowed network slice and the third allowed network slice are alternative network slices.

14. The apparatus according to any one of claims 11 to 13, wherein the apparatus includes access and mobility functions.

15. The apparatus of claim 14, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The update information is provided in the user equipment configuration update message.

16. The apparatus according to any one of claims 11 to 14, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The update information is received via non-access stratum signaling.

17. The apparatus according to any one of claims 11 to 16, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: Receive information indicating support for network slice replacement using temporarily available network slice replacement.

18. The apparatus according to any one of claims 11 to 17, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The second allowed network slice becomes unavailable by determining that the second allowed network slice is congested or that the availability period for the second allowed network slice has expired.

19. The apparatus of claim 18, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: Based on the load information received from network data and analysis functions, an indication is determined to provide the at least one third permitted network slice.

20. An apparatus for communication, the apparatus comprising at least one processor and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to perform at least: For a PDU session, trigger the replacement of the first allowed network slice with the second allowed network slice; Receive an instruction from the access management function to replace the second allowed network slice with at least one third network slice; as well as Provide the user equipment with: update information indicating the second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and the at least one third allowed network slice to the first network slice.

21. The apparatus of claim 20, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform at least: The update information is provided in the protocol data unit session modification message.

22. The apparatus of claim 20 or 21, wherein the second allowed network slice and the third allowed network slice are alternative network slices.

23. A method for communication, the method comprising: Receive information from the network indicating that the first network slice is permitted; Establish a first Protocol Data Unit (PDU) session with the network using the first allowed network slice; Receive a trigger from the network for replacing the first network slice with a second allowed network slice; For the PDU session, the replacement of the first network slice with the second network slice is triggered; Receive update information from the network indicating the second allowed network slice and at least one third allowed network slice; Based on the updated information, each of the alternative second allowed network slice and at least one alternative third allowed network slice is mapped to the first network slice; as well as Based on the received update information, for the PDU session, the second allowed network slice is replaced with one of the at least one third allowed network slices.

24. A method for communication, the method comprising: Provide the user equipment with information indicating the first permitted network slice; Establish a first protocol data unit session with the user equipment using the first allowed network slice; For the PDU session, the first allowed network slice is replaced with the second network slice; Determine that the second allowed network slice becomes unavailable; Provide the user equipment with: update information indicating the second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and the at least one third allowed network slice to the first network slice.

25. A method for communication, the method comprising: For a PDU session, trigger the replacement of the first allowed network slice with the second allowed network slice; Receive an instruction from the access management function to replace the second allowed network slice with at least one third network slice; as well as Provide the user equipment with: update information indicating the second allowed network slice and at least one third allowed network slice, and information for mapping each of the second allowed network slice and the at least one third allowed network slice to the first network slice.

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