Heterogeneous slice deployment within the registered area of ​​a cellular communication network

Abstract

Systems and methods are provided for heterogeneous slice deployment within a registration area. In some embodiments, a method performed by a user equipment (UE) to access a network slice includes, during registration with a network node, requesting network slice assistance, receiving network slice assistance from the network node indicating access to a first network slice in a first tracking area (TA) that is not the entire registration area (RA), and accessing the first network slice in the first TA. Some embodiments allow for deploying slices in very small geographic areas to fit special use cases without necessarily having to deploy small RAs. Some possible use cases are stadium, factory slices, etc. The ability to deploy small slices within a large RA mitigates issues such as high registration load that may be addressed when the RA is too small. [Representative diagram] Figure 7

Description

[Technical Field]

[0001] [Related Application] The present application claims the benefit of Provisional Patent Application No. 63 / 140,135 filed on January 21, 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0002] [Technical Field] The present disclosure relates to accessing network slices. [Background Art]

[0003] FIG. 1 is a schematic block diagram of a current fifth generation (5G) radio access network (RAN) architecture, also referred to as next generation RAN (NG-RAN). NG-RAN is described in 3rd Generation Partnership Project (3GPP®) Technical Specification (TS) 38.401. The NG architecture can be further described as follows: • NG-RAN consists of a set of enhanced or evolved Node Bs (eNBs) and new radio (NR) base stations (gNBs) connected to a 5th generation core (5GC) via a next generation (NG) interface. • An eNB / gNB can support frequency division duplexing (FDD) mode, time division duplexing (TDD) mode, or dual-mode operation. • eNBs / gNBs can be interconnected with each other via the Xn interface. • A gNB may consist of a gNB Central Unit (gNB-CU) and a gNB Distributed Unit (gNB-DU). • The gNB-CU and the gNB-DU are connected via an F1 logical interface. • One gNB-DU is connected to only one gNB-CU.

[0004] NG, Xn, and F1 are logical interfaces. In the case of NG-RAN, the NG interface and Xn-C interface for the gNB, consisting of gNB-CU and gNB-DU, terminate at gNB-CU. In the case of New Radio's Dual Connectivity (EN-DC), the S1-U and X2-C interfaces for the gNB, consisting of gNB-CU and gNB-DU, terminate at gNB-CU. The gNB-CU and connected gNB-DU can only be seen as a gNB by other gNBs and 5GCs.

[0005] NG-RAN is layered into the Radio Network Layer (RNL) and the Transport Network Layer (TNL). The NG-RAN architecture, i.e., the NG-RAN logical nodes and the interfaces between them, is defined as part of the RNL. For each NG-RAN interface (NG, Xn, F1), the associated TNL protocol and function are specified. The TNL provides services for user plane transport and signaling transport. In an NG-Flex configuration, each gNB connects to all Access and Mobility Management Functions (AMF) within the AMF domain. The AMF domain is defined in 3GPP® TS 23.501.

[0006] (Network slicing) Network slicing is the process of creating logically separated partitions of a network to address different business purposes. These "network slices" are logically separated to the extent that each network slice can be considered and managed as part of its own network.

[0007] This is a new concept that is potentially applicable to both Long-Term Evolution (LTE) and the new 5G Radio Access Technology (RAT), also known as New Radio (NR). The main driver for introducing network slicing is business expansion, namely improving the ability of cellular operators to serve other industries by providing connectivity services with different network characteristics (performance, security, robustness, and complexity), for example.

[0008] Figure 2 is a schematic diagram of a cellular communications network with a common RAN connected to multiple network slices of a core network. The current assumption of operation is that there is one shared RAN infrastructure connecting several core network instances (having one or more common control network functions (CCNFs) interface with the RAN, and additional core network functions that may be slice-specific). When core network functions are virtualized, it is assumed that the operator instantiates a new core network or part thereof when a new slice should be supported. For example, slice 0 may be a mobile broadband (MBB) slice, and slice 1 may be a machine-type communications (MTC) network slice.

[0009] 3GPP® is currently working on introducing enhancements to the network slicing framework implemented in 3GPP® 5G systems. As of Release 16, 3GPP® specifies that the slice availability of a user device (UE) should not be altered within a registration area (RA) consisting of a list of tracking areas (TAs). The UE expects all cells comprising different TAs within the RA to provide the same set of slices provided to the UE in the Network Slice Selection Assistance Information (NSSAI) permitted during the registration procedure. Improved systems and methods are needed for slice deployment within registration areas. [Overview of the project]

[0010] A system and method are provided for heterogeneous slice deployment within a registration area. In some embodiments, a method performed by a user device (UE) to access a network slice includes, during registration with a network node, requesting network slice assistance, receiving network slice assistance from the network node indicating access to a first network slice in a first tracking area (TA) rather than the entire registration area (RA), and accessing the first network slice in the first TA.

[0011] The present disclosure and certain aspects of its embodiments can provide solutions to the aforementioned or other problems. A heterogeneous slice deployment within a registration area (RA) is provided. The proposed solution enables an Application and Mobility Management Function (AMF) to configure a User Equipment (UE) using an RA that includes a Tracking Area (TA) with heterogeneous network slice support. This enables support for a specific network slice in an area limited to a single TA, eliminating the need to assign an RA limited to that specific TA to the UE. This is achieved by: 1. Set up a TA that precisely matches the area covered by the network slice. 2. Include TA in RA. 3. Notify the UE of the RA that the network slice is only available within the TA and not the entire RA. 4. Notify the UE of the slices supported by each TA to the Serving Radio Access Network (RAN).

[0012] Conventional technologies cannot place slices in areas smaller than the RA (Network Address). The proposed solution enables the deployment of smaller slices without requiring any changes to how the RA is deployed, by modifying the information elements (IEs) communicated during different phases of the registration procedure. This solution also simplifies much of the network planning required to support network slicing.

[0013] This specification proposes various embodiments that address one or more of the problems disclosed herein. In some embodiments, the method is performed by a UE to access a network slice, and the method, during registration with a network node, includes one or more of the following: requesting network slice assistance; receiving network slice assistance from the network node indicating access to a first network slice in a first TA, but not the entire RA; and accessing the first network slice in the first TA.

[0014] In some embodiments, requesting network slice assistance includes including the requested network slice selection assistance information (NSSAI) IE in the registration request message, and receiving network slice assistance from a network node includes receiving the permitted NSSAI IE, the denied NSSAI IE, or both the permitted and denied NSSAI IE from the network node in the registration acceptance message.

[0015] In some embodiments, the method further includes indicating to the network node that the UE is capable of supporting slice deployments that are not available across the entire RA.

[0016] In some embodiments, receiving network slice assistance from a network node includes receiving an indication at each TA of the RA of which network slices are permitted. In some embodiments, the indication at each TA of the RA of which network slices are permitted is received in the Allowed NSSAI IE. In some embodiments, the indication at each TA of the RA of which network slices are permitted is received in the Allowed NSSAI Per TA IE. In some embodiments, the method further includes not accessing the first network slice at the second TA when the first network slice is not indicated as permitted at the second TA. In some embodiments, the method further includes accessing the first network slice at the second TA with reduced quality of service (QoS) when the first network slice is not indicated as permitted at the second TA.

[0017] In some embodiments, receiving network slice assistance from a network node includes receiving an indication at each TA of the RA that any network slice is not permitted. In some embodiments, the indication at each TA of the RA that any network slice is not permitted is received in a rejected NSSAI IE. In some embodiments, the indication at each TA of the RA that any network slice is not permitted is received in a rejected NSSAI Per TA IE. In some embodiments, the method further includes not accessing the first network slice at the second TA when the first network slice is indicated to be not permitted at the second TA. In some embodiments, the method further includes accessing the first network slice at the second TA with reduced QoS when the first network slice is indicated to be not permitted at the second TA.

[0018] In some embodiments, receiving network slice assistance from a network node includes receiving an indication that a first network slice is not available in the current TA. In some embodiments, accessing a first network slice in a first TA includes entering the first TA, requesting network slice assistance between entering the first TA and registering with the network node, and receiving network slice assistance from the network node indicating that a first network slice is available in the first TA.

[0019] In some embodiments, the UE is configured to communicate with a network node, and the UE comprises a wireless interface and processing circuitry configured to perform any of the methods described in the embodiments above.

[0020] In some embodiments, the method is performed by a network node for heterogeneous slice deployment in a RA, and the method comprises one or more of: receiving a request for network slice assistance from a UE; determining that the UE is permitted to access a first network slice in a first TA that does not cover the entire RA; and providing network slice assistance to the UE according to access to the first network slice in the first TA.

[0021] In some embodiments, receiving the request for network slice assistance comprises receiving the requested NSSAI IE in a registration request message, and providing network slice assistance to the UE comprises including an allowed NSSAI IE, a rejected NSSAI IE, or both an allowed NSSAI IE and a rejected NSSAI IE in a registration accept message to the UE.

[0022] In some embodiments, the method further comprises receiving an indication from the UE that the UE is capable of supporting slice deployment that is not available across the entire RA.

[0023] In some embodiments, if the network node does not have an indication that the UE is capable of supporting slice deployment that is not available across the entire RA, providing network slice assistance to the UE comprises indicating that the UE is not permitted to access the first network slice in the RA.

[0024] In some embodiments, determining that the UE is permitted to access the first network slice in a first TA that does not cover the entire RA comprises: determining that an area covered by the first network slice is smaller than the entire RA; and configuring the first TA to match the area covered by the first network slice.

[0025] In some embodiments, providing network slice assistance to a UE includes providing an indication of which network slices are allowed in each TA of an RA. In some embodiments, the indication of which network slices are allowed in each TA of an RA is provided in an allowed NSSAI IE. In some embodiments, the indication of which network slices are allowed in each TA of an RA is provided in a per-TA allowed NSSAI IE. In some embodiments, when a first network slice is not indicated as allowed in a second TA, the UE is not allowed to access the first network slice in the second TA. In some embodiments, when the UE is not indicated that the first network slice is allowed in the second TA, the UE is allowed to access the first network slice with reduced QoS in the second TA.

[0026] In some embodiments, providing network slice assistance to a UE comprises providing an indication of which network slices are not allowed in each TA of an RA. In some embodiments, the indication of which network slices are not allowed in each TA of an RA is provided in a rejected NSSAI IE. In some embodiments, the indication of which network slices are not allowed in each TA of an RA is provided in a per-TA rejected NSSAI IE. In some embodiments, when the UE is indicated that a first network slice is not allowed in a second TA, the UE is not allowed to access the first network slice in the second TA. In some embodiments, when the UE is indicated that the first network slice is not allowed in the second TA, the UE is allowed to access the first network slice with reduced QoS in the second TA.

[0027] In some embodiments, providing network slice assistance to the UE includes providing an indication that a first network slice is not available in the current TA. In some embodiments, the method further comprises receiving another request for network slice assistance when the UE enters the first TA, and providing the UE with network slice assistance indicating that a first network slice is available in the first TA.

[0028] In some embodiments, the network node is configured to communicate with the UE, and the network node includes processing circuitry configured to perform one of the methods of the embodiments described above.

[0029] Certain embodiments may offer one or more of the following technical advantages: The proposed solution allows for the deployment of slices in very small geographical areas to suit specific use cases, without necessarily requiring the deployment of small RAs. Some feasible use cases include stadium and factory slices. The ability to deploy small slices within a large RA mitigates issues that can arise when an RA is too small, such as high registration load. At the same time, this avoids the 3GPP® requirement to deploy slices across RAs where the business / deployment does not require it.

[0030] The various embodiments described herein explore different trade-offs with the solutions described above. Some embodiments maintain messaging simplicity (Non-Access Tier (NAS) registration acceptance messages) at the expense of potentially more signaling to the UE using UE mobility. Some embodiments propose the use of more complex message structures that do not alter the signaling load between the UE and the network compared to the previous approach. [Brief explanation of the drawing]

[0031] The accompanying drawings incorporated herein and forming part of herein illustrate several aspects of this disclosure and, together with the description, are useful in illustrating the principles of this disclosure.

[0032] [Figure 1] Figure 1 is a schematic block diagram of the current fifth-generation (5G) radio access network (RAN) architecture, also known as next-generation RAN (NG-RAN).

[0033] [Figure 2] Figure 2 is a conceptual diagram of a cellular communication network having a common RAN connected to multiple network slices of the core network.

[0034] [Figure 3] Figure 3 illustrates an example of a cellular communication system in which embodiments of the present disclosure may be implemented.

[0035] [Figure 4] Figure 4 illustrates a wireless communication system represented as a 5G network architecture consisting of core network functions (NFs) according to some embodiments of the present disclosure, where the interaction between any two NFs is represented by a point-to-point reference point / interface.

[0036] [Figure 5] Figure 5 shows a 5G network architecture, according to some embodiments of this disclosure, that uses a service-based interface between NFs in the control plane (CP) instead of the point-to-point reference point / interface used in the 5G network architecture of Figure 4.

[0037] [Figure 6] Figure 6 shows the cellular communication system of Figure 3, which provides heterogeneous deployments of network slices within a registered area (RA) according to some embodiments of the present disclosure.

[0038] [Figure 7] Figure 7 is a flowchart of a method for accessing a network slice according to some embodiments of the present disclosure.

[0039] [Figure 8] Figure 8 is a flowchart of the method for heterogeneous slice deployment in RA.

[0040] [Figure 9] Figure 9 is a schematic block diagram of a network node according to some embodiments of the present disclosure.

[0041] [Figure 10] Figure 10 is a schematic block diagram showing a virtualized embodiment of a network node according to some embodiments of the present disclosure.

[0042] [Figure 11] This is a schematic block diagram of an exemplary embodiment of a wireless access node. [Figure 12] This is a schematic block diagram of an exemplary embodiment of a wireless access node. [Figure 13] This is a schematic block diagram of an exemplary embodiment of a wireless access node.

[0043] [Figure 14] This is a schematic block diagram of UE. [Figure 15] This is a schematic block diagram of UE. [Modes for carrying out the invention]

[0044] The embodiments described below provide information to enable those skilled in the art to implement the embodiments and illustrate the best mode of implementation. By reading the following description in reference to the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and recognize the applications of these concepts that are not specifically addressed herein. It should be understood that these concepts and applications are within the scope of this disclosure.

[0045] Wireless node: As used herein, “wireless node” refers to either a wireless access node or a wireless communication device.

[0046] Radio Access Node: As used herein, “radio access node,” “radio network node,” or “radio access network node” is any node in a radio access network (RAN) of a cellular communications network that operates to transmit and / or receive signals wirelessly. Some examples of radio access nodes, but not limited to, include base stations (e.g., New Radio (NR) base stations (gNBs) in the 3rd Generation Partnership Project (3GPP®) 5th Generation (5G) NR network, or Extended or Advanced Node B (eNBs) in the 3GPP® Long-Term Evolution (LTE) network), high-power or macro base stations, low-power base stations (e.g., micro base stations, pico base stations, home eNBs, etc.), relay nodes, network nodes that implement some of the functions of a base station (e.g., a network node implementing a gNB Central Unit (gNB-CU) or a network node implementing a gNB Distributed Unit (gNB-DU)), or network nodes that implement some of the functions of any other type of radio access node.

[0047] Core Network Node: As used herein, “core network node” refers to any type of node within the core network, or any node that performs core network functions. Some examples of core network nodes include, for example, Mobility Management Entity (MME), Packet Data Network Gateway (P-GW), Capability of Service Exposure Function (SCEF), and Home Subscriber Server (HSS). Some other examples of core network nodes include nodes that perform Access and Mobility Management Function (AMF), User Plane Function (UPF), Session Management Function (SMF), Authentication Server Function (AUSF), Network Slice Selection Function (NSSF), Network Exposure Function (NEF), Network Function (NF) Repository Function (NRF), Policy Control Function (PCF), and Unified Data Management (UDM).

[0048] Communication device: As used herein, “communication device” is any type of device having access to an access network. Some examples of communication devices include, but are not limited to, mobile phones, smartphones, sensor devices, meters, vehicles, home appliances, medical devices, media players, cameras, or any type of consumer electronic device, such as, but are not limited to, televisions, radios, lighting fixtures, tablet computers, laptops, or personal computers (PCs). A communication device may be a portable, handheld, computer-integrated, or in-vehicle mobile device capable of communicating voice and / or data via a wireless or wired connection.

[0049] Wireless Communication Devices: One type of communication device is a wireless communication device, and a wireless communication device can be any type of wireless device that accesses (i.e., is serviced by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to, user equipment devices (UEs), machine-type communication (MTC) devices, and Internet of Things (IoT) devices in 3GPP® networks. Such wireless communication devices may be, or may be integrated into, mobile phones, smartphones, sensor devices, meters, vehicles, home appliances, medical devices, media players, cameras, or any type of consumer electronics, such as, but not limited to, televisions, radios, lighting fixtures, tablet computers, laptops, or PCs. Wireless communication devices may be portable, handheld, computer-integrated, or in-vehicle mobile devices capable of communicating voice and / or data over a wireless connection.

[0050] Network node: As used herein, “network node” is any node that is part of either the RAN or the core network of a cellular communication network / system.

[0051] Transmit / Receive Point (TRP): In some embodiments, a TRP can be a network node, a radio head, a spatial relationship, or a transmit configuration indicator (TCI) state. In some embodiments, a TRP can be represented by a spatial relationship or a TCI state. In some embodiments, a TRP can use multiple TCI states. In some embodiments, a TRP may be part of a gNB that transmits and receives radio signals to and from the UE according to physical layer characteristics and parameters specific to that element. In some embodiments, multi-TRP operation allows a serving cell to schedule UEs from two TRPs, providing better physical downlink shared channel (PDSCH) coverage, reliability, and / or data rate. Multi-TRP has two distinct operating modes: single downlink control information (DCI) and multi-DCI. For both modes, control of uplink and downlink operations is performed by both the physical layer and media access control (MAC). In single-DCI mode, the UE is scheduled by the same DCI for both TRPs, while in multi-DCI mode, the UE is scheduled by independent DCIs from each TRP.

[0052] The descriptions provided herein focus on 3GPP® cellular communication systems, and therefore, it should be noted that 3GPP® terminology or similar terminology is frequently used. However, the concepts disclosed herein are not limited to 3GPP® systems.

[0053] While the term "cell" may be used in this specification, it should be noted that a beam may be used instead of a cell, particularly in the context of the 5G NR concept, and therefore, the concepts described herein are equally applicable to both cells and beams.

[0054] Figure 3 shows an example of a cellular communication system 300 in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communication system 300 is a 5G system (5GS) including a next-generation RAN (NG-RAN) and a 5G core (5GC). In this example, the RAN includes base stations 302-1 and 302-2, the 5GS includes NR base stations (gNB) and optionally next-generation eNBs (ng-eNB) (e.g., LTE RAN nodes connected to the 5GC), and the EPS includes eNBs that control the corresponding (macrocell) cells 304-1 and 304-2. Base stations 302-1 and 302-2 are generally referred to collectively as base station 302 and individually as base station 302 in this specification. Similarly, (macrocell) cells 304-1 and 304-2 are generally referred to collectively as (macrocell) cell 304 and individually as (macrocell) cell 304 in this specification. The RAN may also include several low-power nodes 306-1 to 306-4 that control the corresponding small cells 308-1 to 308-4. The low-power nodes 306-1 to 306-4 may be small base stations (such as pico or femto base stations) or remote radio heads (RRHs), etc. In particular, although not illustrated, one or more of the small cells 308-1 to 308-4 may alternatively be provided by base station 302. The low-power nodes 306-1 to 306-4 are generally referred to collectively as low-power node 306 and individually as low-power node 306 in this specification. Similarly, the small cells 308-1 to 308-4 are generally referred to collectively as small cell 308 and individually as small cell 308 in this specification. The cellular communication system 300 also includes a core network 310, which is called 5GC in a 5G system (5GS). Base stations 302 (and optionally low-power nodes 306) are connected to the core network 310.

[0055] Base station 302 and low-power node 306 provide services to wireless communication devices 312-1 to 312-5 in corresponding cells 304 and 308. Wireless communication devices 312-1 to 312-5 are generally referred to collectively as wireless communication device 312 in this specification, and individually as wireless communication device 312. In the following description, wireless communication device 312 is often a UE, but this disclosure is not limited thereto.

[0056] Figure 4 shows a wireless communication system represented as a 5G network architecture consisting of core network functions (NFs), where the interaction between any two NFs is represented by a point-to-point reference point / interface. Figure 4 can be seen as one specific implementation of system 300 in Figure 3.

[0057] From the access side, the 5G network architecture shown in Figure 4 comprises multiple UE312s connected to either the RAN 302 or the access network (AN) and the AMF 400. Typically, the R(AN)302 comprises base stations, such as eNBs or gNBs. The 5GC NF shown in Figure 4, from the core network side, includes the NSSF 402, AUSF 404, UDM 406, AMF 400, SMF 408, PCF 410, and Application Function (AF) 412.

[0058] The representation of reference points in the 5G network architecture is used to develop detailed call flows in normative standardization. Reference point N1 is defined to carry signals between UE 312 and AMF 400. Reference points for connecting AN 302 and AMF 400, and AN 302 and UPF 414 are defined as N2 and N3, respectively. There is a reference point N11 between AMF 400 and SMF 408, which means that SMF 408 is at least partially controlled by AMF 400. N4 is used by SMF 408 and UPF 414, and as a result, UPF 414 can be configured using control signals generated by SMF 408, and UPF 414 can report its state to SMF 408. N9 is a reference point for connections between different UPF 414s, and N14 is a reference point connecting different AMF 400s. N15 and N7 are defined because PCF 410 applies policies to AMF 400 and SMF 408 respectively. N12 is required for AMF 400 to authenticate UE 312. N8 and N10 are defined because UE 312 subscription data is required by AMF 400 and SMF 408.

[0059] The 5GC network aims to separate the UP and CP. The UP carries user traffic, while the CP carries signaling within the network. In Figure 4, the UPF 414 is located within the UP, while all other NFs, namely AMF 400, SMF 408, PCF 410, AF 412, NSSF 402, AUSF 404, and UDM 406, are located within the CP. Separating the UP and CP ensures that each plane resource scales independently. It is also possible to distribute the UPF separately from its CP function. In this architecture, the UPF can be deployed very close to the UE to reduce the round-trip time (RTT) between the UE and the data network for some applications that require low latency.

[0060] The core 5G network architecture consists of modularized functions. For example, the AMF 400 and SMF 408 are independent functions in the CP. The isolated AMF 400 and SMF 408 allow for independent evolution and scaling. Other CP functions, such as the PCF 410 and AUSF 404, can be isolated as shown in Figure 4, and this modularized functional design allows the 5GC network to flexibly support a variety of services.

[0061] Each NF interacts directly with other NFs. Intermediate functions can be used to route messages from one NF to another. In CP, a set of interactions between two NFs is defined as a service that can be reused. This service enables support for modularity. UP supports interactions such as forwarding operations between different UPFs.

[0062] Figure 5 shows a 5G network architecture that uses service-based interfaces between NFs within a CP instead of the point-to-point reference points / interfaces used in the 5G network architecture of Figure 4. However, the NFs mentioned above with reference to Figure 4 correspond to the NFs shown in Figure 5. Services that an NF provides to other authorized NFs can be exposed to authorized NFs via the service-based interface. In Figure 5, the service-based interface is indicated by the letter "N," followed by the name of the NF, for example, Namf for the service-based interface of AMF 400, Nsmf for the service-based interface of SMF 408, and so on. The NEF 500 and NRF 502 in Figure 5 are not shown in Figure 4 mentioned above. However, it should be made clear that although not explicitly shown in Figure 4, all NFs shown in Figure 4 can interact with the NEF 500 and NRF 502 in Figure 5 as needed.

[0063] Some of the characteristics of the NF shown in Figures 4 and 5 can be described as follows: The AMF 400 provides UE-based authentication, authorization, mobility management, etc. The UE 312 essentially connects to a single AMF 400, even when using multiple access technology, because the AMF 400 is independent of the access technology. The SMF 408 is responsible for session management and assigns Internet Protocol (IP) addresses to the UE. It also selects and controls the UPF 414 for data transfer. If the UE 312 has multiple sessions, different SMF408s can be assigned to each session to manage them individually and, in some cases, provide different functions for each session. The AF 412 provides information about packet flow to the PCF 410, which is responsible for policy control, in order to support Quality of Service (QoS). Based on this information, the PCF 410 determines policies regarding mobility and session management to ensure that the AMF 400 and SMF 408 operate properly. AUSF 404 supports authentication functionality for UEs or similar entities and therefore stores data for UE or similar entity authentication, while UDM 406 stores subscription data for UEs 312. The Data Network (DN) is not part of the 5GC network and provides internet access or operator services, etc.

[0064] NF can be implemented as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an appropriate platform, such as a cloud infrastructure.

[0065] Assuming that network slices are expected to be deployed uniformly across RAs, slice deployments are restricted to be tightly coupled to the RA. Generally, an RA is a large geographic area served by multiple nodes (defined by a TA list, where all TAs are served by the same AMF) that defines the granularity at which UE locations are known when UEs are not connected via Radio Resource Control (RRC). By taking UE mobility into account, RAs are configured for areas large enough so that registrations due to UE mobility are not excessive. RAs typically cover a considerable geographic area.

[0066] The requirement for homogeneous slice deployments within a RA forces operators to define RAs that may consist of only a few TAs. This is especially true when business / technical requirements necessitate deploying slices in a limited geographic area. The resulting RAs can experience very frequent registration activity due to UE mobility across the RA, which interferes with the network's ability to provide its normal services.

[0067] A system and method are provided for heterogeneous slice deployment within a registration area. In some embodiments, the method performed by a user device (UE) to access a network slice includes, during registration with a network node, requesting network slice assistance, receiving network slice assistance from the network node indicating access to a first network slice in a first tracking area (TA) rather than the entire registration area (RA), and accessing the first network slice in the first TA. Some embodiments allow for the deployment of slices in very small geographical areas to suit specific use cases, without necessarily requiring the deployment of a small RA. Some feasible use cases include stadium and factory slices. The ability to deploy small slices within a large RA mitigates problems that can be encountered when the RA is too small, such as high registration load.

[0068] Figure 6 shows the cellular communication system 300 of Figure 3, which provides a heterogeneous deployment of network slices within a registration area (RA) 600. The cellular communication system 300 includes an NG-RAN infrastructure that can connect to multiple network slices 602-1, 602-2. Embodiments described herein enable the AMF 400 to configure the UE 312 using an RA 600 that includes tracking areas (TAs) TA1-TA8 having heterogeneous network slice support. For example, a first network slice 602-1 (e.g., slice 0) may be supported throughout the entire RA 600, while a second network slice 602-2 (e.g., slice 1) may be supported only in TA1, TA2, and TA3.

[0069] This enables support for specific network slice 602 in areas as small as a single TA, eliminating the need to assign RA 600 to UE 312, which is limited to that specific TA. This is achieved by: 1. Configure TAs (e.g., TA1, TA2, TA3) that precisely match the area covered by network slice 602. 2. Include TA in RA 600. 3. Notify UE 312 of RA 600 and inform it that network slice 602 is only available within the TA and not the entire RA 600. 4. Notify the serving RAN of slice 602 supported per TA for UE 312.

[0070] In this regard, during registration in the Public Land Mobile Network (PLMN), as part of the Non-Accessible Tier (NAS) procedure as defined in 3GPP® Technical Specification (TS) 24.501 16.6.0, UE 312 includes an Information Element (IE) called "Requested NSSAI" as part of the registration request message. The IE includes a set of Single Network Slice Selection Assistance Information (S-NSSAI) indicating the set of network slices 602 that UE 312 is requesting permission to use in the PLMN. Upon receiving this IE, the core network considers this information to determine the RA 600 for UE 312. Then, based on slice deployment, UE subscription, and other policies, UE 312 determines which sets of S-NSSAI are allowed and not allowed to be used within the RA in terms of the IE, and communicates this to UE 312 via the NAS registration acceptance message. The set of permitted and denied S-NSSAIs in the response is assumed to be valid throughout the current RA.

[0071] First, the UE capability requirements common to the embodiments described herein are listed. UE 312 must indicate to the network that it is capable of supporting messages indicating slice deployments that are not available across RA 600. This can be indicated to the network, for example, by the UE's fifth-generation mobility management (5GMM) capability, the UE's fifth-generation session management (5GSM) capability, or, in newer IEs, by newer UE capabilities. If UE 312 does not indicate this capability, the network automatically assumes that UE 312 should not be permitted in any slice 602 that is not uniformly deployed across RA. This prevents future attempts by UE 312 to use slice 602 that is not deployed across RA 600.

[0072] In another variation, if UE 312 does not support the capability, the network assumes that UE 312 has uniform access to all slices 602 within the NSSAI permitted throughout the RA 600, and therefore the network can serve some slices 602 with limited QoS in certain areas of the RA 600, while having optimized QoS in other areas of the RA 600.

[0073] <Embodiment 1: Expansion of slice information permitted for each TA information> The first embodiment adds information to the message sent to the UE to communicate which network slices included in an Allowed NSSAI are permitted in which TAs, as a means of communicating a non-homogeneous slice deployment to the UE. This can be achieved by multiple means, for example, via a registration acceptance message or via other NAS messages. In each case, the communication involves sending UE information about the TAs that constitute its RA and which slices are explicitly permitted in those TAs.

[0074] This can be achieved by adding an optional IE, such as "Allowed NSSAI Per TA," (to the registration acceptance message or other similar NAS message) that includes, in addition to or instead of the allowed NSSAIs, a set of S-NSSAIs, with each S-NSSAI associated with one or more TA Information (TAIs) in the current RA for which the S-NSSAI is permitted.

[0075] The UE interprets any S-NSSAI present in a message as an S-NSSAI that is permitted in the explicitly listed TA and not permitted in other TAs; that is, a slice not listed in a given TA is considered unavailable in that TA. This information must be viewed together with the list of denied S-NSSAIs and applies to all TAs in the RA, except those that are sent in accordance with the specification without any TA-specific information and marked as permitted in the modified IE.

[0076] In a dependent embodiment, a new list of slices per TA that is signaled to the UE means that the listed slices are served with optimal QoS in that TA. When a slice is in a TA that is not listed, the UE can still access that slice, but the network will serve that slice with a limited QoS. In a dependent embodiment, such various QoSes can be set from the core network to the RAN by an Alternative QoS Parameters Set List as defined in 3GPP® TS 38.413.

[0077] This list includes several QoS parameter sets associated with the same packet data unit (PDU) session. For example, a PDU session associated with a slice may be served with the best QoS parameters set when the UE is in the TA to which the slice is associated (as part of the NAS signaling described above), while a PDU session associated with the same slice may be served with a lower QoS parameter set (included in the alternative QoS parameter set list) when the slice is not in the TA to which it is associated.

[0078] In these dependent embodiments, additional information signaled to the UE in the form of a list of slices per TA represents the TA where the listed slices receive maximum QoS, and outside of such TAs, the slices receive lower QoS.

[0079] Since the alternative QoS parameter set list defined in 3GPP® TS 38.413 is defined to provide applications with adaptive QoS, a new (but essentially equivalent) signaling can be defined to separate the current alternative QoS signaling from the signaling of QoS parameters related to QoS support in unsupported slices.

[0080] <Embodiment 2: Expansion of rejected slice information for each TA information> The second embodiment is similar to the first embodiment, but the same ultimate goal can be achieved by communicating what is not permitted, compared to communicating what is permitted. In this case, an optional IE is added in which the slice in the RA communicates a mapping that is not permitted in a particular TA. The UE interprets any S-NSSAI present in the message as an S-NSSAI that is considered not permitted in the explicitly associated listed TA. For TAs that do not mention a particular S-NSSAI as not permitted, the UE assumes that the slice is available on that TA. It is important to note here that the list of denied S-NSSAIs is only extended by TA information. The list of permitted S-NSSAIs is still sent to the UE without any modification from the current specification. This makes it easier for the UE to understand which slices are generally permitted using more specific denied S-NSSAI information.

[0081] As described in the embodiments above, some embodiments consist of interpreting a new list of S-NSSAIs that are not permitted for each TA, which in this case is a list of S-NSSAIs that do not achieve maximum QoS in the relevant TA.

[0082] <Embodiment 3: Expansion of permitted and denied slice information for each TA information> In a third embodiment, the same capability can also be communicated to the UE per TA using a combination of permitted and unpermitted S-NSSAIs per TAI. In this case, the optional IE structure includes support for mentioning whether an S-NSSAI is permitted or unpermitted within a TA. When an S-NSSAI is listed as permitted, the UE interprets that the S-NSSAI is permitted in the current TA and not supported in other TAs (except for other TAs where the corresponding S-NSSAI is listed as permitted). When an S-NSSAI is listed as unpermitted, the UE assumes that other TAs (that do not have a particular unpermitted S-NSSAI) support this slice. This proposed optional IE structure facilitates communication of both permitted and unpermitted slices in an extended form, i.e., the UE does not need to compare globally permitted slices or unpermitted slices and derive per-TA applicable rules.

[0083] As described above, in the alternative embodiment, when S-NSSAI is listed as permitted, the UE interprets this to mean that S-NSSAI is permitted in the current TA with the maximum QoS and supported in other TAs with lower QoS (excluding other TAs that list the corresponding S-NSSAI as permitted). When S-NSSAI is listed as not permitted, the UE assumes that other TAs (that do not have the specific S-NSSAI that is not permitted) support this slice with the maximum QoS.

[0084] <Embodiment 4: Extension of slice rejection message in current TA information> A rejected S-NSSAI IE has the following supported cause values ​​(3GPP® TS 24.501 16.6.0): Causal value (octet 3) bit 4 3 2 1 0 0 0 0 S-NSSAI is not available in the current PLMN or SNPN. 0 0 0 1 S-NSSAI is not available in your current registered area. 0 0 1 0 S-NSSAI is unavailable because network slice-specific authentication and authorization failed or were revoked.

[0085] To enable the deployment of slices to an area smaller than the RA, in the fourth embodiment, the rejected S-NSSAI IE includes the cause value "S-NSSAI not available in the current tracking area". This cause value indicates to the UE that the S-NSSAI is not supported in the current TA, but may be available in other TAs that are part of the current RA. Note that the UE is also composed of the current RA, i.e., the set of TAs in the registration acceptance message.

[0086] Whenever a UE finds that a slice is in a new TA within the same RA, it can either assume that the slice rejected in the previous TA is available in the current TA and attempt to use the slice for the new PDU session, or the previous PDU session may be reallocated by the core to a newly allocated slice. The reason here is that the UE was simply explicitly denied the use of the slice on the previous TA, and the same slice is also available in the set of available slices in the current RA. However, the core can also deny the slice on the new TA. This new cause value facilitates the deployment of slices per TA level.

[0087] As part of this embodiment, the UE may also retain memory of slices rejected in a particular TA. This memory is retained as long as the UE is in the same RA or as long as the UE is unregistered. This memory is also cleared each time the UE is powered on or off. This prevents the UE from re-requesting slices that were previously rejected in the TA.

[0088] Handling PDU sessions on unsupported slices There may be instances where a UE stays in or connects to a cell that does not support one or more of the S-NSSAIs from which it established a PDU session. In these cases, the following is suggested:

[0089] 1. A UE in the CM-IDLE and / or CM-CONNECTED state may maintain a PDU session on the NAS layer even if the cell in which the UE is currently residing or being serviced is configured on a TA, and the S-NSSAI (network slice) associated with that PDU session is not among the set of authorized network slices (S-NSSAI) / authorized NSSAI provided to the UE by the network for this TA.

[0090] 2. A CM-CONNECTED UE in the RRC_INACTIVE state can maintain a PDU session on the NAS layer even if the cell in which the UE is currently residing or being serviced is configured on a TA, and the S-NSSAI (network slice) associated with that PDU session is not among the set of authorized network slices (S-NSSAI) / authorized NSSAIs provided to the UE by the network for this TA.

[0091] 3. A CM-CONNECTED UE in the RRC_INACTIVE state can maintain access hierarchy configuration for resources associated with a PDU session, even if the cell where the UE is currently residing or being serviced is configured on a TA, and the S-NSSAI (network slice) associated with that PDU session is not among the set of permitted network slices (S-NSSAI) / permitted NSSAI provided to the UE by the network for this TA.

[0092] In a dependent embodiment, the list of slices permitted in the TA can be interpreted as a list of slices that receive the maximum QoS processing in that TA, as described above, while the list of slices not permitted in the TA can be interpreted as a list of slices that receive a QoS processing lower than the maximum QoS processing in that TA, as described above.

[0093] <Embodiment 5: Exchange of per-TA authorization / priority S-NSSAI lists from the core network to RAN nodes> From the above embodiments, it can be derived that the new information signaled to the UE may take the form of either a list of permitted / not permitted S-NSSAI per TA, or a list of preferred / not preferred S-NSSAI per TA.

[0094] In the fifth embodiment, a list of authorized / preferred S-NSSAIs per TA associated with the UE is signaled to the RAN serving the UE from the core network. For example, such information may be signaled as part of an NG: Initial UE Context Setup message or an NG: UE Context Modification Request message.

[0095] Using this information, the RAN can determine whether a slice is supported or supported by a TA with maximum QoS, and based on this, the RA can trigger UE mobility with the intention of achieving service continuity by handing over the UE to a cell of a TA that supports the slice being used by the UE, and achieving maximization of QoS processing for the slice service being used by the UE by handing over the UE to a cell of a TA that provides the slice being used by the UE with maximum QoS.

[0096] If a list of permitted / preferred S-NSSAI per TA is exchanged for a list of denied / non-preferred S-NSSAI per TA, the RAN will gain awareness of TAs whose listed slices are not permitted or serviced at maximum QoS, and based on that, if a UE has active service for the slices enumerated for such TAs, the RAN may attempt not to hand over the UE to the cells of those TAs.

[0097] Figure 7 is a flowchart of a method for accessing a network slice according to some embodiments of the present disclosure. The method may be performed by a UE. The method optionally begins in step 700, in which the UE indicates to the network node that it is possible to support a slice deployment that is not available across the entire RA. The method follows step 702, requesting network slice assistance while registering with the network node. The method follows step 704, in which receiving network slice assistance from the network node indicates access to a first network slice in a first TA rather than across the entire RA. The method proceeds to step 706, accessing the first network slice within the first TA. Some embodiments do not necessarily require the deployment of a small RA and allow for the deployment of slices in very small geographical areas to suit specific use cases. Some feasible use cases include stadium and factory slices. The ability to deploy small slices within a large RA mitigates problems that can be encountered when the RA is too small, such as high registration load.

[0098] Figure 8 is a flowchart of a method for heterogeneous slice deployment in a RA. This method can be executed by a network node. The method selectively starts at step 800, receiving an indication from the UE that it is capable of supporting slice deployments that are not available across the entire RA. The method proceeds to step 802, receiving a request for network slice assistance from the UE. The method continues to step 804, determining that the UE is permitted to access a first network slice in a first TA, not the entire RA. The method continues to step 806, providing network slice assistance to the UE in accordance with the fact that the UE is permitted to access a first network slice in a first TA, not the entire RA. Some embodiments allow for the deployment of slices in very small geographical areas to suit specific use cases, without necessarily requiring the deployment of a small RA. Some feasible use cases include stadium and factory slices. The ability to deploy small slices within a large RA mitigates problems that can be encountered when the RA is too small, such as high registration load.

[0099] Figure 9 is a schematic block diagram of a network node 900 according to some embodiments of the present disclosure. Optional functions are represented by dashed boxes. The network node 900 may be, for example, a base station 302 or 306 or another network node that performs all or some of the functions of a base station 302 or gNB described herein. In some embodiments, the network node 900 performs one or more functions of the core network. As shown, the network node 900 includes a control system 902 that includes one or more processors 904 (e.g., a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc.), memory 906, and a network interface 908. The one or more processors 904 are also referred to herein as processing circuits. Furthermore, the network node 900 may include one or more radio units 910, each including one or more transmitters 912 and one or more receivers 914 coupled to one or more antennas 916. The radio units 910 may be referred to as radio interface circuits or may be part of radio interface circuits. In some embodiments, the wireless unit 910 is located outside the control system 902 and is connected to the control system 902, for example, via a wired connection (e.g., optical cable). However, in some other embodiments, the wireless unit 910 and potentially the antenna 916 are integrated with the control system 902. One or more processors 904 operate to provide one or more functions of the network node 900 as described herein. In some embodiments, the functions are implemented by software stored, for example, in memory 906 and executed by one or more processors 904.

[0100] Figure 10 is a schematic block diagram showing a virtualized embodiment of a network node 900 according to several embodiments of the present disclosure. This description is equally applicable to wireless access nodes and other types of network nodes. Furthermore, other types of network nodes may have similar virtualization architectures. Again, selective functions are represented by dashed boxes.

[0101] As used herein, a “virtualized” network node is an implementation of network node 900, where at least some of the functions of network node 900 are implemented as virtual components (for example, via virtual machines running on physical processing nodes in the network). As shown in the figure, in this example, network node 900 may include a control system 902 and / or one or more wireless units 910, as described above. The control system 902 may be connected to the wireless units 910 via, for example, optical cables. Network node 900 includes one or more processing nodes 1000 that are coupled to or included as part of network 1002. If present, the control system 902 or wireless units are connected to the processing nodes 1000 via network 1002. Each processing node 1000 includes one or more processors 1004 (e.g., CPU, ASIC, FPGA, etc.), memory 1006, and a network interface 1008.

[0102] In this example, the functions 1010 of the network node 900 described herein are implemented in one or more processing nodes 1000, or distributed across one or more processing nodes 1000 and a control system 902 and / or wireless unit 910 in any desired manner. In some specific embodiments, some or all of the functions 1010 of the network node 900 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment hosted by the processing node 1000. As will be understood by those skilled in the art, additional signaling or communication between the processing node 1000 and the control system 902 is used to perform at least some of the desired functions 1010. In particular, in some embodiments, the control system 902 may not be included, in which case the wireless unit 910 communicates directly with the processing node 1000 via a suitable network interface.

[0103] In some embodiments, a computer program is provided which, when executed by at least one processor, causes at least one processor to perform a function of a network node 900 or a node (e.g., a processing node 1000) that implements one or more of the functions 1010 of the network node 900 in a virtual environment according to any of the embodiments described herein. In some embodiments, a carrier is provided which includes the aforementioned computer program product. The carrier is one of the following: an electrical signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-temporary computer-readable medium such as memory).

[0104] Figure 11 is a schematic block diagram of a network node 900 according to some other embodiments of the present disclosure. The network node 900 includes one or more modules 1100, each implemented in software. The modules 1100 provide the functionality of the network node 900 as described herein. This description is equally applicable to the processing node 1000 of Figure 10, where the modules 1100 may be implemented in one of the processing nodes 1000, or distributed across multiple processing nodes 1000, and / or distributed across processing nodes 1000 and a control system 902.

[0105] Figure 12 is a schematic block diagram of a wireless communication device 1200 according to some embodiments of the present disclosure. As shown, the wireless communication device 1200 includes one or more processors 1202 (e.g., CPU, ASIC, FPGA, etc.), a memory 1204, and one or more transceivers 1206, each including one or more transmitters 1208 and one or more receivers 1210 coupled to one or more antennas 1212. The transceiver 1206 includes a wireless front-end circuit connected to the antenna 1212, configured to adjust signals communicated between the antenna 1212 and the processor 1202, as will be understood by those skilled in the art. The processor 1202 may also be referred to herein as a processing circuit. The transceiver 1206 is also referred to herein as a wireless circuit. In some embodiments, the functions of the wireless communication device 1200 described above may be fully or partially implemented by software stored in the memory 1204 and executed by (one or more) processors 1202, for example. It should be noted that the wireless communication device 1200 may include, for example, one or more user interface components (input / output interfaces including, for example, a display, buttons, a touchscreen, a microphone, a speaker, etc., and / or any other components that enable the input of information to and / or the output of information from the wireless communication device 1200), a power supply (for example, a battery and associated power circuit), and additional components not shown in Figure 12.

[0106] In some embodiments, a computer program is provided which, when executed by at least one processor, causes at least one processor to perform the functions of a wireless communication device 1200 according to any of the embodiments described herein. In some embodiments, a carrier is provided which includes the aforementioned computer program product. The carrier is one of the following: an electrical signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-temporary computer-readable medium such as memory).

[0107] Figure 13 is a schematic block diagram of a wireless communication device 1200 according to some other embodiments of the present disclosure. The wireless communication device 1200 includes one or more modules 1300, each implemented in software. The modules 1300 provide the functions of the wireless communication device 1200 as described herein.

[0108] Referring to Figure 14, according to one embodiment, the communication system includes a telecommunications network 1400, such as a 3GPP® type cellular network, which has an access network 1402 such as a RAN, and a core network 1404. The access network 1402 comprises a plurality of base stations 1406A, 1406B, 1406C, such as node B, eNB, gNB, or other types of radio access points (APs), each defining a corresponding coverage area 1408A, 1408B, 1408C. Each base station 1406A, 1406B, 1406C is connectable to the core network 1404 via a wired or wireless connection 1410. A first UE 1412 located in coverage area 1408C is configured to wirelessly connect to or be paged by the corresponding base station 1406C. A second UE 1414 in coverage area 1408A is wirelessly connectable to the corresponding base station 1406A. Although multiple UEs 1412 and 1414 are shown in this example, the disclosed embodiments are equally applicable to situations where a single UE is located within a coverage area, or where a single UE is connected to a corresponding base station 1406.

[0109] The telecommunications network 1400 is itself connected to the host computer 1416, which can be embodied in the hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 1416 may be owned or under the control of a service provider, or may be operated by or on behalf of a service provider. Connections 1418 and 1420 between the telecommunications network 1400 and the host computer 1416 may extend directly from the core network 1404 to the host computer 1416, or via an optional intermediate network 1422. The intermediate network 1422 may be one of public, private, or hosted networks, or a combination of two or more of these, and the intermediate network 1422 may be a backbone network or the internet, if any, and in particular may have two or more subnets (not shown).

[0110] The communication system in Figure 14, as a whole, enables connectivity between the connected UEs 1412, 1414 and the host computer 1416. This connectivity can be described as an over-the-top (OTT) connection 1424. The host computer 1416 and the connected UEs 1412, 1414 are configured to communicate data and / or signals over the OTT connection 1424 using an access network 1402, a core network 1404, an optional intermediate network 1422, and possible further infrastructure (not shown) as intermediaries. The OTT connection 1424 can be transparent in the sense that participating communication devices through which the OTT connection 1424 passes are unaware of the routing of uplink and downlink communications. For example, base station 1406 does not need to know, or is not required to know, the past routing of incoming downlink communications with data originating from host computer 1416 to be forwarded (e.g., handed over) to connected UE 1412. Similarly, base station 1406 does not need to be aware of the future routing of outgoing uplink communications from UE 1412 to host computer 1416.

[0111] Here, with reference to Figure 15, exemplary embodiments are described, according to the embodiments of the UE, base station, and host computer discussed in the previous paragraph. In the communication system 1500, the host computer 1502 includes hardware 1504, which includes a communication interface 1506 configured to set up and maintain wired or wireless connections with the interfaces of different communication devices of the communication system 1500. The host computer 1502 further includes processing circuitry 1508 which may have storage and / or processing capabilities. In particular, the processing circuitry 1508 may include one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. The host computer 1502 further includes software 1510 which is stored in or accessible by the host computer 1502 and executable by the processing circuitry 1508. The software 1510 includes a host application 1512. The host application 1512 may be configured to provide services to remote users, such as UE 1514, via an OTT connection 1516 that terminates at UE 1514 and host computer 1502. When providing services to remote users, the host application 1512 can provide user data transmitted using the OTT connection 1516.

[0112] The communication system 1500 further includes a base station 1518 equipped with hardware 1520 that is located within the telecommunications system and enables communication with a host computer 1502 and a UE 1514. The hardware 1520 may include a communication interface 1522 for setting up and maintaining wired or wireless connections with interfaces of different communication devices of the communication system 1500, and a wireless interface 1524 for setting up and maintaining at least a wireless connection 1526 with a UE 1514 located in a coverage area (not shown in Figure 15) served by the base station 1518. The communication interface 1522 may be configured to facilitate a connection 1528 to the host computer 1502. The connection 1528 may be direct, or it may pass through the core network of the telecommunications system (not shown in Figure 15), and / or it may pass through one or more intermediate networks outside the telecommunications system. In the illustrated embodiment, the base station 1518 hardware 1520 further includes a processing circuit 1530 which may comprise one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. The base station 1518 further includes software 1532 which is stored internally or accessible via an external connection.

[0113] The communication system 1500 further includes the already referenced UE 1514. The hardware 1534 of the UE 1514 may include a radio interface 1536 configured to set up and maintain a radio connection 1526 with a base station serving the coverage area in which the UE 1514 is currently located. The hardware 1534 of the UE 1514 further includes a processing circuit 1538 which may comprise one or more programmable processors, ASICs, FPGAs, or a combination thereof (not shown) adapted to execute instructions. The UE 1514 further includes software 1540 which is stored in or accessible by the UE 1514 and executable by the processing circuit 1538. The software 1540 includes a client application 1542. The client application 1542 may operate to provide services to human or non-human users via the UE 1514 with the support of the host computer 1502. On the host computer 1502, the running host application 1512 can communicate with the running client application 1542 via the UE 1514 and an OTT connection 1516 terminating on the host computer 1502. When providing services to a user, the client application 1542 can receive request data from the host application 1512 and provide user data in response to the request data. The OTT connection 1516 can transfer both the request data and the user data. The client application 1542 can interact with the user to generate the user data it provides.

[0114] Note that the host computer 1502, base station 1518, and UE 1514 shown in Figure 15 may be similar to or identical to the host computer 1416, one of the base stations 1406A, 1406B, and 1406C, and one of the UEs 1412 and 1414 in Figure 14, respectively. In other words, the internal operation of these entities is as shown in Figure 15, and independently, the surrounding network topology may be that of Figure 14.

[0115] In Figure 15, the OTT connection 1516 is abstractly depicted to show the exact routing of messages through the base station 1518 between the host computer 1502 and the UE 1514, without explicitly referring to any intermediate devices. The network infrastructure can determine the routing, and the routing can be configured to be hidden from the UE 1514, or from the service provider running the host computer 1502, or both. While the OTT connection 1516 is active, the network infrastructure can make further decisions to dynamically change the routing (for example, based on load balancing considerations or network reconfiguration).

[0116] The radio connection 1526 between the UE 1514 and the base station 1518 follows the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT services provided to the UE 1514 using the OTT connection 1516, in which the radio connection 1526 forms the final segment.

[0117] Measurement procedures may be provided for the purpose of monitoring data rate, latency, and other factors that one or more embodiments improve. Further optional network functions may exist for reconfiguring the OTT connection 1516 between the host computer 1502 and the UE 1514 in response to variations in measurement results. Measurement procedures and / or network functions for reconfiguring the OTT connection 1516 may be implemented in the software 1510 and hardware 1504 of the host computer 1502, or in the software 1540 and hardware 1534 of the UE 1514, or both. In some embodiments, sensors (not shown) may be deployed in or associated with the communication devices through which the OTT connection 1516 passes, and the sensors may participate in the measurement procedures by supplying values ​​of the monitored quantities exemplified above, or by supplying values ​​of other physical quantities that the software 1510, 1540 can calculate or estimate the monitored quantities. Reconfiguration of the OTT connection 1516 may include message formatting, retransmission settings, preferred routing, etc., and the reconfiguration does not need to affect the base station 1518 and may be unknown or imperceptible to the base station 1518. Such procedures and functions are known and can be practiced in the art. In certain embodiments, the measurements may involve proprietary UE signaling that facilitates measurements of the host computer 1502 such as throughput, propagation time, latency, etc. Measurements may be carried out in such a way that the OTT connection 1516 is used to send messages, particularly empty or "dummy" messages, while software 1510 and 1540 monitor propagation time, errors, etc.

[0118] Any suitable step, method, feature, function, or benefit disclosed herein may be performed through one or more functional units or modules of one or more virtual devices. Each virtual device may comprise several of these functional units. These functional units may be implemented via one or more microprocessors or microcontrollers through logic processing circuits, as well as other digital hardware such as digital signal processors (DSPs), dedicated digital logic, etc. The processing circuits may include one or more types of memory, such as read-only memory (ROM), random access memory (RAM), cache memory, flash memory devices, optical storage devices, etc., and may be configured to execute program code stored in memory. The program code stored in memory includes program instructions for executing one or more telecommunications and / or data communication protocols, and instructions for executing one or more of the techniques described herein. In some embodiments, the processing circuits may be used to cause each functional unit to perform a corresponding function according to one or more embodiments of this disclosure.

[0119] The processes shown in the figures may illustrate a specific sequence of operations performed by some embodiments of this disclosure, but it should be understood that such sequences are illustrative (for example, alternative embodiments may perform operations in a different order, combine some operations, and overlap some operations).

[0120] Embodiment

[0121] Group A Embodiment

[0122] Embodiment 1: A method performed by a user device (UE) (312) to access a network slice, comprising, during registration with a network node (900), requesting network slice assistance (702), receiving network slice assistance from the network node indicating access to a first network slice in a first tracking area (TA) that is not the entire registration area (RA) (704), and accessing the first network slice in the first TA (706).

[0123] Embodiment 2: The method according to Embodiment 1, wherein requesting network slice assistance (702) includes including the requested network slice selection assistance information (NSSAI) information element (IE) in the registration request message, and receiving network slice assistance from a network node (900) (704) includes receiving an allowed NSSAI IE, a denied NSSAI IE, or both an allowed NSSAI IE and a denied NSSAI IE from the network node in the registration acceptance message.

[0124] Embodiment 3: The method according to Embodiment 1 or 2, further comprising indicating to the network node (900) that the UE (312) is capable of supporting slice deployments that are not available across the entire RA (700).

[0125] Embodiment 4: The method according to any one of Embodiments 1 to 3, wherein receiving network slice assistance (704) from a network node includes receiving an indication at each TA of the RA of which network slice is permitted.

[0126] Embodiment 5: The method according to Embodiment 4, wherein the indication of which network slices are permitted in each TA of the RA is received in the permitted network slice selection assistance information (NSSAI) information element (IE).

[0127] Embodiment 6: The method according to Embodiment 4 or 5, wherein the indication of which network slices are permitted at each TA of the RA is received in the NSSAI IE permitted for each TA.

[0128] Embodiment 7: The method according to any one of Embodiments 4 to 6, further comprising not accessing the first network slice in the second TA when the first network slice is not indicated as permitted in the second TA.

[0129] Embodiment 8: The method according to any one of Embodiments 4 to 6, further comprising the second TA accessing the first network slice with reduced quality of service (QoS) when the first network slice is not indicated as permitted at the second TA.

[0130] Embodiment 9: The method according to any one of Embodiments 1 to 8, wherein receiving network slice assistance (704) from a network node includes receiving an indication at each TA of the RA that no network slice is permitted.

[0131] Embodiment 10: The method according to Embodiment 9, wherein an indication of which network slices are not permitted in each TA of the RA is received in the rejected network slice selection assistance information (NSSAI) information element (IE).

[0132] Embodiment 11: The method according to Embodiment 9 or 10, wherein the indication of which network slices are not permitted in each TA of the RA is received in the rejected NSSAI for each TA IE.

[0133] Embodiment 12: The method according to any one of embodiments 9 to 11, further comprising the second TA not accessing the first network slice when the first network slice is indicated as not permitted in the second TA.

[0134] Embodiment 13: The method according to any one of embodiments 9 to 11, further comprising the second TA accessing the first network slice with reduced quality of service (QoS) when the first network slice is indicated as not permitted at the second TA.

[0135] Embodiment 14: The method according to any one of Embodiments 1 to 13, wherein receiving network slice assistance (704) from a network node includes receiving an indication that the first network slice is not available in the current TA.

[0136] Embodiment 15: The method according to Embodiment 14, wherein accessing a first network slice in a first TA (706) includes, between entering the first TA and registering with a network node (900), requesting network slice assistance (702) and receiving network slice assistance from the network node (704) indicating that the first network slice is available in the first TA.

[0137] Embodiment 16: A user device (UE) (312) configured to communicate with a network node (900) and comprising a wireless interface and a processing circuit configured to perform any of the methods of the previous embodiments.

[0138] Group B Embodiment

[0139] Embodiment 17: A method performed by a network node (900) for heterogeneous slice deployment in a registration area (RA), comprising: receiving a request for network slice assistance from a user device (UE) (312) (802); determining that the UE is permitted to access a first network slice in a first tracking area (TA) that is not the entire registration area (RA) (804); and providing network slice assistance to the UE in accordance with the access to the first network slice in the first TA that is not the entire RA (806).

[0140] Embodiment 18: The method of Embodiment 17, wherein receiving a request for network slice assistance (802) comprises receiving the requested network slice selection assistance information (NSSAI) information element (IE) in a registration request message, and providing network slice assistance to the UE (312) (806) comprises including an allowed NSSAI IE, a denied NSSAI IE, or both an allowed NSSAI IE and a denied NSSAI IE in a registration acceptance message to the UE.

[0141] Embodiment 19: The method of Embodiment 17 or 18, further comprising the UE receiving an indication from UE(312) that it is capable of supporting slice deployments that are not available across the entire RA (800).

[0142] Embodiment 20: The method according to Embodiment 17 or 18, wherein if a network node does not have an indication that the UE is capable of supporting a slice deployment that is not available across the entire RA, providing network slice assistance to the UE (806) is to indicate that the UE is not permitted to access a first network slice in the RA.

[0143] Embodiment 21: The method according to any one of Embodiments 17 to 20, wherein determining that a UE is permitted to access a first network slice in a first TA that is not the entire RA (804) includes determining that the area covered by the first network slice is smaller than the entire RA, and configuring the first TA to match the area covered by the first network slice.

[0144] Embodiment 22: The method according to any one of Embodiments 17 to 21, wherein providing network slice assistance (806) to the UE includes providing an indication of which network slice is permitted at each TA of the RA.

[0145] Embodiment 23: The method according to Embodiment 22, wherein the indication of which network slices are permitted in each TA of the RA is provided in the permitted network slice selection assistance information (NSSAI) information element (IE).

[0146] Embodiment 24: The method of Embodiment 22 or 23, wherein the indication of which network slices are permitted at each TA of the RA is provided in the permitted NSSAI IE for each TA.

[0147] Embodiment 25: The method according to Embodiment 22 or 23, wherein the UE is not permitted to access the first network slice at the second TA when the first network slice is not indicated as permitted at the second TA.

[0148] Embodiment 26: The method according to Embodiment 22 or 23, wherein when the UE is not indicated that the first network slice is permitted at the second TA, the second TA is permitted to access the first network slice with reduced quality of service (QoS).

[0149] Embodiment 27: The method according to any one of Embodiments 17 to 26, wherein providing network slice assistance (806) to the UE includes providing an indication at each TA of the RA that no network slice is permitted.

[0150] Embodiment 28: The method according to Embodiment 27, wherein an indication of which network slices are not permitted in each TA of the RA is provided in the rejected network slice selection assistance information (NSSAI) information element (IE).

[0151] Embodiment 29: The method of Embodiment 27 or 28, wherein the indication of which network slices are not permitted in each TA of the RA is provided in the rejected NSSAI IE for each TA.

[0152] Embodiment 30: The method according to any one of Embodiments 27 to 29, wherein when the first network slice is indicated to be not permitted in the second TA, the UE is not permitted to access the first network slice in the second TA.

[0153] Embodiment 31: The method according to any one of Embodiments 27 to 29, wherein when the UE indicates that the first network slice is not permitted at the second TA, the second TA is permitted to access the first network slice with reduced quality of service (QoS).

[0154] Embodiment 32: The method according to any one of Embodiments 17 to 31, wherein providing network slice assistance (806) to the UE includes providing an indication that a first network slice is not available in the current TA.

[0155] Embodiment 33: The method according to Embodiment 32, further comprising receiving another request for network slice assistance when the UE enters the first TA (802), and providing the UE with network slice assistance indicating that the first network slice is available in the first TA (806).

[0156] Embodiment 34: A network node (900) configured to communicate with a user device (UE) (312), the network node comprising processing circuitry configured to perform any of the methods of the embodiments described above.

[0157] This disclosure may use at least some of the following abbreviations. In the event of any inconsistency between abbreviations, the usage described above shall prevail. If an abbreviation is listed multiple times below, the first listing shall take precedence over subsequent listings. 3GPP Third Generation Partnership Project 5G (5th generation) 5GC (5th Generation Core) 5GMM (5th Generation Mobility Management) 5GS (5th Generation System) 5GSM 5th Generation Session Management AF Application Function AMF access and mobility features AN Access Network AP Access Point ASIC (Application-Specific Integrated Circuit) AUSF Authentication Server Function CCNF Common Control Network Function CP control plane CPU (Central Processing Unit) DCI Downlink Control Information DN Data Network DSP (Digital Signal Processor) eNB Enhanced or Evolved Node B FDD Frequency Division Multiplexing FPGA Field-Programmable Gate Array gNB (GNB New Radio Base Station) gNB-CU New Radio Base Station Central Unit gNB-DU New Radio Base Station Distributed Unit HSS Home Subscriber Server IE Information Element IoT (Internet of Things) LTE Long-Term Evolution MAC Media Access Control MBB Mobile Broadband MME Mobility Management Entity MTC Machine Type Communication NAS Non-Accessible Tier NEF Network Publishing Function NF Network Function NG Next generation NG-RAN Next Generation Wireless Access Network NR New Radio NRF Network Function Repository Function NSSAI Network Slice Selection Support Information NSSF Network Slice Selection Function OTT Over the Top PC (Personal Computer) PCF Policy Control Function PDSCH Physical Downlink Shared Channel PDU Packet Data Unit P-GW Packet Data Network Gateway PLMN Public Land Mobile Network QoS (Quality of Service) RA Registration Area RAM (Random Access Memory) RAN (Radio Access Network) RNL (Radio Network Layer) ROM (Read-only memory) RRC (Radio Resource Control) RRH Remote Radio Head RTT (Round Trip Time) CSEF Service Capability Disclosure Function SMF session management function S-NSSAI Single Network Slice Selection Support Information TA Tracking Area TAI Tracking Area Information TCI Transmit Settings Indicator TDD Time Division Duplex TNL Transport Network Layer TRP transmission point TS Technical Specifications UDM (Unified Data Management) UE User Equipment UPF User Plane Functionality

[0158] Those skilled in the art will recognize improvements and modifications to embodiments of the present disclosure. All such improvements and modifications are considered to fall within the scope of the concepts disclosed herein.

Claims

1. A method performed by a user device (UE) (312) to access a network slice, During registration with the wireless access network node (900), the registration request message (702) is sent, which is a registration request message requesting network slice assistance, and which includes an indication of a first network slice. Receiving network slice assistance from the wireless access network node indicating access to the first network slice in a first tracking area (TA) that is not the entire registered area (RA), and not indicating all network slices in all TAs of the RA (704), Accessing the first network slice within the first TA (706), A method that includes this.

2. The method according to claim 1, Requesting network slice assistance (702) includes including the requested network slice selection assistance information (NSSAI) information element (IE) in the registration request message. Receiving network slice assistance from the wireless access network node (900) (704) is a method comprising receiving at least one of the permitted NSSAI IEs and denied NSSAI IEs from the wireless access network node in a registration acceptance message.

3. A method according to claim 1 or 2, further comprising indicating to the radio access network node (900) (700) that the UE (312) is capable of supporting slice deployments that are not available across the entire RA.

4. A method according to any one of claims 1 to 3, wherein receiving network slice assistance from the wireless access network node (704) includes receiving an indication of which network slice is permitted in which TA of the RA, The indication of which network slices are permitted at which TA of the RA is received in the NSSAI IE for each TA for slices that are unavailable at all TAs of the RA, in a method.

5. A method according to any one of claims 1 to 4, wherein receiving network slice assistance from the radio access network node (704) includes receiving an indication that any network slice is not permitted in any of the TAs of the RA, A method in which the indication of which network slice is not permitted in any of the TAs of the RA is received in one or more of the following: a list of one or more TAs in which the network slice is available, and a list of one or more TAs in which the network slice is not available.

6. A method according to any one of claims 1 to 5, wherein receiving network slice assistance from the wireless access network node (704) includes receiving an indication that the first network slice is not available in the current TA, Accessing the first network slice within the first TA (706) is, Entering the first TA, Requesting a service provided by the first network slice, Receiving a rejection with the cause value "S-NSSAI is not available in the current tracking area," Methods that include...

7. A user device (UE) (312) configured to communicate with a wireless access network node (900), wherein the UE comprises a wireless interface and a processing circuit configured to perform the method according to any one of claims 1 to 6.

8. A method performed by a radio access network node (900) for heterogeneous slice deployment in a registered area (RA), Receiving a registration request message from a user device (UE) (312) requesting network slice support, the registration request message including an indication of a first network slice (802), Determining that the UE is permitted to access the first network slice in a first tracking area (TA) that is not the entire RA (804), To provide network slice support to the UE that does not show all network slices in all TAs of the RA, in accordance with access to the first network slice in the first TA, which is not the entire RA (806), Methods that include...

9. The method according to claim 8, Receiving the aforementioned request for network slice support (802) includes receiving the requested network slice selection support information (NSSAI) information element (IE) in the registration request message, A method for providing network slice support to the UE (312) (806) includes including in the registration acceptance message to the UE at least one of the permitted NSSAI IEs and the denied NSSAI IEs.

10. A method according to claim 8 or 9, further comprising receiving an indication from the UE (312) (800) that the UE is capable of supporting slice deployments that are not available across the entire RA.

11. A method according to claim 8 or 9, wherein providing network slice assistance to the UE (806) when the radio access network node does not have an indication that the UE is capable of supporting a slice deployment that is not available across the entire RA includes indicating that the UE is not permitted to access the first network slice in the RA.

12. A method according to any one of claims 8 to 11, wherein determining that the UE is permitted to access the first network slice in the first TA, not the entire RA (804), Determining that the area covered by the first network slice is smaller than the entire RA, The first TA is configured to coincide with the area covered by the first network slice, Methods that include...

13. A method according to any one of claims 8 to 12, wherein providing network slice support to the UE (806) includes providing an indication of which network slice is permitted in which TA of the RA.

14. A method according to any one of claims 8 to 13, wherein providing network slice support to the UE (806) includes providing an indication of which network slice is not permitted in any of the TAs of the RA, The indication of which network slice is not permitted in any of the TAs of the RA is provided in one or more of the following: a list of one or more TAs in which the network slice is available, and a list of one or more TAs in which the network slice is not available.

15. A method according to any one of claims 8 to 14, wherein providing network slice support to the UE (806) includes providing an indication that the first network slice is not available in the current TA, The UE receives a request for the service provided by the first network slice, To provide the aforementioned UE with a rejection having the cause value "S-NSSAI is not available in the current tracking area", Methods that further include this.

16. A wireless access network node (900) configured to communicate with user equipment (UE) (312), comprising a processing circuit configured to perform the method described in any one of claims 8 to 15.

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