Method and apparatus for supporting priority of network slices in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by an access and mobility management function (AMF) entity in a wireless communication system includes receiving a registration request message including a network slice access layer (AS) group (NSAG) information request from a UE; receiving, from another entity, NSAG information including single network slice selection assistance information (S-NSSAI) priority information and mapping information between the S-NSSAI and an NSAG identifier; transmitting at least one of the NSAG information or NSAG tracking area (TA) boundary information to a policy control function (PCF) entity; receiving NSAG priority information from the PCF entity based on the NSAG information; and transmitting a registration response message including at least one of the NSAG information, the NSAG TA boundary information, or the NSAG priority information to the UE.

Description

Technical Field

[0001] The present disclosure generally relates to a wireless communication system, and more particularly to a method and apparatus for supporting network slice groups and priorities in a wireless communication system. Background Art

[0002] The fifth generation (5G) mobile communication technology defines a wide frequency band, making high transmission rates and new services possible, and can be implemented not only in sub-6 gigahertz (GHz) bands such as 3.5 GHz, but also in bands above 6 GHz (including 28 GHz and 39 GHz) called millimeter waves (mmWave). In addition, the implementation of the sixth generation (6G) mobile communication technology (called a super 5G system) in a terahertz (THz) band (e.g., a 95 GHz to 3 THz band) has been considered in order to achieve a transmission rate fifty times faster than that of the 5G mobile communication technology and an ultra-low latency that is one-tenth of that of the 5G mobile communication technology.

[0003] At the beginning of the development of 5G mobile communication technology, in order to support services and meet the performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC) and massive machine type communication (mMTC), standardization on beamforming and massive MIMO is underway to reduce radio wave path loss in millimeter waves and increase radio wave transmission distance, thereby supporting parameter sets for dynamic operation of millimeter wave resources and time slot formats for efficient utilization (for example, operating multiple subcarrier spacings), initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods (such as LDPC (low-density parity check) codes for large-scale data transmission and polarization codes for high-reliability transmission of control information), L2 preprocessing, and network slicing for providing dedicated networks dedicated to specific services.

[0004] Currently, in view of the services supported by 5G mobile communication technology, discussions on the improvement and performance enhancement of initial 5G mobile communication technology are underway, and there is already physical layer standardization on the following technologies, for example, V2X (Vehicle-to-Everything) for assisting driving decisions by autonomous vehicles based on information about the location and status of the vehicle transmitted by the vehicle and for improving user convenience, NR-U (New Radio Unlicensed) for system operation designed to comply with various regulatory requirements in unlicensed bands, NR UE energy saving, and non-terrestrial network (NTN) for UE-satellite direct communication for providing coverage and positioning in areas where terrestrial network communications are not available.

[0005] In addition, the air interface architecture / protocols for the following technologies are being standardized, such as the Industrial Internet of Things (IIoT) for supporting new services through interworking and integration with other industries, IAB (Integrated Access and Backhaul) for providing nodes for network service area extension by supporting wireless backhaul links and access links in an integrated manner, mobility enhancement including conditional switching and DAPS (Dual Active Protocol Stack) switching, and two-step random access (2-step RACH for NR) for simplifying the random access process. The system architecture / services for the following technologies are also being standardized: 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software defined network (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, the number of connected devices, which has been growing exponentially, will be connected to the communication network, and it is therefore expected that there will be a need to enhance the functions and performance of the 5G mobile communication systems and the integrated operations of the connected devices. To this end, new research is planned related to the following technologies: Extended Reality (XR) for effectively supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), etc., as well as 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, virtual world service support, and drone communication.

[0007] In addition, such developments in 5G mobile communication systems will serve as a foundation for developing new waveforms for providing coverage in the terahertz band for 6G mobile communication technology, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and large antennas, metamaterial-based lenses and antennas for improving the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (orbital angular momentum), RIS (reconfigurable smart surface), full-duplex technology for increasing the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technology for achieving system optimization by utilizing satellites and AI (artificial intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at a complexity level that exceeds the limits of UE operating capabilities by utilizing ultra-high-performance communication and computing resources.

[0008] In the 3rd Generation Partnership Project (3GPP) 5G system, network slice group priorities and mapping information between network slices and network slice groups are provided so that the UE can perform slice-based cell reselection. When there are tracking areas (TAs) using different mapping rules, it is necessary to provide mapping information between network slices and network slice groups in the TAs using different mapping rules, respectively, so that the UE can perform cell reselection in the TAs using different mapping rules. However, since it is inefficient to provide mapping information between network slices and network slice groups for TAs using different mapping rules, it is necessary to determine when it is necessary to provide mapping information between network slices and network slice groups.

[0009] It is necessary to consider the policy information about the network slices used for the existing UEs to determine the network slice priority. However, the prior art currently does not provide a method for doing so.

[0010] Therefore, there is a need in the art for a method and apparatus to allow a home network operator to control network slice priority for cell reselection on a per-subscriber basis even in roaming situations. Summary of the invention

[0011] Solution to the problem

[0012] Accordingly, the present disclosure provides embodiments designed to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below.

[0013] One aspect of the present disclosure is to provide a device and method to enable a network operator to control network slice priority for cell reselection of each subscriber during roaming in a wireless communication system.

[0014] Another aspect of the present disclosure is to provide a method and device for determining network slice priority based on network slice policy information of an existing UE.

[0015] According to one aspect of the present disclosure, a method performed by an access and mobility management function (AMF) entity in a wireless communication system includes: receiving a registration request message including a network slice access stratum (AS) group (NSAG) information request from a UE; receiving NSAG information including single network slice selection assistance information (S-NSSAI) priority information and mapping information between S-NSSAI and NSAG identifier from another entity; transmitting at least one of NSAG information or NSAG tracking area (TA) boundary information to a policy control function (PCF) entity; receiving NSAG priority information from the PCF entity based on the NSAG information; and transmitting a registration response message including at least one of NSAG information, NSAG TA boundary information or NSAG priority information to the UE.

[0016] According to one aspect of the present disclosure, a method performed by a UE in a wireless communication system includes transmitting a registration request message including an NSAG information request to an AMF entity, and receiving a registration response message from the AMF entity, the registration response message including at least one of NSAG information, NSAG TA boundary information, or NSAG priority information, wherein the NSAG information is associated with S-NSSAI priority information transmitted from another entity and mapping information between the S-NSSAI and the NSAG identifier, and wherein the NSAG priority information is associated with the NSAG information transmitted from the PCF entity.

[0017] According to one aspect of the present disclosure, an AMF entity in a wireless communication system includes a transceiver and at least one processor, which is connected to the transceiver and configured to: receive a registration request message including an NSAG information request from a UE, receive NSAG information including S-NSSAI priority information and mapping information between S-NSSAI and NSAG identifiers from another entity, transmit at least one of NSAG information or NSAG TA boundary information to a PCF entity, receive NSAG priority information from the PCF entity based on the NSAG information; and transmit a registration response message including at least one of NSAG information, NSAG TA boundary information or NSAG priority information to the UE.

[0018] According to one aspect of the present disclosure, a UE in a wireless communication system includes a transceiver and at least one processor, which is connected to the transceiver and configured to: transmit a registration request message including an NSAG information request to an AMF entity, and receive a registration response message from the AMF entity, the registration response message including at least one of NSAG information, NSAG TA boundary information or NSAG priority information, wherein the NSAG information is associated with S-NSSAI priority information transmitted from another entity and mapping information between the S-NSSAI and the NSAG identifier, and wherein the NSAG priority information is associated with the NSAG information transmitted from the PCF entity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A method for providing network slice access stratum (AS) group (NSAG) information during a UE registration procedure of a wireless communication system according to an embodiment is shown;

[0021] Figure 2A method for determining slice priority or slice group priority via unified data management (UDM) during UE registration process of a wireless communication system according to an embodiment is shown;

[0022] Figure 3 shows the structure of a UE according to an embodiment;

[0023] Figure 4 shows the structure of a RAN according to an embodiment; and

[0024] Figure 5 The structure of a network entity according to an embodiment is shown. DETAILED DESCRIPTION

[0025] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings. When it is determined that the description may make the subject matter of the present disclosure unnecessarily unclear, the detailed description of the known functions or configurations combined herein will be omitted. The terms to be described below are defined in consideration of the functions in the present disclosure and may differ depending on the user, the user's intention or custom. Therefore, the definition of the term should be determined based on the content throughout the entire specification.

[0026] For the same reason, in the drawings, some elements may be exaggerated, omitted or schematically shown. The size of each element does not fully reflect the actual size. In the drawings, the same or corresponding elements have the same reference numerals.

[0027] The present disclosure is not limited to the embodiments set forth below, but may be implemented in a variety of different forms. The embodiments are provided to inform those of ordinary skill in the art of the scope of the present disclosure. Throughout the specification, the same or similar reference numerals represent the same or similar elements.

[0028] In the present disclosure, elements are expressed in the singular or plural depending on the embodiment. However, for ease of description, the singular form or plural form is appropriately selected for the presented situation, and the present disclosure is not limited to elements expressed in the singular or plural form. Therefore, an element expressed in the plural form may also include a single element, or an element expressed in the singular may also include multiple elements.

[0029] As used herein, unit refers to a software element or a hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, a unit does not always have the meaning limited to software or hardware, and can be constructed to be stored in an addressable storage medium or to execute one or more processors. Therefore, a unit includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by the unit can be combined into fewer elements or units, or divided into more elements or units. Elements and units can be implemented as one or more central processing units (CPUs) in a reproduction device or a secure multimedia card. The unit in an embodiment can include one or more processors.

[0030] In the following description, for convenience, the terms used to identify access nodes, and the terms referring to network entities, messages, interfaces between network entities, and various identification information are used illustratively. Therefore, the present disclosure is not limited to the terms used below, and other terms referring to the subject matter with equivalent technical meanings may be used.

[0031] The terms used in the present disclosure are only used to describe specific embodiments, and are not intended to limit the present disclosure. Unless absolutely different in context, singular expressions may include plural expressions. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as the meaning generally understood by those skilled in the art to which the present disclosure belongs. These terms defined in commonly used dictionaries may be interpreted as having the same meaning as the contextual meaning in the relevant field, and unless clearly defined in the present disclosure, should not be interpreted as having an ideal or overly formal meaning. In some cases, even the terms defined in the present disclosure should not be interpreted as excluding embodiments of the present disclosure.

[0032] Hereinafter, various embodiments of the present disclosure will be described based on a hardware method. However, the embodiments of the present disclosure include techniques using both hardware and software, and therefore may not exclude the software aspect.

[0033] In the following description, for the convenience of description, the terminology and names defined in the Long Term Evolution (LTE) and NR standards, which are the latest standards specified by 3GPP in the existing communication standards, will be used to describe the present disclosure. However, the present disclosure is not limited to these terms and names, and can be applied in the same manner as systems that comply with other standards. Specifically, the present disclosure can be applied to the 3GPP NR standard and other communication systems with similar technical backgrounds or channel types. The present disclosure can also be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure.

[0034] In the following description, for the convenience of description, the terms related to signals, channels, control information, network entities and device elements are exemplarily used. Therefore, the present disclosure is not limited to the terms used below, and other terms referring to the subject matter with equivalent technical meanings may be used.

[0035] In addition, the embodiments of the present disclosure will be described using terms used in some communication standards, but the use of these terms is only for the purpose of description as an example. The embodiments of the present disclosure can also be easily applied to other communication systems by modification.

[0036] The 5G mobile communication network includes 5G UE (terminal), 5G radio access network (RAN, base station, 5G Node B (gNB), evolved Node B (eNB), etc.) and 5G core network. The 5G core network includes network functions, including access and mobility management function (AMF) that provides mobility management of UE, session management function (SMF) that provides session management, user plane function (UPF) that performs data transmission, policy control function (PCF) that provides policy control, UDM that provides functions such as management of subscriber data, policy control data, etc., unified data repository (UDR) that stores various network function data such as UDM, etc.

[0037] In the 5G system, network slicing technology refers to the technology and structure of implementing multiple virtualized and independent logical networks on one physical network. Network operators provide services by configuring virtual end-to-end networks (called network slices) to meet specific service / application requirements. Network slices are distinguished by an identifier called single network slice selection assistance information (S-NSSAI). The network transmits a set of allowed slices (e.g., allowed NSSAI) to the UE during the UE registration process, and the UE transmits and receives application data via a protocol data unit (PDU) session generated by one S-NSSAI (i.e., network slice) in the slice set.

[0038] In the 5G system, the RAN is responsible for one or more TAs, which refers to a unit defined in the 5G system for tracking the location of the UE, and each TA or each cell within the TA can support different frequencies and network slices. The RAN can broadcast the network slice information supported by each TA to the UE, and the UE can identify the network slices supported by each TA based on the network slice information supported by each TA. In this case, the slice information of each TA and each cell broadcast by the RAN may include information about the slice group to which the S-NSSAI of each slice is mapped instead of the identifier (i.e., slice group ID) of the S-NSSAI of each slice. The UE can identify the slice group supported by the cells in the TA for each TA, and can identify the S-NSSAI supported by the TA respectively based on the mapping relationship information between the slice group id and the S-NSSAI received from the AMF via the non-access stratum (NAS). NAS can be a communication protocol between the UE and the AMF, and the UE can identify the S-NSSAI supported by the cells in the TA for each TA based on the mapping relationship information between the S-NSSAI and the slice group ID.

[0039] In the cell reselection process, i.e., the process for selecting a more suitable cell, the UE can determine the cell based on the S-NSSAI received from the NAS or the priority value of each slice group ID. In addition, the UE can determine the cell based on the slice related information broadcast by the RAN. For example, when the network operator wants to move the UE to a cell supporting a specific slice, a slice or slice group related to the cell supporting the specific slice can be given a high priority.

[0040] In the 5G RAN, the mapping between the slice group ID and the S-NSSAI is configured in units of TAs. Therefore, different mapping rules between the slice group ID and the S-NSSAI can be applied to each TA. For example, the same slice group ID can be used to indicate different S-NSSAIs in different TAs. The UE can receive mapping relationship information between the S-NSSAI and the slice group ID of certain TAs belonging to the registration area (RA) from the AMF via NAS during the network registration process. When there are TAs using different mapping rules for the slices to be mapped, the TAs using different mapping rules and the different mapping relationship information in the TAs using different mapping rules can be included therein and transmitted together. When the UE has moved to another TA that does not belong to the RA in which reception was performed during the last network registration process, the UE can perform the network registration process again and receive the mapping information between the slice group ID and the S-NSSAI for the new TA.

[0041] When a UE moves to a TA adjacent to a RA with a different mapping rule, and in order to support cell reselection, it is necessary to allow the UE to receive mapping information between a slice group ID and an S-NSSAI for the TA adjacent to the RA with a different mapping rule. The present disclosure proposes a method for doing so.

[0042] The priority of each network slice or group of network slices needs to be determined without violating the network operator's policy. In addition, the priority of each network slice or group of network slices needs to be considered together with the determination of other policy control information of the network slice. For example, other policy control information of the network slice may be UE routing policy (URSP) information, including rules about the network slice to which the traffic provided to the UE is to be transmitted. Therefore, the policy control function (PCF) needs to be able to support the priority verification function for each network slice or group of slices, which is a network function (NF) located in the network where the UE is located and manages the policy information of the network where the UE is located. For example, the network where the UE is located may be a service network.

[0043] The home network operator may want to control the priority of each network slice or network slice group for each subscriber. For example, when multiple subscribers want to access a specific network slice, a higher priority value is given to subscribers using a higher rate plan to give priority to using a specific network slice. Therefore, the UDM, which is a NF located in the UE's home network and stores and manages subscriber information of the UE located in the home network, needs to be able to support the function of controlling the priority determination of each network slice or slice group for the UE located in the home network. In addition, when the home network operator provides priority information of each network slice or slice group in the home network to the UE roaming in the visited network, the priority information of each network slice or slice group in the home network needs to be converted into priority information of each network slice identifier or network slice group identifier supported by the visited network and provided to the UE. The visited network can be a visited network for which a roaming agreement on network slice priority has been reached between operators.

[0044] In the 3GPP 5G system, when network slice group priority and mapping information between network slices and network slice groups are provided for slice-based cell reselection of UE, the UE is prevented from referring to incorrect mapping information, and the network operator's policy is effective, thereby enabling the home network operator to control the network slice priority for cell reselection of each subscriber even in roaming situations.

[0045] Figure 1A method for providing NSAG information during UE registration in a wireless communication system according to an embodiment is shown. The NSAG information includes mapping relationship information between a slice group identifier of a slice and an S-NSSAI and priority information for cell reselection to be used for a slice or a slice group to which a slice is to be mapped.

[0046] refer to Figure 1 In step 101, the UE may transmit an AN message (registration request) to the RAN. The registration request message may include at least one of a UE identifier (subscription hidden identifier (SUCI), a 5G globally unique temporary identifier (5G-GUTI), a permanent equipment identifier (PEI), etc.), a requested NSSAI, UE mobility management (MM) core network capabilities, etc. When the UE supports network slice groups and network slice priorities for cell reselection, the UE may include support for NSAG in the UE MM core network capabilities.

[0047] When a UE supporting NSAG determines that a slice group mapping needs to be updated, or when a UE supporting NSAG determines that a slice priority needs to be updated, the UE may perform a registration procedure by transmitting a registration request message, and may also include an indication of requesting NSAG. The situation in which the UE determines that a slice group mapping needs to be updated may correspond to receiving a slice group ID from the RAN that the UE may not recognize. When the AMF receives an indication of requesting NSAG, the information transmitted to the UE may include NSAG information or information including an indicator indicating that the UE disables slice-based cell reselection.

[0048] In step 102, the RAN may select an AMF based on information in an AN message received from the UE. The RAN may deliver an N2 message (N2 parameters, registration request) to the selected AMF. The N2 parameters may include a selected PLMN ID, UE location information, UE context request, etc. The N2 message may include a RAN ID.

[0049] In step 103, operations necessary for the UE registration process may be performed. When the 5GMM core network capabilities provided by the UE in step 101 include information indicating support for NSAG, the AMF may store the UE's support for NSAG in the UE context information of the UE. When there is no UE context for the UE, the AMF may determine the UE's old AMF based on the 5G-GUTI received in step 101, and transmit a UE context request message including an identifier of the UE to the old AMF to receive the UE context of the UE from the old AMF. The received UE context may include one or more of information about whether the UE supports NSAG, priority information about slices or slice groups provided to the UE, and mapping information between slice group ids and S-NSSAI.

[0050] In step 104, the AMF may determine the Registration Area (RA), which is used to manage the mobility of the UE, and the allowed NSSAI, i.e., information about the slices allowed within the RA. In addition, when the configured NSSAI needs to be updated, the AMF may determine the configured NSSAI, i.e., information about the slices available to the UE in the current network.

[0051] In step 104, when the 5GMM core network capabilities provided by the UE include information indicating support for NSAG, the AMF may determine the NSAG information, including mapping information between the S-NSSAI and the slice group ID for some or all slices in the configured NSSAI, and priority information for each slice or slice group.

[0052] The AMF can operate in the following two ways to address the situation when the external TA adjacent to the RA boundary uses different mapping rules between S-NSSAI and slice group ID.

[0053] -When the AMF identifies that a TA outside the RA and adjacent to the RA boundary uses a different mapping rule between the S-NSSAI and the slice group ID, the AMF may include, in the information to be transmitted to the UE, the identifier information of the TA that uses the different mapping rule between the S-NSSAI and the slice group ID, and the mapping relationship information between the S-NSSAI and the slice group ID relative to the TA that uses the different mapping rule between the S-NSSAI and the slice group ID. The information to be transmitted to the UE may be the NSAG information of the TA boundary. When the AMF cannot identify the mapping relationship information between the S-NSSAI and the slice group ID of the TA that uses the different mapping rule between the S-NSSAI and the slice group ID, the AMF may request the Network Slice Selection Function (NSSF) for the mapping relationship information between the S-NSSAI and the slice group ID of the TA that uses the different mapping rule between the S-NSSAI and the slice group ID to receive the mapping relationship information, and then determine the NSAG information of the TA boundary.

[0054] -RA can be configured so that the external TA adjacent to the RA boundary has the same mapping rule between S-NSSAI and slice group ID as in RA.

[0055] In addition, the AMF may provide information about TAs for which slice-based cell reselection should not be performed (NSAG forbidden areas).

[0056] In step 105, the AMF may request the PCF to select or verify the priority value of the slice or slice group within the NSAG information and the NSAG information of the TA boundary determined in step 104. To this end, the AMF may transmit the NSAG information and the NSAG information of the TA boundary in the request message transmitted to the PCF. In the NSAG information and the NSAG information of the TA boundary information, the AMF may provide only the priority information of each slice.

[0057] Alternatively, when a new NSAG priority or slice priority of the UE is determined in step 104 and thus changes, the AMF may notify the PCF of the NSAG priority or slice priority information and the UE ID determined in step 104 via an Npcf_UEPolicyControl create request or an Npcf_UEPolicyControl update request, so that the new NSAG priority or slice priority of the UE may be considered when generating the UE policy of the UE, or the UE policy may be appropriately updated in consideration of the new NSAG priority or slice priority of the UE. When the UE is in a roaming state, the NSAG priority or slice priority information and the UE ID determined in step 104 may be transmitted to a home PCF (H-PCF) via a visited PCF (V-PCF). The H-PCF is a policy control decision function based in a home public land mobile network (HPLMN), while the V-PCF is a policy control decision function based in a visited public land mobile network (VPLMN). In step 106, when the message from the AMF includes NSAG information, NSAG information of a TA boundary, or priority information of each slice corresponding to the NSAG information, NSAG information of a TA boundary in step 105, the PCF may select a priority value for each slice or slice group. The PCF may consider a predetermined URSP rule and a policy of a network operator.

[0058] Alternatively, when a UE policy does not yet exist in the case where an Npcf_UEPolicyControl create request message is received in step 105, and the NSAG priority or slice priority is included in the Npcf_UEPolicyControl create request message, the PCF may consider the NSAG priority or slice priority when generating a new UE policy, thereby generating a UE policy. After the UE policy is generated, the generated UE policy may be transmitted to the UE via the AMF. The NSAG priority may be priority information for each slice group, and the slice priority may be priority information for each slice. The UE policy is to be transmitted to the UE and may include a mapping rule between traffic and slices. When the UE is in a roaming state, the H-PCF may transmit the generated UE policy to the UE via the V-PCF and the AMF.

[0059] When the UE policy exists in the case where the Npcf_UEPolicyControl update request message is received in step 105, and the NSAG priority or slice priority is included in the Npcf_UEPolicyControl update request message, the PCF may determine whether a UE policy update is required based on the received NSAG priority or slice priority. When the PCF determines that the UE policy needs to be updated based on the received NSAG priority or slice priority, the PCF may calculate a new UE policy and transmit the updated UE policy to the UE via the AMF. When the UE is in a roaming state, the H-PCF may transmit the updated UE policy to the UE via the V-PCF and the AMF.

[0060] In step 107, the PCF may include information about the priority value of each slice or slice group determined in step 106 in a response message transmitted by the PCF to the AMF.

[0061] In step 108, the remaining UE registration procedures may be performed.

[0062] In step 109, the AMF may include the registration accept message in the N2 message transmitted by the AMF to the RAN.

[0063] When the AMF determines the NSAG information, the NSAG information of the TA boundary, and the NSAG restricted area in step 104, the AMP may include the NSAG information, the NSAG information of the TA boundary, and the NSAG restricted area in a registration accept message to be transmitted to the UE.

[0064] In step 110, the RAN may transmit a registration accept message to the UE within the message received from the AMF in step 109.

[0065] When the UE moves to the RA boundary after the UE receives the NSAG information of the TA boundary to receive the slice group ID supported by the cell in the TA included in the NSAG information of the TA boundary information, the UE can identify the slice corresponding to the received slice group ID. For example, when the UE receives the slice group ID, the UE can identify the slice corresponding to the received slice group ID via the information included in the NSAG information of the TA boundary. The UE can perform cell reselection based on the slice corresponding to the received slice group ID.

[0066] When the UE receives the NSAG restricted zone, the slice-based cell reselection is not performed in the TA included in the NSAG restricted zone. That is, the cell reselection can be performed without considering the slice group ID broadcasted in the TA included in the NSAG restricted zone.

[0067] Figure 2A method for determining slice priority or slice group priority via UDM during UE registration process of a wireless communication system according to an embodiment is shown.

[0068] refer to Figure 2 In step 201, the UE may transmit an AN message (AN parameters, registration request) to the RAN. The registration request message may include at least one of a UE identifier (SUCI, 5G-GUTI or PEI, etc.), a requested NSSAI, UE MM core network capabilities, etc. When the UE supports network slice groups and network slice priorities for cell reselection, the UE may include support for NSAG in the UE MM core network capabilities.

[0069] In step 202, the RAN may select an AMF based on information in an AN message received from the UE. The RAN may deliver an N2 message (N2 parameters, registration request) to the selected AMF. The N2 parameters may include a selected PLMN ID, UE location information, UE context request, etc. The N2 message may include a RAN ID.

[0070] In step 203, the AMF may include the UE identifier and the identifier for requesting information in the Nudm_SDM_Get request message transmitted by the AMF to the UDM and requesting the UE's subscriber information. In this case, when the UE supports NSAG, the AMF may include the identifier for requesting slice priority information in the UDM.

[0071] In step 204, the UDM may include the UE identifier of the message received from the AMF in step 203 and the subscriber information about the requested information in the response message transmitted by the UDM to the AMF. The response message that transmits the UE identifier of the message received from the AMF and the subscriber information about the requested information to the AMF may include the following information.

[0072] Subscribed slice information (subscribed S-NSSAI), slice priority information of each slice within the subscribed slice (slice priority of subscribed S-NSSAI) (priority information can be provided for each slice or slice group) and NSAG disabling information.

[0073] The NSAG disabling information may be one of an indicator for disabling slice-based cell reselection of the UE, an indicator for disabling slice-based cell reselection of the UE when roaming, and an indicator for disabling cell reselection in a specific geographic location.

[0074] In step 205, when there is NSAG disabling information in the information received in step 204 and the NSAG disabling information indicates an indicator for disabling slice-based cell reselection of the UE, the AMF may not provide NSAG information to the UE. When the NSAG disabling information is an indicator for disabling slice-based cell reselection of the UE when roaming, the AMF may not provide NSAG information to the UE when roaming. When the NSAG disabling information is an indicator for disabling slice-based cell reselection in a specific geographical location, the AMF may provide information about the TA for disabling slice-based cell reselection to the UE together with the NSAG information.

[0075] When the information received in step 204 does not include NSAG disabling information, the AMF calculates NSAG information including slice priority information to be provided to the UE for cell reselection based on the information received from the UDM in step 204.

[0076] The AMF may request the NSSF to determine the NSAG information, and the message requesting the NSSF may include the following information.

[0077] The slice priority of the subscribed S-NSSAI, the subscribed S-NSSAI, and the NSAG information request indicator indicating that the UE supports NSAG are received from the UDM.

[0078] When the NSSF contains the NSAG information request indicator and the slice priority of the subscribed S-NSSAI, the NSSF determines whether to use the slice priority of the subscribed S-NSSAI as is based on the operator policy. When the UE is in roaming state, the NSSF determines whether to use the slice priority for the subscribed S-NSSAI according to the agreement between the home network operator and the visited network operator.

[0079] The response message transmitted by NSSF to AMF may include:

[0080] NSAG information, configured NSSAI, and mapping of configured NSSAI.

[0081] The NSAG information includes mapping information between the slice group ID and the S-NSSAI corresponding to the slice priority information of each slice or slice group determined by the NSSF. When the UE is in a roaming state, the slice identifier in the NSAG information includes the slice identifier of the visited network. Therefore, when the NSSF determines that the UE is in a roaming state, the NSSF can jointly provide the mapping of the configured NSSAI and the configured NSSAI. The mapping of the configured NSSAI indicates the mapping relationship between the subscribed S-NSSAI (i.e., the home network identifier) ​​contained in the configured NSSAI and the slice identifier (i.e., the visited network slice identifier).

[0082] The AMF may directly calculate the NSAG information by using the subscribed S-NSSAI received from the UDM and the slice priority of the subscribed S-NSSAI without requesting it to the NSSF.

[0083] In step 206, the AMF may request the PCF to select or verify the priority value of the slice or slice group within the NSAG information determined in step 205. To this end, the AMF may transmit the NSAG information in a request message to be transmitted to the PCF. The AMF may only provide the priority information of each slice in the NSAG information.

[0084] Alternatively, when the new NSAG priority or slice priority of the UE is determined in step 205 and thus changes, the AMF may notify the PCF of the NSAG priority or slice priority information and the UE ID determined in step 205 via an Npcf_UEPolicyControl create request or an Npcf_UEPolicyControl update request, so that the new NSAG priority or slice priority of the UE may be considered when generating the UE policy of the UE, or the UE policy may be appropriately updated in consideration of the new NSAG priority or slice priority of the UE. When the UE is in a roaming state, the NSAG priority or slice priority information and the UE ID determined in step 205 may be transmitted to the H-PCF via the V-PCF.

[0085] In step 207, when the message from the AMF in step 206 includes NSAG information or priority information of each slice, the PCF may select a priority value for each slice or slice group. The PCF may consider predetermined URSP rules and policies of the network operator.

[0086] Alternatively, when no UE policy exists when the Npcf_UEPolicyControl create request message is received in step 206, and the NSAG priority or slice priority is included in the Npcf_UEPolicyControl create request message, the PCF may consider the NSAG priority or slice priority when generating a new UE policy, thereby generating the UE policy. Slice priority is information for each slice. The UE policy is information to be transmitted to the UE and may include a mapping rule between traffic and slices. When the UE is in a roaming state, the H-PCF may transmit the generated UE policy to the UE via the V-PCF and the AMF.

[0087] When the UE policy exists when the Npcf_UEPolicyControl update request message is received in step 206, and the NSAG priority or slice priority is included in the Npcf_UEPolicyControl update request message, the PCF may determine whether a UE policy update is required based on the received NSAG priority or slice priority. When the PCF determines that the UE policy needs to be updated based on the received NSAG priority or slice priority, the PCF may calculate a new UE policy and transmit the updated UE policy to the UE via the AMF. When the UE is in a roaming state, the H-PCF may transmit the updated UE policy to the UE via the V-PCF and the AMF.

[0088] In step 208, the PCF may include information about the priority value of each slice or slice group determined in step 207 in a response message transmitted by the PCF to the AMF.

[0089] In step 209, the remaining UE registration process may be performed.

[0090] In step 210, the AMF may include the registration accept message in the N2 message transmitted by the AMF to the RAN. When the AMP determines the NSAG information in step 205, the AMP may include the NSAG information in the registration accept message transmitted by the AMF to the UE. When the AMF determines the NSAG information in step 205, the AMF may include the NSAG information, the configured NSSAI, and the mapping of the configured NSSAI information in the registration accept message transmitted by the RAN to the UE.

[0091] Specifically, in step 211, the RAN may transmit a registration accept message to the UE within the message received from the AMF in step 210.

[0092] Figure 3 The structure of a UE according to an embodiment is shown.

[0093] like Figure 3 As shown, the UE may include a processor 320, a transceiver 300, and a memory 310. However, the components of the UE are not limited to the above examples. For example, the UE may include more or fewer components than the above components. In addition, the processor 320, the transceiver 300, and the memory 310 may be implemented as a single chip.

[0094] The processor 320 may control a series of processes, and the UE may perform these processes according to the above-mentioned embodiments. For example, the processor 320 may control the components of the UE to perform the method of supporting the priority of network slicing according to the above-mentioned embodiments. The processor 320 may execute the program stored in the memory 310 to control the components of the UE, thereby performing the above-mentioned embodiments of the present disclosure. In addition, the processor 320 may be an application processor (AP), a communication processor (CP), a circuit, a dedicated circuit, or at least one processor.

[0095] The transceiver 300 may transmit / receive signals to / from a network entity, another UE, or RAN. The signals transmitted to and received from the network entity, another UE, or RAN may include control information and data. The transceiver 300 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-conversion of the frequency of the received signal. However, the components of the transceiver 300 are not limited to the RF transmitter and the RF receiver. In addition, the transceiver 300 may receive a signal via a wireless channel, output the signal to the processor 320, and transmit the signal output from the processor 320 via the wireless channel.

[0096] The memory 310 may store programs and data required for the operation of the UE. In addition, the memory 310 may store control information or data included in the signal transmitted and received by the UE. The memory 310 may include a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, and a digital versatile disk (DVD) or a combination of storage media. In addition, a plurality of memories 310 may be provided, and the memory 310 may store a program for executing the method for supporting the priority of network slicing according to the above-mentioned embodiment.

[0097] Figure 4 The structure of a RAN according to an embodiment is shown.

[0098] like Figure 4 As shown, the RAN may include a processor 420, a transceiver 400, and a memory 410. However, the components of the RAN are not limited to the above examples. For example, the RAN may include more or fewer components than the above components. In addition, the processor 420, the transceiver 400, and the memory 410 may be implemented as a single chip.

[0099] The processor 420 may control a series of processes, and the RAN may perform these processes according to the above embodiments. For example, the processor 420 may control the components of the RAN to perform the method of supporting the priority of network slicing according to the above embodiments. The processor 420 may execute the program stored in the memory 410 to control the components of the RAN, thereby performing the above embodiments of the present disclosure. In addition, the processor 420 may be at least one processor.

[0100] The transceiver 400 may transmit / receive signals to / from a network entity, another RAN, or a UE. The signals transmitted to and received from the network entity, another RAN, or a UE may include control information and data. The transceiver 400 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-conversion of the frequency of the received signal. However, the components of the transceiver 400 are not limited to the RF transmitter and the RF receiver. In addition, the transceiver 400 may receive a signal via a wireless channel, output the signal to the processor 420, and transmit the signal output from the processor 420 via the wireless channel.

[0101] The memory 410 may store programs and data required for the operation of the RAN and may store control information or data included in a signal transmitted and received by the RAN. The memory 410 may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media, and a plurality of memories 410 may be provided. In addition, the memory 410 may store a program for executing the method of supporting priority of network slicing according to the above-described embodiment.

[0102] Figure 5 The structure of a network entity according to an embodiment is shown.

[0103] like Figure 5 As shown, the network entity may include a processor 520, a transceiver 500, and a memory 510. However, the components of the network entity are not limited to the above examples. For example, the network entity may include more or fewer components than the above components. In addition, the processor 520, the transceiver 500, and the memory 510 may be implemented as a single chip.

[0104] The processor 520 may control a series of processes, and the network entity may perform these processes according to the above embodiments. For example, the processor 520 may control the components of the network entity to perform the method of supporting the priority of network slicing according to the above embodiments. The processor 520 may execute the program stored in the memory 510 to control the components of the network entity, thereby performing the above embodiments of the present disclosure. In addition, the processor 520 may be at least one processor.

[0105] The transceiver 500 may transmit a signal to / receive a signal from another network entity, RAN or UE. The signal transmitted to and received from another network entity or UE may include control information and data. The transceiver 500 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-conversion of the frequency of the received signal. However, the components of the transceiver 500 are not limited to the RF transmitter and the RF receiver. In addition, the transceiver 500 may receive a signal via a wireless channel, output the signal to the processor 520, and transmit the signal output from the processor 520 via the wireless channel.

[0106] The memory 510 may store programs and data required for the operation of the network entity. In addition, the memory 510 may store control information or data included in the signal transmitted and received by the network entity. The memory 510 may include a storage medium such as a ROM, RAM, hard disk, CD-ROM and DVD or a combination of storage media. A plurality of memories 510 may be provided, and the memory 510 may store a program for executing the method for supporting the priority of network slicing according to the above-described embodiment.

[0107] As described above, a method performed by an AMF entity in a wireless communication system includes: receiving a registration request message including an NSAG information request from a UE, receiving NSAG information including S-NSSAI priority information and mapping information between S-NSSAI and NSAG identifiers from another entity, transmitting at least one of NSAG information or NSAG TA boundary information to a PCF entity, and receiving NSAG priority information from the PCF entity based on the NSAG information; and transmitting a registration response message including at least one of NSAG information, NSAG TA boundary information or NSAG priority information to the UE.

[0108] According to one embodiment, the other entity comprises an old AMF entity.

[0109] The method also includes receiving NSAG information from another entity, including: receiving S-NSSAI priority information from a UDM entity, and receiving mapping information between S-NSSAI and NSAG identifier from a network slice selection function (NSSF) entity.

[0110] The method also includes, wherein the registration response information further includes NSAG restricted area information.

[0111] The method also includes transmitting a UE policy update request message to a PCF entity based on the NSAG priority, and receiving a UE policy update response message including an updated UE policy from the PCF entity.

[0112] As described above, a method performed by a UE in a wireless communication system includes: transmitting a registration request message including an NSAG information request to an AMF entity, receiving a registration response message from the AMF entity, the registration response message including at least one of NSAG information, NSAG TA boundary information, or NSAG priority information, wherein the NSAG information is associated with S-NSSAI priority information from another entity and mapping information between the S-NSSAI and the NSAG identifier, wherein the NSAG priority information is associated with the NSAG information from the PCF entity.

[0113] The method also includes another entity including an old AMF entity.

[0114] The method also includes, wherein S-NSSAI priority information is transmitted from a UDM entity, and wherein mapping information between the S-NSSAI and the NSAG identity is transmitted from a NSSF entity.

[0115] The method also includes, wherein the registration response information further includes NSAG restricted area information.

[0116] The method further includes receiving an updated UE policy from the PCF entity based on the NSAG priority.

[0117] As described above, an AMF entity in a wireless communication system includes a transceiver and at least one processor, which is connected to the transceiver and configured to: receive a registration request message including an NSAG information request from a UE, receive NSAG information including S-NSSAI priority information and mapping information between S-NSSAI and NSAG identifier from another entity, transmit at least one of NSAG information or NSAG TA boundary information to a PCF entity, receive NSAG priority information from the PCF entity based on the NSAG information; and transmit a registration response message including at least one of NSAG information, NSAG TA boundary information or NSAG priority information to the UE.

[0118] As described above, a UE in a wireless communication system includes a transceiver and at least one processor, which is connected to the transceiver and configured to transmit a registration request message including an NSAG information request to an AMF entity, and receive a registration response message from the AMF entity, the registration response message including at least one of NSAG information, NSAG TA boundary information or NSAG priority information, wherein the NSAG information is associated with S-NSSAI priority information transmitted from another entity and mapping information between S-NSSAI and NSAG identifier, wherein the NSAG priority information is associated with NSAG information transmitted from a PCF entity.

[0119] As described above, a method performed by a UE may include: transmitting a registration request message to a RAN, and receiving a registration acceptance message including NSAG information related to a priority of each network slice from the RAN via an AMF, wherein the registration request message includes NSAG support information, transmitting the registration request message to the AMF via the RAN, and determining the NSAG information based on the NSAG support message.

[0120] The methods according to the embodiments described herein may be implemented by hardware, software, or a combination of hardware and software.

[0121] When the method is implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors in an electronic device. At least one program may include instructions that cause an electronic device to perform a method according to an embodiment of the present disclosure.

[0122] The program (software module or software) can be stored in a non-volatile memory, including random access memory and flash memory, ROM, electrically erasable programmable read-only memory (EEPROM), magnetic disk storage, compact disc-ROM (CD-ROM), DVD or other type of optical storage, or magnetic tape cassette. Alternatively, any combination of some or all of the memories can form a memory storing the program. Multiple such memories may be included in an electronic device.

[0123] In addition, the program can be stored in an attachable storage device that can access the electronic device through a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), and a storage area network (SAN), or a combination thereof. Such a storage device can access the electronic device via an external port. A separate storage device on a communication network can access the portable electronic device.

[0124] In this article, each frame of the flowchart diagram and the frame combination in the flowchart description can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the function specified in one or more flowchart frames. These computer program instructions can also be stored in a computer-available or computer-readable memory, which can instruct the computer or other programmable data processing device to operate in a particular manner, so that the instructions stored in the computer-available or computer-readable memory produce an article including an instruction device, which implements the function specified in the one or more flowchart frames. Computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operating steps are performed on a computer or other programmable device, thereby generating a computer-implemented process, so that the instructions executed on a computer or other programmable device provide steps for implementing the function specified in one or more flowchart frames.

[0125] Each frame of the flowchart diagram can represent a module, a code segment or a code portion, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the frame may not occur in order. For example, depending on the functionality involved, two frames shown in succession can actually be executed roughly at the same time, or these frames can sometimes be executed in reverse order.

[0126] While the present disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the subject matter defined by the appended claims and their equivalents.

Claims

1. A method performed by an access and mobility management function AMF entity in a wireless communication system, the method include: receiving a registration request message including a network slice access stratum AS group NSAG information request from a user equipment UE; Receiving NSAG information including single network slice selection assistance information S-NSSAI priority information and mapping information between the S-NSSAI and the NSAG identifier from another entity; transmitting at least one of the NSAG information or the NSAG tracking area TA boundary information to a policy control function PCF entity; receiving NSAG priority information from the PCF entity based on the NSAG information; as well as A registration response message including at least one of the NSAG information, the NSAG TA boundary information, or the NSAG priority information is transmitted to the UE.

2. The method according to claim 1, wherein the other entity comprises an old AMF entity, and The registration response message also includes NSAG restricted area information.

3. The method of claim 1, wherein the NSAG information is received from the other entity include: Receiving the S-NSSAI priority information from a unified data management (UDM) entity; as well as The mapping information between the S-NSSAI and the NSAG identifier is received from the network slice selection function NSSF entity.

4. The method according to claim 1, further comprising: include: Based on the NSAG priority, transmitting a UE policy update request message to the PCF entity; as well as A UE policy update response message including an updated UE policy is received from the PCF entity.

5. A method performed by a user equipment UE in a wireless communication system, the method include: Sending a registration request message including a request for network slice access stratum AS group NSAG information to the access and mobility management function AMF entity; as well as receiving a registration response message including at least one of NSAG information, NSAG tracking area TA boundary information or NSAG priority information from the AMF entity, The NSAG information is associated with single network slice selection assistance information S-NSSAI priority information transmitted from another entity and mapping information between the S-NSSAI and the NSAG identifier, and The NSAG priority information is associated with the NSAG information transmitted from a policy control function PCF entity.

6. The method according to claim 5, wherein the other entity comprises an old AMF entity, and The registration response information also includes NSAG restricted area information.

7. The method according to claim 5, wherein the S-NSSAI priority information is transmitted from a unified data management (UDM) entity, and The mapping information between the S-NSSAI and the NSAG identifier is transmitted from the network slice selection function NSSF entity.

8. An access and mobility management function AMF entity in a wireless communication system, the AMF entity include: Transceiver; as well as at least one processor connected to the transceiver and configured to: receiving a registration request message including a network slice access stratum AS group NSAG information request from a user equipment UE; Receiving NSAG information including single network slice selection assistance information S-NSSAI priority information and mapping information between the S-NSSAI and the NSAG identifier from another entity; transmitting at least one of the NSAG information or the NSAG tracking area TA boundary information to a policy control function PCF entity; receiving NSAG priority information from the PCF entity based on the NSAG information; as well as A registration response message including at least one of the NSAG information, the NSAG TA boundary information, or the NSAG priority information is transmitted to the UE.

9. The AMF entity as claimed in claim 8, wherein the other entity comprises an old AMF entity, and The registration response information also includes NSAG restricted area information.

10. The AMF entity of claim 8, wherein in order to receive the other entity, the at least one processor is further configured to: Receiving the S-NSSAI priority information from a unified data management (UDM) entity; and The mapping information between the S-NSSAI and the NSAG identifier is received from the network slice selection function NSSF entity.

11. The AMF entity of claim 8, wherein the at least one processor is further configured to: Transmitting a UE policy update request message to the PCF entity based on the NSAG priority; and A UE policy update response message including an updated UE policy is received from the PCF entity.

12. A user equipment UE in a wireless communication system, the UE include: Transceiver; as well as At least one processor connected to the transceiver and configured to: Transmitting a registration request message including a network slice access stratum AS group NSAG information request to the access and mobility management function AMF entity; and receiving a registration response message including at least one of NSAG information, NSAG tracking area TA boundary information or NSAG priority information from the AMF entity, The NSAG information is associated with single network slice selection assistance information S-NSSAI priority information transmitted from another entity and mapping information between the S-NSSAI and the NSAG identifier, and The NSAG priority information is associated with the NSAG information transmitted from a policy control function PCF entity.

13. The UE according to claim 12, wherein the other entity comprises an old AMF entity, and The registration response information also includes NSAG restricted area information.

14. The UE according to claim 12, wherein the S-NSSAI priority information is transmitted from a unified data management (UDM) entity, and The mapping information between the S-NSSAI and the NSAG identifier is transmitted from the network slice selection function NSSF entity.

15. The UE of claim 12, wherein the at least one processor is further configured to: Based on the NSAG priority, an updated UE policy is received from the PCF entity.

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