Network slice admission control based on slice bandwidth

Abstract

A method performed by a network slice admission control function (NSACF) is provided. The method includes requesting a subscription to information for a network function, the information indicating a current load or a remaining maximum slice data rate per network slice for a network slice(s), and receiving the information from the network function based on the subscription. And the method includes performing a network slice admission control procedure for the network slice(s) based on an event related to a user equipment (UE), the event causing an increase in a number of packet data unit (PDU) sessions associated with a network slice of the network slice(s). The network slice admission control procedure is performed based on at least a total number or a quota of PDU sessions allowed to be admitted for the network slice and the current load or the remaining maximum slice data rate on the network slice.

Description

Technical Field

[0001] This disclosure relates generally to telecommunications, and more particularly to network slicing access control in telecommunications systems. Background Technology

[0002] A telecommunications system can be viewed as a facility that enables communication sessions between two or more entities (such as user terminals, base stations, and / or other nodes) by providing carrier waves between the various entities involved in the communication path. A telecommunications system can, for example, be provided through a communication network and one or more compatible communication devices. The communication session can include, for example, data communication for carrying communications such as voice, video, email, SMS, multimedia, and / or content data. Non-limiting examples of the services provided include two-way or multi-way calling, data communication or multimedia services, and access to data network systems such as the Internet.

[0003] In wireless communication systems, at least a portion of a communication session between at least two stations is conducted via a wireless link. Examples of wireless communication systems include Public Land Mobile Networks (PLMNs), satellite communication systems, and various wireless local area networks (WLANs). Some wireless systems can be divided into cells and are therefore often referred to as cellular systems.

[0004] Users can access the telecommunications system through appropriate communication equipment or terminals. The user's communication equipment may be referred to herein as User Equipment (UE) or User Device. The communication equipment is provided with appropriate signal receiving and transmitting means to enable communication, such as enabling access to the communication network via an access node of the communication network, or directly communicating with other user equipment. The communication equipment can access a carrier provided by a station (e.g., a base station in a cell) and transmit and / or receive communication on that carrier.

[0005] Telecommunication systems and associated equipment typically operate according to a given standard or specification that defines the permitted operations of the various entities associated with the communication system and how those operations should be implemented. The communication protocols and / or parameters used to connect the various entities are also typically defined. An example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems include Long Term Evolution (LTE) networks, Advanced LTE networks, and so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP). Summary of the Invention

[0006] The example implementations of this disclosure are intended for the telecommunications domain, and in particular for network slice access control in telecommunications systems. This disclosure includes, but is not limited to, the following example implementations.

[0007] Some example embodiments provide an apparatus for implementing a Network Slice Admission Control Function (NSACF), the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to at least: request a subscription to a network function for information indicating the current load or remaining maximum slice data rate for one or more network slices, the NSACF being configured with a total number or quota of Packet Data Unit (PDU) sessions allowed to be admitted to the one or more network slices; receive information from the network function based on the subscription, the information indicating the current load or remaining maximum slice data rate for the one or more network slices; and perform a network slice admission control procedure for the one or more network slices based on an event associated with a User Equipment (UE), the event causing an increase in the number of PDU sessions for the network slices in the one or more network slices, wherein the network slice admission control procedure is performed at least based on the total number or quota of PDU sessions allowed to be admitted to the network slice, and the current load or remaining maximum slice data rate on the network slice.

[0008] Some example implementations provide a method performed by a Network Slice Admission Control Function (NSACF), the method comprising: requesting a subscription for a network function for information indicating the current load or remaining maximum slice data rate for one or more network slices, the NSACF being configured with a total number or quota of Packet Data Unit (PDU) sessions allowed to be admitted to the one or more network slices; receiving information from the network function based on the subscription, the information indicating the current load or remaining maximum slice data rate for the one or more network slices; and performing a network slice admission control procedure for the one or more network slices based on an event associated with a User Equipment (UE), the event causing an increase in the number of PDU sessions for the network slices in the one or more network slices, wherein the network slice admission control procedure is performed at least based on the total number or quota of PDU sessions allowed to be admitted to the network slice, and the current load or remaining maximum slice data rate on the network slice.

[0009] Some example embodiments provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to at least: detect an event related to a user equipment (UE) causing an increase in the number of packet data unit (PDU) sessions associated with a network slice for admission of PDU sessions for the UE associated with the network slice; determine an estimated load of PDU sessions for a network slice admission control process performed at least based on the total number or quota of PDU sessions allowed to be admitted for the network slice, the estimated load of the PDU sessions, and information indicating the current load or remaining maximum slice data rate on the network slice; and admit or deny PDU sessions based on the result of the network slice admission control process.

[0010] Some example implementations provide a method comprising: detecting an event related to a user equipment (UE) that causes an increase in the number of packet data unit (PDU) sessions associated with a network slice for admission of PDU sessions for a UE associated with the network slice; determining an estimated load of the PDU sessions for a network slice admission control procedure performed at least based on the total number or quota of PDU sessions allowed to be admitted for the network slice, the estimated load of the PDU sessions, and information indicating the current load or remaining maximum slice data rate on the network slice; and admitting or denying the PDU sessions based on the result of the network slice admission control procedure.

[0011] Some example implementations provide an apparatus for implementing a mobility management (MM) network function, the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to at least: detect an event related to a user equipment (UE) causing an increase in the number of UEs registered to a network slice in one or more network slices, the increase relating to the UE's registration to the network slice, the MM network function being configured with a total number or quota of allowed UEs to register to the network slice; perform a network slice admission control process at least based on information indicating the current number of UEs registered to the network slice and the total number or quota of allowed UEs to register to the network slice; and admit or deny the UE's registration to the network slice based on the result of the network slice admission control process.

[0012] Some example implementations provide a method performed by a mobility management (MM) network function, the apparatus comprising: detecting an event related to a user equipment (UE) causing an increase in the number of UEs registered to a network slice in one or more network slices, the increase relating to the UE's registration to the network slice, the MM network function being configured with a total number or quota of allowed UEs to register to the network slice; performing a network slice admission control procedure based at least on information indicating the current number of UEs registered to the network slice and the total number or quota of allowed UEs to register to the network slice; and admitting or denying the UE's registration to the network slice based on the result of the network slice admission control procedure.

[0013] By reading the following detailed description and appendix Figure 1 From this point forward, these and other features, aspects, and advantages of this disclosure will become apparent, as will be briefly described below in the accompanying drawings. This disclosure includes any combination of two, three, four, or more features or elements specified herein, whether or not such features or elements are explicitly combined in the specific example implementations described herein or otherwise referenced. This disclosure is intended to be interpreted holistically, such that any separable feature or element of this disclosure, in any aspect and example implementation thereof, shall be considered composable unless the context of this disclosure expressly provides otherwise.

[0014] Therefore, it should be understood that the summary portion of this invention is provided only to summarize some exemplary implementations in order to provide a basic understanding of certain aspects of this disclosure. Consequently, it should be understood that the above-described exemplary implementations are merely examples and should not be construed as limiting the scope or spirit of this disclosure in any way. Other exemplary implementations, aspects, and advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate by way of example the principles of some of the said exemplary implementations. Attached Figure Description

[0015] Therefore, an exemplary implementation of this disclosure has been described in general terms, and reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in the drawings:

[0016] Figure 1 The present disclosure illustrates a telecommunications system comprising one or more Public Land Mobile Networks (PLMNs) coupled to one or more external data networks, implemented according to some examples.

[0017] Figure 2 The deployment of a PLMN is shown based on some examples;

[0018] Figure 3 An example of single network slice selection assistance information (S-NSSAI) is shown.

[0019] Figure 4This is a signaling diagram illustrating the Network Slice Admission Control Function (NSACF) and Policy and Charging Function (PCF) services, which address problems solved by some example implementations.

[0020] Figure 5 It is a signaling diagram of one or more processes implemented based on some examples;

[0021] Figure 6 It is a signaling diagram of one or more processes implemented based on other examples;

[0022] Figure 7A , 7B And 7C is a signaling diagram illustrating the various steps in a method performed by the Network Slice Admission Control Function (NSACF) according to some examples;

[0023] Figure 8A , 8B 8C, 8D, 8E, 8F, 8G, and 8H are flowcharts illustrating the various steps in a method implemented according to some examples;

[0024] Figure 9A , 9B 9C and 9D are flowcharts illustrating the various steps in a method implemented according to some examples; and

[0025] Figure 10 The apparatus is shown based on some examples. Detailed Implementation

[0026] Some implementations of this disclosure will now be described more fully below with reference to the accompanying drawings, some, but not all, of which are shown in the drawings. In fact, various implementations of this disclosure may be embodied in many different forms and should not be construed as limited to those described herein; rather, these exemplary implementations are provided so that this disclosure will be comprehensive and complete, and will fully convey the scope of this disclosure to those skilled in the art. The same reference numerals throughout refer to the same elements.

[0027] Unless otherwise specified or explicitly stated in the context, references to "first," "second," etc., should not be construed as implying a particular order. A feature described as being above another feature (unless otherwise specified or explicitly stated in the context) may be located below that feature, and vice versa; similarly, a feature described as being to the left of another feature may be located to the right of that feature, and vice versa. Furthermore, while quantitative measurements, numerical values, geometric relationships, etc., may be referred to herein, one or more (if not all) of these may be absolute or approximate values ​​to account for acceptable variations that may occur, such as those due to engineering tolerances, etc.

[0028] As used herein, unless otherwise specified or the context clearly indicates otherwise, "OR" for a set of operands is "inclusive OR," meaning it is true only if one or more operands are true, as opposed to "exclusive OR," which is false if all operands are true. Thus, for example, "[A] OR [B]" is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Furthermore, the articles "a" and "an" mean "one or more," unless otherwise specified or the context clearly indicates that they refer to the singular form. Additionally, it should be understood that, unless otherwise specified, the terms "data," "content," "digital content," "information," and similar terms may sometimes be used interchangeably. The term "network" can refer to a group of interconnected computers, including clients and servers; and within a network, these computers may be interconnected directly or indirectly in various ways, including via one or more switches, routers, gateways, access points, etc.

[0029] While specific terminology may be used, the systems and architectures discussed in this disclosure are applicable across a wide range of technologies. For example, while this disclosure may refer to technologies from 3GPP, such as Global System for Mobile Communications (GSM), UMTS, LTE, Advanced LTE, 5G NR, Advanced 5G, and 6G, this disclosure is also relevant to non-3GPP technologies such as IEEE 802, Bluetooth, and Bluetooth Low Energy. The example implementations of this disclosure described herein also refer to Public Land Mobile Networks (PLMNs) and Mobile Network Operators (MNOs), but the example implementations are equally applicable to Standalone Non-Public Networks (SNPNs) and the private entities operating these networks. Furthermore, although some examples and diagrams focus on Radio Access Networks (RANs) and 3GPP access, the example implementations are applicable to any type of network access. This includes not only 5G or 6G 3GPP access, but also non-3GPP access, such as wired access, untrusted non-3GPP access, and trusted non-3GPP access using the Radio Access Gateway Function (W-AGF), Non-3GPP Interoperability Function (N3IWF), or Trusted Non-3GPP Gateway Function (TNGF) to connect to the 5G or 6G core network.

[0030] Furthermore, as used in this application, the term "circuit system" may refer to one or more or all of the following: (a) a hardware circuit implementation only (e.g., an implementation only in an analog and / or digital circuit system); (b) a combination of hardware circuits and software, such as (if applicable): (i) a combination of (multiple) analog and / or digital hardware circuits with software / firmware, and (ii) any part of (multiple) hardware processors having software (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable a device (such as a mobile phone or a server) to perform various functions; or (c) (multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or a portion thereof, which require software (e.g., firmware) to operate, but may be absent when operation does not require software.

[0031] The above definition of "circuit system" applies to all uses of the term in this application, including in any claim. As another example, as used in this application, the term "circuit system" also covers only the implementation of hardware circuitry or a processor (or multiple processors) or portions thereof and their accompanying software and / or firmware. For example, if applicable to a particular claim element, the term "circuit system" also covers baseband integrated circuits or processor integrated circuits for mobile devices (such as user equipment), or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0032] Figure 1 A telecommunications system 100 implemented according to various examples of this disclosure is illustrated. This telecommunications system typically includes one or more telecommunications networks. As shown, for example, the system includes one or more PLMNs 102 coupled to one or more other external data networks 104—particularly including wide area networks (WANs), such as the Internet. As will be understood, PLMNs can be deployed in a variety of different ways. In particular, some 4G LTE and 5G NR deployments are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G technologies and are referred to as non-standalone (NSA) deployments.

[0033] Each PLMN 102 includes a core network (CN) 106 backbone, such as the Evolved Packet Core Network (EPC) for 4G LTE and the 5G Core Network (5GC) for 5G NR (sometimes also referred to as NGC); and each core network and internet are coupled to one or more RAN 108, air interfaces, etc., implementing one or more Radio Access Technologies (RATs). Examples of these RANs include the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) for 4G LTE and the Next Generation (NG) Radio Access Network (NG-RAN) for 5G NR, as well as the 6G RAN. As used herein, “network equipment” refers to any suitable equipment on the network side of a telecommunications network. Examples of suitable network equipment will be described in more detail below.

[0034] Examples of RATs include 3GPP radio access technologies such as GSM, UMTS, LTE, LTE Advanced, 5G NR, 5G Advanced, and 6G. Other examples of RATs include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee), and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), Ultra Wideband (UWB), etc. Generally, RAT can refer to any 2G, 3G, 4G, 5G, 6G, or higher generation RAT and its different versions, as well as any other RAT that can be deployed to interoperate with such mobile communication technologies to provide access to a Mobile Network Operator (MNO) under CN 106.

[0035] Telecommunication system 100 also includes one or more radio units, which may be referred to differently as user equipment (UE) 110, terminal equipment, mobile station, etc. A UE is typically a device configured to communicate with network equipment or other UEs in a telecommunications network. A UE may be a portable computer (e.g., laptop, notebook, tablet), a mobile phone (e.g., cell phone, smartphone), a wearable computer (e.g., smartwatch), etc. In other examples, a UE may be an Internet of Things (IoT) device, an Industrial IoT (IIoT) device, a vehicle equipped with vehicle-to-everything (V2X) communication technology, etc. In some examples, as described by 3GPP, a UE may be a narrowband IoT (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a redcap device, an environmental IoT device, etc.

[0036] In operation, these UEs 110 can connect to one or more of the RANs 108 based on their specific radio access technologies, thereby accessing a specific CN 106 of the PLMN 102, or accessing one or more external data networks 104 (e.g., the Internet). External data networks can provide Internet access, operator services, third-party services, etc. For example, the International Telecommunication Union (ITU) has categorized 5G mobile network services into three classes: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) or massive Internet of Things (MIoT).

[0037] In various examples, RAN 108 can be configured as one or more macro cells, micro cells, pico cells, femto cells, etc. Figure 2 The diagram illustrates the deployment of a PLMN 102 based on several examples. As shown, the RAN can typically include one or more RAN nodes 202 that interact with the UE 110. In various examples, RAN nodes can be referred to as base stations (BS), access points (APs), base transceiver stations (BTS), Node Bs (NBs), evolved NBs (eNBs), macro BSs, NBs (MNBs) or eNBs (MeNBs), home BSs, NBs (HNBs) or eNBs (HeNBs), next-generation NBs (gNBs), enhanced gNBs (en-gNBs), next-generation eNBs (ng-eNBs), etc. The term "gNB" in 5G NR may correspond to an eNB in ​​4G LTE. Additionally, an NG-RAN node can refer to either a gNB or an ng-eNB.

[0038] RAN 108 may include some type of network control / governance entity responsible for controlling the RAN nodes. The network control / governance entity and the RAN nodes may be separate or integrated into a single device. The network control / governance entity may include processing circuitry configured to perform various management functions, etc. This processing circuitry system may be associated with memory, computer-readable storage media, or a database for maintaining the information required for the management functions.

[0039] In some deployments, the operation of RAN node 202 can be distributed or functionally broken down into multiple components, including one or more Remote Radio Heads (RRHs) or Radio Units (RUs) and Baseband Units (BBUs); and in some architectures, the BBU can be split into Centralized Units (CUs) (central nodes) and Distributed Units (DUs) (distributed nodes). CUs can be, for example, servers, hosts, or nodes. In some architectures, RRHs / RUs and DUs can be co-located. Node operations can also be distributed across multiple servers, hosts, or nodes.

[0040] It should also be understood that the division of labor between core network operations and RAN node operations may vary depending on the implementation. 5G network architecture can be based on a so-called CU-DU split. One gNB-CU (CU) can control one or more gNB-DUs (DUs). A gNB-CU can control multiple spatially separated gNB-DUs, at least acting as a transmit / receive (Tx / Rx) node. However, in some example implementations, a gNB-DU may include, for example, the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and the Physical (PHY) layer, while the gNB-CU may include layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, the Radio Resource Control (RRC) layer, and the Internet Protocol (IP) layer. Other functional divisions are also possible. It is generally assumed that engineers are familiar with the OSI model and the functions within each layer.

[0041] In some example implementations, the server or CU can generate a virtual network through which the server communicates with the radio nodes. Typically, virtual networking may involve the process of combining hardware and software network resources and network functions into a single software-based management entity (i.e., the virtual network). Such a virtual network can provide flexible operational allocation between the server and the radio heads / nodes. In fact, any digital signal processing task can be performed within the CU or DU 210, and the boundaries through which responsibility is transferred between the CU and DU can be chosen depending on the implementation.

[0042] For example Figure 2 As shown, (multiple) RAN nodes 202 can be configured to connect (multiple) UEs 110 to RAN 108 for access to CN 106. CN may include multiple network functions (NFs) that are partitioned between the control plane (CP) and the user plane (UP). Specifically, CN may include, for example, NFs for Mobility Management (MM) 204 (sometimes referred to as MM NF), Session Management (SM) 206 (sometimes referred to as SM NF), and User Plane Function (UPF) 208. MM may be, for example, an Access and Mobility Management Function (AMF) in 5GC, or a 6G MM in 6GC. Similarly, SM may be, for example, a Session Management Function (SMF) in 5GC, or a 6G SM in 6GC. Examples of other suitable NFs include Policy and Charging Function (PCF) 210, Unified Data Repository (UDR) 212, Network Data Analysis Function (NWDAF) 214, etc.

[0043] Network slicing is a key 5G feature that enables the delivery of different services using the same underlying mobile network infrastructure. Network slices can differentiate themselves based on their service requirements (such as eMBB and URLLC) or the tenants providing these services.

[0044] Network slices can be uniquely identified by Single Network Slice Selection Auxiliary Information (S-NSSAI). Current 3GPP specifications allow UE 110 to be simultaneously connected and served by up to eight slices, meaning eight S-NSSAIs. On the other hand, each cell can support dozens or even hundreds of slices. For example, in the current specification, a Tracking Area (TA) can support up to 1024 network slices.

[0045] Figure 3 An example S-NSSAI 300 is shown. As illustrated, an S-NSSAI can include both an 8-bit Slice Service Type (SST) field and a 24-bit Slice Distinguisher (SD) field, for a total length of 32 bits. Alternatively, an S-NSSAI can include only the SST field portion, in which case its length can be only 8 bits. The SST field can have normalized and non-normalized values. Values ​​from 0 to 127 belong to the normalized SST range. For example, an SST value of 1 indicates that the slice is suitable for processing 5G eMBB, an SST value of 2 indicates that the slice is suitable for processing URLLC, and so on. SD is an operator-defined field.

[0046] A limit can be imposed on the maximum slice data rate for network slices, corresponding to the maximum allowed data rate across all guaranteed bit rate (GBR) and non-GBR quality of service (QoS) flows for all UEs operating on that network slice. Such a policy can be implemented by PCF 210 in both the downlink and uplink directions. During the establishment or modification of a Packet Data Unit (PDU) session, the PCF can check whether the maximum data rate used for the slice has been exceeded. If the maximum data rate is exceeded, the PCF can refuse association with the SM policy of Session Management (SM) network function 206; otherwise, if the maximum data rate is not exceeded, the PCF can accept the SM policy association, and the PDU session can be established. The PCF can implement this policy control by consuming statistics on network slice usage from NWDAF 214 or by interacting with UDR 212, where the PCF can detect the remaining maximum slice data rate (S-NSSAI) for a particular slice.

[0047] To enable monitoring at the slice level within CN 106, an NF known as Network Slice Admission Control Function (NSACF) 216 can be established, such as... Figure 2As shown in the diagram. For a slice (S-NSSAI) subject to Network Slice Admission Control (NSAC), the NSACF can control the number of registered UEs (110) for each S-NSSAI, and / or the number of PDU sessions that can be generated for that S-NSSAI. The NSACF can be configured with the maximum allowed number of UEs or quotas for each S-NSSAI subject to NSAC, and / or the maximum number of PDU sessions or quotas. Additionally, the NSACF can be configured with details regarding the applicable access types for the S-NSSAI, such as 3GPP access type, non-3GPP access type, or both 3GPP and non-3GPP access types.

[0048] To facilitate further slice monitoring, NSACF 216 can enable event-based network slice status notifications (e.g., the number of UEs 110) and report status notifications to NF service consumers (e.g., MM 204, SM 206). An NSACF can be responsible for one or more S-NSSAIs, and one or more NSACFs can be deployed in the network.

[0049] Furthermore, various deployment architectures are possible for NSACF 216, such as a non-hierarchical architecture, where one NSACF is deployed for each NSAC service area, and the NSACF performs admission control for network slicing. In another deployment architecture, the hierarchical NSACF, there are two types of NSACFs: local NSACFs and a master NSACF that controls multiple local NSACFs. In yet another deployment architecture, known as a centralized architecture, even with multiple NSAC service areas, the central NSACF is responsible for slice admission control.

[0050] NSACF 216 can record the maximum number of UEs (110) that can be registered / admitted / allowed to an S-NSSAI subject to NSAC. When an event occurs that increases the number of UEs in an S-NSSAI, such as when MM 204 triggers a UE registration process, the MM can contact NSACF to verify whether UE registration for network slicing is possible. In this case, NSACF can confirm whether the UE ID exists in the list of registered UEs; and if the UE does not exist in the list, NSACF can check whether the maximum number of UEs for that S-NSSAI has been reached. If there is still quota available for that number of UEs in the S-NSSAI, NSACF can respond to the MM with a positive response, and the MM can accept the UE's registration for that S-NSSAI. If no more quota is available, NSACF can respond to the MM with a negative response, and the MM can reject the UE's registration on the grounds that no quota is available for network slicing.

[0051] NSACF 216 can also track the current number of PDU sessions existing in each S-NSSAI subject to NSAC. When an event occurs that triggers an increase in the number of PDU sessions for a UE within a network slice (e.g., SM 206 triggers PDU session establishment), NSACF can check whether the maximum number of PDU sessions for that particular S-NSSAI has been reached. If there is still quota available for establishing that number of PDU sessions for that S-NSSAI, NSACF can respond with a positive response to SM, and SM can establish PDU sessions for the UE associated with that S-NSSAI. If no more quota is available, NSACF can respond with a negative response to SM, and SM can refuse the PDU session establishment on the grounds that no quota is available for the network slice.

[0052] As mentioned above, the current 3GPP mechanism utilizes the external network function NSACF 216 to record counters and performs admission control checks for the number of registered UEs 110 in each S-NSSAI, the number of PDU sessions in each S-NSSAI, and the number of UEs with at least one PDN connection / PDU session in each S-NSSAI. However, this design option can cause several problems.

[0053] For example, in a centralized architecture, an external (central) NSACF 216 can generate significant network message load between MM 204 / SM 206 and the NSACF to increment / decrement counters on a per-transaction basis and check if the increment will exceed quota limits / thresholds. Potential synchronization issues can also arise between MM / SM and NSACF if any NF loses registration or PDU session counts. This can occur during maintenance activities or unexpected problems where the counts between MM / SM and NSACF may become out of sync.

[0054] Another issue that can arise in a centralized architecture is the duplicate binding of performance measurement counters, which also exists in MM 204 for the number of registered UE 110 per S-NSSAI and in SM 206 for the number of PDU sessions per S-NSSAI. The incrementing / decrementing of these counters is performed locally in the MM / SM and externally in NSACF 216.

[0055] Another issue that may arise in a centralized architecture is the potential performance measurement discrepancy between the MM 204 / SM 206 and NSACF 216 due to potential message loss caused by overload, congestion, or network problems. When both the local MM / SM and the external NSACF are independently incrementing / decrementing the counters, the counters may not perfectly match between the two locations.

[0056] In addition to the problems with the existing NSACF method mentioned above, the counting of PDU sessions based on per-slice (S-NSSAI) assumes that each PDU session in each slice has the same weight (e.g., it will consume the same load in terms of traffic data rate). For example, if the maximum PDU session quota for a slice is 50, these 50 PDU sessions can be maintained simultaneously, but this does not necessarily mean that the traffic running on these PDU sessions is the same in terms of load.

[0057] Continuing with the existing counting method could lead to a situation where PDU sessions with very high traffic loads may have exceeded the maximum slice data rate of S-NSSAI maintained by PCF 210. Furthermore, even if the maximum number of PDU session quotas is not exceeded at NSACF 216, from NSACF's perspective, accepting such PDU sessions may ultimately result in those sessions being unused / rejected within that PCF, leading to wasted signaling.

[0058] Figure 4 Signaling diagram 400 for NSACF and PCF services illustrates the aforementioned issues. As shown, at step 401, UE 110 registers with the network for network slice S-NSSAI 1, which is subject to NSAC; and after a period of time, the UE requests to establish a PDU session associated with S-NSSAI 1 at step 402. S-NSSAI 1 has a specific maximum number or quota for PDU sessions at NSACF 216, and the maximum slice data rate is also controlled at PCF 210. When the UE requests to establish a PDU session, SM 206 checks with NSACF at steps 403, 404, and 405 to see if there is any quota available for S-NSSAI 1 from NSACF's perspective. At step 406, PCF and NWDAF 214 exchange information about the remaining maximum slice data rate for S-NSSAI 1.

[0059] If the check by SM 206 is successful, the SM checks with PCF 210 at step 407 to establish an SM policy association. However, if the PCF identifies that there is no remaining data rate for S-NSSAI, the PCF rejects the SM policy association, and ultimately the SM will reject the PDU session establishment, as shown in steps 408, 409, and 410. This causes the following problem: When a network slice constrained by NSAC passes the NSACF check due to available quotas at NSACF 216, the PDU session establishment may still be rejected because resources are unavailable from the PCF's perspective. In this case, additional signaling is wasted in the network used by UE 110, and even if the PDU session is ultimately rejected, the process may be very time-consuming from the UE's perspective.

[0060] In light of the foregoing, the example implementations of this disclosure provide solutions(s) to one or more of the aforementioned problems. Some example implementations may also provide additional means for the network to perform more fine-grained NSAC, avoid additional signaling in the event of resource unavailability, and identify design options to avoid unnecessary signaling in NSACF overall.

[0061] According to some example implementations involving an externally centralized NSACF 216, the NSACF can subscribe to NWDAF 214 for slice load information, which indicates the current load for one or more network slices. Subscribing to NWDAF can occur when an NSACF supporting an NSAC-dependent slice is initiated, or when the UE 110 first registers with an NSAC-dependent network slice. NWDAF can provide slice load information to the NSACF based on timely updates or based on set load thresholds (such as when X% of the slice load is exceeded).

[0062] Alternatively, in some examples, NSACF 216 may subscribe to a UDR 212 for information indicating the remaining maximum slice data rate for one or more network slices. Similar to NWDAF 214, subscription to the UDR may occur when an NSACF supporting an NSAC-bound slice is initiated, or when the UE 110 first registers with an NSAC-bound network slice. The UDR may provide the NSACF with the remaining maximum slice data rate information for the network slice based on timely updates or based on a set load threshold (e.g., when Y% of the maximum slice data rate remains).

[0063] In some examples, the network slice admission process can be triggered by the detection of an event at SM 206 that causes an increase in the number of PDU sessions associated with the network slice, such as admission for PDU sessions for UE 110 to the network slice. In this regard, the SM may be triggered to contact NSACF 216 to perform the network slice admission process for PDU session admission. As mentioned above, the NSACF can be configured with a maximum number of PDU sessions allowed per network slice. The NSACF can receive, or otherwise configure, the total number or quota (sometimes referred to as the maximum quota, or more generally, the quota) of PDU sessions that are allowed to be admitted for one or more network slices, and use this information to verify whether the UE associated with the network slice has an available PDU session quota (e.g., a PDU session establishment request received by the UE).

[0064] In some of these examples, SM 206 can determine the estimated load of a PDU session for comparison with a PDU session quota. For example, the SM can determine the estimated load based on GBR flow information for one or more GBR flows carried by the PDU session, or based on Aggregated Minimum Bit Rate (AMBR) information for one or more non-GBR flows carried by the PDU session; or the SM can utilize other internal SM mechanisms to determine the estimated load. The SM can then send a request or other message to NSACF 216 to increase the number of PDU sessions used for network slicing (PDU session count), including information indicating the estimated load of the PDU session and a message indicating the increase in the PDU session count used for network slicing.

[0065] NSACF 216 can verify that the quota of PDU sessions allowed to be admitted for network slices has not been exceeded by the admission of PDU sessions. In some examples, NSACF can calculate the number of PDU sessions used on the network slice based on the PDU sessions and the current number of PDU sessions associated with the network slice, and verify that the number of used PDU sessions has not exceeded the quota. When the quota is exceeded, NSACF can send (and SM 206 can receive) a response indicating that the request to increase the number of PDU sessions is rejected, and the SM can then reject the PDU session. However, when the quota is not exceeded, NSACF 216 can also verify that the maximum slice data rate on the network slice has not been exceeded based on the estimated load of the PDU sessions.

[0066] In some examples, NSACF can calculate the used data rate for a network slice based on the current load on the network slice (from NWDAF 214) or the remaining maximum slice data rate (from UDR 212) and the estimated load of the PDU session. The used data rate can be the sum of the current network slice load (from the current network slice load or the remaining maximum slice data rate) and the estimated load. NSACF can then verify that the used data rate (current + estimated) does not exceed the maximum slice data rate on the network slice.

[0067] When the maximum slice data rate is exceeded, NSACF 216 can send (and SM 206 can receive) a response indicating that the request to increase the number of PDU sessions is rejected, and the SM can then reject the PDU session. Otherwise, if neither the PDU session quota nor the maximum slice data rate is exceeded, NSACF can send a response to the SM indicating that the request to increase the number of PDU sessions is accepted, and the SM can then admit the PDU session. This method can avoid the request to PCF 210 to establish SM policy associations for the PDU session (in step 407) if the PDU session is ultimately rejected, thereby saving signaling.

[0068] Based on some example implementations involving distributed NSACF 216, NSACF functionality can be distributed to other NFs, such as MM 204 and / or SM 206. In some of these examples, the other NFs can perform network slice admission control procedures, such as in the same or similar manner as described above. In some examples, the MM / SM can subscribe to information indicating the current load or remaining maximum slice data rate for each network slice (each S-NSSAI), such as by subscribing to NWDAF 214 for slice load information for each network slice, which can occur as described above. The MM can store information from the NWDAF indicating the current number of UEs registered per network slice across the network, while the SM can store information from the NWDAF indicating the current number of PDU sessions associated with network slices across the network. The SM can also store information from the NWDAF indicating the current load (e.g., current data rate) per network slice across the network.

[0069] MM 204 can maintain a count of the number of UEs registered to the network slice by the MM, and SM 206 can maintain a count of the number of PDU sessions admitted to the network slice by the SM. NWDAF 214 can subscribe to this information from the MM / SM and from other MM / SMs across the network. Subscription from NWDAF to the MM / SM can be made when the MM / SM first subscribes to information from NWDAF, and subscription can be used to obtain information about the count on a timely basis (e.g., every five minutes) or on a demand basis. NWDAF can collect counts from MM / SMs across the network to derive the current number of registered UEs and the current number of PDU sessions for that network slice across the network. The current number for that network slice in that network can be provided back to the MM / SM based on the MM / SM's subscription to NWDAF. And in some examples, when the derived current number is close to the slice's maximum limit, NWDAF may shorten the time between collection intervals or trigger on-demand requests to obtain the most accurate count.

[0070] In some examples, MM 204 can be configured with a maximum number or quota of UEs that are allowed to register / admit to each network slice (each S-NSSAI). In this regard, MM may receive a total number or quota (sometimes referred to as the maximum quota, or more generally, the quota) of UEs that are allowed to register to one or more network slices, configured or otherwise configured, and use this information to verify the existence of available UE quotas for UEs to register to the network slice (e.g., PDU session establishment requests received by the UE).

[0071] In some more specific examples, MM 204 can detect events related to UE 110 that cause an increase in the number of UEs registering to the network slice, such as for UE registration to the network slice. MM can calculate the number of UEs used for the network slice based on the UEs and the current number of UEs. When the number of used UEs does not exceed the quota of UEs allowed to register to the network slice, MM can grant UE registration to the network slice. Otherwise, when the number of used UEs exceeds the quota of UEs allowed to register to the network slice, MM can deny UE registration to the network slice.

[0072] Alternatively, in some examples, the SM 206 may be configured with a maximum number of PDU sessions allowed per network slice (per S-NSSAI). The SM may receive, or otherwise configure, a maximum quota of PDU sessions allowed to be admitted for one or more network slices, and use this information to verify that a PDU session quota is available for the UE on the network slice. In some examples of these examples, the SM may also be configured with a maximum slice data rate per network slice (per S-NSSAI). The SM may then determine an estimated load on the PDU sessions and verify, based on the current load and the estimated load on the PDU sessions, that the maximum slice data rate on the network slice has not been exceeded.

[0073] In some more specific examples, SM 206 can detect events associated with UE 110 that cause an increase in the number of PDU sessions for the network slice, such as, for example, admission of PDU sessions for UEs associated with the network slice. SM can calculate the number of used PDU sessions on the network slice based on the PDU sessions and the current number of PDU sessions on the network slice. SM can also determine the estimated load of the PDU sessions and calculate the used data rate for the network slice based on the estimated load of the PDU sessions and the current load on the network slice. SM can then admit a PDU session if the number of used PDU sessions does not exceed the quota of PDU sessions allowed to be admitted for the network slice and the used data rate does not exceed the maximum slice data rate on the network slice. Otherwise, SM can reject a PDU session if the number of used PDU sessions exceeds the quota of PDU sessions allowed to be admitted for the network slice, or if the used data rate exceeds the maximum slice data rate on the network slice.

[0074] In some examples, SM 206 can effectively perform the check for any remaining data rate, which is otherwise performed by PCF 210 (at step 408), and can only send a request to PCF to establish an SM policy association for the PDU session (at step 407) if the SM determines that the PDU session has been admitted based on the successful outcome of the network slice admission control process. Then, in some of these examples, the request to establish an SM policy association for the PDU session when the PDU session is admitted can include an indication that the used data rate has not exceeded the maximum slice data rate on the network slice. Therefore, PCF can avoid re-checking the remaining data rate.

[0075] To further illustrate some example implementations, Figure 5Signaling diagram 500 is implemented according to some examples of this disclosure, involving one or more processes of an externally centralized NSACF 216. In an alternative (Alt-1), in some examples, the NSACF may register with and subscribe to the NWDAF 214 at step 501 to receive slice load information for network slices and information indicating the maximum slice data rate for that network slice. As described above, this subscription may be based on timely updates, such as updating information about network slices every five minutes. In other examples, the subscription may be based on a threshold level, such as updating information only when the load has reached X% of the maximum slice data rate.

[0076] In another alternative (Alt-2), in some examples, NSACF 216 may register with UDR 212 at step 502 and subscribe to receive information indicating the remaining maximum slice data rate and the maximum slice data rate used for network slicing. Again, this subscription may be based on timely updates, such as updating information about network slices every five minutes. In other examples, the subscription may be based on a threshold level, such as updating information only when Y% of the maximum slice data rate is exceeded.

[0077] At step 503, UE 110 can register a network slice subject to NSAC with the network. For example, as shown in the figure, the UE can register S-NSSAI 1 with the network, and the UE can include S-NSSAI 1 in the list of allowed NSSAIs.

[0078] At steps 504 and 505, NSACF 216 may receive updates of information from NWDAF 214 or UDR 212, which indicates the current load or remaining maximum slice data rate for network slices (e.g., S-NSSAI 1).

[0079] At step 506, UE 110 may send a request to the network to establish a PDU session with S-NSSAI 1. At steps 507 and 508, SM 206 may send a request to NSACF 216 to check the availability of quotas for admission control for S-NSSAI 1 by indicating an increase in the number of PDU sessions used for network slicing. SM may also determine the estimated load of the PDU session, such as based on GBR flow information, AMBR information for (multiple) non-GBR flows, or certain internal mechanisms. SM may send information indicating the estimated load of the PDU session to NSACF.

[0080] At steps 509 and 510, NSACF 216 can check whether the quota for the PDU session used for S-NSSAI 1 has been exceeded. If the quota for the PDU session has been exceeded, NSACF can respond to SM 206 with the indication that the quota has been exceeded, and SM can reject the request from UE 110 to establish a PDU session. If the quota for the PDU session has not been exceeded, NSACF can also compare the estimated load of the PDU session with the slice load or the remaining maximum slice data rate and the maximum slice data rate.

[0081] NSACF 216 can calculate the used data rate for S-NSSAI 1 based on the current load or remaining maximum slice data rate, and the estimated load. When the used data rate exceeds the maximum slice data rate, NSACF can reply to SM with an indication that the maximum slice data rate has been exceeded, and SM can reject the request from UE to establish a PDU session. Otherwise, when the used data rate does not exceed the maximum slice data rate, NSACF can reply to SM with an indication that neither the quota for the PDU session nor the maximum slice data rate has been exceeded, and SM can accept the request from UE to establish a PDU session (admission to the PDU session).

[0082] Figure 6 Signaling diagram 600, implemented according to other examples of this disclosure, involves one or more processes related to a distributed NSACF 216, whereby NSACF functionality can be distributed to other NFs, such as MM 204 and / or SM 206. As shown in steps 601, 602, and 603, the MM and SM can be configured accordingly via orchestration and management (OAM) to have a maximum number of UEs or quotas that will be registered / allowed for S-NSSAI, and a maximum number of PDU session quotas that will be admitted to each S-NSSAI, in a manner similar to how NSACF 216 can be configured.

[0083] Both MM 204 and SM 206 can also subscribe to NWDAF 214 for current load information for each S-NSSAI subject to NSAC. The MM can subscribe to slice load analysis for each S-NSSAI subject to NSAC, for the maximum number of UEs allowed to register per network slice. The SM can subscribe to slice load analysis for each S-NSSAI subject to NSAC, for the maximum number of PDU sessions allowed per network slice. In some examples, subscription to NWDAF may occur when an MM / SM supporting a network slice subject to NSAC is initiated, or when a UE first registers to a network slice subject to NSAC. NWDAF can provide slice load analysis based on timely updates or based on set load thresholds (such as when Y% of the slice load is exceeded).

[0084] If not already subscribed, NWDAF 214 can use multiple discovery procedures at steps 604, 605, and 606 to locate NFs supporting S-NSSAI (e.g., MM 204, SM 206) and trigger a subscription to MM / SM statistics, including counts related to network slice admission control. When an MM / SM first subscribes to slice load analysis, NWDAF can subscribe to MM / SM statistics, and the subscription can be for timely (e.g., every five minutes) or demand-based access to information about the counts. In some examples, when the current number of S-NSSAI results across the network approaches the slice maximum limit, NWDAF can shorten the time between collection intervals for S-NSSAI or trigger an on-demand request to obtain the most accurate counts.

[0085] At step 607, MM 204 / SM 206 can provide NWDAF 214 with corresponding MM / SM statistics, which accordingly include local counts at the MM of the number of UEs registered for each network slice and at the SM of the number of PDU sessions associated with the network slice. At steps 608 and 609, NWDAF can send a notification of slice load analysis to the MM / SM. The MM can store information from the NWDAF indicating the current number of UEs registered across the network per network slice; and the SM can store information from the NWDAF indicating the current number of PDU sessions across the network per network slice. The SM can also store information from the NWDAF indicating the current load (e.g., current data rate) across the network per network slice.

[0086] At step 610, UE 110 may send a registration request to MM 204, requesting a specific network slice (e.g., S-NSSAI 1). At step 611, MM may perform a network slice admission control procedure for S-NSSAI 1 based on the current number of UEs registered for each S-NSSAI received from NWDAF 214 and the maximum number of allowed UEs to be registered per S-NSSAI configured by OAM. If quotas remain, MM may accept the registration request, and S-NSSAI 1 may be added to the list of allowed NSSAIs for that UE.

[0087] After a period of time, UE 110 may send a request to SM 206 at step 612 to establish a PDU session on S-NSSAI 1. At step 613, the SM may perform a network slice admission control procedure for S-NSSAI 1 based on information received from NWDAF 214 regarding the current number of PDU sessions, the remaining maximum slice data rate for each S-NSSAI, and the maximum number of PDU sessions allowed per S-NSSAI configured by OAM. If quotas are still available, the SM may accept the PDU session establishment request. The SM may also send a request to PCF at step 614 to establish an SM policy association for the PDU session, and this request may include an indication that the used data rate has not exceeded the maximum slice data rate on the network slice.

[0088] Figures 7A to 7C This is a flowchart illustrating the various steps in method 700 performed by a Network Slice Admission Control Function (NSACF) implemented according to various examples. The method includes: requesting a subscription for a network function for information indicating the current load or remaining maximum slice data rate for one or more network slices, wherein the NSACF is configured with the total number or quota of Packet Data Unit (PDU) sessions allowed to be admitted for one or more network slices, such as... Figure 7A As shown in block 702, the method includes: receiving information from a network function based on the subscription, the information indicating the current load or remaining maximum slice data rate for one or more network slices, as shown in block 704. The method also includes: performing a network slice admission control procedure for one or more network slices based on an event related to a user equipment (UE), the event causing an increase in the number of PDU sessions for the network slices in the one or more network slices, as shown in block 706. In some examples, the network slice admission control procedure is performed at least based on the total number or quota of PDU sessions allowed to be admitted to the network slice, and the current load or remaining maximum slice data rate on the network slice.

[0089] In some examples, the subscription is requested at block 702 when NSACF is initiated or when the UE first registers with at least one of one or more network slices subject to network slice admission control.

[0090] In some examples, the network function is the Network Data Analysis Function (NWDAF), and the information received from the NWDAF at block 704 includes slice load information, which indicates the current load of the network slice in one or more network slices.

[0091] In some examples, the network function is the Unified Data Repository (UDR), and the information received from the UDR at block 704 indicates the remaining maximum slice data rate on one or more network slices.

[0092] In some examples, method 700 also includes receiving a request from the Session Management (SM) network function to increase the number of PDU sessions on the network slice, such as... Figure 7B As shown at block 708. In some of these examples, the request triggers the network slice admission control process.

[0093] In some examples, the increase in the number of PDU sessions is for admission of PDU sessions of UEs associated with the network slice, and the request from the SM network function includes information indicating the estimated load of the PDU session. In some of these examples, the network slice admission control procedure at block 706 is also performed at least based on the estimated load of the PDU session.

[0094] In some examples, performing the network slice admission control procedure at block 706 includes: calculating the used data rate for the network slice based on the current load or remaining maximum slice data rate on the network slice, and the estimated load of the PDU session, such as... Figure 7C As shown in block 710. In some of these examples, the network slice admission control process further includes accepting the request from the SM network function, as shown in block 712, when the total number or quota of PDU sessions allowed to be admitted for the network slice is not exceeded by the admission of the PDU sessions and the used data rate does not exceed the maximum slice data rate on the network slice.

[0095] Figures 8A to 8H This is a flowchart illustrating the various steps in method 800 implemented according to various examples. The method includes: detecting an event related to a user equipment (UE) that causes an increase in the number of packet data unit (PDU) sessions associated with a network slice, the increase being for admission of PDU sessions for the UE associated with that network slice, such as... Figure 8AAs shown in block 802, the method includes: determining an estimated load of a PDU session for a network slice admission control process, the network slice admission control process being performed based at least on the total number or quota of PDU sessions allowed to be admitted for the network slice, the estimated load of the PDU sessions, and information indicating the current load or remaining maximum slice data rate on the network slice, as shown in block 804. The method also includes: admitting or denying a PDU session based on the result of the network slice admission control process, as shown in block 806.

[0096] In some examples, the estimated load of a PDU session is determined based on GBR stream information for one or more guaranteed bit rate (GBR) streams carried by the PDU session, or aggregated minimum bit rate (AMBR) information for one or more non-GBR streams carried by the PDU session.

[0097] In some examples, method 800 also includes: triggering the Network Slice Admission Control Function (NSACF) to perform the network slice admission control process based on events, such as... Figure 8B As shown at block 808.

[0098] In some examples, triggering NSACF at block 808 includes sending a request to NSACF to increase the number of PDU sessions on the network slice, such as... Figure 8C As shown in block 810. In some of these examples, method 800 further includes receiving a response from NSACF indicating whether the request is accepted or rejected based on the result of the network slice admission control process, as shown in block 812. And in some of these examples, the PDU session is admitted or rejected at block 806 based on the response from NSACF.

[0099] In some examples, the method is performed by a Session Management (SM) network function configured with a total number or quota of PDU sessions allowed to be admitted for one or more network slices, which include network slices. In some of these examples, method 800 further includes performing the network slice admission control process based on the total number or quota of PDU sessions allowed to be admitted for the network slice, the estimated load of the PDU sessions, and information indicating the current load or remaining maximum slice data rate of the network slice. Figure 8D As shown at block 814.

[0100] In some examples, method 800 also includes: requesting a subscription to a Network Data Analysis Function (NWDAF) for information indicating the current load per network slice for one or more network slices, such as... Figure 8EAs shown in block 816. In some of these examples, the method further includes: receiving information from the NWDAF based on the subscription, the information indicating the current load on the network slice, as shown in block 818. In still some of these examples, the network slice access control procedure is performed at block 814 based at least on the total number or quota of PDU sessions allowed to be admitted for the network slice, the estimated load of the PDU sessions, and the information indicating the current load on the network slice.

[0101] In some examples, the method is performed by the Session Management (SM) network function, and the subscription is requested when the SM network function is initiated or when the UE first registers with at least one of one or more network slices subject to network slice admission control.

[0102] In some examples, performing the network slice admission control procedure at block 814 includes: calculating the used data rate for the network slice based on the estimated load of the PDU session and the current load on the network slice, such as... Figure 8F As shown in block 820. In some of these examples, a PDU session is admitted at block 806 when the total number or quota of PDU sessions allowed to be admitted for that network slice is not exceeded by the admission of that PDU session and the used data rate does not exceed the maximum slice data rate on that network slice.

[0103] In some examples, performing the network slice admission control procedure at block 814 further includes: calculating the number of used PDU sessions on the network slice based on the PDU session and the current number of PDU sessions on the network slice, such as... Figure 8G As shown in block 822. In some of these examples, a PDU session is admitted at block 806 when the number of used PDU sessions does not exceed the total number or quota of PDU sessions that are allowed to be admitted for that network slice, and the used data rate does not exceed the maximum slice data rate on that network slice.

[0104] In some examples, method 800 further includes: receiving a request from a Network Data Analysis Function (NWDAF) for subscribing to information indicating the current number of PDU sessions per network slice for one or more network slices, such as... Figure 8H As shown in block 824. In some of these examples, the method further includes: sending information to the NWDAF, based on the subscription, indicating the current number of PDU sessions per network slice, as shown in block 826. And the method includes: receiving information from the NWDAF indicating the current load and the current number of PDU sessions on the network slice, as shown in block 828.

[0105] In some examples, method 800 further includes sending a request to establish a session management policy association for the PDU session when the PDU session is admitted. And in some of these examples, the request includes an indication that the used data rate does not exceed the maximum slice data rate on the network slice.

[0106] Figures 9A to 9D This is a flowchart illustrating the various steps of a method 900 implemented according to various examples. The method includes: detecting an event related to a user equipment (UE) that causes an increase in the number of UEs registered to a network slice in one or more network slices, the increase relating to UE registration to that network slice, wherein the MM network function is configured with a total number or quota of allowed UEs to register to that network slice, such as... Figure 9A As shown in block 902, the method includes: performing a network slice admission control procedure, as shown in block 904, based at least on information indicating the current number of UEs to the network slice and the total number or quota of allowed UEs to register with the network slice. Furthermore, the method includes: admitting or denying the UE's registration with the network slice based on the result of the network slice admission control procedure, as shown in block 906.

[0107] In some examples, method 900 further includes: requesting a subscription to a Network Data Analysis Function (NWDAF) for information indicating the current number of registered UEs per network slice for one or more network slices, such as Figure 9B As shown in block 908. In some of these examples, the method further includes: receiving information from the NWDAF based on the subscription, which indicates the current number of registered UEs to the network slice, as shown in block 910.

[0108] In some examples, the subscription is requested at block 908 when the MM network function is initiated, or when the UE first registers with at least one of the one or more network slices subject to network slice admission control.

[0109] In some examples, method 900 further includes: receiving a request from a Network Data Analysis Function (NWDAF) for subscribing to information indicating the current number of registered UEs per network slice for one or more network slices at the MM network function, such as... Figure 9B As shown in block 912. In some of these examples, the method further includes: sending information to the NWDAF, based on the subscription, indicating the current number of registered UEs per network slice for the MM network function, as shown in block 914. And the method includes: receiving information from the NWDAF indicating the current number of UEs on the network slice, as shown in block 916.

[0110] In some examples, the network slice admission control procedure at block 904 includes: calculating the number of UEs already used for network slicing based on the UE and the current number of UEs, such as... Figure 9D As shown in block 918. In some of these examples, UE registration to the network slice is granted at block 906 when the number of used UEs does not exceed the total number or quota of allowed UEs to register with the network slice.

[0111] According to the example implementations of this disclosure, the telecommunications system 100 or PLMN 102 and its components (such as UE 110, CN 106, RAN 108, 5GC 202, MM 204, SM 206, UPF 208, PCF b, UDR 212, NWDAF 214 and / or NSACF 216) can be implemented in various ways. Components used to implement the system and its components may include hardware, firmware, software, or combinations thereof. In some examples, one or more devices may be configured to serve as or otherwise implement the system and its components shown and described herein. In examples involving more than one device, the respective devices may be interconnected or otherwise communicate in a variety of different ways, such as directly or indirectly via wired or wireless networks.

[0112] Based on some example implementations, regarding Figures 7A to 7C At least some of the described methods 700 can be performed by means including components for performing functions corresponding to the steps of the method. Similarly, regarding Figures 8A to 8H At least some of the described method 800 can be performed by means including components for performing functions corresponding to the steps of the method. And regarding Figures 9A to 9C At least some of the described method 900 can be performed by means including components for performing functions corresponding to the steps of the method. Examples of suitable means may include RAN nodes such as NSACF, SM (e.g., SMF, 6G SM), MM (e.g., AMF, 6G MM) or any suitable means such as a server, host or node.

[0113] Figure 10 An apparatus 1500 implemented according to some examples of the present disclosure is shown, wherein components for performing various functions include hardware, which may be used alone or in the guidance of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory. The apparatus may include one or more of each of a plurality of components, such as, for example, a processing circuitry system 1002 connected to a computer-readable storage medium or other memory 1004.

[0114] The processing circuit system 1002 may be comprised of one or more processors individually, or in combination with one or more computer-readable storage media. The processing circuit system is typically any computer hardware capable of processing information, such as, for example, data, computer programs, and / or other suitable electronic information. The processing circuit system consists of an assembly of electronic circuits, some of which may be packaged as integrated circuits or multiple interconnected integrated circuits (integrated circuits are sometimes more commonly referred to as “chips”). The processing circuit system may be configured to execute computer programs, which may be stored on the processing circuit system or otherwise stored in memory 1004 (of the same device or other devices).

[0115] Depending on the specific implementation, the processing circuit system 1002 may be multiple processors, a multi-core processor, or other types of processors. Furthermore, the processing circuit system may be implemented using multiple heterogeneous processor systems, where a main processor resides on a single chip along with one or more auxiliary processors. As another exemplary example, the processing circuit system may be a symmetric multiprocessor system comprising multiple processors of the same type. In another example, the processing circuit system may be embodied as one or more application-specific integrated circuits (ASICs), FPGAs, etc., or otherwise include one or more ASICs, FPGAs, etc. Therefore, while the processing circuit system may be able to execute a computer program to perform one or more functions, the processing circuit systems in the various examples may also be able to perform one or more functions without the aid of a computer program. In either case, the processing circuit system can be appropriately programmed according to the exemplary implementations of this disclosure to perform functions or operations.

[0116] Memory 1004 generally refers to any computer hardware capable of temporarily or permanently storing information such as, for example, data, computer programs, instructions 1006 (e.g., computer-readable program code), and / or other suitable information. The memory may include volatile and / or non-volatile memory and may be fixed or removable. Examples of suitable memory include recording media, random access memory (RAM), read-only memory (ROM), hard disk drives, flash memory, USB flash drives, removable computer floppy disks, optical disks, or some combination thereof.

[0117] Memory 1004 is a non-transitory device capable of storing information. An example of a suitable memory is a computer-readable storage medium, which differs from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media include electronic carrier signals, telecommunication signals, or some combination thereof. As used herein, the term "non-transitory" refers to a limitation of the medium itself (i.e., tangible, not signaling), rather than a limitation on the persistence of data storage (e.g., RAM and ROM). As described herein, computer-readable media generally refers to computer-readable storage media or computer-readable transmission media. A computer-readable medium is any entity or device capable of storing or carrying any information therein, such as one or more computer programs or portions thereof.

[0118] In addition to memory 1004 (e.g., a computer-readable storage medium), processing circuitry 1002 may also be connected to one or more interfaces for displaying, sending, and / or receiving information. These interfaces may include communication interface 1008 and / or one or more user interfaces (e.g., a display, a user input interface). The communication interface may be configured to send and / or receive information, such as sending to and / or receiving from other devices, networks, etc. The communication interface may be configured to send and / or receive information via physical (wired) and / or wireless communication links. Examples of suitable communication interfaces include network interface controllers (NICs), wireless NICs (WNICs), etc.

[0119] The processing circuitry 1002 executes instructions 1006 or instructions stored in memory 1004, supporting combinations of operations for implementing exemplary embodiments of this disclosure. In this manner, apparatus 1000 may include at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, wherein the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It should also be understood that one or more functions, and combinations of functions, may be implemented by a dedicated hardware-based computer system and / or processing circuitry that performs a particular function, or by a combination of dedicated hardware and program code instructions.

[0120] Some example implementations of this disclosure can also be executed as a computer process defined by one or more computer programs or portions thereof. Example implementations of this disclosure can be executed by executing at least a portion of a computer program including instructions. The computer program can be in source code form, object code form, or some intermediate form. The computer program can be stored in a computer-readable medium readable by a computer, processing circuitry system, or other suitable device. As mentioned above, for example, the computer program can be stored in memory (such as a computer-readable storage medium). Alternatively or additionally, for example, the computer program can be stored in a computer-readable transmission medium. The coding of software used to perform example implementations of this disclosure is entirely within the scope of those skilled in the art.

[0121] It should be understood that any suitable instructions can be loaded from memory or a computer-readable medium (e.g., a computer-readable storage medium, a computer-readable transmission medium) onto a computer, processing circuitry, or other programmable means to produce a particular machine, such that the particular machine becomes a component for implementing the functions described herein. The instructions can also be stored in a computer-readable medium that is capable of directing a computer, processing circuitry, or other programmable means to operate in a particular manner to produce a particular machine or a particular article of manufacture. In some examples, instructions stored in a computer-readable medium can produce an article of manufacture, wherein the article of manufacture becomes a component for implementing the functions described herein. Instructions can be obtained from a computer-readable medium and loaded onto a computer, processing circuitry, or other programmable means to configure the computer, processing circuitry, or other programmable means to perform operations to be performed on or by the computer, processing circuitry, or other programmable means.

[0122] The fetching, loading, and execution of instructions, including program code instructions, can be performed sequentially, such that one instruction is fetched, loaded, and executed at a time. In some example implementations, fetching, loading, and / or execution can be performed in parallel, such that multiple instructions are fetched, loaded, and / or executed together. The execution of program code instructions can produce computer-implemented processes, such that the instructions, executed by a computer, processing circuitry system, or other programmable device, provide operations for implementing the functions described herein.

[0123] As stated above and reiterated below, this disclosure includes, but is not limited to, the following example implementations.

[0124] Clause 1. A method performed by a Network Slice Admission Control Function (NSACF), the method comprising: requesting a subscription for a network function for information indicating information for one or more network slices, the information indicating current load or remaining maximum slice data rate for each network slice, the NSACF being configured with a total number or quota of Packet Data Unit (PDU) sessions allowed to be admitted to the one or more network slices; receiving information from the network function based on the subscription, the information indicating current load or remaining maximum slice data rate for the one or more network slices; and performing a network slice admission control procedure for the one or more network slices based on an event associated with a User Equipment (UE), the event causing an increase in the number of PDU sessions for the network slices in the one or more network slices, wherein the network slice admission control procedure is performed at least based on the total number or quota of PDU sessions allowed to be admitted to the network slice, and the current load or remaining maximum slice data rate on the network slice.

[0125] Clause 2. The method of Clause 1, wherein a subscription is requested when NSACF is initiated or when the UE first registers with at least one of one or more network slices subject to network slice admission control.

[0126] Clause 3. The method according to Clause 1 or Clause 2, wherein the network function is a network data analysis function (NWDAF), and the information received from the NWDAF includes slice load information indicating the current load of a network slice in one or more network slices.

[0127] Clause 4. The method according to any one of Clauses 1 to 3, wherein the network function is a Unified Data Repository (UDR), and information received from the UDR indicates the remaining maximum slice data rate on one or more network slices.

[0128] Clause 5. The method according to any one of Clauses 1 to 4, wherein the method further comprises: receiving a request from a Session Management (SM) network function to increase the number of PDU sessions on a network slice, and wherein the request triggers a network slice admission control process.

[0129] Clause 6. The method according to Clause 5, wherein the increase in the number of PDU sessions is for admission of PDU sessions of UEs associated with network slices, and the request from the SM network function includes: information indicating the estimated load of the PDU sessions, and wherein the network slice admission control process is also performed at least based on the estimated load of the PDU sessions.

[0130] Clause 7. The method of Clause 6, wherein the network slice admission control process includes: calculating the used data rate for the network slice based on the current load or remaining maximum slice data rate on the network slice and the estimated load of the PDU sessions; and accepting a request from the SM network function when the total number or quota of PDU sessions allowed to be admitted for the network slice is not exceeded by the admission of at least the number of PDU sessions and the used data rate does not exceed the maximum slice data rate on the network slice.

[0131] Clause 8. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to perform at least one method according to any one of Clauses 1 to 7.

[0132] Clause 9. An apparatus comprising components for performing the method pursuant to any one of Clauses 1 to 7.

[0133] Clause 10. A computer-readable medium comprising instructions that, in response to execution by at least one processor circuitry system, cause a device to perform a method according to any one of Clauses 1 to 7.

[0134] Clause 11. A computer-readable storage medium comprising instructions that, in response to execution by at least one processor circuitry, cause a device to perform a method according to any one of Clauses 1 to 7.

[0135] Clause 12. A computer program comprising instructions that, in response to execution by at least one processor circuitry system, cause a device to perform a method according to any one of Clauses 1 to 7.

[0136] Clause 13. A method comprising: detecting an event related to a user equipment (UE) that causes an increase in the number of packet data unit (PDU) sessions associated with a network slice for admission of PDU sessions for a UE associated with the network slice; determining an estimated load of the PDU sessions for a network slice admission control procedure performed at least based on the total number or quota of PDU sessions allowed to be admitted for the network slice, the estimated load of the PDU sessions, and information indicating the current load or remaining maximum slice data rate on the network slice; and admitting or denying the PDU sessions based on the result of the network slice admission control procedure.

[0137] Clause 14. The method of Clause 13, wherein the estimated load of the PDU session is determined based on GBR stream information for one or more guaranteed bit rate (GBR) streams carried by the PDU session, or aggregated minimum bit rate (AMBR) information for one or more non-GBR streams carried by the PDU session.

[0138] Clause 15. The method pursuant to Clause 13 or Clause 14, wherein the method further comprises: triggering the Network Slice Admission Control Function (NSACF) to perform the network slice admission control process on an event-based basis.

[0139] Clause 16. The method of Clause 15, wherein triggering NSACF further includes: sending a request to NSACF to increase the number of PDU sessions on the network slice, wherein the method further includes: receiving a response from NSACF indicating that the request is accepted or rejected based on the result of the network slice admission control process, and wherein the PDU session is admitted or rejected based on the response from NSACF.

[0140] Clause 17. The method according to any one of Clauses 13 to 16, wherein the method is performed by a Session Management (SM) network function configured with a total number or quota of PDU sessions allowed to be admitted for one or more network slices, the one or more network slices including network slices, and wherein the method further comprises: performing a network slice admission control process based on the total number or quota of PDU sessions allowed to be admitted for network slices, an estimated load of PDU sessions, and information indicating the current load or remaining maximum slice data rate on the network slice.

[0141] Clause 18. The method of Clause 17, wherein the method further comprises: requesting a subscription to a Network Data Analysis Function (NWDAF) for information indicating the current load per network slice for one or more network slices; and receiving information from the NWDAF based on the subscription, the information indicating the current load on the network slice, and wherein the network slice access control process is performed based at least on the total number or quota of PDU sessions that are permitted to be admitted to the network slice, the estimated load of the PDU sessions, and the information indicating the current load on the network slice.

[0142] Clause 19. The method of Clause 18, wherein a subscription is requested when an SM network function is initiated or when the UE first registers with at least one of one or more network slices subject to network slice admission control.

[0143] Clause 20. The method according to any one of Clauses 17 to 19, wherein performing the network slice admission control process includes: calculating the used data rate for the network slice based on the estimated load of the PDU session and the current load on the network slice, and wherein the PDU session is admitted when the total number or quota of PDU sessions allowed to be admitted for the network slice is not exceeded by the admission of the PDU sessions and the used data rate does not exceed the maximum slice data rate on the network slice.

[0144] Clause 21. The method of Clause 20, wherein the network slice admission control process further comprises: calculating the number of used PDU sessions on the network slice based on the PDU sessions and the current number of PDU sessions on the network slice, and wherein a PDU session is admitted when the number of used PDU sessions does not exceed the total number or quota of PDU sessions that are permitted to be admitted for the network slice, and the used data rate does not exceed the maximum slice data rate on the network slice.

[0145] Clause 22. The method of Clause 21, wherein the method further comprises: receiving a request from a Network Data Analysis Function (NWDAF) for subscribing to information indicating the current number of PDU sessions per network slice for one or more network slices; sending the information indicating the current number of PDU sessions per network slice to the NWDAF based on the subscription; and receiving information from the NWDAF indicating the current load and the current number of PDU sessions on the network slice.

[0146] Clause 23. The method according to any one of Clauses 20 to 22, wherein the method further comprises: sending a request to establish a session management policy association for the PDU session when the PDU session is admitted, and wherein the request includes an indication that the used data rate does not exceed the maximum slice data rate on the network slice.

[0147] Clause 24. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to perform at least one method according to any one of Clauses 13 to 23.

[0148] Clause 25. An apparatus comprising components for performing the method pursuant to any one of Clauses 13 to 23.

[0149] Clause 26. A computer-readable medium comprising instructions that, in response to execution by at least one processor circuitry, cause a device to perform a method according to any one of Clauses 13 to 23.

[0150] Clause 27. A computer-readable storage medium comprising instructions that, in response to execution by at least one processor circuitry, cause a device to perform a method according to any one of Clauses 13 to 23.

[0151] Clause 28. A computer program comprising instructions that, in response to execution by at least one processor circuitry system, cause a device to perform a method according to any one of Clauses 13 to 23.

[0152] Clause 29. A method performed by a Mobility Management (MM) network function, the apparatus comprising: detecting an event related to a User Equipment (UE) causing an increase in the number of UEs registered to a network slice in one or more network slices, the increase relating to the UE's registration to the network slice, the MM network function being configured with a total number or quota of UEs to register to the network slice; performing a network slice admission control procedure based at least on information indicating the current number of UEs registered to the network slice and the total number or quota of allowed UEs to register to the network slice; and admitting or denying the UE's registration to the network slice based on the result of the network slice admission control procedure.

[0153] Clause 30. The method of Clause 29, wherein the method further comprises: requesting a subscription to a Network Data Analysis Function (NWDAF) for information indicating the current number of registered UEs per network slice for one or more network slices; and receiving information from the NWDAF based on the subscription, indicating the current number of registered UEs to the network slice.

[0154] Clause 31. The method according to Clause 30, wherein a subscription is requested when the MM network function is initiated or when the UE first registers with at least one of one or more network slices subject to network slice admission control.

[0155] Clause 32. The method according to any one of Clauses 29 to 31, wherein the method further comprises: receiving a request from the Network Data Analysis Function (NWDAF) for subscribing to information indicating the current number of registered UEs per network slice for one or more network slices at the MM network function; sending the information indicating the current number of registered UEs per network slice at the MM network function to the NWDAF based on the subscription; and receiving information from the NWDAF indicating the current number of UEs on the network slice.

[0156] Clause 33. The method according to any one of Clauses 29 to 32, wherein performing the network slice admission control process includes: calculating the number of UEs used for the network slice based on the UE and the current number of UEs, and wherein the registration of a UE to the network slice is admitted when the number of UEs used does not exceed the total number or quota of allowed UEs registered to the network slice.

[0157] Clause 34. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to perform at least one method according to any one of Clauses 29 to 33.

[0158] Clause 35. An apparatus comprising components for performing the method pursuant to any one of Clauses 29 to 33.

[0159] Clause 36. A computer-readable medium comprising instructions that, in response to execution by at least one processor circuitry system, cause a device to perform a method according to any one of Clauses 29 to 33.

[0160] Clause 37. A computer-readable storage medium comprising instructions that, in response to execution by at least one processor circuitry, cause a device to perform a method according to any one of Clauses 29 to 33.

[0161] Clause 38. A computer program comprising instructions that, in response to execution by at least one processor circuitry system, cause a device to perform a method according to any one of Clauses 29 to 33.

[0162] Benefiting from the teachings presented in the foregoing specification and associated drawings, those skilled in the art will conceive of numerous modifications and other implementations of the disclosure described herein. Therefore, it should be understood that the disclosure is not limited to the specific implementations disclosed, and that modifications and other implementations are intended to be included within the scope of the appended claims. Furthermore, although the foregoing specification and associated drawings describe exemplary implementations in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, combinations of elements and / or functions different from those explicitly described above may also be contemplated as being set forth in some of the appended claims. Although specific terms are used herein, they are used only in a general and descriptive sense and not for limiting purposes.

Claims

1. An apparatus for implementing Network Slicing Admission Control Function (NSACF), the apparatus comprising: At least one memory, the at least one memory being configured to store instructions; as well as At least one processing circuitry system is configured to access the at least one memory and execute the instructions to cause the device to at least: The request is for a subscription to network functions for information indicating the current load or remaining maximum slice data rate for one or more network slices, and the NSACF is configured with the total number or quota of Packet Data Unit (PDU) sessions that are allowed to be admitted for the one or more network slices. Based on the subscription, the information is received from the network function, the information indicating the current load or the remaining maximum slice data rate for the one or more network slices; as well as Based on events related to the User Equipment (UE), a network slice admission control procedure is executed for the one or more network slices, the events causing an increase in the number of PDU sessions for the network slices in the one or more network slices, wherein the network slice admission control procedure is executed based at least on the total number or quota of PDU sessions that are allowed to be admitted to the network slice, and the current load or the remaining maximum slice data rate on the network slice.

2. The apparatus of claim 1, wherein the subscription is requested when the NSACF is initiated or when the UE first registers with at least one of the one or more network slices subject to network slice admission control.

3. The apparatus of claim 1, wherein the network function is a network data analysis function (NWDAF), and the information received from the NWDAF includes slice load information indicating the current load of the network slice in the one or more network slices.

4. The apparatus of claim 1, wherein the network function is a unified data repository (UDR), and the information received from the UDR indicates the remaining maximum slice data rate on the network slice in one or more network slices.

5. The apparatus of claim 1, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to also receive a request from the Session Management (SM) network function to increase the number of PDU sessions on the network slice, and wherein the request triggers the network slice admission control process.

6. The apparatus of claim 5, wherein the increase in the number of PDU sessions is for admission of PDU sessions of the UE associated with the network slice, and the request from the SM network function includes: Information indicating the estimated load of the PDU session, and The network slice admission control process is also performed at least based on the estimated load of the PDU session.

7. The apparatus of claim 6, wherein the apparatus is configured to perform the network slice admission control process, the network slice admission control process comprising the apparatus being configured to: Based on the current load or the remaining maximum slice data rate on the network slice, and the estimated load of the PDU session, calculate the used data rate for the network slice; and The request from the SM network function is accepted when the total number or quota of PDU sessions that are allowed to be admitted for the network slice is not exceeded by the admission of the PDU sessions and the used data rate does not exceed the maximum slice data rate on the network slice.

8. A device for communication, comprising: At least one memory, the at least one memory being configured to store instructions; as well as At least one processing circuitry system is configured to access the at least one memory and execute the instructions to cause the device to at least: Detect events related to a user equipment (UE) that cause an increase in the number of packet data unit (PDU) sessions associated with a network slice, the increase being for admission purposes of the PDU sessions of the UE associated with the network slice; The estimated load of the PDU session used in the network slice admission control process is determined, which is performed based at least on the total number or quota of PDU sessions that are allowed to be admitted to the network slice, the estimated load of the PDU session, and information indicating the current load or remaining maximum slice data rate on the network slice. as well as The PDU session is admitted or denied based on the result of the network slice admission control process.

9. The apparatus of claim 8, wherein the estimated load of the PDU session is determined based on GBR stream information for one or more guaranteed bit rate GBR streams carried by the PDU session, or aggregated minimum bit rate (AMBR) information for one or more non-GBR streams carried by the PDU session.

10. The apparatus of claim 8, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further trigger a network slice admission control function (NSACF) to perform the network slice admission control process based on the event.

11. The apparatus of claim 10, wherein triggering the NSACF comprises: The device is configured to send a request to the NSACF to increase the number of PDU sessions on the network slice. The at least one of the processing circuitry systems is configured to execute the instructions such that the device also receives a response from NSACF indicating whether the request is accepted or rejected based on the result of the network slice admission control process. The PDU session is admitted or denied based on the response from the NSACF.

12. The apparatus of claim 8, wherein the apparatus is configured to implement a Session Management (SM) network function, the SM network function being configured with a total number or quota of PDU sessions allowed to be admitted for one or more network slices, the one or more network slices including the network slice, and The at least one of the processing circuitry systems is configured to execute the instructions to cause the device to perform the network slice admission control process based at least on the total number or quota of PDU sessions allowed to be admitted to the network slice, the estimated load of the PDU sessions, and the information indicating the current load or the remaining maximum slice data rate on the network slice.

13. The apparatus of claim 12, wherein the at least one processing circuit system is configured to execute the instructions such that the apparatus further comprises at least: Request a subscription to the Network Data Analysis Function (NWDAF) for information indicating the current load per network slice for one or more network slices; and Based on the subscription, the information is received from the NWDAF, indicating the current load on the network slice, and The network slice access control process is performed based at least on the total number or quota of PDU sessions that are allowed to be admitted to the network slice, the estimated load of the PDU sessions, and the information indicating the current load on the network slice.

14. The apparatus of claim 13, wherein the subscription is requested when the SM network function is initiated or when the UE first registers with at least one of the one or more network slices subject to network slice admission control.

15. The apparatus of claim 12, wherein the apparatus is configured to perform the network slice admission control process, the network slice admission control process comprising: The device is configured to calculate the used data rate for the network slice based on the estimated load of the PDU session and the current load on the network slice, and A PDU session is admitted when the total number or quota of PDU sessions allowed to be admitted for the network slice is not exceeded by the admission of the PDU session and the used data rate does not exceed the maximum slice data rate on the network slice.

16. The apparatus of claim 15, wherein the apparatus is configured to perform the network slice admission control process further comprises: The device is configured to calculate the number of used PDU sessions on the network slice based on the PDU session and the current number of PDU sessions on the network slice, and A PDU session is admitted when the number of used PDU sessions does not exceed the total number or quota of PDU sessions that are allowed to be admitted for the network slice, and the used data rate does not exceed the maximum slice data rate on the network slice.

17. The apparatus of claim 16, wherein the at least one processing circuit system is configured to execute the instructions such that the apparatus further comprises at least: Receive a request from the Network Data Analysis Function (NWDAF) for subscribing to information indicating the current number of PDU sessions per network slice for one or more network slices; Based on the subscription, information indicating the current number of PDU sessions per network slice is sent to the NWDAF; as well as Receive information from the NWDAF indicating the current load and the current number of PDU sessions on the network slice.

18. The apparatus of claim 15, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send a request to establish a session management policy association for the PDU session when the PDU session is admitted, and wherein the request includes an indication that the used data rate does not exceed the maximum slice data rate on the network slice.

19. An apparatus for implementing mobility management (MM) network functions, the apparatus comprising: At least one memory, the at least one memory being configured to store instructions; as well as At least one processing circuitry system is configured to access the at least one memory and execute the instructions to cause the device to at least: The MM network function detects events related to a user equipment (UE) that cause an increase in the number of UEs registered to one or more network slices, the increase being related to the UEs' registration to the network slices, and the MM network function is configured with a total number or quota of allowed UEs to register to the network slices. The network slice admission control process is performed based at least on information indicating the current number of UEs registered to the network slice and the total number or quota of allowed UEs to register to the network slice. as well as Based on the result of the network slice admission control process, the UE's registration with the network slice is either admitted or denied.

20. The apparatus of claim 19, wherein the at least one processing circuitry is configured to execute the instructions such that the apparatus further comprises at least: The request is for subscription to the Network Data Analysis Function (NWDAF) for information indicating the current number of registered UEs per network slice for the one or more network slices; and Based on the subscription, information is received from the NWDAF indicating the current number of registered UEs to the network slice.

21. The apparatus of claim 20, wherein the subscription is requested when the MM network function is initiated or when the UE first registers with at least one of the one or more network slices subject to network slice admission control.

22. The apparatus of claim 19, wherein the at least one processing circuitry is configured to execute the instructions such that the apparatus further comprises at least: A request is received from the Network Data Analysis Function (NWDAF) for subscribing to information indicating the current number of registered UEs per network slice for the one or more network slices at the MM network function; Based on the subscription, the information indicating the current number of registered UEs for each network slice at the MM network function is sent to the NWDAF; as well as Receive information from the NWDAF indicating the current number of UEs on the network slice.

23. The apparatus of claim 19, wherein the apparatus is configured to perform the network slice admission control process, the network slice admission control process comprising: The device is configured to calculate the number of UEs used for the network slice based on the UEs and the current number of UEs, and The registration of a UE to a network slice is granted when the number of UEs used does not exceed the total number or quota of allowed UEs to register with the network slice.

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