Enhancements for handling network slice quotas

Abstract

The present disclosure relates to enhancements for handling network slice quotas. A public land mobile network includes a network slice quota (NSQ) node to implement a quota on the number of user equipment (UE) or (UE, PDU session) pairs that can be registered on a network slice. The access and mobility management function (AMF) queries the NSQ in response to a notification of a successful authorization and / or authentication (AAA) of the UE: whether the quota is available for the UE's registration on the network slice. Alternatively, the AMF may pre-capture one or more units of the UE's network slice quota before the AAA process is initiated. The AMF may start a timer after the UE deregistration is initiated and not relinquish the quota units held by the UE until the timer expires. The network may also include a session management function (SMF) that provides a UE identity and a PDU session ID when requesting registration of the UE.

Description

Technical Field

[0001] The present application relates to wireless communications, and more particularly, to mechanisms for implementing a quota on the number of user equipment that are allowed to use network slices in a communication network.

[0002] Related technical description

[0003] The use of wireless communication systems is growing rapidly. In addition, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with WCDMA or TD-SCDMA air interfaces), 3GPP LTE, Advanced LTE (LTE-A), 3GPP 5G, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX), Bluetooth, etc.

[0004] In order to perform cellular communication, the user equipment (UE) usually first selects a public land mobile network (PLMN) and registers with the PLMN, which will then provide cellular communication services to the UE. The PLMN is a land-based network provided by a specific operator in a specific country. For example, the PLMN in a given country may support a combination of cellular technologies, such as GSM / 2G, UMTS / 3G, and LTE / 4G.

[0005] A PLMN may support multiple network slices, e.g., logical (or virtual) end-to-end networks. Each network slice may provide a different set of functions and services. Different UEs may need or desire access to different network slices, or different groups of network slices. For example, a smartphone and a home meter may need access to different groups of network slices. Or a given UE may need access to a different slice when reading an email than when having a phone conversation. Each slice is uniquely identified by a corresponding S-NSSAI value. (S-NSSAI is an acronym for "Single Network Slice Selection Assistance Information.") Summary of the invention

[0006] Various embodiments described herein refer to a "network slice quota (NSQ) node". An NSQ node may be configured to manage a quota for a corresponding network slice of a PLMN. (A quota for a network slice may be interpreted as a maximum number of user equipment devices that are allowed to access a network slice.) An NSQ node is considered to implement a network slice quota function, or in other words a network slice access control function (NSACF). An NSQ node may also be referred to as an NSACF node.

[0007] In some embodiments, a method for operating a network node may be performed as follows. The network node may initiate a process of authenticating and / or authorizing a first user equipment (UE) to use a network slice of a network. In response to receiving an indication that the process has successfully authenticated and / or authorized the first UE to use the network slice, the network node may send a query message to a network slice quota node. The query message may represent a query as to whether there is an available quota to add the first UE to multiple user equipments using the network slice. In response to receiving an affirmative response to the query message, the network node may send a quota update message requesting the network slice quota node to update the available quota. In response to receiving a confirmation message that the available quota has been updated based on the quota update message, the network node may send a registration acceptance message to the first UE, indicating that the first UE is authorized to use the network slice.

[0008] In some embodiments, the method for operating a network node may be performed as follows. In response to receiving a request from a user equipment (UE) to register to use a network slice, the network node may send a query message to a network slice quota (NSQ) node, wherein the query message represents a query as to whether there is an available quota to add the UE to multiple user equipments using the network slice. In addition, in response to receiving a positive response to the query message from the NSQ node, before initiating a process of authenticating and / or authorizing the UE to use the network slice, the network node may pre-declare a unit of the UE's network slice quota, wherein the pre-declaration includes sending a request to the NSQ node for the NSQ to update the available quota of the network slice.

[0009] In some embodiments, a method for operating a network node may be performed as follows. In response to determining that a user equipment (UE) is to deregister from at least a network slice of a network, the network node may start a timer and avoid relinquishing units of a network slice quota held by the UE while the timer is running. In response to receiving a request from the UE to register with the network slice before the timer expires, the network node may stop the timer and send a registration accept message to the UE, the registration accept message indicating that the UE is allowed to use the network slice.

[0010] In some embodiments, a method for operating a network node may be performed as follows. The network node may receive a first request to register a protocol data unit (PDU) session on a network slice of the network. The first request may include an identifier of the PDU session, an identifier of a user equipment requesting the registration, and an identifier of the network slice. In response to receiving the first request, the network node may search a list of records associated with the network slice to determine whether the list contains a specific record, the specific record including the UE identifier and the PDU session identifier of the first request, wherein each record in the list includes a different combination of the UE identifier and the PDU session identifier. In response to determining that the list does not include the specific record and the maximum number of PDU sessions allowed to use the network slice has not been reached, the network node may add a new record to the list, wherein the new record includes the UE identifier and the PDU session identifier of the first request, and the count of PDU sessions using the network slice is incremented.

[0011] The techniques described herein may be implemented in and / or used with a number of different types of devices, including, but not limited to, any of cellular telephones, tablet computers, wearable computing devices, portable media players, and a variety of other computing devices.

[0012] This disclosure is intended to provide a brief overview of some of the topics described in this document. Therefore, it should be understood that the above features are only examples and should not be construed as narrowing the scope or essence of the topics described herein in any way. Other features, aspects and advantages of the topics described herein will become apparent through the following detailed description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A better understanding of the present subject matter may be obtained when the following detailed description of various embodiments is considered in conjunction with the following drawings, in which:

[0014] Figure 1 An example wireless communication system is shown according to some embodiments;

[0015] Figure 2 illustrates a base station (BS) in communication with a user equipment (UE) device according to some embodiments;

[0016] Figure 3 illustrates an example block diagram of a user equipment (UE) according to some embodiments;

[0017] Figure 4 An example block diagram of a BS according to some embodiments is shown.

[0018] Figure 5A method for managing network slice quotas according to some embodiments is shown.

[0019] Figure 6 A method for managing network slice quotas in conjunction with authorization and / or authentication (AAA) of a UE according to some embodiments is shown.

[0020] Fig. 7A A method for processing UE registration requests in an environment of network slice authorization and / or authentication according to some embodiments is shown.

[0021] Figure 7B A method for operating a network node (such as an access and mobility management function node) in an environment of network slice authorization and / or authentication according to some embodiments is shown.

[0022] Figure 7C A method for processing UE registration requests in an environment of network slice authorization and / or authentication according to some embodiments is shown.

[0023] Fig.7D A method for pre-acquiring network slice quota prior to initiating an authorization and / or authentication process for a UE according to some embodiments is shown.

[0024] Figure 8 A method for managing UE quotas for a network slice during UE deregistration according to some embodiments is shown.

[0025] Fig.9A A method for avoiding losing access to a network slice when a UE encounters an abnormal event of short duration according to some embodiments is shown.

[0026] Fig. 9B A timer-based mechanism according to some embodiments is shown for maintaining a network slice quota held by a UE by an event that causes the UE to temporarily deregister from the network.

[0027] Fig.10 A method for PDU session establishment according to some embodiments is shown.

[0028] Fig.11 A method for PDU session establishment according to some embodiments is shown, the method involving maintenance of session records, each session record including a UE identifier and a PDU session identifier.

[0029] Fig.12 A method of PDU session establishment notified by providing UE identification information according to some embodiments is shown.

[0030] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and described in detail herein. However, it should be understood that the drawings and detailed description thereof are not intended to limit this document to the specific forms disclosed, but on the contrary, their purpose is to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0031] Acronyms

[0032] Various acronyms are used throughout this disclosure. The definitions of the most prominent acronyms used that may appear throughout this disclosure are as follows:

[0033] 3GPP: Third Generation Partnership Project

[0034] 4G: 4th generation

[0035] 5G: 5th generation

[0036] 5G NR: 5G New Radio

[0037] 5GS: 5G system

[0038] AMF: Access and mobility management function

[0039] EAP: Extensible Authentication Protocol

[0040] LTE: Long Term Evolution

[0041] NR: New Radio

[0042] PDCCH: Physical Downlink Control Channel

[0043] PDU: Protocol Data Unit

[0044] PLMN: Public Land Mobile Network

[0045] NRF: Network Repository Function

[0046] NSAAA: Network Slicing Authentication, Authorization and Accounting

[0047] NSACF: Network Slice Access Control Function

[0048] NSQ: Network Slice Quota

[0049] NSSAI: Network Slice Selection Auxiliary Information

[0050] NSSF: Network Slice Selection

[0051] RAN: Radio Access Network

[0052] RAT: Radio Access Technology

[0053] S-NSSAI: Single Network Slice Selection Auxiliary Information

[0054] SMF: Session Management Function

[0055] UDM: Unified Data Management

[0056] UDR: Unified Data Repository

[0057] UMTS: Universal Mobile Telecommunications System

[0058] the term

[0059] The following is a glossary of terms used in this disclosure:

[0060] Memory medium - any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROM, floppy disk or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, for example, hard disk drive or optical storage device; registers or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or their combination. In addition, the memory medium may be located in the first computer system executing the program, or may be located in a different second computer system connected to the first computer system through a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that may reside in different locations in different computer systems connected, for example, through a network. The memory medium may store program instructions (e.g., expressed as a computer program) that can be executed by one or more processors.

[0061] Carrier Medium—storage media as described above, and physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic or digital signals.

[0062] Programmable hardware element - includes various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGA (field programmable gate array), PLD (programmable logic device), FPOA (field programmable object array), and CPLD (complex PLD). Programmable function blocks can vary from fine-grained (combinational logic unit or lookup table) to coarse-grained (arithmetic logic unit or processor core). Programmable hardware elements may also be referred to as "configurable logic units".

[0063] Computer System - Any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0064] User Equipment (UE) (or "UE device") - any of various types of computer systems or devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile phones or smart phones (e.g., iPhone TM , based on Android TM phones), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), laptops, wearable devices (e.g., smart watches, smart glasses), PDAs, portable Internet devices, music players, data storage devices or other handheld devices, unmanned aerial vehicles (UAVs), unmanned aerial vehicle controllers (UACs), vehicles, etc. In general, the term "UE" or "UE device" can be broadly defined to include any electronic device, computing device, and / or telecommunication device (or combination of devices) that is convenient for a user to transport and capable of wireless communication.

[0065] Base Station—The term “base station” has the full breadth of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0066] Processing Element - refers to various elements or combinations of elements. Processing elements include, for example, circuits such as ASICs (application specific integrated circuits), portions or circuits of individual processor cores, entire processor cores, individual processors, programmable hardware devices such as field programmable gate arrays (FPGAs), and / or larger portions of systems including multiple processors.

[0067] Channel - a medium used to transmit information from a sender (transmitter) to a receiver. It should be noted that since the characteristics of the term "channel" may vary according to different wireless protocols, the term "channel" used in the present invention may be considered to be used in a manner that conforms to the standards of the type of device to which the term is used. In some standards, the channel width may be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths of 1.4 MHz to 20 MHz. In contrast, a WLAN channel may be 22 MHz wide, while a Bluetooth channel may be 1 MHz wide. Other protocols and standards may include different definitions of channels. In addition, some standards may define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0068] Frequency band—The term “frequency band” has the full breadth of its ordinary meaning and includes at least a segment of the spectrum (eg, radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0069] Automatic—refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the need for user input to directly specify or perform the action or operation. Thus, the term "automatic" is in contrast to a user manually performing or specifying an action, where the user provides input to directly perform the action. An automatic process may be initiated by input provided by a user, but subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing in information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user action. The form may be automatically filled out by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills out the form without any user input specifying the answers to the fields. As indicated above, a user may invoke automatic filling out of a form, but not participate in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields but rather they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions taken by a user.

[0070] Figure 1 and Figure 2 —Communications system

[0071] Figure 1 A simplified exemplary wireless communication system according to one embodiment is shown. Note that Figure 1 The system is only one example of possible systems, and features of the present disclosure may be implemented in any of a variety of systems as desired.

[0072] As shown, the exemplary wireless communication system includes a base station 102A, which communicates with one or more user equipment 106A, user equipment 106B to user equipment 106N, etc. through a transmission medium. Each user equipment may be referred to as a "user equipment" (UE) in this article. Therefore, user equipment 106 is referred to as UE or UE device.

[0073] Base station (BS) 102A may be a base transceiver station (BTS) or a cell site (cellular base station) and may include hardware to enable wireless communications with UEs 106A through 106N.

[0074] The communication area (or coverage area) provided by a base station may be referred to as a "cell". The base station 102A and the UE 106 may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs), which are also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (e.g., associated with WCDMA or TD-SCDMA air interfaces), LTE, Advanced LTE (LTE-A), 5G NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), and the like. Note that if the base station 102A is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB". If the base station 102A is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB".

[0075] As shown, base station 102A may also be configured to communicate with network 100 (e.g., a cellular service provider's core network, a telecommunications network such as a public switched telephone network (PSTN), and / or the Internet, among other possibilities). Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100. In particular, cellular base station 102A may provide UE 106 with various communication capabilities, such as voice, SMS, and / or data services.

[0076] Base station 102A and other similar base stations (such as base stations 102B...102N) operating according to the same or different cellular communication standards can therefore provide a network of cells that can provide spatially continuous or nearly spatially continuous service to UE 106A-N and similar devices over a wide geographic area via one or more cellular communication standards.

[0077] Thus, although base station 102A may function as Figure 1 106A-N, each UE 106 may also be capable of receiving signals from one or more other cells (which may be provided by base stations 102B-N and / or any other base stations), which may be referred to as "neighboring cells." Such cells may also be capable of facilitating communications between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells of any other variety of granularity of service area size. For example, in Figure 1 The base stations 102A-B shown in FIG. 1 may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0078] In some embodiments, a base station may provide multiple cells, for example, cells operating at different frequencies (or in the case of FDD, cells operating at different uplink-downlink frequency pairs). Thus, different groups of UEs may be connected to different cells of the same base station simultaneously. In addition, a given UE may be connected to more than one cell of a base station simultaneously.

[0079] It should be noted that the UE 106 is capable of communicating using multiple wireless communication standards. For example, in addition to being configured to use at least one cellular communication protocol, the UE 106 can also be configured to communicate using wireless networking (e.g., Wi-Fi) and / or peer-to-peer wireless communication standards (e.g., Bluetooth, Wi-Fi peer-to-peer, etc.). Cellular communication standards include standards such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), etc. If desired, the UE 106 can also be configured or alternatively configured to communicate using one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one or more mobile television broadcast standards (e.g., ATSC-M / H or DVB-H), and / or any other wireless communication standards. Other combinations of wireless communication standards (including, for example, more than two wireless communication standards) are also possible.

[0080] Figure 2A user equipment 106 (eg, one of devices 106A-106N) is shown in communication with base station 102 according to one embodiment. UE 106 may be a device with cellular communication capabilities, such as a mobile phone, handheld device, computer or tablet computer, or virtually any type of wireless device.

[0081] UE 106 may include a processor configured to execute program instructions stored in a memory. UE 106 may perform any of the method embodiments described herein by executing such stored instructions. Alternatively or in addition, UE 106 may include a programmable hardware element, such as a field programmable gate array (FPGA) configured to perform any of the method embodiments described herein or any portion of any of the method embodiments described herein.

[0082] UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some embodiments, UE 106 may be configured to communicate using, for example, CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio component and / or GSM or LTE using a single shared radio component. The shared radio may be coupled to a single antenna, or may be coupled to multiple antennas (e.g., for MIMO) for performing wireless communications. Typically, the radio component may include any combination of a baseband processor, an analog radio frequency (RF) signal processing circuit (e.g., including filters, mixers, oscillators, amplifiers, etc.), or a digital processing circuit (e.g., for digital modulation and other digital processing). Similarly, the radio component may use the aforementioned hardware to implement one or more receive chains and transmit chains. For example, UE 106 may share one or more parts of a receive chain and / or transmit chain between multiple wireless communication technologies such as those discussed above.

[0083] In some embodiments, the UE 106 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As another possibility, the UE 106 may include one or more radio components shared between multiple wireless communication protocols, and one or more radio components used uniquely by a single wireless communication protocol. For example, the UE 106 may include a shared radio for communicating using either LTE or NR (or LTE or 1xRTT, or LTE or GSM), and a separate radio component for communicating using each of Wi-Fi and Bluetooth. Other configurations are also possible.

[0084] Figure 3 —UE block diagram

[0085] Figure 3 An example block diagram of a UE 106 according to one embodiment is shown. As shown, the UE 106 may include a system on chip (SOC) 300, which may include parts for various purposes. For example, as shown, the SOC 300 may include a processor 302 that can execute program instructions for the UE 106, and a display circuit 304 that can perform graphics processing and provide display signals to a display 360. One or more processors 302 may also be coupled to a memory management unit (MMU) 340 (which may be configured to receive addresses from one or more processors 302 and convert those addresses into locations in a memory (e.g., a memory 306, a read-only memory (ROM) 350, a NAND flash memory 310), and / or coupled to other circuits or devices (such as a display circuit 304, a wireless communication circuit 330, a connector I / F 320, and / or a display 360). The MMU 340 may be configured to perform memory protection and page table conversion or setup. In some embodiments, the MMU 340 may be included as part of the processor 302.

[0086] As shown, the SOC 300 may be coupled to various other circuits of the UE 106. For example, the UE 106 may include various types of memory (e.g., including NAND flash memory 310), a connector interface 320 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 360, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, CDMA2000, Bluetooth, Wi-Fi, GPS, etc.). The UE may also include at least one SIM device, and may include two SIM devices, each SIM device providing a respective International Mobile Subscriber Identity (IMSI) and associated functionality.

[0087] As shown, the UE device 106 may include at least one antenna (and in various possibilities, multiple antennas, such as for MIMO and / or for implementing different wireless communication technologies) for performing wireless communications with base stations, access points, and / or other devices. For example, the UE device 106 may use antenna 335 to perform wireless communications.

[0088] UE 106 may also include and / or be configured for use with one or more user interface elements. User interface elements may include various elements such as display 360 (which may be a touch screen display), keyboard (which may be a separate keyboard or may be implemented as part of the touch screen display), mouse, microphone and / or speaker, one or more cameras, one or more buttons, and / or any of various other elements capable of providing information to a user and / or receiving or interpreting user input.

[0089] As described herein, UE 106 may include hardware components and software components for implementing functions such as those described herein for performing more efficient cellular base station scanning. The processor 302 of UE device 106 may be configured to implement some or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application-specific integrated circuit). Alternatively (or in addition thereto), in combination with one or more of other components 300, 304, 306, 310, 320, 330, 335, 340, 350, 360, the processor 302 of UE device 106 may be configured to implement part or all of the features described herein.

[0090] Figure 4 —Block diagram of a base station

[0091] Figure 4 An example block diagram of a base station 102 according to one embodiment is shown. Note that Figure 4 The base station of is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuit or device, which may be configured to receive addresses from the processor 404 and convert these addresses to locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0092] Base station 102 may include at least one network port 470. Network port 470 may be configured to couple to a telephone network and provide access to the telephone network described above. Figure 1 and Figure 2 Multiple devices of the telephone network described in, such as UE device 106.

[0093] The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices, such as the UE device 106. In some cases, the network port 470 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., in other UE devices served by the cellular service provider).

[0094] The base station 102 may include at least one antenna 434 and possibly multiple antennas. The at least one antenna 434 may be configured to function as a wireless transceiver and may be further configured to communicate with the UE device 106 via the radio component 430. The antenna 434 communicates with the radio component 430 via a communication chain 432. The communication chain 432 may be a receive chain, a transmit chain, or both. The radio component 430 may be configured to communicate via various wireless communication standards, including but not limited to LTE, LTE-A, 5G NR, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0095] Base station 102 may be configured to communicate wirelessly using multiple wireless communication standards. In some cases, base station 102 may include multiple radios that enable base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, base station 102 may include an LTE radio for performing communications according to LTE and a Wi-Fi radio for performing communications according to Wi-Fi. In such cases, base station 102 may be capable of operating as both an LTE base station and a Wi-Fi access point. As another possibility, base station 102 may include a multimode radio component capable of performing communications according to any of multiple wireless communication technologies (e.g., LTE and NR, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0096] As further described later herein, the base station 102 may include hardware and software components for implementing or supporting the implementation of the features described herein. The processor 404 of the base station 102 may be configured to implement or support a portion or all of the implementation of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application-specific integrated circuit) or a combination thereof. Alternatively (or in addition thereto), in combination with one or more of the other components 430, 432, 434, 440, 450, 460, 470, the processor 404 of the base station 102 may be configured to implement or support a portion or all of the implementation of the features described herein.

[0097] Enhancements to Network Slice Quota (NSQ) handling

[0098] A fundamental problem for a network (e.g., a public land mobile network) that supports network slicing is how to support a quota on the maximum number of UEs per slice. (Such a quota may be necessary to avoid compromising the quality of service for the UE.) The fundamental problems include: how does the network (e.g., a 5G system) know about the current number of UEs accessing a network slice; which network functions need to know this information; and whether and how the network enforces such quotas when a UE requests registration on a network slice and the registration would cause the quota to be exceeded. In some embodiments, the network may include a network slice quota (NSQ) function that manages this quota.

[0099] Figure 5 A method for managing network slice quotas according to some embodiments is shown. The method may involve a UE 510, an access and mobility management function (AMF) 512, a network slice quota (NSQ) function 514, and a UDM / UDR function 516. UDM stands for "Unified Data Management". UDR stands for "Unified Data Repository".

[0100] The UE may send a registration request 520 to the AMF. The registration request indicates that the UE is requesting to register with one or more network slices of the network. The registration request may include an identification of the UE and an identification of each requested network slice. The identification of the network slice may be an S-NSSAI value. (S-NSSAI is an acronym for "Single Network Slice Selection Assistance Information.")

[0101] In response to receiving the registration request, the AMF may send a check request 522 to the NSQ. The check request indicates that the AMF is querying whether there is an available quota for the UE to register on the network slice. The check request may include the UE identity, the S-NSSAI value, and the control mode value set equal to the "number of UEs per network slice".

[0102] In response to receiving the check request, the NSQ may check the UE quota for the requested network slice, as shown in 524, and send a check response 526 to the AMF. The check response may indicate, for each requested network slice, whether a quota is available for the UE's registration on the network slice. The check response may include the S-NSSAI value of the network slice and one or more indications of whether a quota is available. (In some embodiments, the check response may also include a UE identity.)

[0103] If the quota is not available for all slices requested by the UE, the AMF may send a registration reject message 528A to the UE. The registration reject message indicates that the UE is not allowed to use the requested network slice. The registration reject message may include the S-NSSAI value of the network slice, an indication of the rejection reason (e.g., reject_cause = "maximum number of UEs on the network slice reached"), and a backoff timer value. The backoff timer value may indicate the minimum amount of time that the UE should wait (e.g., after receiving a registration reject message) before attempting another registration request.

[0104] Alternatively, if quota is available on one or more requested network slices, the AMF may continue the registration of the UE, as shown in 528B. Therefore, the AMF may send an update request 530 for one or more network slices to the NSQ. The update request represents a request by the NSQ to update the quota of each of the one or more network slices based on the current registration of the UE. The update request may include the UE identity, the S-NSSAI value of each of the one or more network slices, and a flag indicating that the available quota of the one or more network slices should be decreased. (The available quota and the used quota of a given network slice are complementary because their sum is equal to the maximum number of UEs allowed on the given network slice.)

[0105] In response to receiving the update request, as shown in 532, the NSQ updates the available quota of each network slice in the one or more network slices, for example, the number of UEs allowed to use the network slice, and sends an update response 534 to the AMF. The update response indicates that the NSQ has updated the quota. The update response may include the S-NSSAI value of each network slice in the one or more network slices that have been successfully updated. The update response may also include a UE identity.

[0106] In response to receiving the update response, the AMF may send a registration accept message 536 to the UE. The registration accept message indicates that the UE's registration request has been accepted (allowed). The registration accept message may include the S-NSSAI value of each requested network slice that has been successfully updated by the NSQ and thus successfully registered with the network.

[0107] In response to receiving the registration acceptance message, the UE may start using the registered network slice, i.e., use the communication services provided by the registered network slice.

[0108] Figure 6A method for managing network slice quotas in conjunction with authorization and authentication (AAA) of a UE according to some embodiments is shown. The method may involve a UE 610, an access and mobility management function (AMF) 612, a network slice quota (NSQ) function 614, and a UDM / UDR function 616. (UDM stands for "Unified Data Management". UDR stands for "Unified Data Repository".)

[0109] At 618, it may be assumed that the registration process (for the UE) is completed by temporarily rejecting the requested S-NSSAI value for pending network slice specific authentication and authorization (NSSAA), or that the AAA server triggers a network slice specific re-authentication and re-authorization for the S-NSSAI value.

[0110] At 620, the AMF may trigger NSSAA for the requested network slice of the UE, i.e., for the requested S-NSSAI value. For example, the AMF may send an AAA request to an AAA server. (The AAA server may reside outside the PLMN, in an external network.)

[0111] At 622, the AAA server may exchange messages, such as Extensible Authentication Protocol (EAP) messages, with the UE to authorize and authenticate the UE to use the network slice corresponding to the S-NSSAI value.

[0112] If the AAA process is completed successfully, the operations in the dashed box 623A may be performed. The AMF may send an update request 624 to the NSQ. (The AAA server may send a message to the AMF indicating whether the authorization and authentication of the UE with respect to the network slice is successful.) The update request indicates a request by the NSQ to update the network slice quota. The update request may include the UE identifier (UE ID), the S-NSSAI value of the requested network slice, and a quota update flag.

[0113] In response to receiving the update request, the NSQ may update the network slice quota (as shown in 626) and send an update response 628 to the AMF. The update response indicates that the requested update has been performed. The update response may include the S-NSSAI value of the network slice.

[0114] In response to receiving the update request, the AMF may perform a configuration update procedure 630A to inform the UE that it is allowed to use the requested network slice. The configuration update procedure may include sending to the UE an allowed NSSAI list including the S-NSSAI value, and / or a rejected NSSAI list excluding the S-NSSAI value.

[0115] Alternatively, if the AAA procedure is unsuccessful, the AMF may perform a configuration update procedure 630B to inform the UE that it is not allowed to use the requested network slice. The configuration update procedure 630B may include sending an allowed NSSAI list excluding the S-NSSAI value, and / or a rejected NSSAI list including the S-NSSAI value to the UE.

[0116] In some embodiments, for S-NSSAIs affected by NSAAA, the AMF may not check with the NSQ (for available quota) before starting the NSAAA, because these S-NSSAIs will not be allowed until the NSAAA process is completed, which may take, for example, 10 seconds to 15 seconds, depending on the home / roaming scenario, and the response time of the AAA server. (Unless otherwise specified, none of the embodiments disclosed herein is limited to a specific range of values ​​for the NSAAA process duration.) In the case of such a large elapsed time, the probability of quota changes is very large. Therefore, any indication of available quota received before NSAAA is started may be invalid after NSAAA has completed.

[0117] In some embodiments, the AMF may check with the NSQ before initiating NSAAA and receive an indication of available quota. After NSAAA is completed, the AMF may assume that quota is still available and request the NSQ to decrement the available quota for the network slice if NSAAA for the network slice is successful. (If NSAAA is unsuccessful, no quota change is required.)

[0118] In some embodiments, a method for processing a UE registration request in the context of a network slice authorization and authentication (NSAAA) may be performed, such as Fig. 7A The method may involve a user equipment (710), an access and mobility management function (AMF) 712, and a network slice quota (NSQ) function 714.

[0119] Before starting NSAAA, AMF may send a query message 718 to NSQ to check whether the UE has quota to use the network slice requested by the UE. (The network slice is identified by the S-NSSAI value.) NSQ sends a response 720 to indicate whether the quota for the network slice is available or unavailable.

[0120] If quota is not available, the AMF may not attempt to proceed with NSAAA for the network slice, but instead sends a response message 722 to the UE indicating that the requested network slice (S-NSSAI value) is rejected. The response message may include a reason code set to a value indicating "quota not available" as the reason for the rejection. Therefore, the UE is not allowed to use the requested network slice. (For example, the response message 722 may respond to a registration request sent by the UE, as described above.)

[0121] If quota is available, the AMF may initiate a NSAAA process (e.g., an EAP-based process) by sending an initial AAA message 726 to the AAA server 724. The NSAAA process may typically take 10 to 15 seconds based on the home / roaming scenario, and the response time of the AAA server. (However, it should be understood that the inventive principles disclosed herein are not limited to any particular range of values ​​for the duration of the NSAAA process.)

[0122] Assuming that the AAA server responds with an AAA success message 728 (indicating successful completion of authorization and authentication of the UE to use the network slice), the AMF may send a query message 730 to the NSQ to check whether the quota for the requested network slice is still available. The NSQ may send a response message 732 indicating whether the quota is available.

[0123] If the response message 732 indicates that quota is available, the AMF may send an update request 734 to the NSQ and a response message 736 to the UE indicating registration acceptance (i.e., the requested network slice is allowed). The update request 734 indicates that the NSQ updates its quota to reflect the UE's request to add to the network slice. The NSQ may implement quota updates by decrementing the allowed quota and / or incrementing the used quota.

[0124] Alternatively, if the response message 732 indicates that quota is not available, the AMF may send a response 736 to the UE indicating a registration rejection, i.e., indicating that the UE is not allowed to use the requested network slice. The response 736 may include a reason code set to a value indicating "quota is not available" as the rejection reason.

[0125] The above assumes that the NSAAA process is completed successfully. Alternatively, if the NSAAA process fails, the AMF may not contact the NSQ and may send a rejection message to the UE indicating the rejection of the requested network slice (S-NSSAI value).

[0126] In some embodiments, a method 750 for operating a network node, such as an access and mobility management function node, may include: Figure 7B The operations shown in . (Method 750 may also include the above combined Figures 1 to 7A) The network node may include a processing element configured to perform method 750. For example, the processing element may perform method 750 by executing program instructions stored in a memory of the network node. The network node may reside in a core network of a public land mobile network (PLMN), such as a 5G network.

[0127] At 755, the processing element may initiate a process of authenticating and / or authorizing a first user equipment (UE) to use a network slice of a network. The processing element may have identified a network slice (or an S-NSSAI value for a network slice) as being subject to authentication and / or authorization. (Not all slices of a network need to be subject to authentication and / or authorization. For example, some network slices may have a more open access policy for UEs.)

[0128] At 760, in response to receiving an indication that the process has successfully authenticated and / or authorized the first UE to use the network slice, the processing element may send a query message to the network slice quota node. The query message represents a query as to whether there is available quota to add the first UE to a plurality of user equipments using the network slice.

[0129] At 765, in response to receiving an affirmative response to the query message, the processing element may send a quota update message requesting the network slice quota node to update the available quota.

[0130] At 770, in response to receiving a confirmation message that the available quota has been updated based on the quota update message, the processing element may send a registration acceptance message to the first UE, indicating that the first UE is authorized to use the network slice.

[0131] In some embodiments, the processing element is configured to perform the initiation in response to: receiving a request for access to a network slice from a first UE; determining that the network slice has undergone authentication and / or authorization; based on the access request, sending a preliminary query to a network slice quota node, indicating a query as to whether there is available quota to add the first UE to multiple user equipment using the network slice; and receiving an affirmative response to the preliminary query.

[0132] In some embodiments, the processing element may be configured to initiate the process by sending an initiation message to an authentication and authorization (AAA) server in the network or external to the network. (The AAA server may be owned or operated by an entity other than the network owner or operator.)

[0133] In some embodiments, the network is a 3GPP 5G core network; and the network nodes implement access and mobility management functions.

[0134] In some embodiments, the processing element may be configured to send a registration acceptance message to the UE via a wireless base station of the network (e.g., a gNB for 5G NR).

[0135] In some embodiments, a network node may also include a network interface configured to interact with a network.

[0136] In some embodiments, a method for processing a UE registration request in the context of a network slice authorization and authentication (NSAAA) may be performed, such as Figure 7C The method may involve user equipment (771), access and mobility management function (AMF) 772 and network slice quota (NSQ) function 773.

[0137] Before starting NSAAA, the AMF may send a query message 774 to the NSQ to check whether the UE has a quota to use the network slice requested by the UE. (The network slice is identified by the S-NSSAI value.) The NSQ sends a query response 775 indicating whether the quota for the requested network slice is available or unavailable.

[0138] If the quota is not available, the AMF does not attempt to proceed with the NSAAA for the network slice, but instead sends a response message 776 to the UE indicating that the requested network slice (S-NSSAI value) is rejected. Therefore, the UE is not allowed to use the requested network slice. The response message may include a cause field that is set to a value indicating "quota not available" as the reason for the rejection. (For example, the response message 776 may be in response to a registration request sent by the UE, as described above.)

[0139] If quota is available, the AMF may send an update request 777 to the NSQ, requesting the NSQ to decrement the available quota for the requested network slice. Thus, the AMF proactively (and pre-) declares the quota units of the UE before the NSAAA process is initiated.

[0140] If the NSQ responds with an update confirmation 778 (indicating that the requested update has been successfully performed), the AMF may initiate an NSAAA procedure (e.g., an EAP-based procedure) by sending an AAA request message 779 to the AAA server 780. The NSAAA procedure may typically take about 10 to 15 seconds based on the home / roaming scenario, and the response time of the AAA server. (However, it should be understood that the inventive principles described herein are not limited to any range of values ​​for the duration of the NSAAA procedure.) The AAA server may respond with an AAA response message 781, indicating whether the authorization and authentication of the UE (in order to use the network slice) was successful.

[0141] In response to receiving the AAA response message 781, the AMF may send a registration response message 782 to the UE, indicating whether the UE's request to register with the network slice is accepted or rejected. Fig. 7A compared to, Figure 7C The AMF does not check quota availability after the NSAAA procedure is completed because it has already declared the quota units for the UE before the NSAAA procedure was started.) If the AAA response indicates that the authorization and authentication are successful, the registration response indicates that the use of the requested network slice is accepted. If the AAA response indicates that the authorization and authentication failed, the registration response indicates that the request to use the requested network slice is rejected.

[0142] In addition, if the AAA response 781 indicates that the NSAAA process has failed, the AMF may send an update request 783 to the NSQ, requesting the NSQ to increment the available quota for the network slice requested by the UE, thereby releasing the quota units held on behalf of the UE.

[0143] In some embodiments, a method 785 for operating a network node, such as an access and mobility management function node, may include: Fig.7D The operations shown in . (Method 785 may also include the above combined Figures 1 to 7A and Figure 7C ) The network node may include a processing element configured to perform method 785. For example, the processing element may perform method 785 by executing program instructions stored in a memory of the network node. The network node may reside in a core network of a public land mobile network (PLMN), such as a 5G network.

[0144] At 789, in response to receiving a request from a user equipment (UE) to register to use a network slice, the processing element may send a query message to a network slice quota (NSQ) node, wherein the query message represents a query as to whether there is available quota to add the UE to multiple user equipments using the network slice.

[0145] At 790, in response to receiving an affirmative response to the query message from the NSQ node, the processing element may pre-declare units of the UE's network slice quota before initiating the process of authenticating and / or authorizing the UE to use the network slice, wherein the pre-declaration includes sending a request to the NSQ node for the NSQ to update the available quota of the network slice.

[0146] In some embodiments, in response to receiving a confirmation from the NSQ node that the available quota for the network slice has been updated, the processing element may initiate the process of authenticating and / or authorizing the UE to use the network slice.

[0147] In some embodiments, in response to receiving an indication that the process has successfully authenticated and / or authorized the UE to use the network slice, the processing element may send a registration acceptance message to the UE indicating that the UE is allowed to use the network slice.

[0148] In some embodiments, in response to receiving confirmation from the NSQ node that the available quota has been updated, the processing element may initiate the process of authenticating and / or authorizing the UE to use the network slice.

[0149] In some embodiments, in response to receiving an indication that the process failed to authenticate and / or authorize the UE to use the network slice, the processing element may send a registration reject message to the UE indicating that the UE is not allowed to use the network slice.

[0150] In some embodiments, in response to receiving a negative response to the query message from the NSQ node, the processing element may send a registration reject message to the UE indicating that the UE is not allowed to use the network slice.

[0151] In some embodiments, the network node is an Access and Mobility Management Function (AMF) node of a 3GPP 5G core network.

[0152] In some embodiments, a method for managing UE quotas for a network slice during UE deregistration may be performed, such as Figure 8 As shown. The method may involve user equipment (810), access and mobility management function (AMF) 812, network slice quota (NSQ) function 814, and UDM / UDR nodes. UDM stands for "unified data management". UDR stands for "unified data repository".

[0153] At 820, it is assumed that the UE is registered to the network slice (corresponding to the NSSAI value). The UE or the network (e.g., AMF) may trigger the UE to deregister from the network slice (or network).

[0154] In response to the triggered deregistration, the AMF may send an update request 822 to the NSQ, requesting an increase in the available quota of the network slice. The update request may include an identifier of the UE (UE ID), an identifier of the network slice (S-NSSAI value), and a quota update flag indicating that the available quota should be increased.

[0155] In response to receiving the update request, the NSQ may update the quota (as indicated by 824) and send an update response 826 indicating that the requested update was successfully performed. The update response may include an S-NSSAI value. The update response may also include a UD IE.

[0156] In response to receiving the update response, the AMF may send a deregistration accept message 828 indicating that the UE has been deregistered from the network slice (or network).

[0157] like Figure 8 As shown, the AMF may send an update request 822 to the NSQ, requesting the NSQ to increment the available quota of the network slice. However, if the deregistration is due to an exception (e.g., a crash of the UE baseband processing, a hard reset of the UE, confusion in the UE operating system, etc.) or due to a user action such as switching the airplane mode UI switch, the UE may request to register again to the same network slice in a short time (e.g., within 10 seconds, or within 20 seconds, or within 60 seconds, or within 120 seconds, etc.). (The term "short time" may be interpreted differently in different implementations or application scenarios. UI is an acronym for "user interface.") Therefore, there is a risk that the UE's registration count may be provided to another UE, and the returning UE will encounter a registration rejection. If the quota of the network slice becomes saturated (i.e., the maximum number of UEs is reached) in the interim time, the UE may have to wait for an indefinite time before the quota becomes available.

[0158] Fig.9A A method for avoiding loss of access to a network slice when a UE encounters an abnormal event of short duration according to some embodiments is shown. The method may involve user equipment (910), access and mobility management function (AMF) 912 and network slice quota (NSQ) function 914.

[0159] At 920, the AMF may determine that the UE is to be deregistered (or is being deregistered or has been deregistered) from the network. For example, the AMF may receive a message (from the UE or from a network node) indicating that the UE is to be deregistered. Alternatively, the AMF itself may determine that the UE is to be deregistered from the network, for example, due to a lack of response from the UE, or a lack of a message expected to be sent by the UE.

[0160] In response to determining that the UE is to be deregistered, the AMF may start a timer and refrain from sending a quota relinquishment message while the timer is running, as indicated by 922.

[0161] While the timer is running, if the same UE attempts to register with the network (e.g., by sending a registration request 924 to the AMF), the AMF may send a registration accept message 926 to the UE. (The registration request may include the S-NSSAI value of the requested network slice. The "e" symbol represents the early termination of the timer due to the receipt of the registration request.) The registration accept message may include the S-NSSAI value of the requested network slice. For example, the S-NSSAI value may be included in the allowed S-NSSAI list of the registration accept message.

[0162] Alternatively, if the timer expires without receiving a registration request from the UE, the AMF may send a quota update request 928 to the NSQ, requesting the NSQ to update (e.g., increment) the available quota for the network slice. In response to receiving the update request, the NSQ may update the quota (as indicated by 930) and send an update response 932 to the AMF. The update response indicates that the quota has been updated as requested.

[0163] When the timer is initialized, it may be initialized to a value that balances the interests of a UE that would benefit from keeping its network quota units for a longer period of time with the interests of other UEs that would benefit from the immediate release of network quota units. In one embodiment, the timer may be initialized to a value in the range of 15s to 720s. In another embodiment, the timer may be initialized to a value in the range of 30s to 360s. In another embodiment, the timer may be initialized to a value in the range of 60s to 120s. Any of a variety of values ​​or ranges of values ​​may be utilized.

[0164] In some embodiments, a method 950 for operating a network node, such as an access and mobility management function node, may include: Fig. 9B The operations shown in . (Method 950 may also include the above combined Figures 1 to 9A Any subset of the elements, embodiments and features described herein. ) The network node may include a processing element configured to perform method 950. For example, the processing element may perform method 950 by executing program instructions stored in a memory of the network node. The network node may reside in a core network of a public land mobile network (PLMN), such as a 5G network.

[0165] At 955, in response to determining that a user equipment (UE) is to deregister from at least a network slice of the network, the processing element may start a timer and avoid relinquishing units of network slice quota held by the UE (or on behalf of the UE) while the timer is running.

[0166] At 955, in response to receiving a request from the UE to register with the network slice before the timer expires, the processing element may stop the timer and send a registration acceptance message to the UE, indicating that the UE is allowed to use the network slice.

[0167] In some embodiments, in response to determining that the timer has expired and the UE did not request to register to the network slice while the timer was running, the processing element may send a relinquishment message to the network slice quota node indicating a relinquishment of the unit of network slice quota held by the UE.

[0168] In some embodiments, the starting value of the timer may be based at least in part on the mean and standard deviation of the time it takes for the UE to recover from a temporary abnormal event.

[0169] In some embodiments, the processing element may be configured to determine that the UE is to deregister from the network by receiving a deregistration request from the UE.

[0170] In some embodiments, the processing element may be configured to determine that the UE is to deregister from the network by receiving a deregistration message from a second network node of the network.

[0171] In some embodiments, the network node is an access and mobility management function (AMF) node and the network is a 5G core network.

[0172] In some embodiments, a method for PDU session establishment may be performed, such as Fig.10 (PDU is an acronym for “Protocol Data Unit.”) The method may involve user equipment (1010), an access and mobility management function (AMF) 1012, a slice management function (SMF) 1014, a network slice quota (NSQ) function 1016, and a network repository function (NRF) 1018.

[0173] The UE may send a PDU session establishment request (PSE) 1020 to the AMF. The PSE request represents a request to establish a PDU session on a specific network slice. The PSE request may include the S-NSSAI value of the network slice and the identifier of the PDU session (ie, PDU session ID).

[0174] In response to receiving the PSE request, the AMF may send a context creation (CC) request 1022 to the SMF. The CC request 1022 represents a request to the SMF to create a session management context for the PDU session. The CC request may include the S-NSSAI value of the network slice and the PDU session ID.

[0175] In response to receiving the CC request, the SMF may send a network function discovery (NFD) request 1024 to the network repository function 1018. The NFD request is a request for the network address of the NSQ (or a pointer to the NSQ). The NFD request may include the S-NSSAI value of the network slice, and the network function type set equal to "NSQ".

[0176] In response to receiving the NFD request, the NRF may send an NFD response 1026 to the SMF. The NFD response may include the address / pointer of the NSQ.

[0177] In response to receiving the address / pointer of the NSQ, the SMF may send a registration request 1028 to the NSQ. The registration request represents a request to register the PDU session on the network slice. The registration request may include the S-NSSAI value of the network slice, the PDU session ID, and a control mode indication flag set equal to "PDU session".

[0178] In response to receiving the registration request, the NSQ may check the list of registered PDU session IDs on the network slice (as indicated at 1030) to determine whether the maximum allowed number of PDU sessions on the network slice has been reached. If the maximum number has been reached, the NSQ may add the PDU session ID of the registration request to the list, incrementing the number of registered PDU sessions for the network slice. Alternatively, the NSQ may omit the addition and increment step.

[0179] Based on the result of the check operation 1030, the NSQ may send a registration response 1032 to the SMF indicating whether the registration request was accepted or rejected. (Maximum reached → rejected; Maximum not reached → accepted). In the case of rejection, the registration response may include a rejection reason field set to a value indicating "maximum number of PDU sessions reached" as the rejection reason.

[0180] In response to receiving the registration response 1032, if the status of the registration response is accepted, the SMF may create a session management context for the PDU session on the network slice; and send an environment creation (CC) response 1034 to the AMF. The CC response indicates whether the AMF's request to create a session management context has been accepted or rejected. In the case of rejection, the CC response may include a rejection reason field, which is set to a value indicating "maximum number of PDU sessions reached" as the rejection reason. The CC response may also include a backoff timer value for the S-NSSAI value.

[0181] In response to receiving the CC response 1034, the AMF may send a PDU session establishment (PSE) response 1036 to the UE. The PSE response indicates whether the UE's request to establish a PDU session on the network slice is accepted or rejected. In the case of rejection, the PSE response may include a rejection reason field, which is set to a value indicating "maximum number of PDU sessions reached" as the rejection reason. And a backoff timer value for the S-NSSAI value. The backoff timer value indicates the minimum amount of time that the UE should wait before sending a PDU session establishment request on the same network slice.

[0182] The UE may receive a PSE response from the AMF. If the PSE response indicates acceptance of the request to establish a PDU session on the network slice, the UE may start communication under the PDU session of the network slice. If the PSE response indicates rejection, the UE may (if necessary) choose to start a backoff timer with an initial value equal to the received backoff timer value and, after the timer expires, send another PSE request with the same PDU session ID and the same S-NSSAI value to the AMF.

[0183] As described above, when the SMF sends a registration request 1028 to the NSQ, the SMF may only include the S-NSSAI value and the PDU session ID in the registration request, and may request the NSQ to feedback an indication of whether a quota is available. However, the PDU session ID may be the same between different UEs. Therefore, there is a risk that the PDU session of the second UE may be rejected because its PDU session ID is the same as the PDU session ID of the existing PDU session established by the first UE. In addition, when entering an airplane mode, etc., the UE may not get the opportunity to send an explicit PDU session release command. Therefore, the NSQ may have an outdated quota value for the PDU session of the deregistered UE. When the UE subsequently attempts to establish a PDU session, the NSQ may incorrectly decrement the available quota.

[0184] In some embodiments, a method for PDU session establishment may be performed, such as Fig.11 (PDU is an acronym for “Protocol Data Unit.”) The method may involve user equipment (1110), an access and mobility management function (AMF) 1112, a slice management function (SMF) 1114, a network slice quota (NSQ) function 1116, and a network repository function (NRF) 1118.

[0185] The PSE request 1020, PSC request 1022, NFD request 1024, and NFD response 1026 may be similar to those described above. Fig.10 The registration request 1128 sent by the SMF may include, in addition to the S-NSSAI value and PDU session ID of the network slice, an identification of the UE (i.e., UE ID). In addition, the NSQ may maintain a list of allocated (UE ID, PDU session ID, also referred to as a "pair") combinations. Thus, the NSQ is able to distinguish between the same PDU session ID associated with different UEs. The NSQ may maintain a separate list for each network slice of the network.

[0186] In response to the registration request, the NSQ may check the slice-specific list corresponding to the S-NSAAI value (as shown in 1130) to determine whether the requested pair of UE ID and PDU Session ID is already on the list. (This check may be referred to as an anti-duplication check.) If so, the NSQ does not add the requested pair to the list and does not increment the number of registered pairs (or equivalently, does not decrement the available quota). If not, and if the maximum allowed number of registered pairs associated with the S-NSAAI value has not been reached, the NSQ may add the requested pair to the list and increment the number of registered pairs (or equivalently, decrement the available quota).

[0187] Based on the result of the check operation 1130, the NSQ may send a registration response 1132 to the SMF indicating whether the registration request is accepted or rejected. In the case of rejection, the registration response may include a rejection reason field. The rejection reason field may be set to a value indicating "maximum number of (UE ID, PDU Session ID) pairs reached" as the rejection reason, or to a value indicating that the requested (UE ID, PDU Session ID) already exists in the list corresponding to the requested S-NSSAI value.

[0188] In response to receiving the registration response 1132, if the status of the registration response is accepted, the SMF may create a session management context for the PDU session on the network slice; and send a context creation (CC) response 1134 to the AMF. The CC response indicates whether the AMF's request to create a session management context has been accepted or rejected. In the case of rejection, the CC response may include a rejection reason field set to "maximum reached" or "requested pair already exists", as described above. The CC response may also include a backoff timer value for the S-NSSAI value.

[0189] In response to receiving the CC response 1134, the AMF may send a PDU Session Establishment (PSE) response 1136 to the UE. The PSE response indicates whether the UE's request to establish a PDU session on the network slice is accepted or rejected. In the case of rejection, the PSE response may include a rejection cause field set to "maximum reached" or "requested pair already exists", as described above; and a backoff timer value for the S-NSSAI value. The backoff timer value indicates the minimum amount of time that the UE should wait before sending a PDU session establishment request on the same network slice.

[0190] The UE may receive a PSE response 1136 from the AMF. If the PSE response indicates acceptance of the request to establish a PDU session on the network slice, the UE may start communication under the PDU session of the network slice. If the PSE response indicates rejection, the UE may (if necessary) choose to start a backoff timer with an initial value equal to the received backoff timer value. After the timer expires, the UE may send another PSE request with the same PDU Session ID and the same S-NSSAI value to the AMF.

[0191] When the UE deregisters from the network, the AMF may notify the NSQ. In response to receiving the deregistration notification from the AMF, the NSQ may delete all PDU sessions associated with the UE ID of the UE and thereby increase the available quota of one or more network slices being used by the UE. For example, if the UE has two PDU sessions on the first network slice and one PDU session on the second network slice, the available quota of the first slice and the second slice may be increased by two and one, respectively.

[0192] In some embodiments, a method 1200 for operating a network node, such as a session management function node, may include: Fig.12 The operations shown in . (Method 1200 may also include the above combined Figures 1 to 11 ) The network node may include a processing element configured to perform the method 1200. For example, the processing element may perform the method 1200 by executing program instructions stored in a memory of the network node. The network node may reside in a core network of a public land mobile network (PLMN), such as a 5G network.

[0193] At 1210, a processing element may receive a first request to establish a protocol data unit (PDU) session on a network slice of a network. The first request may include an identification of the PDU session, an identification of a user equipment requesting the establishment, and an identification of the network slice.

[0194] At 1215, in response to receiving the first request, the processing element may search a list of records associated with the network slice to determine whether the list contains a specific record, the specific record including the UE identifier and the PDU session identifier of the first request. Each record of the list may include a different combination of the UE identifier and the PDU session identifier.

[0195] At 1220, in response to determining that the list does not contain the particular record and the maximum number of PDU sessions allowed to use the network slice has not yet been reached, the processing element may: add a new record to the list, wherein the new record includes the UE identifier and the PDU session identifier of the first request; and increment the count of PDU sessions using the network slice.

[0196] In some embodiments, the first request may be received from a session management function (SMF) of the network, and the processing element may be configured to send a setup accept message to the SMF in response to adding the new record.

[0197] In some embodiments, the network node may maintain a plurality of lists associated with respective network slices of the network. The plurality of lists includes the list associated with the network slice. The processing element may be configured to: receive a deregistration message indicating that the UE is to be deregistered from the network, wherein the deregistration message includes a UE identity of the UE; and in response to receiving the deregistration message, delete any record including the UE identity of the UE from the list.

[0198] In some implementations, the deregistration message may be received from an access and mobility management function of the network.

[0199] In some embodiments, the processing element may be configured to: receive a deregistration message indicating that the UE will be deregistered from the network slice, wherein the deregistration message includes a UE identifier of the UE and an identifier of the network slice; and in response to receiving the deregistration message, delete any record including the UE identifier of the UE from the list.

[0200] In some embodiments, the processing element may be configured to: after adding the new record, receive a second establishment request including the same PDU session identifier, UE identifier and network slice identifier as the first request; and in response to determining that the PDU session ID and UE identifier of the second request exist in the record of the list associated with the network slice, avoid adding another record to the list.

[0201] In various embodiments disclosed herein, the user equipment is referred to as sending messages to or receiving messages from the access and mobility function (AMF) of the PLMN. It should be understood that those messages may be sent via a wireless base station of the PLMN (e.g., via a gNB compliant with the 3GPP 5G standard, or a wireless access point of a 5G non-3GPP standard such as WiFi).

[0202] In some embodiments, a network node in a network includes a processing element configured to perform the following operations.

[0203] The processing element may be configured to receive a first request to establish a protocol data unit (PDU) session on a network slice of the network, wherein the first request includes an identifier of the PDU session, an identifier of a user equipment requesting the establishment, and an identifier of the network slice.

[0204] In response to receiving the first request, the processing element may be configured to search a list of records associated with the network slice to determine whether the list contains a specific record, which includes the UE identifier and the PDU session identifier of the first request, wherein each record in the list includes a different combination of the UE identifier and the PDU session identifier.

[0205] In response to determining that the list does not contain the particular record and the maximum number of PDU sessions allowed to use the network slice has not been reached, the processing element may be configured to add a new record to the list, wherein the new record includes the UE identifier and the PDU session identifier of the first request, and increments the count of PDU sessions using the network slice.

[0206] In some embodiments, the first request is received from a session management function (SMF) of the network, and the processing element is configured to send a setup accept message to the SMF in response to adding the new record.

[0207] In some embodiments, the network node maintains a plurality of lists associated with respective network slices of the network, wherein the plurality of lists includes the list associated with the network slice. In these embodiments, the processing element may be configured to: receive a deregistration message indicating that the UE is to be deregistered from the network, wherein the deregistration message includes a UE identity of the UE; and in response to receiving the deregistration message, delete any record including the UE identity of the UE from the list.

[0208] In some embodiments, the deregistration message is received from an access and mobility management function of the network.

[0209] In some embodiments, the processing element may be configured to: receive a deregistration message indicating that the UE will be deregistered from the network slice, wherein the deregistration message includes a UE identifier of the UE and an identifier of the network slice; and in response to receiving the deregistration message, delete any record including the UE identifier of the UE from the list.

[0210] In some embodiments, the processing element may be configured to: after adding the new record, receive a second establishment request including the same PDU session identifier, UE identifier and network slice identifier as the first request; and in response to determining that the PDU session identifier and the UE identifier of the second request are present in the record of the list associated with the network slice, avoid adding another record to the list.

[0211] In some embodiments, the network may be a 3GPP 5G core network.

[0212] In some embodiments, a network node includes a processing element configured to perform the following operations.

[0213] In response to receiving a request from a user equipment (UE) to register to use a network slice, the processing element may be configured to send a query message to a network slice quota (NSQ) node, wherein the query message represents a query as to whether there is available quota to add the UE to multiple user equipments using the network slice.

[0214] In response to receiving a positive response to the query message from the NSQ node, before initiating the process of authenticating and / or authorizing the UE to use the network slice, the processing element may be configured to pre-declare units of the UE's network slice quota, wherein the pre-declaration includes sending a request to the NSQ node for the NSQ to update the available quota of the network slice.

[0215] In some embodiments, the processing element may be configured to: in response to receiving a confirmation from the NSQ node that the available quota of the network slice has been updated, initiate the process of authenticating and / or authorizing the UE to use the network slice; and in response to receiving an indication that the process has successfully authenticated and / or authorized the UE to use the network slice, send a registration acceptance message to the UE indicating that the UE is allowed to use the network slice.

[0216] In some embodiments, the processing element may be configured to: in response to receiving a confirmation from the NSQ node that the available quota has been updated, initiate the process of authenticating and / or authorizing the UE to use the network slice; and in response to receiving an indication that the process failed to authenticate and / or authorize the UE to use the network slice, send a registration reject message to the UE, indicating that the UE is not allowed to use the network slice.

[0217] In some embodiments, the processing element may be configured to, in response to receiving a negative response to the query message from the NSQ node, send a registration reject message to the UE, indicating that the UE is not allowed to use the network slice.

[0218] In some embodiments, the network node may be an Access and Mobility Management Function (AMF) node of a 3GPP 5G core network.

[0219] In some embodiments, a network node in a network includes a processing element configured to perform the following operations.

[0220] The processing element may be configured to initiate a process of authenticating and / or authorizing a first user equipment (UE) to use a network slice of a network.

[0221] In response to receiving an indication that the process has successfully authenticated and / or authorized the first UE to use the network slice, the processing element may be configured to send a query message to the network slice quota node, wherein the query message represents a query as to whether there is available quota to add the first UE to multiple user equipment using the network slice.

[0222] In response to receiving a positive response to the query message, the processing element may be configured to send a quota update message requesting the network slice quota node to update the available quota.

[0223] In response to receiving a confirmation message that the available quota has been updated based on the quota update message, the processing element may be configured to send a registration acceptance message to the first UE, indicating that the first UE is authorized to use the network slice.

[0224] In some embodiments, the processing element may be configured to perform the initiation in response to: receiving a request for access to a network slice from a first UE; determining that the network slice has undergone authentication and / or authorization; based on the access request, sending a preliminary query to a network slice quota node, indicating a query as to whether there is available quota to add the first UE to multiple user equipment using the network slice; and receiving an affirmative response to the preliminary query.

[0225] In some embodiments, the processing element may be configured to initiate the process by sending an initiation message to an authentication and authorization server within the network or external to the network.

[0226] In some embodiments, the network may be a 3GPP 5G core network and the network node may implement an access and mobility management function (AMF).

[0227] In some embodiments, the processing element may be configured to send a registration accept message to the UE via a wireless base station of the network.

[0228] In some embodiments, the network node may also include a network interface configured to interact with a network.

[0229] In some embodiments, a network node in a network may include a processing element configured to perform the following operations.

[0230] In response to determining that a user equipment (UE) is to deregister from at least a network slice of a network, the processing element may be configured to start a timer and avoid relinquishing units of network slice quota held by the UE while the timer is running.

[0231] In response to receiving a request to register with the network slice from the UE before the timer expires, the processing element may be configured to stop the timer and send a registration acceptance message to the UE, indicating that the UE is allowed to use the network slice.

[0232] In some embodiments, the processing element may be configured to: in response to determining that the timer has expired and the UE has not requested to register to the network slice when the timer runs, send a relinquishment message to the network slice quota node indicating a relinquishment of a unit of network slice quota held by the UE.

[0233] In some embodiments, the starting value of the timer is based at least in part on the mean and standard deviation of the time it takes the UE to recover from the temporary abnormal event.

[0234] In some embodiments, the processing element may be configured to determine that the UE is to deregister from the network by receiving a deregistration request from the UE.

[0235] In some embodiments, the processing element may be configured to determine that the UE is to deregister from the network by receiving a deregistration message from a second network node of the network.

[0236] In some embodiments, the network node may be an access and mobility management function (AMF) node and the network may be a 5G core network.

[0237] The embodiments of the present disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as computer-implemented methods, computer-readable storage media, or devices. Other embodiments may be implemented using one or more custom-designed hardware devices such as ASICs. Other embodiments may be implemented using one or more programmable hardware elements such as FPGAs.

[0238] Some embodiments may include a device comprising: an antenna; a radio coupled to the antenna; and a processing element operably coupled to the radio, wherein the device is configured to implement any or all of the foregoing examples.

[0239] In some embodiments, a device (e.g., UE 106) may be configured to include a processor (or a group of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method implementations described herein (or any combination of the method implementations described herein, or any subset of any of the method implementations described herein, or any combination of such subsets). The device may be implemented in any of various forms.

[0240] Still another exemplary embodiment may include an apparatus including means for performing any or all of the elements of any of the preceding examples.

[0241] Yet another example embodiment may include an apparatus including a processing element configured to cause the device to perform any or all elements of any of the foregoing examples.

[0242] By interpreting each message / signal X received in the downlink by a user equipment (UE) communicating with the base station as a message / signal X transmitted by the base station, and interpreting each message / signal Y transmitted in the uplink by the UE as a message / signal Y received by the base station, any of the methods for operating a UE described herein may become the basis for the corresponding method for operating a base station.

[0243] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0244] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A network node in a network, the network node comprising: A processing element, the processing element being configured to: Receiving a first request to establish a protocol data unit (PDU) session on a network slice of the network, wherein the first request comprises a PDU session identifier of the PDU session, a UE identifier of a user equipment UE requesting the establishment, and an identifier of the network slice; In response to receiving the first request, searching a list of records associated with the network slice to determine whether the list contains a specific record, the specific record including the UE identifier and the PDU session identifier of the first request, Each record in the list includes a different combination of a UE identifier and a PDU session identifier; as well as In response to determining that the list does not contain the particular record and the maximum number of PDU sessions allowed to use the network slice has not been reached, a new record is added to the list and the count of PDU sessions using the network slice is incremented, wherein the new record includes the UE identifier and the PDU session identifier of the first request.

2. The network node according to claim 1, wherein the first request is received from a session management function (SMF) of the network, wherein the processing element is configured to: In response to adding the new record, a setup accept message is sent to the SMF.

3. The network node of claim 1 , wherein the network node maintains a plurality of lists associated with respective network slices of the network, wherein the plurality of lists includes the list associated with the network slice, wherein the processing element is configured to: receiving a deregistration message indicating that the UE is to be deregistered from the network, wherein the deregistration message includes the UE identity of the UE; In response to receiving the deregistration message, any record including the UE identity of the UE is deleted from the list.

4. The network node of claim 3, wherein the deregistration message is received from an access and mobility management function of the network.

5. The network node according to claim 1, wherein the processing element is configured to: receiving a deregistration message indicating that the UE is to deregister from the network slice, wherein the deregistration message includes the UE identity of the UE and the identity of the network slice; and In response to receiving the deregistration message, any record including the UE identity of the UE is deleted from the list.

6. The network node according to claim 1, wherein the processing element is configured to: After adding the new record, receiving a second request for establishment, the second request including the same PDU session identifier, UE identifier, and network slice identifier as the first request; and In response to determining that the PDU session identifier and the UE identifier of the second request are present in a record of the list associated with the network slice, avoiding adding another record to the list.

7. The network node of claim 1, wherein the network is a 3GPP 5G core network.

8. The network node according to claim 1, further comprising: A memory is configured to store the list of records.

9. A method performed at a network node, comprising: Receiving a first request to establish a protocol data unit (PDU) session on a network slice of a network, wherein the first request comprises a PDU session identifier of the PDU session, a UE identifier of a user equipment UE requesting the establishment, and an identifier of the network slice; In response to receiving the first request, searching a list of records associated with the network slice to determine whether the list contains a specific record, the specific record comprising the UE identifier and the PDU session identifier of the first request, wherein each record in the list comprises a different combination of the UE identifier and the PDU session identifier; as well as In response to determining that the list does not contain the particular record and the maximum number of PDU sessions allowed to use the network slice has not been reached, a new record is added to the list and the count of PDU sessions using the network slice is incremented, wherein the new record includes the UE identifier and the PDU session identifier of the first request.

10. The method according to claim 9, wherein the first request is received from a session management function (SMF) of the network, the method further comprising: In response to adding the new record, a setup accept message is sent to the SMF.

11. The method according to claim 9, further comprising: maintaining a plurality of lists associated with respective network slices of the network, wherein the plurality of lists includes the list associated with the network slice; receiving a deregistration message indicating that the UE is to be deregistered from the network, wherein the deregistration message includes the UE identity of the UE; and In response to receiving the deregistration message, any record including the UE identity of the UE is deleted from the list.

12. The method of claim 11, wherein the deregistration message is received from an access and mobility management function of the network.

13. The method according to claim 9, further comprising: receiving a deregistration message indicating that the UE is to deregister from the network slice, wherein the deregistration message includes the UE identity of the UE and the identity of the network slice; as well as In response to receiving the deregistration message, any record including the UE identity of the UE is deleted from the list.

14. The method according to claim 9, further comprising: After adding the new record, receiving a second request for establishment, the second request including the same PDU session identifier, UE identifier and network slice identifier as the first request; as well as In response to determining that the PDU session identifier and the UE identifier of the second request are present in a record of the list associated with the network slice, avoiding adding another record to the list.

15. The method of claim 9, wherein the network is a 3GPP 5G core network.

16. The method according to claim 9, further comprising: A list of said records is stored.

17. A non-transitory computer-readable storage medium storing software instructions executable by a processor of a network node to cause the network node to perform the method of any one of claims 9 to 16.

Images