Method and apparatus for supporting network slicing when interworking networks

Abstract

This disclosure relates to pre-fifth-generation (5G) or 5G communication systems to be provided for supporting higher data rates than fourth-generation (4G) communication systems such as Long Term Evolution (LTE). A method is provided for processing network slicing by a Packet Data Network Gateway Control Plane (PGW-C) in a wireless communication system. The method includes receiving a session creation request message from a Mobility Management Entity (MME), identifying whether information instructing a User Equipment (UE) to support slice-based quota operations is included in the session creation request message, and sending a session creation response message configured based on the identification result to the MME.

Description

Technical Field

[0001] This disclosure relates to network slicing techniques applicable to various network architectures. Background Technology

[0002] To meet the increased demand for wireless data traffic since the deployment of fourth-generation (4G) communication systems, efforts have been made to develop improved fifth-generation (5G) or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "post-LTE systems".

[0003] 5G communication systems are considered to be implemented in higher frequency (millimeter wave) bands (e.g., the 60 GHz band) to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G communication systems.

[0004] In addition, in 5G communication systems, development is underway to improve system networks based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receiver interference cancellation.

[0005] In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding modulation (ACM), as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0006] Meanwhile, network slicing technology has been introduced to support multiple services in various network architectures. Network slicing is a technology used to logically configure a network with a set of network functions (NFs) to support a specific service and separate it from other slices. When receiving various services, a UE can access two or more slices.

[0007] The above information is presented as background information only to aid in understanding this disclosure. No determination or assertion is made regarding whether any of the above can be applied to this disclosure as prior art. Summary of the Invention

[0008] Technical issues

[0009] The aspects of this disclosure at least address the aforementioned problems and / or disadvantages, and at least provide the following advantages. Therefore, one aspect of this disclosure is to provide a method for processing network slicing-related signaling between a user equipment (UE) and the network during network interconnection in various network architectures.

[0010] Additional aspects will be set forth in part in the description which follows, and will also be apparent in part from the description, or may be learned by practice of the presented embodiments.

[0011] Problem Solution

[0012] According to aspects of this disclosure, a method is provided for processing network slices by a Packet Data Network Gateway Control Plane (PGW-C) in a wireless communication system. The method includes receiving a session creation request message from a Mobility Management Entity (MME), identifying whether information instructing a User Equipment (UE) to support slice-quota-based operations is included in the session creation request message, and sending a session creation response message configured based on the identified result to the MME.

[0013] According to an embodiment, when the session creation request message includes information indicating that the UE supports slice quota-based operations, the session creation response message may include at least one of the following: information indicating that the session creation request from the UE is rejected due to a lack of slice quota; a back-off timer value to be applied by the UE; unaccessible single network slice selection assistance information (S-NSSAI); and target access point name (APN).

[0014] According to an embodiment, when the session creation request message does not include information indicating that the UE supports slice quota-based operations, the session creation response message may include information indicating that the session creation request from the UE is rejected and the reason is the congestion state of the PGW, a timer value, congestion level information, and at least one of one or more target APNs.

[0015] According to another aspect of this disclosure, a method for a UE to handle network slicing in a wireless communication system is provided. The method includes: identifying whether the UE supports slice-based quota operation; sending a Packet Data Network (PDN) connection request message for accessing a fourth-generation (4G) network to an MME based on the identification result; and receiving a PDN connection rejection message from the MME configured to respond to the PDN connection request message.

[0016] According to an embodiment, when the PDN connection request message includes information indicating that the UE supports slice quota-based operations, the PDN connection rejection message may include at least one of the following: information indicating that a session creation request from the UE is rejected due to a lack of slice quota, a fallback timer value to be applied by the UE, unaccessible single network slice selection assistance information (S-NSSAI), and target access point name (APN).

[0017] According to an embodiment, when the PDN connection request message does not include information indicating that the UE supports slice quota-based operations, the PDN connection rejection message includes information indicating that the session creation request from the UE is rejected and the reason is the congestion state of the PGW, a timer value, congestion level information, and at least one of one or more target APNs.

[0018] According to another aspect of this disclosure, a PGW-C configured to process network slices in a wireless communication system is provided. The PGW-C includes a transceiver and a controller, the controller being coupled to the transceiver and configured to receive a session creation request message from an MME, identify whether information indicating that the UE supports slice quota-based operations is included in the session creation request message, and send a session creation response message configured based on the identification result to the MME.

[0019] According to another aspect of this disclosure, a UE configured to process network slicing in a wireless communication system is provided. The UE includes a transceiver and a controller, the controller being coupled to the transceiver and configured to control whether the UE supports slice-based quota operation, send a Packet Data Network (PDN) connection request message for accessing a fourth-generation (4G) network to an MME based on the identification result, and receive a PDN connection rejection message from the MME configured to respond to the PDN connection request message.

[0020] This disclosure enables efficient handling of network slicing during network interconnection in various network structures.

[0021] Considering the UE's operational capabilities based on network slice quotas, this disclosure can effectively restrict the UE's access to slices in the network.

[0022] Other aspects, advantages, and distinctive features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments disclosed in conjunction with the accompanying drawings.

[0023] Beneficial effects of the invention

[0024] One aspect of this disclosure is to provide a method for efficiently processing network slicing-related signaling between a user equipment (UE) and the network during network interconnection in various network architectures. Attached Figure Description

[0025] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A wireless communication system according to an embodiment of the present disclosure is shown;

[0027] Figure 2 This is a view illustrating a network architecture for providing services via interoperability between a 5G communication system and a 4G (or LTE) communication system, according to embodiments of the present disclosure;

[0028] Figure 3 The operation of a UE accessing a 4G network according to an embodiment of the present disclosure is illustrated;

[0029] Figure 4 The operation of the UE and the network according to embodiments of this disclosure is illustrated;

[0030] Figure 5 The operation of the UE and the network according to embodiments of this disclosure is illustrated;

[0031] Figure 6 The operation of the UE and the network according to embodiments of this disclosure is illustrated;

[0032] Figure 7 The structure of a UE according to an embodiment of this disclosure is shown; and

[0033] Figure 8 The structure of a network entity according to an embodiment of this disclosure is shown.

[0034] In all the accompanying drawings, similar reference numerals will be understood to refer to similar parts, components and structures. Detailed Implementation

[0035] The following description, provided with reference to the accompanying drawings, is intended to aid in a full understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. It includes various specific details to aid understanding, but these are to be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures may be omitted.

[0036] The terms and words used in the following description and claims are not limited to their documentary meaning, but are used solely by the inventors to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is provided for illustrative purposes only and is not intended to limit the disclosure as defined by the appended claims and their equivalents.

[0037] It should be understood that the singular forms “a,” “one,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, referring to “the surface of a component” includes referring to one or more such surfaces.

[0038] The terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this disclosure pertain. It should also be understood that terms, such as those defined in common dictionaries, should be interpreted as having the meaning consistent with their meaning in the context of the relevant field, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein. In some cases, the terms defined herein may be interpreted as excluding embodiments of this disclosure.

[0039] The methods described below with reference to embodiments are hardware-based. However, embodiments of this disclosure include techniques using both hardware and software, and therefore software-based methods are not excluded.

[0040] This disclosure relates to methods and apparatus for supporting various services in a wireless communication system. Specifically, this disclosure describes a technique for supporting various services in a wireless communication system by supporting the mobility of a UE.

[0041] As used herein, terms for identifying access nodes, terms for representing network entities or network functions (NFs), terms for representing messages, terms for representing inter-network entity interfaces, and terms for representing various identifying information are provided as readily descriptive examples. Therefore, this disclosure is not limited to these terms, and these terms may be replaced by other terms representing objects having equivalent technical concepts.

[0042] For ease of description, this disclosure uses the terms and names defined in the 3GPP Long Term Evolution (LTE) and 5G standards. However, this disclosure is not limited to these terms and names and can be equally applied to systems conforming to other standards.

[0043] In the following text, for ease of description, the entities used to exchange access control and state management information will be collectively referred to as NFs. An NF may be at least one of, for example, an Access and Mobility Management Function (AMF) device, a Session Management Function (SMF) device, or a Network Slice Selection Function (NSSF) device. However, the embodiments of this disclosure can be applied in the same way even when an NF is actually implemented as an instance (e.g., an AMF instance, an SMF instance, or an NSSF instance).

[0044] In this disclosure, an instance can refer to a state in which a specific NF exists in the form of software code and can be executed by allocating physical and / or logical resources from a physical computing system (e.g., a specific computing system existing on the core network) to perform the NF's functionality. Therefore, an AMF instance, an SMF instance, and an NSSF instance can refer to instances that allocate physical and / or logical resources from a specific computing system existing on the core network to perform AMF, SMF, and NSSF operations, respectively. Consequently, an AMF instance, SMF instance, and NSSF instance that receives and uses physical and / or logical resources from a specific computing system existing on the network can perform the same operations as when physical AMF, SMF, and NSSF devices are present.

[0045] Therefore, in describing embodiments of this disclosure, an NF (AMF, SMF, UPF, NSSF, NRF, or SCP) can be replaced by an NF instance, or conversely, an NF instance can be replaced by an NF. Similarly, in describing embodiments of this disclosure, an NW slice can be replaced by an NW slice instance, or an NW slice instance can be replaced by an NW slice.

[0046] Figure 1 A wireless communication system according to an embodiment of the present disclosure is shown.

[0047] refer to Figure 1 , Figure 1 Radio access node (RAN) 110 and user equipment (UE) 120 are shown as some nodes using radio channels in a wireless communication system.

[0048] although Figure 1 Only one base station (e.g., RAN 110) and one UE 120 are shown, but other base stations identical or similar to the base station (e.g., RAN 110) may be further included in the wireless communication system. Furthermore, although... Figure 1 The illustration shows a scenario where only one UE 120 communicates with one base station (e.g., RAN 110), but it is clear that multiple UEs can communicate with one base station (e.g., RAN 110).

[0049] A base station (e.g., RAN 110) is the network infrastructure that provides radio access to UE 120. A base station (e.g., RAN 110) has a coverage area defined as a specific geographic region based on the distance at which it can transmit signals. Figure 1 (Not shown in the image). A base station (e.g., RAN 110) may be referred to by other terms, such as 'access point (AP)', 'eNodeB (eNB)', 'fifth-generation (5G) node', 'wireless point', or 'transmit / receive point (TRP)' or various other terms with equivalent technical meanings.

[0050] UE 120 is a device used by the user and performs communication with the base station (e.g., RAN 110) via a radio channel. In some cases, UE 120 can operate without user intervention.

[0051] For example, UE 120 can be a machine-type communication (MTC) device that can be carried by the user. Figure 1 The UE120 shown may include at least one portable user equipment and may include at least one MTC.

[0052] Figure 1 UE 120 may also be referred to by other terms (such as 'terminal', 'mobile station', 'subscriber station', 'remote terminal', 'wireless terminal' or 'user equipment'), or by various other terms with equivalent technical meaning.

[0053] AMF device 131 can be a network entity that manages the wireless network access and mobility of UE 120.

[0054] SMF device 132 can be a network entity that manages connections for a packet data network used to provide packet data to UE 120. The connection between UE 120 and SMF 132 can be a PDU session.

[0055] User plane function (hereinafter referred to as UPF) device 133 may be a gateway or a network entity acting as a gateway for transmitting packets sent / received by UE 120. UPF 133 may be connected to data network (DN) 140 (connected to the Internet) and may provide a path for data transmission / reception between UE 120 and DN 140. Therefore, UPF 133 may route data in packets sent by UE 120 destined for the Internet to the Internet data network.

[0056] The Network Slice Selection Function (NSSF) device 134 may be a network entity that performs the network selection operations (e.g., operations for selecting network slices) described in this disclosure. The operation of the NSSF device 134 is described in more detail below with reference to the accompanying drawings.

[0057] The Authentication Server Function (AUSF) device 151 can be a device (network entity) that provides services for processing subscriber authentication.

[0058] Network Exposure Function (NEF) device 152 can be a network entity capable of accessing information for managing UE 120 in a 5G network and sending UE subscriptions to mobility management events, UE subscriptions to session management events, requests for session-related information, UE billing information settings, requests to change UE PDU session policies, and UE small data.

[0059] The Network Storage Function (NRF) device 153 can be a network entity that can store the state information of an NF and can handle requests to find an NF that can be accessed by other NFs.

[0060] The Policy and Charging Function (PCF) device 154 can be a network entity that applies mobile operator service policies, billing policies, and PDU session policies to the UE 120.

[0061] The Unified Data Management (UDM) device 155 may be a network entity that stores information about subscribers and / or UEs 120.

[0062] Application Function (AF) device 156 may be a network entity that has the function of providing services to users in conjunction with a mobile communication network.

[0063] Service Communication Agent (SCP) device 157 is a network entity that provides functions such as NF discovery and message passing between NFs for communication between NFs. Depending on the operator's choice, SCP 157 may operate in a form integrated with NRF 153, in which case SCP 157 may include the functionality of NRF 153, or conversely, NRF 153 may include the functionality of SCP 157.

[0064] AMF device 131, SMF device 132, UPF device 133, NSSF device 134, AUSF device 151, NEF device 152, NRF device 153, PCF device 154, UDM device 155, AF device 156, and SCP device 157 can be implemented as at least one or more devices and / or as software or firmware running on a system. Furthermore, if desired, devices 131, 132, 133, 134, 151, 152, 153, 154, 155, 156, and 157 can be implemented in hardware.

[0065] In the following description, for ease of description, the term "device" may be omitted. For example, AMF device 131 may be abbreviated as AMF 131, and SMF device 132 may be abbreviated as SMF 132.

[0066] At the same time, Figure 1 In the diagram, the symbols next to the lines between network entities, UE 120, and RAN 110 can indicate the interfaces of the entities. For example, the N1 interface can be used between UE 120 and AMF 131, the N2 interface between RAN 110 and AMF 131, and the N3 interface between RAN 110 and UPF 133. Similarly, the N4 interface can be used between SMF 132 and UPF 133, the N9 interface can be used between or within UPF 133, and the N6 interface can be used between UPF 133 and DN 140.

[0067] Figure 2 This is a view illustrating a network architecture for providing services via interoperability between a 5G communication system and a 4G (or LTE) communication system, according to embodiments of the present disclosure.

[0068] Reference Figure 2 Networks used to provide services through interoperability between 5G and 4G (or LTE) communication systems may include E-UTRAN 210, NG-RAN 211, UE 220 and 221, MME 230, AMF 240, SGW 250, HSS+UDM260, PCF+PCRF 270, SMF+PGW-C 280, and UPF+PGW-U 290.

[0069] Here, HSS+UDM 260, PCF+PCRF 270, SMF+PGW-C 280 and UPF+PGW-U 290 can each represent a 4G entity and a 5G entity, and they perform the same or similar functions to provide 4G (or LTE) communication services and 5G communication services to UE 220 and 221.

[0070] To control the same user, the Unified Data Management (UDM) and Home Subscriber Subsystem (HSS) need to interoperate. To support session continuity (IP address retention), the SMF / UPF needs to support PGW functionality. Furthermore, the MME and AMF, as mobility management nodes in the 4G network, can exchange information via the N26 interface to support UE mobility between 5G and 4G.

[0071] The communication system disclosed herein (including UE, base station, and core) can operate based on network slicing. A network slice can be viewed as a logically separate network and can consist of a set of NFs that support network functions.

[0072] If the network is operated based on network slicing, the network can operate with different capacities, configurations, and policies for each network slice. In this disclosure, quotas can be introduced for each network slice. Quotas can include the maximum number of UEs that can simultaneously access the slice, the maximum number of sessions (PDU sessions or PDN connections) that can be created simultaneously, and the maximum data rate that can be used by each slice subscriber. However, this is not the only limitation; quotas can include other types of parameters required for network operation, and the key points, operations, and configurations of this disclosure can be extended to them.

[0073] If network slicing is used, interoperability between 5G networks that explicitly support the concept of network slicing through standardized protocols and operations and 4G networks that do not explicitly support network slicing needs to be considered.

[0074] Specifically, as mentioned above, if all or some network functions (NFs) are shared to ensure service continuity between 5G and 4G networks, then slicing quotas should apply not only to 5G access but also to 4G access, and should be considered even when a UE switches between 5G and 4G. This operation can be selectively applied to users who subscribe to 5G services using 5G-enabled UEs.

[0075] If operators of communication systems use network slicing to provide services in the interoperability between 5G and 4G networks, then it supports the coexistence of 5G systems that take into account the detailed operation of network slicing and 4G systems that only have the minimum functionality to help use network slicing when transitioning to 5G.

[0076] In communication systems, quotas can be considered for operating network slices. A quota can be represented as the number of UEs that can simultaneously access a specific network slice, the number of connections (PDU sessions or PDN connections) that can be created simultaneously, or the upper limit of the maximum transmission rate that can be provided simultaneously. For example, if a specific slice is operated with the maximum number of connected UEs as the quota, the communication system can implement controls to limit the number of UEs to less than or equal to the quota.

[0077] If multiple NFs or NF instances belong to a single network slice, then an NF with slice quota management capabilities is required, which manages quotas on a slice-by-slice basis. Slice quota management may include operations for receiving and collecting the current state of the network slice from the NF or NF instance and comparing it with quotas to make a decision, as well as additional functionality for those operations. It can be defined as a separate NF and NF service with only slice quota management capabilities, or it can be defined as adding the corresponding functionality to an existing NF (e.g., PCF, NSSF, NRF, or UDM).

[0078] This quota-based access control or detailed operation can only be used if the network (represented as base stations in NG-RAN and NF within the core) and the UE support it. If a UE with control capabilities that take into account slicing quotas (e.g., a 5G UE) and a UE that does not support control capabilities that take into account slicing quotas (e.g., a 4G UE) coexist in the network, then control considering the UE's capability level is required. If a UE supports both 5G and 4G, the above example can be expressed as having quota control capabilities when operating in 5G mode and not having quota control capabilities when operating in 4G mode.

[0079] Figure 3 The operation of a UE accessing a 4G network according to an embodiment of the present disclosure is illustrated.

[0080] refer to Figure 3 The wireless communication system according to the embodiments may include UE 10, MME 20 and PGW-C / SMF 30.

[0081] In Operation 301, an attachment or PDN connection establishment procedure can be triggered between UE 10, MME 20, and PGW-C / SMF 30. In this case, UE 10 can be in a state that already meets the conditions for accessing the 4G network.

[0082] In operation 303, UE 10 may send a request message (PDN connectivity request (PDN Request) (or Attach Request)) to MME 20 for accessing the 4G network (creating a session or PDN connection) or registering in the 4G network. The request message for creating a new PDN connection may include information indicating the target service (e.g., APN) and may include information indicating that UE 10 supports operations that take into account slice quotas.

[0083] Here, UE 10's consideration of slice quota operations includes understanding and using information transmitted to the UE by the network when access to a slice is not possible due to quota (timer values ​​for limiting access, values ​​indicating the reason). This information can be transmitted as a separate information element included in the PDN connection establishment request or as details of one of the Protocol Configuration Options (PCO), ePCO, and APCO.

[0084] During the attachment process, when establishing a PDN connection, the PDN connection creation request can be included in the attachment message. Alternatively, it can be included as one of the IEs that enables UE 10 to transmit the attachment request message to MME 20 during the attachment process.

[0085] If the request message for creating a new PDN connection does not include information indicating that UE 10 supports operations considering slice quotas, then UE 10 can be considered not to support the corresponding function. Alternatively, UE 10 can explicitly indicate in the corresponding field that it does not support operations considering slice quotas, and send the corresponding field.

[0086] In operation 305, MME 20 can determine whether to allow session creation and access based on the request received from UE 10, and send a create session request message for session creation to PGW-C / SMF 30. According to an embodiment, SGW can transmit messages between MME 20 and PGW-C.

[0087] The session creation request message may include information about whether UE 10 supports operations that consider slice quotas, and this information is included in the message received from UE 10. If the message received by MME 20 from UE 10 in operation 303 is a PDN connection establishment request message, and the PCO (or ePCO / APCO) is included in that message, then it should be inserted into the session creation request message.

[0088] In Operation 307, PGW-C 30 can determine the capabilities supported by UE 10 based on the information included in the received session creation request message.

[0089] According to an embodiment, if the UE 10 supports the operation of considering slice quotas based on the information included in the received session creation request message, the PGW-C 30 can perform the operation of explicitly transmitting timers, reasons, and slice information based on the slice quota status to the UE.

[0090] According to an embodiment, when UE 10 does not support operations that consider slice quotas based on the information included in the received Create Session Request message, PGW-C 30 can use NAS-level congestion control to restrict slice access instead of explicitly transmitting timers, reasons, and slice information based on slice quota status to the UE.

[0091] In Operation 309, UE 10, MME 20, and PGW-C / SMF 30 can perform the remaining procedures of the attachment or PDN connection establishment process.

[0092] Figure 4 The operation of the UE and the network according to embodiments of this disclosure is illustrated.

[0093] refer to Figure 4 The wireless communication system according to the embodiment may include UE 10, MME 20, PGW-C / SMF 30, and quota management function (Quota Mgmt Func) 40. Here, quota management function 40 may refer to NF or NE that manages the quota status of slices in the network.

[0094] Operations 401 to 405 and part of operation 407 are referenced above. Figure 3 The operations described in 301 to 307 are basically the same.

[0095] In other words, during operation 403, UE 10 can send a request message (PDN connection request (or attachment request)) to MME 20 for accessing the 4G network (creating a session or PDN connection) or registering in the 4G network. The request message for creating a new PDN connection may include information instructing UE 10 to support operations that take slice quotas into account (Quota Mgmt.Support indicator).

[0096] In operation 405, MME 20 can determine whether session creation and access are permitted based on the request received from UE 10, and send a Create Session Request message for session creation to PGW-C / SMF 30. The Create Session Request message may include information indicating that UE 10 supports operations that take slice quotas into account (quota management support indicator).

[0097] When it is determined that UE 10 supports operations that take into account slice quotas, the subsequent operations of this disclosure (part of operations 407 to 421) may be applied.

[0098] In operation 407, the PGW-C 30 can select a slice (S-NSSAI) to continue UE 10 access. If the PGW-C 30 determines that quota management is necessary for the corresponding slice, the PGW-C 30 can identify the quota status of that slice.

[0099] If it is possible to consider the operation of slice quotas through this information or the internal configuration of PGW-C 30, then the operations 409 to 413 described below can be performed through the internal operation of PGW-C 30 without the help of a separate NF / NE.

[0100] In operation 409, the PGW-C / SMF 30 can send a Slice Quota Check Request message, including the selected slice (S-NSSAI), to the quota management function 40. Here, the quota management function 40 can represent an NF or NE that manages the quota status of slices in a separate network. The Slice Quota Check Request message can include not only the S-NSSAI but also the APN that the UE wants to use.

[0101] In operation 411, the quota management function 40, which manages quota status, can determine that it is impossible to establish a new access UE / session due to slice quota limitations. The quota management function 40 can also determine whether the limitation is due to the number of UEs or the number of sessions.

[0102] In operation 413, quota management function 40 can send a reason to PGW-C 30 indicating that a new connection is not possible due to slice quota limitations. Additionally, quota management function 40 can send a fallback timer to PGW-C 30 to be applied to each slice. The reason can indicate whether the limitation is due to the number of UEs or the number of sessions.

[0103] In operation 415, PGW-C 30 can determine whether to reject the session creation request from UE 10 or select an alternative slice (S-NSSAI). If an alternative slice is selected, operations 407 to 413 can be repeated.

[0104] If the session creation request from UE 10 is rejected in operation 415, then in operation 417, PGW-C 30 can transmit a session creation response message to MME 20 via SGW.

[0105] The session creation response message may include a PCO (or ePCO / APCO), which includes information indicating that the session creation request of UE 10 has been rejected and indicating the reason as a lack of slice quota, a fallback timer value to be applied by the UE, at least one of the S-NSSAI and target APN that cannot be accessed.

[0106] In operation 419, MME 20 can send a PDN connection rejection (or attachment rejection) message to UE 10, which is a NAS response message sent to the UE.

[0107] A PDN connection rejection (or attachment rejection) message may include a PCO (or ePCO, a PCO) transmitted by PGW-C 30. The PCO (or ePCO, APCO) may include information indicating that the reason is due to a lack of slice quota, a backoff timer value to be applied by the UE, an S-NSSAI that cannot be accessed, and one or more of the target APN.

[0108] In operation 421, UE 10 can store information included in the NAS response message received from MME 20, and can use the information included in the NAS response message to perform access control on the slice. When a timer is included in the NAS response message, UE 10 can start the timer and delay NAS requests using the corresponding slice or corresponding APN until the timer expires.

[0109] If the response does not include the APN, and if UE 10 includes the APN in the request message in Operation 401, then UE 10 can determine that access to the corresponding APN is denied. Even when the UE switches to and operates on a 5G network, the timer can be maintained and applied.

[0110] If S-NSSAI is explicitly received in Operation 419, UE 10 can control not to perform mobility management operations (registration requests) in the 5G network associated with the slice.

[0111] Figure 5 The operation of the UE and the network according to embodiments of this disclosure is illustrated.

[0112] Reference Figure 5 The wireless communication system according to the embodiment may include UE 10, MME 20, PGW-C / SMF 30 and quota management function (Quota Mgmt Func) 40.

[0113] Operations 501 to 505 and a portion of operation 507 are referenced above. Figure 3 The operations described in 301 to 307 are basically the same.

[0114] In other words, in operation 503, UE 10 can send a request message (PDN connection request (or attachment request)) to MME 20 for accessing the 4G network (creating a session or PDN connection) or registering in the 4G network. The request message for creating a new PDN connection may not include information instructing UE 10 to support operations that take slice quotas into account (quota management support indicator).

[0115] In operation 505, MME 20 can determine whether session creation and access are permitted based on the request received from UE 10, and send a Create Session Request message for session creation to PGW-C / SMF 30. The Create Session Request message may not include information indicating that UE 10 supports operations that take slice quotas into account (quota management support indicator).

[0116] When it is determined that UE 10 does not support operations that take into account slice quotas, the subsequent operations of this disclosure (part of operations 507 to 521) may be applied.

[0117] In operation 507, the PGW-C 30 can select a slice (S-NSSAI) to continue UE 10 access. If the PGW-C 30 determines that quota management is necessary for the corresponding slice, it can identify the quota status of that slice. If the operation of considering slice quotas is possible through this information or the internal configuration of the PGW-C 30, then operations 509 to 513 described below can be performed through the internal operation of the PGW-C 30 without the assistance of a separate NF / NE.

[0118] In operation 509, PGW-C / SMF 30 can send a slice quota check request message, including the selected slice's (S-NSSAI), to quota management function 40. Here, quota management function 40 can represent an NF or NE that separately manages the quota status of slices in the network. The slice quota check request message can include S-NSSAI and may include the APN to be used by the UE.

[0119] In operation 511, the quota management function 40, which manages the quota status, can determine that it is impossible to establish a new access UE / session due to slice quota limitations.

[0120] In operation 513, quota management function 40 can transmit a reason to PGW-C 30 indicating that a new connection is not possible due to slice quota limitations. Additionally, quota management function 40 can transmit a fallback timer to be applied to each slice. Furthermore, quota management function 40 can additionally transmit a value indicating the load status relative to the current quota.

[0121] In operation 515, PGW-C 30 can determine whether to reject the session creation request from the UE or select an alternative slice (S-NSSAI). If an alternative slice is selected, operations 507 through 513 can be repeated.

[0122] If PGW-C 30 rejects the session creation request from UE 10 during operation 515, then during operation 517, PGW-C30 can send a session creation response message to MME 20 via SGW.

[0123] The session creation response message may include a rejection reason, a timer value, congestion level information, and at least one of one or more target APNs. The rejection reason indicates that the session creation request from UE 10 has been rejected, the PGW is overloaded or congested, or network resources are insufficient.

[0124] In Operation 519, MME 20 can send a NAS response message (PDN connection creation response or attachment response) to UE 10 based on the session creation response message received from PGW-C 30. The NAS response message can be a PDN connection rejection (or attachment rejection) message.

[0125] A PDN connection rejection (or attachment rejection) message may include at least one of the following: information received in operation 517 indicating the reason for the rejection, a fallback timer value to be applied by the UE, and a target APN.

[0126] In operation 521, UE 10 may store information included in the NAS response message received from MME 20, and may use the information included in the NAS response message to perform access control.

[0127] When a timer is included in a NAS response message, the UE 10 can start the timer and delay NAS requests using the corresponding APN until the timer expires.

[0128] If the response does not include the APN, and if UE 10 includes the APN in the request message in Operation 501, then UE 10 can determine that access to the corresponding APN is denied. Even when the UE switches to and operates on a 5G network, the timer can be maintained and applied.

[0129] Figure 6 The operation of the UE and the network according to embodiments of this disclosure is illustrated.

[0130] refer to Figure 6 The wireless communication system according to the embodiment may include MME 20, PGW-C / SMF 30 and quota management function (Quota Mgmt Func) 40.

[0131] If the PGW-C 30 determines that quota management is necessary for a particular slice, the PGW-C 30 can identify the quota status of that slice. According to an embodiment, if the operation of considering slice quotas is possible through this information or the internal configuration of the PGW-C 30, the following operations can be performed through the internal operation of the PGW-C 30 without the assistance of a separate NF / NE.

[0132] In operation 601, the PGW-C / SMF 30 can send a slice quota check request message, including the selected slice's (S-NSSAI), to the quota management function 40. Here, the quota management function 40 can represent an NF or NE that manages the quota status of slices in a separate network. The slice quota check request message can include the S-NSSAI and may additionally include the interoperability APN.

[0133] In operation 603, the quota management function 40, which manages quota status, can identify the slice status and generate a response message based on the identification result. In operation 603, the quota management function 40 can determine that a new connection is not possible due to limitations on slice quotas.

[0134] In operation 605, quota management function 40 can send a slice quota check response message to PGW-C 30. In this case, quota management function 40 can transmit a reason to PGW-C 30 indicating that a new connection is not possible due to slice quota limitations. Additionally, quota management function 40 can transmit a fallback timer or APN to be applied to each slice. Furthermore, quota management function 40 can additionally transmit a value indicating the load status relative to the current quota.

[0135] Even when no explicit request is received from PGW-C 30, a slice quota check response message (Operation 605) can be provided. If PGW-C 30 subscribes to slice status information, this information can be provided as a notification.

[0136] In Operation 607, PGW-C 30 can determine restrictions on new connections to S-NSSAI, and if it is necessary to restrict new connections to a specific slice, a target APN can be selected.

[0137] In operation 609, PGW-C 30 can send GTP-C messages to MME 20 via SGW. The GTP-C message may include information indicating the current status of PGW-C 30, reasons indicating that the PGW is in an overloaded or congested state or that network resources are insufficient, timer values, congestion level information, and at least one of one or more target APNs.

[0138] In operation 611, MME 20 can receive an access request from the UE, and if it is determined from the information received in operation 609 that the target PGW-C 30 for the corresponding connection is in a congested state, then MME 20 can perform the following actions: Figure 5 The same operation as operation 519, and upon receiving a response message, the UE can perform the same operation. Figure 5 The operation is the same as operation 521.

[0139] In Operation 611, the MME 20 can store the backoff timer and the PGW load information of the APN, reject the UE's connection request, and provide the backoff timer and reason.

[0140] Figure 7 The structure of a UE according to an embodiment of the present disclosure is shown.

[0141] The above combination Figures 1 to 6 The described UE can correspond to Figure 7 UE.

[0142] refer to Figure 7 The UE may include a transceiver 710, a memory 720, and a controller 730. The transceiver 710, controller 730, and memory 720 of the UE can operate according to the communication method described above. However, the components of the UE are not limited thereto. For example, the UE may include more or fewer components than those described above. The transceiver 710, controller 730, and memory 720 may be implemented as a single chip. The controller 730 may include one or more processors.

[0143] Transceiver 710 is collectively referred to as a transmitter and receiver of a UE, and can transmit and receive signals to and from a base station, network entity, server, or other UE. Signals transmitted to and received from a base station, network entity, server, or other UE may include control information and data. For this purpose, transceiver 710 may include a radio frequency (RF) transmitter for up-converting and amplifying the transmitted signals, and an RF receiver for low-noise amplification of the received signals and down-converting the received signals. However, this is merely an example of transceiver 710, and the components of transceiver 710 are not limited to RF transmitters and RF receivers.

[0144] The transceiver 710 can receive signals via a radio channel, output signals to the controller 730, and transmit signals output from the controller 730 via a radio channel.

[0145] The memory 720 can store programs and data required for UE operation. The memory 720 can store control information or data included in signals received by the UE. The memory 720 may include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. The memory 720 may be embedded in the controller 730, rather than being provided separately.

[0146] The controller 730 can control a series of processes of the UE to enable operation according to the above embodiments. For example, the controller 730 can receive and process control signals and data signals through the transceiver 710. The controller 730 can also transmit the processed control signals and data signals through the transceiver 710. Multiple controllers 730 may be provided. The controller 730 can control the components of the UE by executing a program stored in the memory 420.

[0147] The controller 730 can perform control to identify whether the UE supports slice quota-based operation, send a Packet Data Network (PDN) connection request message for accessing the fourth-generation (4G) network to the MME based on the identification result, and receive a PDN connection rejection message configured to respond to the PDN connection request message from the MME.

[0148] According to an embodiment, when the PDN connection request message includes information indicating that the UE supports slice quota-based operations, the PDN connection rejection message may include at least one of the following: information indicating that a session creation request from the UE is rejected due to a lack of slice quota; a fallback timer value to be applied by the UE; unaccessible single network slice selection assistance information (S-NSSAI); and target access point name (APN).

[0149] According to an embodiment, when the PDN connection request message does not include information indicating that the UE supports slice quota-based operations, the PDN connection rejection message includes information indicating that the session creation request from the UE is rejected and the reason is the congestion state of the PGW, a timer value, congestion level information, and at least one of one or more target APNs.

[0150] Figure 8 The structure of a network entity according to an embodiment of this disclosure is shown.

[0151] refer to Figures 1 to 6 Each network entity described may include Figure 8 The components. Specifically, Figures 3 to 6 Each of the UE 10, MME 20, PGW-C 30, and quota management function (quota management function) 40 shown can be implemented to include Figure 8 Components.

[0152] refer to Figure 8 The network entity according to the embodiment may include a transceiver 810, a memory 820, and a controller 830. The transceiver 810, controller 830, and memory 820 of the network entity can operate according to the communication method of the network entity described above.

[0153] However, the components of a network entity are not limited to these. For example, a network entity may include more or fewer components than those described above. Transceiver 810, controller 830, and memory 820 may be implemented as a single chip. Controller 830 may include one or more processors.

[0154] Transceiver 810 is collectively referred to as a transmitting transmitter and receiver, and can transmit and receive signals to / from a base station, UE, network entity, or server. The signals transmitted and received to / from the base station, UE, network entity, or server may include control information and data. For this purpose, transceiver 810 may include a radio frequency (RF) transmitter for up-converting and amplifying the transmitted signals, and an RF receiver for low-noise amplification of the received signals and down-converting the received signals. However, this is merely an example of transceiver 810, and the components of transceiver 810 are not limited to RF transmitters and RF receivers.

[0155] The transceiver 810 can receive signals via a radio channel, output signals to the controller 830, and transmit signals output from the controller 830 via a radio channel.

[0156] Memory 820 can store programs and data required for the operation of the network entity or server. Memory 820 can store control information or data included in signals received by the network entity or server. Memory 820 may include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Memory 820 may be embedded in controller 830, rather than being provided separately.

[0157] Controller 830 can control a series of operations to allow network entities or servers to operate according to the embodiments described above. For example, controller 830 can receive and process control and data signals via transceiver 810. Controller 830 can also transmit the processed control and data signals via transceiver 810. Multiple controllers 830 may be provided. Controller 830 can control components of the network entity by executing a program stored in memory 820.

[0158] According to an embodiment, the controller 830 implemented in the Packet Data Network Gateway Control Plane (PGW-C) can control the reception of session creation request messages from the MME, identify whether information indicating that the UE supports slice quota-based operations is included in the session creation request message, and send a session creation response message configured based on the identification result to the MME.

[0159] According to an embodiment, when the session creation request message includes information indicating that the UE supports slice quota-based operations, the session creation response message may include at least one of the following: information indicating that the session creation request from the UE is rejected due to a lack of slice quota; a fallback timer value to be applied by the UE; unaccessible single network slice selection assistance information (S-NSSAI); and target access point name (APN).

[0160] According to an embodiment, when the session creation request message does not include information indicating that the UE supports slice quota-based operations, the session creation response message may include information indicating that the session creation request from the UE is rejected and the reason is the congestion state of the PGW, a timer value, congestion level information, and at least one of one or more target APNs.

[0161] The methods described in the embodiments of this disclosure or the claims can be implemented in hardware, software, or a combination of hardware and software.

[0162] When implemented in software, a computer-readable storage medium may be provided to store one or more programs (software modules). The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions that enable the electronic device to perform methods according to embodiments described in the specification or claims of this disclosure.

[0163] The program (software module or software) can be stored in random access memory, including flash memory, ROM, electrically erasable programmable read-only memory (EEPROM), non-volatile memory, disk storage devices, optical disc ROM, digital versatile disc (DVD), or other types of optical storage devices or magnetic tape. Alternatively, the program can be stored in a memory consisting of all or some of the programs. Each component memory may include multiple memories.

[0164] The program can be stored in an attachable storage device, which can be accessed via a communication network (such as the Internet, intranet, local area network (LAN), wide area network (WAN), or storage area network (SAN), or a combination thereof). The storage device can be connected to a device executing embodiments of this disclosure via an external port. A separate storage device on the communication network can be connected to a device executing embodiments of this disclosure.

[0165] In the specific embodiments described above, the components included in this disclosure are represented in a singular or plural form, depending on the specific embodiment presented. However, the singular or plural form is chosen to suit the context suggested for ease of description, and this disclosure is not limited to singular or plural components. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it should be noted that in some alternative execution examples, the functions mentioned in the boxes may appear in different orders. For example, depending on the corresponding functions, two boxes shown consecutively may be executed substantially simultaneously or in reverse order.

[0166] Although this disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method for processing network slicing in a wireless communication system by a session management function and a packet data network gateway control plane (SMF+PGW-C), the method comprising: Network slice admission control is supported, wherein network slice admission control is associated with at least one of the maximum number of user equipment (UE) per network slice and the maximum number of protocol data unit (PDU) sessions per network slice in the evolved packet core (EPC). During the establishment of a packet data network (PDN) connection in EPC using SMF+PGW-C, the selection assistance information S-NSSAI for a single network slice associated with the PDN connection is used, where the network slice is identified by S-NSSAI; and The SMF+PGW-C sends the first message to the network slice admission control function to check the availability of the network slice.

2. The method according to claim 1, further comprising: The network slice admission control function receives a second message in response to the first message, which is associated with the availability of the network slice. The availability of network slices refers to at least one of the maximum number of UEs per network slice and the maximum number of PDU sessions per network slice.

3. The method according to claim 1, further comprising: The reason given is that the number of UEs in the network slice has exceeded the limit, and PDN connections are rejected.

4. The method according to claim 3, further comprising: Another S-NSSAI associated with the PDN connection is selected by SMF+PGW-C.

5. The method according to claim 1, further comprising: In response to the session creation request message, which includes information instructing the UE to support slice quota-based operations, a session creation response message is sent to the Mobility Management Entity (MME). The session creation response message includes at least one of the following: information indicating that the session creation request from the UE was rejected due to a lack of slice quota, the fallback timer value to be applied by the UE, the unaccessible S-NSSAI, and the target access point name APN.

6. The method according to claim 1, further comprising: Determine whether the selected S-NSSAI is subject to network slice admission control.

7. A session management function and packet data network gateway control plane (SMF+PGW-C) in a wireless communication system, wherein the SMF+PGW-C comprises: transceiver; and A processor, coupled to the transceiver, is configured to control: Network slice admission control is supported, wherein the network slice admission control is associated with at least one of the maximum number of User Equipments (UEs) per network slice and the maximum number of Protocol Data Unit (PDU) sessions per network slice in the Evolved Packet Core (EPC). During the establishment of a packet data network (PDN) connection in EPC using SMF+PGW-C, the selection of a single network slice selection auxiliary information (S-NSSAI) associated with the PDN connection is performed. The network slice is identified by S-NSSAI, and... The SMF+PGW-C sends the first message to the network slice admission control function to check the availability of the network slice.

8. The SMF+PGW-C according to claim 7, wherein, The processor is also configured to control: The network slice admission control function receives a second message in response to the first message, which is associated with the availability of the network slice. The availability of network slices refers to at least one of the maximum number of UEs per network slice and the maximum number of PDU sessions per network slice.

9. The SMF+PGW-C according to claim 7, wherein, The processor is also configured to control: The reason given is that the number of UEs in the network slice has exceeded the limit, and PDN connections are rejected.

10. The SMF+PGW-C according to claim 9, wherein, The processor is also configured to control: Another S-NSSAI associated with the PDN connection is selected by SMF+PGW-C.

11. The SMF+PGW-C according to claim 7, wherein, The processor is also configured to control: In response to the session creation request message, which includes information instructing the UE to support slice quota-based operations, a session creation response message is sent to the Mobility Management Entity (MME). The session creation response message includes at least one of the following: information indicating that the session creation request from the UE was rejected due to a lack of slice quota, the fallback timer value to be applied by the UE, the unaccessible S-NSSAI, and the target access point name APN.

12. The SMF+PGW-C according to claim 7, wherein, The processor is also configured to control: Determine whether the selected S-NSSAI is subject to network slice admission control.

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