RU2790581C1 - Device and method for provision of inter-network interaction at level of network slices in wireless communication system - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: invention relates to a communication system before the fifth generation (5G) or 5G-, presented to support a communication system after the fourth generation (4G). The method for UE operation contains: transmission to the first BS of a message with a request for establishment of connection in a packet data transmission network (hereinafter – PDN); reception from the first BS of information relatively to the first single network slice selection assistance information (hereinafter – S-NSSAI) selected by means of a combination of PDN gateway control (PGW-C) plane and a session management function (SMF) of at least one signed S-NSSAI of UE; transmission to the second BS of a message with a request for registration, including requested NSSAI, which includes the first S-NSSAI; and reception from the second BS of a message with registration confirmation, including allowed NSSAI, which includes the second S-NSSAI converted into the first S-NSSAI.

EFFECT: possibility of separation of a network into slices (S-NSSAI) in a wireless communication system.

14 cl, 10 dwg, 1 tbl

Description

The field of technology to which the invention belongs

[0001] The disclosure relates to a wireless communication system. More specifically, the disclosure relates to an apparatus and method for providing network slicing in a wireless communication system.

State of the art

[0002] In order to meet the demand for increasing wireless data traffic since the deployment of fourth generation (4G) communication systems, efforts are being made to develop an improved fifth generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also referred to as "out-of-4G network" or "post-Long Term Evolution (LTE) system".

[0003] It is believed that the 5G communication system is implemented in higher frequency bands (mmWave), for example, in the frequency bands of 28 GHz to 60 GHz, in order to achieve higher data rates. In order to reduce the propagation loss and increase the transmission distance, Beamforming, Massive Multiple Input Multiple Output (MIMO), Full Size MIMO (FD-MIMO), Array Antenna, Analog Beamforming, Large Scale Antenna Technologies are discussed in 5G communication systems.

[0004] In addition, in 5G communication systems, developments are underway to improve the system network based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D), wireless reverse backhaul, roaming network, collaborative communication, coordinated multipoint transmission (CoMP), interference suppression at the receiving end, and the like.

[0005] In the 5G system, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (FQAM) and variable duration windowing coding (SWSC) are developed as advanced coded modulation (ACM), as well as a wireless access interface on multiple filterbank carriers (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology.

[0006] In a 5G system, various communication schemes are discussed. For example, a permissionless communication scheme for transmitting data without permission on an uplink is proposed. In addition, various discussions are being held to effectively support communication without permission to transfer. The above information is provided as background information only to assist in understanding the disclosure. No determination is made and no judgment is made as to whether or not any of the foregoing may or may not be applicable as prior art with respect to the disclosure.

[0007] Based on the above discussion, the disclosure provides a method and apparatus for interworking between an Evolved Packet Switched System (EPS) network system architecture and a 5G network system to provide a function based on network slices in a wireless communication system.

[0008] The above information is provided as background information only to assist in understanding the disclosure. No determination is made and no judgment is made as to whether or not any of the foregoing may or may not be applicable as prior art with respect to the disclosure.

The essence of the invention

The solution of the problem

[0009] Aspects of the disclosure are to address at least the above problems and/or disadvantages and provide at least the benefits described below. Accordingly, an aspect of the disclosure is to provide an apparatus and method for providing network slicing in a wireless communication system.

[0010] Additional aspects of the embodiments are set forth in part in the description which follows, and in part are obvious from the description or may be recognized through practice of the presented embodiments.

[0011] In accordance with an aspect of the disclosure, a method is provided for operating a user equipment (UE) in a wireless communication system. The method comprises: sending, to a first base station (BS), a connection request message over a packet data network (PDN); receiving, from the first BS, information regarding the first single network slice selection assistance information (S-NSSAI) selected by a combination of a packet data network control plane gateway entity (PGW-C) and a session management function (SMF) from at least at least one subscribed S-NSSAI UE; transmitting, to the second BS, a registration request message including the requested NSSAI in which the first S-NSSAI is included; and receiving, from the second BS, a registration confirmation message including the allowed NSSAI, which includes the second S-NSSAI mapped to the first S-NSSAI.

[0012] In accordance with another aspect of the disclosure, a user equipment (UE) in a wireless communication system is provided. The UE contains: a transceiver; and at least one processor operatively connected to the transceiver and configured to: transmit, to the first base station (BS), a connection request message over a packet data network (PDN); receive, from the first BS, information regarding the first single network slice selection assistance information (S-NSSAI) selected by a combination of a packet data network control plane gateway entity (PGW-C) and a session management function (SMF) from at least at least one subscribed S-NSSAI UE; transmit, to the second BS, a registration request message including the requested NSSAI in which the first S-NSSAI is included; and receive, from the second BS, a registration confirmation message including the allowed NSSAI, which includes the second S-NSSAI mapped to the first S-NSSAI.

[0013] The apparatus and method according to various embodiments of the disclosure provide a method for interworking between the architecture of an EPS network system and a 5G network system to provide a function based on network slices so as to efficiently provide a service in a mobile communication system.

[0014] Other aspects, advantages, and features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, when considered in conjunction with the accompanying drawings, discloses various embodiments of the disclosure.

Brief description of the drawings

[0015] The above and other exemplary aspects, features, and advantages of specific embodiments of the disclosure should become more apparent from the description below, taken in conjunction with the accompanying drawings, in which:

[0016] FIG. 1 illustrates a framework for interworking at the 5G network slice level (no roaming) according to an embodiment of the disclosure;

[0017] FIG. 2 illustrates a configuration for interworking at the network slice level (no roaming) according to an embodiment of the disclosure;

[0018] FIG. 3 illustrates a configuration for slice level interworking (local break based roaming) according to an embodiment of the disclosure;

[0019] FIG. 4 illustrates a configuration for slice level internetworking (roaming based on home routing) according to an embodiment of the disclosure;

[0020] FIG. 5 illustrates the session management function+control gateway mode operation in a packet data network (SMF+PGW-C) to support slice level interworking according to an embodiment of the disclosure;

[0021] FIG. 6 illustrates operation in SMF+PGW-C mode to support slice level interworking according to an embodiment of the disclosure;

[0022] FIG. 7 illustrates a configuration of a base station in a wireless communication system according to an embodiment of the disclosure;

[0023] FIG. 8 illustrates a configuration of a UE in a wireless communication system according to an embodiment of the disclosure;

[0024] FIG. 9 illustrates a configuration of a network core device in a wireless communication system according to an embodiment of the disclosure; And

[0025] FIG. 10 illustrates a procedure for registering in a 5G network of a UE according to an embodiment of the disclosure.

[0026] Throughout the drawings, like reference numerals are to be understood as referring to like parts, components, and structures.

Optimal Mode for Carrying Out the Invention

[0027] The following description, with reference to the accompanying drawings, is provided to assist in a thorough understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various details to assist in this understanding, but they are to be regarded as merely exemplary. Accordingly, those skilled in the art will recognize that various changes and modifications to the various embodiments described herein may be made without departing from the spirit and scope of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and brevity.

[0028] The terms and words used in the following description and in the claims are not limited to bibliographical meanings, but are used by the inventor simply to provide a clear and consistent understanding of the disclosure. Accordingly, those skilled in the art will appreciate that the following description of various embodiments of the disclosure is provided for purposes of illustration only, and not for purposes of limiting the disclosure as defined by the appended claims and their equivalents.

[0029] It should be understood that the singular forms "a", "an", and "the" include multiple reference objects, unless the context clearly dictates otherwise. Thus, for example, a reference to a "component surface" includes a reference to one or more such surfaces.

[0030] The terms used in the disclosure are used only to describe specific embodiments, and may not be intended to limit the scope of other embodiments. Unless otherwise indicated, all terms used in this document, including technical and scientific terms, may have a meaning identical to the meaning commonly understood by those skilled in the art to which the disclosure relates. Such terms, which are defined in a general use dictionary, may be interpreted as having meanings that are equivalent or similar to contextual meanings in the relevant art, and should not be interpreted as having ideal or overly formal meanings, unless the disclosure explicitly states otherwise. In some cases, even a term defined in an entity disclosure should not be interpreted as excluding various embodiments of the entity disclosure.

[0031] Later in this document, various embodiments of the entity disclosure based on a hardware-based approach are described. However, various embodiments of the disclosure include technology that uses both hardware and software, whereby the various embodiments of the disclosure do not preclude a software approach.

[0032] The disclosure relates to an apparatus and method for providing network slice internetworking in a wireless communication system. Specifically, the disclosure describes a technology for interworking between an architecture of an EPS network system and a 5G network system to provide a function based on network slices in a wireless communication system.

[0033] The terms used below are illustrated for convenience of description, and the terms include a term indicating a signal, a term indicating a channel, a term indicating control information, a term indicating a network entity, and a term indicating a device element. Accordingly, the disclosure is not limited to the following terms, and other terms having the same technical meaning may be used.

[0034] In addition, the disclosure describes various embodiments by using terms used in the communication standards part (eg, 3rd Generation Partnership Project (3GPP)), but the embodiments are illustrated for description only. Various embodiments of the disclosure may be easily modified and applied to other communication systems.

[0035] In 3GPP standards, the architecture and procedure in a 5G network system is standardized. A mobile service provider may provide multiple services on a 5G network. In order to provide each service, the mobile service provider must meet the different service needs for each service (eg, delay time, communication range, data rate, bandwidth, reliability, etc.). To this end, the mobile service provider may compose a network slice and allocate network resources suitable for a particular service according to the network slice or set of network slices. The network resource may indicate a network function (NF), a logical resource that the NF grants, or a base station radio resource allocation.

[0036] For example, a mobile service provider may compose network slice A to provide a mobile broadband service, network slice B to provide a vehicle communication service, and network slice C to provide an IoT service. As described above, in a 5G network, a corresponding service may be provided for a network slice specialized for each service characteristic. The Single Network Slice Selection Auxiliary Information (S-NSSAI) specified by 3GPP may be used as an identifier that identifies a network slice.

[0037] A mobile service provider may manage both a 5G network and an EPS (alternatively referred to as "LTE") network. The mobile communication UE may move to the EPS network when accessing the 5G network and using the service. In addition, the mobile communication UE can move to the 5G network when accessing the EPS network and using the service.

[0038] The disclosure specifies a method for interworking between the architecture of an EPS network system and a 5G network system to provide a function based on network slices. Fig. 1, 2, and 3 illustrate a framework for interworking between a 5G system (5GS) and an Evolved Packet Switched System (EPS).

[0039] In addition, the disclosure specifies network operation and UE operation in which a session connection is established in the EPS to enable the UE using the communication service to use the service without disconnection even when the UE moves to 5GS.

[0040] FIG. 1 illustrates a framework for 5GS and EPS interworking in case of no roaming according to an embodiment of the disclosure.

[0041] Referring to FIG. 1, the 5GS may include a new radio standard (NR) based base station 150, an access and mobility management function (AMF) 145, a session management function (SMF) 120, a user plane function (UPF) 125 , a policy management function (PCF) 115 , and a unified data management (UDM) function 110 . The EPS may include an Evolved Universal Terrestrial Radio Access (E-UTRA) base station 140, a Mobility Management Entity (MME) 135, a Serving Gateway 130 (SGW), a Packet Data Network User Gateway 125 (PGW-U), a 120 packet data network control (PGW-C), function 115 rules and policies charging and charging services (PCRF) and the server 110 home subscribers (HSS). UDM 110 5GS and HSS 110 EPS can be configured as one combined unit. SMF 120 5GS and PGW-C 120 EPS can be configured as one combined unit. Node UDM+HSS 110 may store information on UE subscriptions. UPF 125 5GS and PGW-U 125 EPS can be combined as one combined unit. The UE 155 may access the EPS MME 135 via the E-UTRA base station 140 to use the EPS network service. In addition, the UE 155 may access the 5GS AMF 145 via the NR base station 150 to use the 5GS network service.

[0042] FIG. 2 illustrates a framework for 5GS and EPS interworking in the case of local break based roaming according to an embodiment of the disclosure. As illustrated in FIG. 1, UE 260 may access EPS MME 240 via E-UTRA base station 245 to use EPS network service.

[0043] Referring to FIG. 2, in addition, the UE 260 may access the 5GS AMF 250 via the NR base station 255 to use the 5GS network service. In the framework for 5GS and EPS interworking, in the case of local break based roaming, the SMF+PGW-C node 225 may be located in a Visited PLMN (VPLMN). N1, N2, N3, N8, N10, N11, N15, N26, S1-MME, S1-U, S6a, S11, S5-C and S5-U shown in FIG. 1 and FIG. 2 represent interfaces between network elements in EPS and 5GS.

[0044] FIG. 3 illustrates a framework for 5GS and EPS interworking in the case of home routing based roaming according to an embodiment of the disclosure. As illustrated in FIG. 1, the UE 370 may access the EPS MME 335 via the E-UTRA base station 340 to use the EPS network service.

[0045] Referring to FIG. 3, in addition, the UE 370 may access the 5GS AMF 360 via an NR base station (NG-RAN) 365 to use the 5GS network service. In the framework for 5GS and EPS interworking, in the case of home routing based roaming, the SMF+PGW-C 320 may be located in a home PLMN (HPLMN). N1, N2, N3, N8, N9, N10, N11, N15, N16, N24, N26, S1-MME, S1-U, S6a, S11, S8-C and S8-U shown in FIG. 3 represent interfaces between network elements in EPS and 5GS.

[0046] FIG. 4 illustrates a procedure for establishing, by UE 410 according to an embodiment of the disclosure, a packet data network (PDN) connection in an EPS.

[0047] Referring to FIG. 4, UE 410 may establish a PDN connection by accessing MME 420 via E-UTRA base station 415 to exchange service messages with PGW-C 430 located in EPS. When the PDN connection establishment is completed, UE 410 may transmit uplink data to PGW-U 435 or receive downlink data from PGW-U 435.

[0048] Procedure 1: UE 410 may send a PDN connection request message to MME 420 to establish a PDN connection. The PDN connection request message may be sent to the MME 420 via the E-UTRA base station 415.

[0049] Procedure 2: Upon receiving the PDN connection request message in procedure 1, the MME 420 may send a session creation request message to the S-GW 425.

[0050] Procedure 3: Upon receiving the session request message in procedure 2, the S-GW 425 may send a session request message to the SMF+PGW-C 430.

[0051] Procedure 4: upon receiving the session creation request message in procedure 3, the SMF+PGW-C 430 may perform a session establishment/modification procedure in an Internet Protocol connection-based access network (IP-CAN) along with PCF+ PCRF 440.

[0052] Procedure 5: Upon receiving the session creation request message in procedure 3, the SMF+PGW-C 430 may send a Nudm_SDM_Get request message to the UDM+HSS 445. The Nudm_SDM_Get request message may include the data type of the requested information subscription information and information regarding the key available for the subscription information data type. According to an embodiment of the disclosure, "slice selection subscription data" may be included as the requested subscription information data type, and the UE identifier "SUPI" may be included as a key available for the subscription information data type.

[0053] Procedure 6: Upon receipt of the Nudm_SDM_Get request message in procedure 5, UDM+HSS 445, from the database (UDR), may retrieve subscription information in the UE network slice corresponding to the SUPI of the received UE when the request message for Nudm_SDM_Get includes a "subscription data for slicer selection" parameter. According to an embodiment of the disclosure, subscription information in a network slice may be configured by at least one S-NSSAI and referred to as "Subscribed S-NSSAI". When retrieving the signed S-NSSAIs of the UE corresponding to the received SUPI, the UDM+HSS 445 may send a Nudm_SDM_Get response message to the SMF+PGW-C 430. The Nudm_SDM_Get response message may include "S-NSSAI signed" information of the corresponding SUPI. "Subscribed S-NSSAI" may include at least one default S-NSSAI. To describe entity disclosure, "signed S-NSSAI" may be described as an example as follows.

[0054] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0055] UE 410 subscribes to three S-NSSAIs, and it can be assumed that out of the three S-NSSAIs, S-NSSAI 3 is the default S-NSSAI.

[0056] When the PLMN ID included in the UE ID SUPI matches the PLMN ID in which the SMF+PGW-C 430 is located (ie, according to the embodiments of FIGS. 1 and 3), as illustrated in FIG. 5, upon receiving the Nudm_SDM_Get response message, the SMF+PGW-C 430 may perform an SMF+PGW-C 430 operation to allow the SMF+PGW-C 430 to select an S-NSSAI.

[0057] FIG. 5 illustrates operation in SMF+PGW-C mode to support slice level interworking according to an embodiment of the disclosure.

[0058] Referring to FIG. 5, steps 510, 515, and 520 correspond to procedures 3, 5, and 6 of FIG. 4. Upon receiving the Nudm_SDM_Get response message (step 520), the SMF+PGW-C 430 may identify (step 525) whether or not the S-NSSAI that the SMF+PGW-C 430 can provide is included in the "signed S- NSSAI" included in the Nudm_SDM_Get response message received in procedure 6.

[0059] When there is no S-NSSAI that SMF+PGW-C 430 can provide (block 530), or when there is no S-NSSAI matching the "signed S-NSSAI" received in procedure 6 from one or more S- NSSAIs that the SMF+PGW-C 430 may provide (step 530), the SMF+PGW-C 430 may select a default S-NSSAI from among the "signed S-NSSAIs" received in procedure 6 (method 1), or may not select S-NSSAI (method 2). At step 550, the PGW-C SMF may not include slice information in the session establishment response (method 2_1), or the PGW-C SMF may reject the session establishment request (method 2_2). Alternatively, at step 545, the session creation response message of procedure 9 may include slicing information that is selected through the procedure.

[0060] When a single S-NSSAI is provided that the SMF+PGW-C 430 can provide, and the corresponding S-NSSAI is included in the "Subscribed S-NSSAI" received in procedure 6 (block 535), or when a single S-NSSAI is provided , matching the "Signed S-NSSAI" received in procedure 6, from two or more S-NSSAIs that the SMF+PGW-C 430 may provide (step 535), the SMF+PGW-C 430 may select one S-NSSAI, which may be provided by SMF+PGW-C 430 and is included in "signed S-NSSAI". At step 545, the session creation response message of procedure 9 may include slicing information that is selected through the procedure.

[0061] When two or more S-NSSAIs are provided that SMF+PGW-C 430 can provide, and of these, two or more S-NSSAIs are included in "Subscribed S-NSSAI" (step 540), SMF+PGW-C 430 may select one S-NSSAI from among two or more S-NSSAIs that are included in "Subscribed S-NSSAIs" and may be provided by SMF+PGW-C 430, based on the mobile service provider policy configured in SMF+PGW- C 430. In step 545, the procedure session creation response message 9 may include slicing information that is selected through the procedure.

[0062] When the PLMN ID included in the UE ID SUPI matches the PLMN ID in which the SMF+PGW-C 430 is located (i.e., according to the embodiments of FIGS. 1 and 3), procedures 7 and 8 may not be performed.

[0063] When the PLMN ID included in the SUPI of the UE ID does not match the PLMN ID in which the SMF+PGW-C 430 is located (i.e., according to the embodiment of FIG. 2), procedures 7 and 8 may be performed .

[0064] Procedure 7: Upon receiving the Nudm_SDM_Get response message in procedure 6, the SMF+PGW-C 430 may send an Nnssf_NSSelection_Get request message to the NSSF 450. The Nnssf_NSSelection_Get request message may include a "PLMN identifier" included in UE ID SUPI and "S-NSSAI signed" UEs received from UDM+HSS 445 in procedure 6. The "PLMN ID" included in the SUPI may indicate the HPLMN of the UE. "S-NSSAI Signed" may indicate slice information used in the HPLMN UE.

[0065] Procedure 8: Upon receipt of the Nnssf_NSSelection_Get request message in procedure 7, the NSSF 450 may extract the "transformed S-NSSAIs" that are mapped to the "signed S-NSSAIs" included in the request message to be used in the VPLMN. To describe the entity disclosure, "signed S-NSSAI" and "transformed S-NSSAI" may be described by way of example as follows.

[0066] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0067] Converted S-NSSAI: {(S-NSSAI 1, S-NSSAI a), (S-NSSAI 2, S-NSSAI b), (S-NSSAI 3, S-NSSAI c)}

[0068] The S-NSSAIs included in "Subscribed S-NSSAIs" may be configured by a slice value (eg, S-NSSAI 1) used in the HPLMN UE. The S-NSSAIs included in "transformed S-NSSAIs" may be configured by a pair of (eg, (S-NSSAI 1, S-NSSAI a)) slice values (eg, S-NSSAI a) mapped to a slice value (eg , S-NSSAI 1) used in the HPLMN by the UE to be used in the VPLMN.

[0069] The NSSF 450 may send an Nnssf_NSSelection_Get response message to the SMF+PGW-C 430. The Nnssf_NSSelection_Get response message may include "transformed S-NSSAIs".

[0070] Upon receipt of the Nnssf_NSSelection_Get Response message, the SMF+PGW-C 430 may perform an SMF+PGW-C 430 operation to allow the SMF+PGW-C 430 to select an S-NSSAI, as illustrated in FIG. 6.

[0071] FIG. 6 illustrates operation in SMF+PGW-C mode to support slice level interworking according to an embodiment of the disclosure.

[0072] Referring to FIG. 6, steps 610, 615, and 620 correspond to procedures 3, 6, and 8 of FIG. 4. Upon receipt of the Nnssf_NSSelection_Get response message (block 620), the SMF+PGW-C 430 may identify (block 625) whether or not the S-NSSAI that can be provided by the SMF+PGW-C 430 is included by using the "transformed S-NSSAI" included in the Nnssf_NSSelection_Get response message to "S-NSSAI signed" included in the Nudm_SDM_Get response message received in procedure 6. For the above step, the SMF+PGW-C 430 may use the received "transformed S-NSSAI" to interpret the information "signed S-NSSAI".

[0073] For example, when the slice provided by SMF+PGW-C 430 is S-NSSAI a, SMF+PGW-C 430 may use the received "transformed S-NSSAI" information to identify that S-NSSAI 1 , converted to S-NSSAI a, which is a slice provided by SMF+PGW-C 430, is included in "signed S-NSSAI".

[0074] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0075] Converted S-NSSAI: {(S-NSSAI 1, S-NSSAI a), (S-NSSAI 2, S-NSSAI b), (S-NSSAI 3, S-NSSAI c)}

[0076] In addition, for example, when the slice provided by the SMF+PGW-C 430 is S-NSSAI d, the SMF+PGW-C 430 may use the received "transformed S-NSSAI" information to identify what the S -NSSAI d, which is a slice provided by SMF+PGW-C 430, is not included in "signed S-NSSAI".

[0077] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0078] Converted S-NSSAIs: {(S-NSSAI 1, S-NSSAI a), (S-NSSAI 2, S-NSSAI b), (S-NSSAI 3, S-NSSAI c)}

[0079] For example, when the slices provided by the SMF+PGW-C 430 are S-NSSAI a and S-NSSAI d, the SMF+PGW-C 430 may use the received "transformed S-NSSAI" information to identify whether that of the slices provided by SMF+PGW-C 430, S-NSSAI a is included in "signed S-NSSAI" but S-NSSAI d is not included in "signed S-NSSAI".

[0080] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0081] Converted S-NSSAI: {(S-NSSAI 1, S-NSSAI a), (S-NSSAI 2, S-NSSAI b), (S-NSSAI 3, S-NSSAI c)}

[0082] For example, when slices provided by SMF+PGW-C 430 are S-NSSAI a and S-NSSAI c, SMF+PGW-C 430 may use "transformed S-NSSAI" information received as follows, with in order to identify that both S-NSSAI a and S-NSSAI c, which are provided by SMF+PGW-C 430, are included in "signed S-NSSAI".

[0083] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0084] Converted S-NSSAI: {(S-NSSAI 1, S-NSSAI a), (S-NSSAI 2, S-NSSAI b), (S-NSSAI 3, S-NSSAI c)}

[0085] When there is no S-NSSAI that the SMF+PGW-C 430 can provide (block 630), or when there is no S-NSSAI matching the "signed S-NSSAI" received in procedure 6 from one or more S- NSSAIs (e.g., S-NSSAI d) that the SMF+PGW-C 430 may provide (step 630), the SMF+PGW-C 430 may select a default S-NSSAI from among the "signed S-NSSAIs" received in procedure 6 (method 1), or may not select S-NSSAI (method 2). At 650, the PGW-C SMF may not include slice information in the session creation response (method 2_1), or the PGW-C SMF may reject the session establishment request (method 2_2). Alternatively, at step 645, the session creation response message of procedure 9 may include slicing information that is selected through the procedure.

[0086] When there is one S-NSSAI (eg, S-NSSAI a) that SMF+PGW-C 430 can provide, and the corresponding S-NSSAI is included in the "Subscribed S-NSSAI" received in Procedure 6 (eg, S -NSSAI 1 mapped to S-NSSAI a) (step 635), or when one S-NSSAI is provided (e.g. S-NSSAI 1 mapped to S-NSSAI a and HPLMN S-NSSAI mapped to S- is not provided) NSSAI d) matching the "Signed S-NSSAI" received in procedure 6 of two or more S-NSSAIs (eg, S-NSSAI a and S-NSSAI d) that the SMF+PGW-C 430 can provide (step 635), SMF+PGW-C 430 may select one S-NSSAI, which may be provided by SMF+PGW-C 430 and included in "Subscribed S-NSSAI". Thus, at step 645, the session creation response message of procedure 9 may include slicing information that is selected through the procedure.

[0087] When two or more S-NSSAIs are provided that SMF+PGW-C 430 can provide, and of these, two or more S-NSSAIs are included in "Subscribed S-NSSAI" (step 640), SMF+PGW-C 430 may select one S-NSSAI from among two or more S-NSSAIs that are included in "Subscribed S-NSSAIs" and may be provided by SMF+PGW-C 430, based on the mobile service provider policy configured in SMF+PGW- C 430. Thus, at step 645, the procedure session creation response message 9 may include slicing information that is selected through the procedure.

[0088] Procedure 9: When receiving a Nudm_SDM_Get response message in procedure 6 (i.e., in the embodiments of FIGS. 1 and 3) or receiving an Nnssf_NSSelection_Get response message in procedure 8 (i.e., in the embodiment of 2), SMF+PGW-C 430 may send a session creation response message to S-GW 425.

[0089] The create session response message may include slicing information that is selected through the procedure of FIG. 5 or 6, in the form of protocol configuration parameters (PCOs) (steps 545, 645). The slice information included in the create session response message may include various methods. The slice information included in the create session response message may be sent to the UE 410 via procedures 10, 11, and 12.

[0090] In addition, the SMF+PGW-C 430 may store, in the UDM+HSS 445, S-NSSAI, which is slice information selected through the procedure of FIG. 5 or 6 and PDN connection information (eg, PDN connection ID, etc.) supported by the S-NSSAI.

[0091] In the case of local break based roaming (ie, in the embodiment of FIG. 2), according to the embodiment of the disclosure, the following describes an example of slice information included in a session creation response message. To describe an embodiment of entity disclosure, it is assumed that SMF+PGW-C 430 performs the operation of FIG. 6 in order to select S-NSSAI 1 as follows.

[0092] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[0093] Converted S-NSSAI: {(S-NSSAI 1, S-NSSAI a), (S-NSSAI 2, S-NSSAI b), (S-NSSAI 3, S-NSSAI c)}

[0094] [LB Embodiment 1]: The SMF+PGW-C 430 according to the entity disclosure embodiment can enable S-NSSAI a, which maps to the selected S-NSSAI 1 to be used in the VPLMN, to be included in the form of configuration parameters protocol (PCO) in the session creation response message. The PCO may include a PLMN identifier using S-NSSAI a, i. e. VPLMN identifier.

[0095] Create Session Response Message: {..., PCO(S-NSSAI a)}

[0096] [LB Embodiment 2]: SMF+PGW-C 430 can provide the capability of S-NSSAI a to be mapped to the selected S-NSSAI 1 to be used in the VPLMN, and mapping information corresponding to S-NSSAI a, be included in the form of a PCO in the session creation response message. The PCO may include a PLMN identifier using S-NSSAI a, i. e. VPLMN identifier.

[0097] Create Session Response Message: {..., PCO(S-NSSAI a, (S-NSSAI 1, S-NSSAI a))}

[0098] or:

[0099] Create Session Response Message: {..., PCO ((S-NSSAI 1, S-NSSAI a))}

[00100] [LB Embodiment 3]: SMF+PGW-C 430 may allow the selected S-NSSAI 1 to be included in the form of a PCO in a session creation response message. The PCO may include a PLMN identifier using S-NSSAI 1, i. e. HPLMN identifier.

[00101] Create Session Response Message: {..., PCO(S-NSSAI 1)}

[00102] [LB Embodiment 4]: SMF+PGW-C 430 may allow the selected S-NSSAI 1 and mapping information corresponding to S-NSSAI 1 to be included in the form of a PCO in a session creation response message. The PCO may include a PLMN identifier using S-NSSAI 1, i. e. HPLMN ID and PLMN ID using S-NSSAI a, i.e. VPLMN identifier.

[00103] Create Session Response Message: {..., PCO(S-NSSAI 1, (S-NSSAI 1, S-NSSAI a))}

[00104] or:

[00105] Create Session Response Message: {..., PCO ((S-NSSAI 1, S-NSSAI a))}

[00106] [LB Embodiment 5]: SMF+PGW-C 430 may allow selected slice information not to be included in the session creation response message.

[00107] Create Session Response Message: {...}

[00108] In the case of home routing based roaming (i.e., in the embodiment of FIG. 3), according to the embodiment of the disclosure, the following describes an example of slice information included in a session creation response message. To describe an embodiment of entity disclosure, it is assumed that SMF+PGW-C 430 performs the operation of FIG. 5 in order to select S-NSSAI 1 as follows.

[00109] Signed S-NSSAI: {S-NSSAI 1, S-NSSAI 2, S-NSSAI 3 (default)}

[00110] [HR Embodiment 1]: SMF+PGW-C 430 according to an entity disclosure embodiment may allow a selected S-NSSAI 1 to be included in PCO form in a session creation response message. The PCO may include a PLMN identifier using S-NSSAI 1, i. e. HPLMN identifier.

[00111] Create Session Response Message: {..., PCO(S-NSSAI 1)}

[00112] [HR Embodiment 2]: SMF+PGW-C 430 may allow selected slice information not to be included in the session creation response message.

[00113] Create Session Response Message: {...}

[00114] Procedure 10: When receiving the create session response message in procedure 9, S-GW 425 may send a create session response message to MME 420. The create session response message that S-GW 425 sends to MME 420 may include slice information included in the session creation response message received in procedure 9.

[00115] Procedure 11: Upon receiving the session creation response message in procedure 10, the MME 420 may send a bearer establishment request message or a PDN Permit Downlink NAS Transport message to the underlying E-UTRA- station 415. The message that the MME 420 transmits to the E-UTRA base station 415 may include slicing information included in the session creation response message received in procedure 10.

[00116] Procedure 12: When receiving a bearer establishment request message or the PDN Permit Downlink NAS Transport message in procedure 11, the E-UTRA base station 415 may transmit an RRC Connection Reconfiguration message, or direct RRC transmission message to UE 410. The message that E-UTRA base station 415 transmits to UE 410 may include slice information included in the message received in procedure 11.

[00117] When receiving an RRC Connection Reconfigure message or a Direct RRC Transfer message, the UE 410 may store the S-NSSAI, i. e. the slice information included in the message and the PLMN identifier using the corresponding S-NSSAI. The slice information may be included in the form of a PCO in the message.

[00118] Procedure 13: Upon receiving the RRC Connection Reconfiguration message in Procedure 12, the UE 410 may send an RRC Connection Reconfiguration Complete message to the E-UTRA base station 415.

[00119] Procedure 14: Upon receiving the RRC Connection Reconfiguration Complete message in procedure 13, the E-UTRA base station 415 may send a bearer establishment response message to the MME 420.

[00120] Procedure 15: When receiving a direct RRC transmission message in procedure 12, UE 410 may transmit a direct transmission message to E-UTRA base station 415.

[00121] Procedure 16: Upon receiving the direct transfer message in procedure 15, the E-UTRA base station 415 may send a PDN connection complete message to the MME 420. Procedure 17: The MME 420 sends a bearer modification request to the S-GW 425. Procedure 18: S-GW 425 forwards to bearer modification request to SMF+PGW-C 430. Procedure 19: SMF+PGW-C 430 sends bearer modification response to S-GW 425. Procedure 20: S-GW 425 redirects in response to bearer modification in MME 420.

[00122] As illustrated in FIG. 4, a UE according to an embodiment of the disclosure may access an EPS network to establish a PDN connection and transmit or receive data. The UE may move to the 5GS network, at which point, the UE may provide PDN connection related information set up in the EPS network to the 5GS network.

[00123] FIG. 10 illustrates a process in which, according to an embodiment of the disclosure, a UE moves to a 5G network to perform a registration procedure. More specifically, UE 260, 370, or 1010 moves to 5GS to send a registration request message to AMF 250, 360, or 1020.

[00124] Referring to FIG. 10, the registration request message may include PDN connection related information set up in the EPS network. The PDN connection related information may include the requested NSSAI, which is slice information requested by the UE, and other slice information (e.g., mapping information, indicator, PLMN identifier using the S-NSSAI included in the requested NSSAI, and etc.). The requested NSSAI may be configured by at least one S-NSSAI. The registration request message may be transmitted to AMF 250, 360, or 1020 via NG-RAN 255, 365, or 1015. The PDN connection related information included in the registration request message may include various methods.

[00125] Hereinafter, in the case of local break-based roaming (i.e., in the embodiment of FIG. 2), an example of a method is described, according to an embodiment of the disclosure, for providing PDN connection-related information established in EPS, in 5GS network.

[00126] According to an embodiment, in the case of the [LB Embodiment 1] procedure 9 of FIG. 4, the registration request message that UE 260 or 1010 according to the entity disclosure embodiment sends to AMF 250 or 1020 via NG-RAN 255 or 1015 may include S-NSSAI a received in procedure 12 of FIG. 4 as the requested NSSAI, and may include a PLMN identifier using S-NSSAI a, i. e. VPLMN identifier.

[00127] According to an embodiment, in the case of the [LB Embodiment 2] procedure 9 of FIG. 4, the registration request message that UE 260 or 1010 according to the entity disclosure embodiment sends to AMF 250 or 1020 via NG-RAN 255 or 1015 may include S-NSSAI a received in procedure 12 of FIG. 4 as the requested NSSAI, and may include mapping information (S-NSSAI 1, S-NSSAI a) of the corresponding S-NSSAI, and a PLMN identifier using S-NSSAI a, i. e. VPLMN identifier.

[00128] When the UE identifier (e.g., 5G-GUTI, GUTI or SUPI) includes information allocated in the EPS, or when the received registration request message includes the VPLMN identifier, AMF 250 or 1020 according to [LB option 1] and [LB Embodiment 2] may identify that the requested NSSAI included in the registration request received from the UE is configured by the S-NSSAI value used in the VPLMN.

[00129] According to an embodiment, in the case of the [LB Embodiment 3] procedure 9 of FIG. 4, the registration request message that UE 260 or 1010 according to the entity disclosure embodiment sends to AMF 250 or 1020 via NG-RAN 255 or 1015 may include S-NSSAI 1 received in procedure 12 of FIG. 4 as the requested NSSAI, and may include a PLMN identifier using S-NSSAI 1, i. e. HPLMN identifier.

[00130] According to an embodiment, in the case of the [LB Embodiment 4] procedure 9 of FIG. 4, the registration request message that UE 260 or 1010 according to the entity disclosure embodiment sends to AMF 250 or 1020 via NG-RAN 255 or 1015 may include S-NSSAI 1 received in procedure 12 of FIG. 4 as the requested NSSAI, and may include mapping information (S-NSSAI 1, S-NSSAI a) corresponding to S-NSSAI 1, and a PLMN identifier using S-NSSAI 1, i. e. HPLMN identifier.

[00131] When a UE identifier (e.g., 5G-GUTI, GUTI, or SUPI) includes information allocated in the EPS, or when a received registration request message includes an HPLMN identifier, AMF 250 or 1020 according to [LB option 3] and [LB embodiment 4] may identify that the requested NSSAI included in the registration request received from the UE is configured by the S-NSSAI value used in the HPLMN.

[00132] According to an embodiment, in the case of the [LB Embodiment 5] procedure 9 of FIG. 4, the registration request message that UE 260 or 1010 according to an embodiment of the entity disclosure sends to AMF 250 or 1020 via NG-RAN 255 or 1015 may not include slice-related information. Thus, the registration request message may not include the requested NSSAI.

[00133] When the UE identifier (e.g., 5G-GUTI, GUTI, or SUPI) includes information allocated in the EPS, the AMF 250 or 1020 according to [LB Embodiment 5] can identify that the UE is a UE that is moved from EPS. AMF 250 or 1020 may receive, from UDM 210 of FIG. 2 or 1030, the PDN connection information that the UE configures in the EPS and the S-NSSAI information supported by the PDN connection. AMF 250 or 1020 may allow the S-NSSAI supported by the PDN connection that is obtained from UDM 210 or 1030 to be included in the NSSAI-allowed registration confirmation message to be sent to the UE, and then may send the S-NSSAI.

[00134] Hereinafter, in the case of roaming based on home routing (i.e., in the embodiment of FIG. 3), according to the embodiment of the disclosure, an example of a method for providing, in a 5GS network associated with a PDN, is described -connection of information set in the EPS.

[00135] According to an embodiment, in the case of the [HR Embodiment 1] procedure 9 of FIG. 4, the registration request message that UE 370 or 1010 according to the entity disclosure embodiment sends to AMF 360 or 1020 via NG-RAN 365 or 1015 may include S-NSSAI 1 received in procedure 12 of FIG. 4 as requested by NSSAI. When the Registration Request message includes S-NSSAI 1, the Registration Request message may include the S-NSSAI 1 session PDU state.

[00136] According to an embodiment, in the case of the [HR Embodiment 1] procedure 9 of FIG. 4, the registration request message that UE 370 or 1010 according to the entity disclosure embodiment sends to AMF 360 or 1020 via NG-RAN 365 or 1015 may include S-NSSAI 1 received in procedure 12 of FIG. 4 as the requested NSSAI, and may include an indicator indicating that S-NSSAI 1 is the value used in the HPLMN. When the Registration Request message includes S-NSSAI 1, the Registration Request message may include the S-NSSAI 1 session PDU state.

[00137] According to an embodiment, in the case of the [HR Embodiment 1] procedure 9 of FIG. 4, the registration request message that UE 370 or 1010 according to the entity disclosure embodiment sends to AMF 360 or 1020 via NG-RAN 365 or 1015 may include S-NSSAI 1 received in procedure 12 of FIG. 4 as the requested NSSAI, and may include a PLMN identifier using S-NSSAI 1, i. e. HPLMN identifier. When the Registration Request message includes S-NSSAI 1, the Registration Request message may include the S-NSSAI 1 session PDU state.

[00138] When the UE identity (e.g., 5G-GUTI, GUTI, or SUPI) includes information allocated in the EPS, when the received registration request message includes an HPLMN identifier, or when the received registration request message includes indicator indicating the HPLMN value, AMF 360 or 1020 according to [HR Embodiment 1] can identify that the requested NSSAI included in the registration request received from the UE is configured by the S-NSSAI value used in the HPLMN.

[00139] In procedure 5 (step 1055) of FIG. 10, AMF 360 or 1020 may obtain "signed S-NSSAI" information of the UE corresponding to the UE ID from the UDM 310 of FIG. 3 or 1030. AMF 360 or 1020 may compare the requested NSSAI received from UE 1010 with the subscription slice information received from the UDM. If the S-NSSAI included in the requested NSSAI is included in the subscription slice information, procedure 6 (step 1060) of FIG. 10 can be performed. Alternatively, procedure 5 (step 1055) of FIG. 10 is omitted and procedure 6 (step 1060) can be directly executed. In addition, in procedure 6 (step 1060) of FIG. 10, AMF 360 or 1020 may send an NSSelection_Get request message to NSSF 1025. The NSSelection_Get request message may include UE subscription slice information, a PLMN identifier (i.e., HPLMN identifier) included in the UE identifier (e.g., , SUPI), HPLMN S-NSSAI value (according to the entity disclosure embodiment, S-NSSAI 1) which is received from the UE and through which the UE establishes a session, and the requested NSSAI received from the UE.

[00140] The NSSF 1025 may define a VPLMN S-NSSAI value that maps to an HPLMN S-NSSAI value (e.g., an HPLMN S-NSSAI value included in the requested NSSAI) received from the AMF 360 or 1020 and available in the VPLMN (ie, in the serving PLMN that the UE is currently accessing). The NSSF 1025 may determine the allowed NSSAI based on the UE's subscription slice information, the VPLMN S-NSSAI value determined by the NSSF, and the requested NSSAI value. The allowed NSSAI may be configured by at least one S-NSSAI value VPLMN available in the serving PLMN that the UE is currently accessing. NSSF 1025 may send an NSSelection_Get response message to AMF 360 or 1020. The NSSelection_Get response message may include the resolved NSSAI determined by the NSSF and the resolved NSSAI transformation according to the resolved NSSAI. Upon receipt of the NSSelection_Get response message, AMF 360 or 1020 may send a registration confirmation message to UE 1010 in procedure 7 (block 1065) and procedure 8 (block 1070) of FIG. 10. The registration confirmation message may include the resolved NSSAI and the resolved NSSAI transform that are received from the NSSF. Upon receiving the registration confirmation message, UE 1010 may store the allowed NSSAI and the allowed NSSAI transform included in the registration confirmation message and may use them to manage (create/modify/delete) a session PDU in the current registration area and transmit or receive data.

[00141] According to an embodiment, in the case of the [HR Embodiment 1] procedure 9 of FIG. 4, the registration request message that the UE 370 or 1010 according to the entity disclosure embodiment sends to the AMF 360 or 1020 via the NG-RAN 365 or 1015 may not include the requested NSSAI or may configure the S-NSSAI value as "unknown". " in the requested NSSAI. In addition, the registration request message may include mapping information (S-NSSAI 1, unknown). Thus, the UE may include S-NSSAI 1 received in procedure 12 of FIG. 4 as the HPLMN S-NSSAI value of the mapping information, and may configure the VPLMN S-NSSAI value as "unknown" or may not include a (blank) value. When the Registration Request message includes S-NSSAI 1, the Registration Request message may include the S-NSSAI 1 session PDU state.

[00142] In procedure 5 (step 1055) of FIG. 10, AMF 360 or 1020 according to [HR Embodiment 1] may obtain UE Signed S-NSSAI information corresponding to the UE Identifier from UDM 310 or 1030. AMF 360 or 1020 may compare the S-NSSAI value received from the UE and used in the HPLMN, with subscription slice information obtained from the UDM. If the HPLMN S-NSSAI value received from the UE is included in the subscription slice information, procedure 6 (step 1060) of FIG. 10 can be performed. Alternatively, procedure 5 (step 1055) of FIG. 10 is omitted and procedure 6 (block 1060) may be performed. AMF 360 or 1020 may send an NSSelection_Get request message to NSSF 1025 (block 1055). The NSSelection_Get request message may include UE subscription slice information, a PLMN identifier (i.e., HPLMN identifier) included in the UE identifier (e.g., SUPI), mapping information received from the UE, HPLMN S-NSSAI value (according to the entity disclosure embodiment, S-NSSAI 1) which is received from the UE and through which the UE establishes a session, and the requested NSSAI received from the UE.

[00143] The NSSF 1025 may determine a VPLMN S-NSSAI value that maps to an HPLMN S-NSSAI value (e.g., an HPLMN S-NSSAI value included in the mapping information or an HPLMN S-NSSAI value by which the UE sets session) received from AMF 360 or 1020 and available in the VPLMN (ie, the serving PLMN that the UE is currently accessing). The NSSF 1025 may determine the allowed NSSAI based on the UE subscription slice information, the HPLMN S-NSSAI value included in the mapping information, the VPLMN S-NSSAI value determined by the NSSF, and the requested NSSAI value. The allowed NSSAI may be configured by at least one S-NSSAI value VPLMN available in the serving PLMN that the UE is currently accessing. NSSF 1025 may send an NSSelection_Get response message to AMF 360 or 1020. The NSSelection_Get response message may include the resolved NSSAI determined by the NSSF and the resolved NSSAI transformation according to the resolved NSSAI. Upon receipt of the NSSelection_Get response message, AMF 1020 may send a registration confirmation message to UE 1010 in procedure 7 (block 1065) and procedure 8 (block 1070) of FIG. 10. The registration confirmation message may include the resolved NSSAI and the resolved NSSAI transform that are received from the NSSF. Upon receiving the registration confirmation message, UE 1010 may store the allowed NSSAI and the allowed NSSAI transform included in the registration confirmation message and may use them to manage (create/modify/delete) a session PDU in the current registration area and transmit or receive data.

[00144] According to an embodiment, in the case of the [HR Embodiment 2] procedure 9 of FIG. 4, the registration request message that UE 370 or 1010 according to an embodiment of the entity disclosure sends to AMF 360 or 1020 via NG-RAN 365 or 1015 may not include slice-related information. Thus, the registration request message may not include the requested NSSAI.

[00145] When the UE identifier (e.g., 5G-GUTI, GUTI, or SUPI) includes information allocated in the EPS, the AMF 360 or 1020 according to [HR Embodiment 2] can identify that the UE is a UE that is moved from EPS. AMF 360 or 1020 may receive, from UDM 1030, the PDN connection information that the UE configures in the EPS and the S-NSSAI information supported by the PDN connection. The AMF 360 or 1020 may allow the S-NSSAI supported by the PDN connection that is obtained from the UDM 310 or 1030 to be included in the NSSAI Allowed Registration Confirm message and may send the message to the UE 370 or 1010.

[00146] According to an embodiment of the disclosure, the step of determining the allowed NSSAI and converting the allowed NSSAI may be performed by the AMF 1020 rather than by the NSSF 1025. Thus, procedure 6 (step 1060) of FIG. 10 may be processed by an internal AMF step.

[00147] A UE according to an entity disclosure embodiment may store slice information that is included in the form of a PCO in a message received in procedure 12 of FIG. 4. Slice information in the PCO form received by the UE may indicate the "S-NSSAI value" associated with the PDN connection, the "PLMN identifier" using the corresponding S-NSSAI, and the "transformed slice" information. The UE may compare the received slice information with slice policy information (eg, UE Route Selection Policy (URSP), Network Slice Selection Policy (NSSP), UE Local Policy, etc.) stored in advance in the UE, and may determine whether whether or not the slicing information matches the slicing policy information. Table 1 shows an example of slicing policy information stored in the UE.

[00148] Tab. 1

Application ID Slice ID (S-NSSAI) Application ID #1 S-NSSAI 1 Application ID #2 S-NSSAI 2 Application ID #3 S-NSSAI 1, S-NSSAI 2 Match with all S-NSSAI 3

[00149] The slicing policy information stored in the UE includes the applications installed in the UE and the slicing information used to use each of the applications. For example, in the case of UE Application ID #1, S-NSSAI 1 is used to provide a service. The UE that intends to use Application ID #1 may perform the registration procedure by accessing the 5G network. In the registration procedure, the UE may send a registration request message to the network, whereby the registration request message may include slice information (S-NSSAI) that the UE intends to use in the form of the requested NSSAI. In the registration procedure, the UE may receive from the network the allowed NSSAI, which is slice information that the UE may use by accessing the network. The UE may use the NSSAI allowed and slice policy information when transmitting the Session PDU Request message for Application Identifier #1 to allow S-NSSAI 1 to be included in the Session PDU Request message.

[00150] When the PCO received by the UE includes the "S-NSSAI Value" (eg, S-NSSAI 1) and the "PLMN Identifier" using the corresponding S-NSSAI, i.e. HPLMN ID, the UE may use the slicing policy information stored in the UE to identify the slicing information converted to an application that the UE uses by accessing the EPS and forming a PDN connection.

[00151] When the application that the UE is currently using is Application Identifier #1, the slice identified based on slice policy information stored in the UE may be S-NSSAI 1. In this case, it may be determined that the slice (S-NSSAI 1) identified based on the slice policy information stored in the UE matches the slice information (S-NSSAI 1) received using the PCO. When in procedure 1 (step 1035) of FIG. 10, the requested NSSAI and the requested NSSAI transform are generated, the UE may enable S-NSSAI 1 to be included in the requested NSSAI or the requested NSSAI transform.

[00152] Alternatively, when the application that the UE is currently using is Application Identifier #2, the slice identified based on slice policy information stored in the UE may be S-NSSAI 2. In this case, it may be determined that that the slice (S-NSSAI 2) identified based on the slice policy information stored in the UE does not match the slice information (S-NSSAI 1) received using the PCO. When in procedure 1 (step 1035) of FIG. 10, the requested NSSAI and the requested NSSAI transform are generated, the UE may enable S-NSSAI 1 and S-NSSAI 2 to be included in the requested NSSAI or the requested NSSAI transform.

[00153] When the PCO received by the UE includes the "S-NSSAI Value" (eg, S-NSSAI a), the "PLMN Identifier" using the corresponding S-NSSAI, i. VPLMN identifier and "transformed slice information" (e.g., {S-NSSAI 1, S-NSSAI a}), the UE may use the slice policy information stored in the UE to identify the slice information converted to the application that the UE uses by implementing access to EPS and formation of a PDN connection.

[00154] When the application that the UE is currently using is Application ID #1, the slice identified based on the slice policy information stored in the UE may be S-NSSAI 1. In this case, it may be determined that the slice (S-NSSAI 1) identified based on the slice policy information stored in the UE matches the slice information ({S-NSSAI 1, S-NSSAI a}) received using the PCO. When in procedure 1 (step 1035) of FIG. 10, the requested NSSAI and the requested NSSAI mapping are generated, the UE may enable S-NSSAI a to be included in the requested NSSAI, and may enable {S-NSSAI 1, S-NSSAI a} to be included in the requested NSSAI mapping.

[00155] Alternatively, when the application that the UE is currently using is Application Identifier #2, the slice identified based on slice policy information stored in the UE may be S-NSSAI 2. In this case, it may be determined that that the slice (S-NSSAI 2) identified based on the slice policy information stored in the UE does not match the slice information ({S-NSSAI 1, S-NSSAI a}) received using the PCO. When in procedure 1 (step 1035) of FIG. 10, the requested NSSAI and the requested NSSAI transform are generated, the UE may enable S-NSSAI a and an unknown indicator to be included in the requested NSSAI, and may enable {S-NSSAI 1, S-NSSAI a} and {S-NSSAI 2, unknown (or empty)} to be included in the requested NSSAI transformation.

[00156] Referring to FIG. 10, in procedure 2 (step 1040), UE 1010 may send a registration request message to base station 1015 to register with the communication system. In procedure 3 (step 1045), the base station 1015 performs the requested NSSAI identification and AMF selection based on the slice information. In procedure 4 (block 1050), base station 1015 may send a registration request message to AMF 1020 for access.

[00157] The registration request message transmitted in procedures 2 and 4 (steps 1040, 1050) may include the requested NSSAI that UE 1010 intends to use after registering with the communication system. In procedure 1 (block 1035), the requested NSSAI may be determined by UE 1010 based on the configured NSSAI. The requested NSSAI and the configured NSSAI may be configured by at least one S-NSSAI.

[00158] In procedure 5 (block 1055), upon receiving the registration request message 1050, AMF 1020 may obtain UE subscription information from UDM 1030. The UE subscription information may include UE 1010 subscribed S-NSSAIs.

[00159] In procedure 6 (block 1060), AMF 1020 may determine the requested NSSAI received from UE 1010 in procedure 4 (block 1050), the signed S-NSSAI received from UDM 1030 in procedure 5 (block 1055), and the allowed NSSAI , which, based on slice information available at the current position of UE 1010, UE 1010 can use after registering with the communication system.

[00160] In procedure 6 (block 1060), AMF 1020 may query NSSF 1025 to determine the allowed NSSAI. To this end, the AMF 1020 may provide, to the NSSF 1025, the requested NSSAI received from the UE 1010 in procedure 4 (block 1050), the signed S-NSSAI received from the UDM 1030 in procedure 5 (block 1055), and the current position information of the UE. 1010. NSSF 1025 may determine the allowed NSSAI that UE 1010 may use after registering with the communication system based on information received from AMF 1020 and slice information available at the current position of UE 1010. NSSF 1025 may send the allowed NSSAI to AMF 1020.

[00161] At this point, if there is no slice that the UE can use after registering with the communication system, AMF 1020 and NSSF 1025 may generate slice-rejected S-NSSAIs included in the requested NSSAI received from UE 1010 in procedure 4 (step 1050 ), and may constitute an authorized NSSAI through the use of various methods as follows.

[00162] According to one or more embodiments, AMF 1020 or NSSF 1025 may identify UE 1010 subscribed S-NSSAIs, and if S-NSSAI is included by default in subscribed S-NSSAIs, AMF 1020 or NSSF 1025 may enable S-NSSAI over be included in the permitted NSSAI by default. In an embodiment, if S-NSSAI is not included by default in subscribed S-NSSAIs, AMF 1020 or NSSF 1025 may configure subscribed S-NSSAIs to be "blank", or may define subscribed S-NSSAIs that should not be sent to UE 1010.

[00163] According to one or more embodiments, AMF 1020 or NSSF 1025 may configure signed S-NSSAIs as "null".

[00164] According to one or more embodiments, AMF 1020 or NSSF 1025 may determine signed S-NSSAIs that should not be transmitted to UE 1010.

[00165] After determining (or obtaining, from NSSF 1025) the allowed NSSAI and rejected S-NSSAIs in procedure 6 (step 1060), AMF 1020 may allow at least one of the allowed NSSAI and rejected S-NSSAIs to be included in the message. registration confirmation sent to UE 1010 in procedure 7 (block 1065). A procedure 7 registration confirmation message (block 1065) may be transmitted to UE 1010 via base station 1015 in procedure 8 (block 1070).

[00166] Upon receiving the registration confirmation message in procedure 8 (block 1070), UE 1010 may identify the allowed NSSAI and/or rejected S-NSSAI included in the registration confirmation message and may perform the operation as follows.

[00167] According to one or more embodiments, if the registration confirmation message received in procedure 8 (block 1070) includes only rejected S-NSSAIs and does not include an allowed NSSAI, UE 1010 may identify that all requested slices that the UE requests from the network via procedures 1, 2, and 4 (steps 1035, 1040, 1050) are rejected. Therefore, UE 1010 may not send a session PDU request prior to receiving the allowed NSSAI from the network. Alternatively, when the UE sends a session PDU request prior to receiving the allowed NSSAI from the network, the UE 1010 may not include the S-NSSAI. Upon receiving a session PDU request message that does not include the S-NSSAI, the network (eg, SMF or AMF) may select the default S-NSSAI and generate a session PDU based on the subscription information of the UE 1010.

[00168] According to one or more embodiments, when the registration confirmation message received in procedure 8 (block 1070) includes rejected S-NSSAIs and the allowed NSSAI is configured to be "blank", UE 1010 may identify that all requested slices that the UE requests from the network via procedures 1, 2, and 4 (steps 1035, 1040, 1050) are rejected. Therefore, UE 1010 may not send a session PDU request prior to receiving the allowed NSSAI from the network. Alternatively, when the UE sends a session PDU request prior to receiving the allowed NSSAI from the network, the UE 1010 may not include the S-NSSAI. Upon receiving a session PDU request message that does not include the S-NSSAI, the network (eg, SMF or AMF) may select the default S-NSSAI and generate a session PDU based on the subscription information of the UE 1010.

[00169] According to one or more embodiments, if the rejected S-NSSAI registration confirmation messages received in procedure 8 (step 1070) include all requested slices that UE 1010 requests from the network prior to procedures 1, 2, and 4 (steps 1035, 1040, 1050) (i.e., all requested slices by the UE are rejected) and the allowed NSSAI includes S-NSSAI, UE 1010 can identify that all requested slices that the UE requests from the network through procedures 1, 2, and 4 (steps 1035, 1040, 1050) are rejected. Additionally, UE 1010 may use the granted NSSAIs that UE 1010 receives in procedure 8 (block 1070) prior to receiving a new granted NSSAI from the network to send a session PDU request. According to one embodiment, when the UE sends a session PDU request, the UE 1010 may allow one S-NSSAI of the allowed NSSAIs received in procedure 8 (block 1070) to be included in the session PDU request message.

[00170] FIG. 7 illustrates a configuration of a base station in a wireless communication system, according to an embodiment of the disclosure. The configuration illustrated in FIG. 7 may be understood as a configuration of an EPS base station 140, 245, or 340, or a 5GS base station 150, 255, or 365. The term "~block" or "~er", as used hereinafter, may mean a block for processing at least one function or operation, and may be implemented in hardware, software, or a combination of hardware and software.

[00171] Referring to FIG. 7, the base station includes a wireless communication unit 710, a backhaul unit 720, a storage unit 730, and a control unit 740.

[00172] The wireless communication unit 710 performs functions for transmitting or receiving signals over a wireless channel. For example, the wireless communication unit 710 performs a conversion function between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when data is transmitted, the wireless communication unit 710 encodes and modulates the transmitted bitstream in such a way as to form complex symbols. In addition, when data is received, the wireless communication unit 710 recovers the received bitstream by demodulating and decoding the baseband signal.

[00173] The wireless communication unit 710 upconverts the baseband signal into a radio frequency (RF) signal and transmits it through the antenna, and downconverts the RFband signal received through the antenna into a baseband signal. frequencies. For example, the RF processing unit 710 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and the like. In addition, the wireless communication unit 710 may include multiple transmit/receive paths. The wireless communication unit 710 may include at least one antenna array configured with multiple antenna elements.

[00174] In a hardware aspect, the wireless communication block 710 may include a digital block and an analog block, and the analog block may include several sub-blocks according to operating power, operating frequency, and the like. The digital block may be implemented as at least one processor (eg, a digital signal processor (DSP)).

[00175] The wireless communication unit 710 may transmit or receive a signal as described above. Therefore, all or part of the wireless communication unit 710 may be referred to as a "transmitter", "receiver", or "transceiver". Hereinafter, transmission and reception performed via a wireless channel may be understood to mean that the above-described processing is performed by the wireless communication unit 710.

[00176] The tandem 720 provides an interface for performing communication with other nodes in a 5GS network or an EPS network. Thus, the backhaul unit 720 converts the bit stream transmitted from the base station to another node, such as another access node, another base station, an upper node, or a core network, into a physical signal, and converts the physical signal received from the other node, to the bitstream.

[00177] The storage unit 730 may store data such as a base station operating program, an application program, and configuration information. The storage unit 730 may be configured as volatile storage, non-volatile storage, or a combination of volatile storage and non-volatile storage. The storage unit 730 provides the stored data as requested by the control unit 740 .

[00178] The control unit 740 can fully control the operation of the base station. For example, control unit 740 transmits or receives a signal via wireless unit 710 or backhaul unit 720. In addition, the control unit 740 writes data to the storage unit 730 and reads the data. The control unit 740 may perform the protocol stack functions required by the communication standards. According to other embodiments, the protocol stack may be included in the wireless communication unit 710. To this end, control unit 740 may include at least one processor. According to various embodiments, control block 740 may include functions for interworking based on network slicing. The functions for slicing network interworking are instruction sets or codes stored in the storage unit 730 and may be instructions/codes permanently located at least temporarily in the control unit 740, in a storage space in where the instructions/codes are stored, or in a portion of the circuit constituting the control unit 740.

[00179] According to various embodiments, the control unit 740 may receive a PDN Permit Downlink NAS Transport message or a bearer establishment request message that includes slice information for interworking based on network division into slices and may control a direct RRC transmission message or an RRC connection reconfigure message, which may include slice information to be transmitted to the UE. For example, control unit 740 may control the base station to perform operations according to the various embodiments described above.

[00180] FIG. 8 illustrates a configuration of a UE in a wireless communication system according to some embodiments of the disclosure. The configuration illustrated in FIG. 8 may be understood as a configuration of UE 155, 260, or 370. The term "~unit" or "~er" as used hereinafter may mean a unit for processing at least one function or operation, and may be implemented in hardware, software or in a combination of hardware and software.

[00181] Referring to FIG. 8, the UE includes a communication unit 810, a storage unit 820, and a control unit 830.

[00182] The communication unit 810 performs functions for transmitting or receiving a signal over a wireless channel. For example, the communication unit 810 performs a conversion function between the baseband signal and the bit stream according to the system physical layer standard. For example, when data is transmitted, communication unit 810 encodes and modulates the transmitted bitstream in such a way as to form complex symbols. In addition, when data is received, the communication unit 810 recovers the received bitstream by demodulating and decoding the baseband signal. The communication unit 810 upconverts the baseband signal into an RF signal and transmits it through an antenna, and downconverts the RF signal received through the antenna into a baseband signal. For example, the communication block 810 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

[00183] In addition, communication unit 810 may include multiple transmit/receive paths. Communication unit 810 may include at least one antenna array configured with multiple antenna elements. In a hardware aspect, communication unit 810 may include digital circuitry and analog circuitry (eg, a radio frequency integrated circuit (RFIC)). The digital circuit and the analog circuit can be implemented as a single set. In addition, communication unit 810 may include multiple RF chains. The communication unit 810 may perform beamforming.

[00184] Communication unit 810 may include various communication modules in order to process signals in different frequency bands. In addition, communication unit 810 may include a plurality of communication modules to support a plurality of different radio access technologies. For example, various radio access technologies may include Bluetooth Low Energy (BLE), High Quality Wireless (Wi-Fi), Gigabyte WiFi (WiGig), Cellular (e.g., Long Term Evolution (LTE)), 5G -network, etc. In addition, the various frequency bands may include a super high frequency (SHF) band (eg, 2.5 GHz and 5 GHz) and a millimeter wave (mm) band (eg, 60 GHz).

[00185] Communication unit 810 may transmit or receive a signal as described above. Therefore, all or part of the communication unit 810 may be referred to as a "transmitter", "receiver", or "transceiver". Hereinafter, transmission and reception performed via a wireless channel may be understood to mean that the above-described processing is performed by the communication unit 810.

[00186] The storage unit 820 may store data such as a base program for running a UE, an application program, configuration information, and the like. The storage unit 820 may be configured as volatile storage, non-volatile storage, or a combination of volatile storage and non-volatile storage. The storage unit 820 provides the stored data as requested by the control unit 830 .

[00187] The control unit 830 may fully control the operation of the UE. For example, control unit 830 transmits or receives a signal through communication unit 810. In addition, the control unit 830 writes data to the storage unit 820 and reads the data. The control unit 830 may perform the protocol stack functions required by the communication standards. To this end, the control unit 830 may include at least one processor or microprocessor, or may be part of the processor. Part of the communication unit 810 and the control unit 830 may be referred to as a "communication processor (CP)". According to various embodiments, control block 830 may include a function to support network slicing. The function for supporting network slicing is a set of instructions or code stored in the storage unit 820, and may be an instruction/code permanently located, at least temporarily, in the control unit 830, in a storage space in which the instructions are stored. /codes, or in part of the circuit constituting the block 830 control.

[00188] According to various embodiments, the control unit 830 may control the UE to access the MME 420 via the E-UTRA base station 415 to exchange a signaling message with the PGW-C 430 located in the EPS and set up a PDN connection, and when the PDN connection establishment is completed, may control the UE 410 to transmit uplink data to the PGW-U 435 or receive downlink data from the PGW-U 435. In particular, the control unit 830 may receive a reconfiguration message RRC connections or direct RRC transmission message from the base station and may store S-NSSAI, ie. the slice information included in the message and the PLMN identifier using the corresponding S-NSSAI. For example, control unit 830 may control the UE to perform operations according to the various embodiments described above.

[00189] FIG. 9 illustrates a configuration of a basic network entity in a wireless communication system according to an embodiment of the disclosure. The configuration illustrated in FIG. 9 can be understood as an equipment configuration having at least one function HSS+UDM 110, 210 or 310, PCF+PCRF 115, 215, 220 or 315, SMF+PGW-C 120, 225 or 320, UPF+PGW -U 125, 230 or 325, SGW 130, 235 or 330, MME 135, 240 or 335, AMF 145, 250 or 360, UPF 355, v-SMF 350 and vPCF 345 of FIG. 1-3. The term "~block" or "~er", as used hereinafter, may mean a block for processing at least one function or operation, and may be implemented in hardware, software, or a combination of hardware and software.

[00190] Referring to FIG. 9, the basic network entity includes a communication unit 910, a storage unit 920, and a control unit 930.

[00191] The communication unit 910 provides an interface for communicating with other devices on the network. Thus, the communication unit 910 converts the bit stream transmitted from the underlying network entity to the other device into a physical signal, and converts the physical signal received from the other device into a bit stream. Thus, communication unit 910 can transmit or receive a signal. Therefore, communication unit 910 may be referred to as a "modem", "transmitter", "receiver", or "transceiver". The communication unit 910 may allow the underlying network entity to communicate with other devices or the system through a backhaul (eg, a wired backhaul or a wireless backhaul) or through a network.

[00192] The storage unit 920 stores data such as a base program for operating the underlying network entity, an application program, and configuration information. The storage unit 920 may be configured as volatile storage, non-volatile storage, or a combination of volatile storage and non-volatile storage. The storage unit 920 provides the stored data as requested by the control unit 930 .

[00193] The control unit 930 manages all operations of the underlying network entity. For example, control unit 930 transmits or receives a signal through communication unit 910. In addition, the control unit 930 writes data to the storage unit 920 and reads the data. To this end, the control unit 930 may include at least one processor. According to various embodiments, control block 930 may include a function to support network slicing. A function for supporting network slicing may be implemented by a set of instructions or code stored in the storage unit 920, and may be an instruction/code permanently located at least temporarily in the control unit 930 in a storage space in which the instruction/code, or part of the circuit constituting the block 930 control.

[00194] According to various embodiments, control unit 930 may: receive a session creation request message; send a message with a request to Nudm_SDM_Get; receive a message with a response via Nudm_SDM_Get; compare the received subscribed S-NNSAIs with the S-NSSAI information that the PGW-C SMF provides separately to select the S-NSSAI to be used; and control the function of enabling the S-SNSSAI to be included in the session creation response message and its transmission to the UE, and the control unit 930 may perform control such that the underlying network entity performs operations according to the various embodiments described above.

[00195] The methods according to the claims or embodiments disclosed in the specification may be implemented in the form of hardware, software, or a combination of hardware and software.

[00196] When the methods are implemented by software, a computer-readable storage medium may be provided for storing one or more programs (program modules). One or more programs stored on a computer-readable storage medium may be executable by one or more processors in an electronic device. At least one program includes instructions that instruct the electronic device to carry out the methods according to the embodiments disclosed in the claims or the detailed description of the disclosure.

[00197] Programs (program module, software) may be stored in non-volatile memory devices, including random access memory and flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), data storage device on magnetic disks, compact disc ROM (CD-ROM), digital versatile disks (DVD), other types of optical storage devices, or a magnetic cassette. Alternatively, the programs may be stored in a storage device configured by any combination of some or all of the foregoing. Additionally, a plurality of such storage devices may be included in an electronic device.

[00198] In addition, programs may be stored in an attachable storage device that is accessible via communications networks such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), and a storage area network (SAN). ) or a combination of the above. Such a storage device can access the electronic device that performs the entity disclosure embodiment via an external port. Additionally, a separate data storage device in the communication network may access the electronic device that performs the entity disclosure embodiment.

[00199] In the above detailed embodiments of the entity disclosure, the component included in the entity disclosure is expressed in singular or plural form according to the present detailed embodiment. However, the singular form or the plural form is chosen for the convenience of description according to the present situation, and the disclosure is not limited to one element or several elements of the signified. Additionally, either multiple items expressed in the description may be configured as one item, or one item expressed in the description may be configured as multiple items.

[00200] While the disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will appreciate that various changes in form and content may be made without departing from the spirit and scope of the disclosure as defined by the appended claims and its equivalents.

Claims (24)

1. A method for operating a user equipment (UE) in a wireless communication system, the method comprising the steps of: transmitting, to the first base station (BS), a connection request message over a packet data network (PDN); - receive, from the first BS, information regarding the first single network slice selection assistance information (S-NSSAI) selected by a combination of a packet data network control plane gateway entity (PGW-C) and a session management function (SMF) from among at least at least one subscribed S-NSSAI UE; - transmitting, to the second BS, a registration request message including the requested NSSAI, in which the first S-NSSAI is included; And - receiving, from the second BS, a registration confirmation message including the allowed NSSAI, which includes the second S-NSSAI mapped to the first S-NSSAI. 2. The method of claim 1, wherein, in the case of home routing (HR) based roaming, the first S-NSSAI is a public home land mobile network S-NSSAI (HPLMN S-NSSAI). 3. The method of claim 1, wherein the second S-NSSAI is a Visited Public Land Mobile Network S-NSSAI (VPLMN S-NSSAI) converted to a first S-NSSAI that is a Home Public Land Mobile Network S-NSSAI. public communications (HPLMN S-NSSAI). 4. The method of claim 1, wherein the second S-NSSAI is determined to be mapped to the first S-NSSAI by a network slice selection function (NSSF). 5. The method of claim 1, wherein the first base station is based on an Evolved Packet Switched System (EPS) and the second base station is based on a fifth generation wireless system (5GS). 6. The method of claim 1, wherein information regarding the first S-NSSAI is received via Protocol Configuration Parameters (PCOs). 7. The method of claim 1, further comprising verifying that the requested NSSAI, in which the first S-NSSAI is included, does not or does not conflict with user equipment route selection policy rules (URSP rules). 8. A user equipment (UE) in a wireless communication system, the UE comprising: - transceiver; And - at least one processor operatively connected to the transceiver and configured to: - transmit, to the first base station (BS), a connection request message over a packet data network (PDN); - receive, from the first BS, information regarding the first single network slice selection assistance information (S-NSSAI) selected by a combination of a packet data network control plane gateway entity (PGW-C) and a session management function (SMF) from among at least at least one subscribed S-NSSAI UE; - transmit, to the second BS, a registration request message including the requested NSSAI, in which the first S-NSSAI is included; And - receive, from the second BS, a registration confirmation message including an allowed NSSAI, which includes the second S-NSSAI mapped to the first S-NSSAI. 9. The subscriber equipment of claim 8, wherein, in the case of home routing (HR) based roaming, the first S-NSSAI is a public home land mobile network S-NSSAI (HPLMN S-NSSAI). 10. The subscriber equipment of claim 8, wherein the second S-NSSAI is the S-NSSAI of the Visited Public Land Mobile Network (VPLMN S-NSSAI) converted to the first S-NSSAI, which is the S-NSSAI of the Home Terrestrial Network public mobile communications (HPLMN S-NSSAI). 11. The user equipment of claim 8, wherein the second S-NSSAI is determined to be mapped to the first S-NSSAI by a network slice selection function (NSSF). 12. The user equipment of claim 8, wherein the first base station is based on an Evolved Packet Switched System (EPS) and the second base station is based on a fifth generation wireless system (5GS). 13. The user equipment of claim 8, wherein the information regarding the first S-NSSAI is received via Protocol Configuration Parameters (PCOs). 14. The user equipment of claim 8, wherein the at least one processor is further configured to verify that the requested NSSAI, in which the first S-NSSAI is included, does not or does not conflict with user equipment route selection policy rules (URSP- rules).

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