Heterogeneous slice deployment within registration area of cellular communications network

Abstract

To provide systems and methods for heterogeneous slice deployment within a registration area.SOLUTION: A method performed by user equipment (UE) for accessing a network slice includes: during registration with a network node, requesting network slice assistance; receiving, from the network node, network slice assistance indicating access to a first network slice in a first Tracking Area (TA) but not in an entire Registration Area (RA); and accessing the first network slice in the first TA.EFFECT: Some embodiments enable deploying slices in very small geographical areas to suit special use cases without necessarily having to deploy small RAs. An ability to deploy small slices within a large RA mitigates problems, such as high registration load, that one might deal with when the RA is too small.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] [Technical field] The present disclosure relates to accessing a network slice. [Background technology]

[0003] Figure 1 is a schematic block diagram of the current fifth-generation (5G) Radio Access Network (RAN) architecture, also referred to as Next-Generation RAN (NG-RAN). The 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 base stations (gNBs) connected to the fifth-generation core (5GC) via the next-generation (NG) interface. · The eNB / gNB can support frequency division duplex (FDD) mode, time division duplex (TDD) mode or dual mode operation. · eNB / gNB can be interconnected 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 gNB-DU are connected via the 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 a gNB consisting of a gNB-CU and a gNB-DU terminate at the gNB-CU. In the case of New Radio Dual Connectivity (EN-DC), the S1-U and X2-C interfaces for a gNB consisting of a gNB-CU and a gNB-DU terminate at the gNB-CU. The gNB-CU and the connected gNB-DU are only visible to other gNBs and 5GC as gNBs.

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

[0006] (Network Slicing) Network slicing is the creation of logically isolated partitions of a network to serve different business purposes. These "network slices" are logically separated to the extent that the network slice can be considered and managed as its own network.

[0007] It is a new concept that potentially applies to both Long Term Evolution (LTE) and the new 5G Radio Access Technology (RAT), also known as New Radio (NR).The primary driver for deploying network slicing is business expansion, i.e., improving cellular operators' ability to serve other industries by offering connectivity services with different network characteristics (performance, security, robustness, and complexity).

[0008] Figure 2 is a schematic diagram of a cellular communication network with a common RAN connected to multiple network slices of the core network. The current operating assumption is that there is one shared RAN infrastructure (with one or more Common Control Network Functions (CCNFs) interfacing with the RAN and additional core network functions that may be slice-specific) connecting to several core network instances. When core network functions are virtualized, it is assumed that operators will instantiate new core networks, or parts of them, when new slices are to be supported. For example, slice 0 may be a mobile broadband (MBB) slice, and slice 1 may be a machine-type communication (MTC) network slice.

[0009] 3GPP® is currently working on introducing enhancements to the network slicing framework introduced in 3GPP® 5G systems. As of Release 16 (Rel-16), 3GPP® specifies that slice availability for a user equipment (UE) should not change within a registration area (RA), which consists of a list of tracking areas (TAs). The UE expects all cells comprising different TAs within an RA to provide the same set of slices that were provided to the UE in the granted network slice selection assistance information (NSSAI) during the registration procedure. Improved systems and methods for slice deployment within a registration area are needed. Summary of the Invention

[0010] In some embodiments, a method for accessing a network slice includes requesting network slice assistance during registration with a network node, receiving network slice assistance from the network node indicating access to a first network slice in a first tracking area (TA) that is not an entire registration area (RA), and accessing the first network slice in the first TA.

[0011] Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned and other problems. 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) with an RA that includes tracking areas (TAs) with heterogeneous network slice support. This enables support for a specific network slice in an area restricted to a single TA, eliminating the need to assign an RA restricted to only that specific TA to the UE. This is achieved by: 1. Configuring a TA that exactly matches the area covered by the network slice; 2. Inclusion of TA in RA; 3. Informing the UE of the RA and informing it that the network slice is available only within the TA and not the entire RA; 4. Informing the serving radio access network (RAN) of the slices supported per TA for the UE.

[0012] Prior art techniques do not allow for the deployment of slices in areas smaller than an RA. The proposed solution allows for the deployment of small slices without requiring any changes to the way RAs are deployed, by modifying 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]

[0013] In some embodiments, a method is performed by a UE to access a network slice, the method including, during registration with a network node, one or more of: requesting network slice assistance; receiving network slice assistance from the network node indicating access to a first network slice in a first TA that is not an entire RA; and accessing the first network slice in the first TA.

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

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

[0017] In some embodiments, receiving network slice assistance from the network node includes receiving an indication of which network slices are not allowed in each TA of the RA. In some embodiments, the indication of which network slices are not allowed in each TA of the RA is received in a Rejected NSSAI IE. In some embodiments, the indication of which network slices are not allowed in each TA of the RA is received in a Rejected NSSAI Per TA IE. In some embodiments, the method further includes not accessing the first network slice in the second TA when the first network slice is indicated as not allowed in the second TA. In some embodiments, the method further includes accessing the first network slice at a reduced QoS in the second TA when the first network slice is indicated as not allowed in the second TA.

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

[0019] In some embodiments, a UE is configured to communicate with a network node, the UE comprising a radio interface and processing circuitry configured to perform the method of any of the previous embodiments.

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

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

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

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

[0024] In some embodiments, determining that the UE is allowed to access a first network slice in a first TA that is not the entire RA includes 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 the UE includes providing an indication of which network slices are allowed in each TA of the RA. In some embodiments, the indication of which network slices are allowed in each TA of the RA is provided in an Allowed NSSAI IE. In some embodiments, the indication of which network slices are allowed in each TA of the RA is provided in a Per-TA Allowed NSSAI IE. In some embodiments, when the first network slice is not indicated as allowed in the second TA, the UE is not allowed to access the first network slice in the second TA. In some embodiments, the UE is allowed to access the first network slice at a reduced QoS in the second TA when the first network slice is not indicated as allowed in the second TA.

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

[0027] In some embodiments, providing the network slice assistance to the UE includes providing an indication that the 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 network slice assistance to the UE indicating that the first network slice is available in the first TA.

[0028] In some embodiments, a network node is configured to communicate with the UE, the network node comprising processing circuitry configured to perform the method of any of the preceding embodiments.

[0029] Certain embodiments may provide one or more of the following technical advantages: The proposed solution allows for the deployment of slices in very small geographic areas to fit special use cases without necessarily having to deploy small RAs. Some possible use cases are stadiums, factory slices, etc. The ability to deploy small slices within large RAs alleviates issues such as high registration load that can be addressed when the RA is too small. At the same time, this avoids the 3GPP requirement to deploy slices across RAs where the business / deployment does not require it.

[0030] Various embodiments described herein explore different tradeoffs with the above solutions: some embodiments keep messaging simple (Non-Access Stratum (NAS) Registration Accept messages) at the expense of potentially more signaling to the UE with UE mobility; some embodiments propose the use of more complex message structures compared to previous approaches, without changing the signaling load between the UE and the network. [Brief explanation of the drawings]

[0031] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0032] [Figure 1] FIG. 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] FIG. 2 is a conceptual diagram of a cellular communication network having a common RAN connected to multiple network slices of a core network.

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

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

[0036] [Figure 5] FIG. 5 illustrates a 5G network architecture that uses service-based interfaces between NFs in the control plane (CP) instead of the point-to-point reference points / interfaces used in the 5G network architecture of FIG. 4 , in accordance with some embodiments of the present disclosure.

[0037] [Figure 6] FIG. 6 illustrates the cellular communication system of FIG. 3 providing heterogeneous deployment of network slices within registration areas (RAs) according to some embodiments of the present disclosure.

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

[0039] [Figure 8] FIG. 8 is a flow diagram of a method for heterogeneous slice deployment in an RA.

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

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

[0042] [Figure 11] FIG. 2 is a schematic block diagram of an exemplary embodiment of a radio access node; [Figure 12] FIG. 2 is a schematic block diagram of an exemplary embodiment of a radio access node; [Figure 13] FIG. 2 is a schematic block diagram of an exemplary embodiment of a radio access node;

[0043] [Figure 14] FIG. 1 is a schematic block diagram of a UE. [Figure 15] FIG. 1 is a schematic block diagram of a UE. DETAILED DESCRIPTION OF THE INVENTION

[0044] The embodiments described below represent information to enable those skilled in the art to practice the embodiments and illustrate the best modes for practicing the embodiments. Upon reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and will recognize applications of these concepts not specifically addressed herein. It is understood that these concepts and applications are within the scope of the present disclosure.

[0045] Wireless Node: As used herein, a "wireless node" is either a wireless access node or a wireless communication device.

[0046] Radio Access Node: As used herein, a "radio access node" or "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 a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a 3rd Generation Partnership Project (3GPP®) Fifth Generation (5G) NR network, or an enhanced or evolved Node B (eNB) in a 3GPP® Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a Home eNB, etc.), a relay node, a network node implementing some of the functionality 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 a network node implementing some of the functionality of some other type of radio access node.

[0047] Core Network Node: As used herein, a "core network node" is any kind of node in a core network or any node that implements a core network function. Some examples of core network nodes include, for example, a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Publication Function (SCEF), a Home Subscriber Server (HSS), etc. Some other examples of core network nodes include nodes that implement an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Publication Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc.

[0048] Communications Device: As used herein, a "communications device" is any type of device that has access to an access network. Some examples of communications devices include, but are not limited to, a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a home appliance, a medical device, a media player, a camera, or any type of consumer electronics device, such as, but not limited to, a television, a radio, a lighting fixture, a tablet computer, a laptop, or a personal computer (PC). A communications device may be a portable, handheld, computer-embedded, or vehicle-mounted mobile device capable of communicating voice and / or data over a wireless or wired connection.

[0049] Wireless Communication Device: One type of communication device is a wireless communication device, which can be any type of wireless device that accesses (i.e., is served 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) in 3GPP networks, machine-type communication (MTC) devices, and Internet of Things (IoT) devices. Such wireless communication devices can be or can 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 can be portable, handheld, computer-based, or vehicle-mounted mobile devices capable of communicating voice and / or data over a wireless connection.

[0050] Network Node: As used herein, a "network node" is any node that is part of either the RAN or core network of a cellular communications 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 transmission configuration indicator (TCI) state. A TRP can be represented by a spatial relationship or a TCI state in some embodiments. In some embodiments, a TRP can use multiple TCI states. In some embodiments, a TRP can be part of a gNB that transmits and receives radio signals to and from a UE according to physical layer characteristics and parameters specific to that element. In some embodiments, multiple TRP (multi-TRP) operation allows a serving cell to schedule a UE from two TRPs, providing better physical downlink shared channel (PDSCH) coverage, reliability, and / or data rates. Multi-TRP has two different modes of operation: single downlink control information (DCI) and multi-DCI. For both modes, control of uplink and downlink operations is provided by both the physical layer and the medium access control (MAC). In single-DCI mode, a UE is scheduled by the same DCI for both TRPs, while in multi-DCI mode, a UE is scheduled by independent DCI from each TRP.

[0052] It should be noted that the description provided herein focuses on 3GPP® cellular communication systems, and therefore 3GPP® terminology or terminology similar to 3GPP® terminology is often used, however, the concepts disclosed herein are not limited to 3GPP® systems.

[0053] It should be noted that although the description herein may refer to the term "cell," it is important to note that, particularly with regard to 5G NR concepts, beams may be used instead of cells, and therefore the concepts described herein are equally applicable to both cells and beams.

[0054] 3 illustrates 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, which in 5GS include NR base stations (gNBs) and optionally Next Generation eNBs (ng-eNBs) (e.g., LTE RAN nodes connected to 5GC), and in EPS include eNBs, which control corresponding (macrocell) cells 304-1 and 304-2. Base stations 302-1 and 302-2 are generally referred to herein collectively as base stations 302 and individually as base stations 302. Similarly, (macrocell) cells 304-1 and 304-2 are generally referred to herein collectively as (macrocell) cell 304 and individually as (macrocell) cell 304. The RAN may also include several low-power nodes 306-1 through 306-4 that control corresponding small cells 308-1 through 308-4. The low-power nodes 306-1 through 306-4 may be small base stations (such as pico or femto base stations) or remote radio heads (RRHs), etc. Notably, although not shown, one or more of the small cells 308-1 through 308-4 may alternatively be provided by the base station 302. The low-power nodes 306-1 through 306-4 are generally collectively referred to herein as low-power nodes 306 and individually referred to as low-power nodes 306. Similarly, the small cells 308-1 through 308-4 are generally collectively referred to herein as small cells 308 and individually referred to as small cells 308. The cellular communication system 300 also includes a core network 310, referred to as 5GC in a 5G system (5GS). The base stations 302 (and optionally the low-power nodes 306) are connected to the core network 310.

[0055] Base station 302 and low power node 306 serve wireless communication devices 312-1 through 312-5 within corresponding cells 304 and 308. Wireless communication devices 312-1 through 312-5 are generally referred to herein collectively as wireless communication devices 312 and individually as wireless communication devices 312. In the following description, wireless communication devices 312 are often UEs, although the disclosure is not limited thereto.

[0056] 4 illustrates 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. FIG. 4 can be viewed as one particular implementation of the system 300 of FIG.

[0057] From the access side, the 5G network architecture shown in Figure 4 comprises a plurality of UEs 312 connected to either a RAN 302 or an access network (AN) and an AMF 400. Typically, the RAN 302 comprises a base station, such as an eNB or a gNB. From the core network side, the 5G NFs shown in Figure 4 include an NSSF 402, an AUSF 404, a UDM 406, an AMF 400, an SMF 408, a PCF 410, and an 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. The N1 reference point is defined to carry signals between the UE 312 and the AMF 400. Reference points for connecting between the AN 302 and the AMF 400 and between the AN 302 and the UPF 414 are defined as N2 and N3, respectively. There is a reference point N11 between the AMF 400 and the SMF 408, which means that the SMF 408 is at least partially controlled by the AMF 400. N4 is used by the SMF 408 and the UPF 414, so that the UPF 414 can be configured using control signals generated by the SMF 408 and the UPF 414 can report its status to the SMF 408. N9 is a reference point for connections between different UPFs 414, and N14 is a reference point connecting between different AMFs 400. N15 and N7 are defined because the PCF 410 applies policies to the AMF 400 and SMF 408, respectively. N12 is required for the AMF 400 to authenticate the UE 312. N8 and N10 are defined because subscription data of the UE 312 is required for the 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 in the network. In Figure 4, the UPF 414 is located in the UP, and all other NFs, namely the AMF 400, SMF 408, PCF 410, AF 412, NSSF 402, AUSF 404, and UDM 406, are located in the CP. Separating the UP and CP ensures that each plane resource is scaled independently. It also allows the UPF to be distributed and deployed separately from the 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 separated AMF 400 and SMF 408 allow for independent evolution and scaling. Other CP functions, such as the PCF 410 and AUSF 404, can be separated as shown in Figure 4. The modularized functional design allows the 5G network to flexibly support various services.

[0061] Each NF interacts directly with another NF. It is possible to route messages from one NF to another using intermediate functions. In a CP, a set of interactions between two NFs is defined as a service, allowing for their reuse. This service allows for modularity support. A UP supports interactions such as forwarding operations between different UPFs.

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

[0063] Some characteristics of the NFs shown in Figures 4 and 5 can be explained in the following way: The AMF 400 provides UE-based authentication, authorization, mobility management, etc. The UE 312 is essentially connected to a single AMF 400, even if multiple access technologies are used, because the AMF 400 is independent of the access technology. The SMF 408 is responsible for session management, assigning Internet Protocol (IP) addresses to the UE. It also selects and controls the UPF 414 for data forwarding. If the UE 312 has multiple sessions, a different SMF 408 can be assigned to each session to manage them separately and possibly provide different capabilities for each session. The AF 412 provides information about packet flows to the PCF 410, which is responsible for policy control, to support quality of service (QoS). Based on this information, the PCF 410 determines policies regarding mobility and session management for the proper operation of the AMF 400 and SMF 408. The AUSF 404 supports authentication functions for the UE or the like and therefore stores data for UE or the like authentication, while the UDM 406 stores subscription data for the UE 312. The data network (DN) is not part of the 5GC network and provides internet access or operator services, etc.

[0064] An NF may be implemented as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on a suitable platform, e.g., a cloud infrastructure.

[0065] Expecting network slices to be deployed uniformly across RAs restricts slice deployment to be tightly coupled with RAs. Generally, an RA is a large geographical area served by multiple nodes (defined by a TA list, all TAs served by the same AMF) that defines the granularity at which a UE's location is known when the UE is not connected by Radio Resource Control (RRC). RAs are configured for areas large enough to avoid excessive registrations due to UE mobility by taking UE mobility into account. RAs typically cover a significant geographical area.

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

[0067] 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), which is not the entire registration area (RA); and accessing the first network slice in the first TA. Some embodiments enable deploying slices in very small geographic areas to suit special use cases without necessarily deploying small RAs. Some possible use cases are stadiums, factory slices, etc. The ability to deploy small slices within a large RA alleviates issues such as high registration load that may be encountered when the RA is too small.

[0068] FIG. 6 illustrates the cellular communication system 300 of FIG. 3, providing 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. The embodiments described herein enable the AMF 400 to configure the UE 312 with the RA 600, which includes tracking areas (TAs) TA1 through TA8, with heterogeneous network slice support. For example, a first network slice 602-1 (e.g., slice 0) may be supported throughout the RA 600, while a second network slice 602-2 (e.g., slice 1) may be supported only in TA1, TA2, and TA3.

[0069] This allows support for a particular network slice 602 in an area as small as a single TA, eliminating the need to assign an RA 600 to the UE 312 that is restricted to only that particular TA. This is achieved by: 1. Configuring TAs (e.g., TA1, TA2, TA3) that exactly match the area covered by the network slice 602; 2. Inclusion of TA in RA 600; 3. Informing the UE 312 of the RA 600 that the network slice 602 is available only within the TA and not the entire RA 600; 4. Informing the serving RAN of the slices 602 supported per TA for the UE 312.

[0070] In this regard, during registration in a public land mobile network (PLMN), as part of the Non-Access Stratum (NAS) procedure defined in 3GPP® Technical Specification (TS) 24.501 16.6.0, the UE 312 includes an information element (IE) called "Requested NSSAI" as part of a registration request message. The IE contains a set of Single Network Slice Selection Assistance Information (S-NSSAI) that indicates the set of network slices 602 that the UE 312 requests permission to use in the PLMN. Upon receiving this IE, the core network takes this information into account to determine the RA 600 for the UE 312. Then, based on slice deployment, UE subscription, and other policies, the core network determines the set of S-NSSAIs that the UE 312 is allowed and not allowed to use in the RA in terms of the Allowed NSSAI and Rejected NSSAI IEs and communicates this to the UE 312 via a NAS Registration Accept message. The set of allowed and rejected S-NSSAIs in the response is assumed to be valid for the entire current RA.

[0071] First, UE capability requirements that are general to the embodiments described herein are listed. The UE 312 needs to indicate to the network that it is capable of supporting messages indicating slice deployments that are not available across the RA 600. This may be indicated to the network by a new UE capability, for example, in the UE's 5th Generation Mobility Management (5GMM) capability, the UE's 5th Generation Session Management (5GSM) capability, or a new IE. When the UE 312 does not indicate this capability, the network automatically assumes that the UE 312 should not be authorized in any of the slices 602 that are not uniformly deployed across the RA. This prevents future attempts by the UE 312 to use slices 602 that are not deployed across the RA 600.

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

[0073] <First embodiment: Extension of slice information permitted for each TA information> A first embodiment adds information to messages sent to the UE to communicate which network slices included in the Allowed NSSAI are allowed in which TAs as a means for communicating non-homogeneous slice deployment to the UE. This can be accomplished by multiple means, for example, via a Registration Accept message or via other NAS messages. In each case, the communication involves the UE sending information about the TAs that make up that RA and which slices are explicitly allowed in those TAs.

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

[0075] The UE interprets the S-NSSAIs present in the message as S-NSSAIs that are considered to be allowed in the TAs where they are explicitly listed and not allowed in other TAs, i.e., slices not listed in a TA are considered to be unavailable in that TA. This information MUST be seen together with the Rejected S-NSSAI List, which is sent according to the specification without any TA-specific information and applies to all TAs in the RA except those marked as allowed in the modified IE.

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

[0077] This list includes several QoS parameter sets associated with the same packet data unit (PDU) session. In one example, a PDU session associated with a slice may be served with the best QoS parameters configured when the UE is in the TA with 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 to the UE with a lower QoS parameter set (included in the alternative QoS parameter set list) when the slice is not in the TA with which the slice is associated.

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

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

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

[0081] As per the previous embodiments, some embodiments consist in interpreting the new list of S-NSSAIs that are not allowed per TA as a list of S-NSSAIs for which maximum QoS is not achieved in the associated TA.

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

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

[0084] <Embodiment 4: Extension of slice reject message with current TA information> The Rejected S-NSSAI IE has the following supported cause values ​​(3GPP TS 24.501 16.6.0): Cause 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 the current registration area 0 0 1 0 S-NSSAI is not available because network slice-specific authentication and authorization failed or was revoked

[0085] To allow for the deployment of slices in areas smaller than the RA, in the fourth embodiment, the rejected S-NSSAI IE contains the cause value "S-NSSAI not available in 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 configured with the current RA, i.e., the set of TAs in the registration accept message.

[0086] Whenever the UE finds itself in a new TA within the same RA, it assumes that the slice rejected in the previous TA is available in the current TA and can either attempt to use the slice for the new PDU session, or the previous PDU session can be reassigned to the newly allocated slice by the core. The reason here is that the UE was only explicitly rejected from using the slice on the previous TA, and the same slice is also in the set of available slices in the current RA. However, the core can also reject 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 maintain a memory of rejected slices in a particular TA. This memory is maintained as long as the UE remains in the same RA or as long as the UE deregisters. This memory is also cleared every time the UE is powered on / off. This prevents the UE from re-requesting slices that were previously rejected in a TA.

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

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

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

[0091] 3. A CM-CONNECTED UE in RRC_INACTIVE state may maintain the access stratum configuration for resources associated with a PDU session even if the cell in which the UE is currently staying or served is configured on a TA and the S-NSSAI (network slice) associated with that PDU session is not among the set of allowed network slices (S-NSSAI) / allowed NSSAIs provided to the UE by the network for this TA.

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

[0093] <Embodiment 5: Exchange of Permitted / Preferred S-NSSAI List from Core Network to RAN Node> From the above embodiments, it can be derived that the new information signaled to the UE can be either in the form of a list of allowed / non-allowed S-NSSAIs per TA or in the form of a list of preferred / non-preferred S-NSSAIs per TA.

[0094] In a fifth embodiment, a list of allowed / preferred S-NSSAIs per TA associated with a UE is signaled from the core network to the RAN serving the UE. As an example, such information can 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 the TAs in which the slice is or is supported with maximum QoS, and based on that, the RA can trigger UE mobility with the intention of achieving service continuity by handing over the UE to a cell in a TA in which the slice in use by the UE is supported, and achieving maximization of QoS treatment for the slice service in use by the UE by handing over the UE to a cell in a TA in which the slice in use by the UE is served with maximum QoS.

[0096] If the list of allowed / preferred S-NSSAIs per TA is replaced with the list of non-allowed / non-preferred S-NSSAIs per TA, the RAN will gain knowledge of TAs where the listed slices are not allowed or served with maximum QoS, and based on that, the RAN may attempt not to handover the UE towards cells in those TAs if the UE has active service of the slices listed for such TAs.

[0097] FIG. 7 is a flow diagram 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 at step 700, where the UE indicates to a network node that it is capable of supporting a slice deployment that is not available throughout the RA. The method continues at step 702, where the UE requests network slice assistance during registration with the network node. The method continues at step 704, where receiving network slice assistance from the network node indicates access to a first network slice in a first TA, rather than the entire RA. The method proceeds to step 706, where the first network slice in the first TA is accessed. Some embodiments do not necessarily require the deployment of a small RA, but allow for the deployment of slices in very small geographic areas to suit special use cases. Some possible use cases are stadium slices, factory slices, etc. The ability to deploy small slices within a large RA alleviates issues, such as high registration load, that may be encountered when the RA is too small.

[0098] FIG. 8 is a flow diagram of a method for heterogeneous slice deployment in an RA. The method may be performed by a network node. The method optionally begins in step 800, receiving an indication from the UE that the UE is capable of supporting a slice deployment that is not available throughout the RA. The method proceeds to step 802, receiving a request for network slice assistance from the UE. The method continues in step 804, determining that the UE is authorized to access a first network slice in a first TA that is not throughout the RA. The method continues in step 806, providing network slice assistance to the UE in accordance with the UE being authorized to access the first network slice in the first TA that is not throughout the RA. Some embodiments enable deploying slices in very small geographic areas to suit special use cases without necessarily deploying small RAs. Some possible use cases are stadium slices, factory slices, etc. The ability to deploy small slices within a large RA alleviates issues such as high registration load that may be encountered when the RA is too small.

[0099] FIG. 9 is a schematic block diagram of a network node 900 according to some embodiments of the present disclosure. Optional functionality is represented by dashed boxes. The network node 900 may, for example, be a base station 302 or 306 or another network node that performs all or a portion of the functionality of the base station 302 or gNB described herein. In some embodiments, the network node 900 performs one or more functions of a 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. Additionally, 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, or be part of, air interface circuitry. In some embodiments, the wireless unit 910 is external to the control system 902 and is connected to the control system 902, for example, via a wired connection (e.g., an optical cable). However, in some other embodiments, the wireless unit 910 and potentially the antenna 916 are integrated with the control system 902. The 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 in software that is stored, for example, in the memory 906 and executed by the one or more processors 904.

[0100] 10 is a schematic block diagram illustrating a virtualized embodiment of a network node 900 in accordance with some embodiments of the present disclosure. This description is equally applicable to radio access nodes and other types of network nodes. Furthermore, other types of network nodes may have a similar virtualization architecture. Again, optional functionality is represented by dashed boxes.

[0101] As used herein, a "virtualized" network node is an implementation of network node 900 in which at least a portion of the functionality of network node 900 is implemented as virtual component(s) (e.g., via virtual machine(s) running on physical processing node(s) in the network). As shown, in this example, network node 900 may include a control system 902 and / or one or more radio units 910, as described above. Control system 902 may be connected to radio unit(s) 910 via, for example, optical cables or the like. Network node 900 includes one or more processing nodes 1000 coupled to or included as part of a network 1002. If present, control system 902 or radio unit(s) is / are connected to processing node(s) 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 functionality 1010 of the network node 900 described herein is implemented in one or more processing nodes 1000, or distributed across one or more processing nodes 1000 and control system 902 and / or radio unit 910 in any desired manner. In some particular embodiments, some or all of the functionality 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 appreciated 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 functionality 1010. Notably, in some embodiments, the control system 902 may not be included, in which case the radio unit 910 communicates directly with the processing node 1000 via an appropriate network interface.

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

[0104] 11 is a schematic block diagram of a network node 900 in accordance with 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 described herein. This description is equally applicable to the processing node 1000 of FIG. 10, where the modules 1100 may be implemented in one of the processing nodes 1000, or may be distributed across multiple processing nodes 1000, and / or may be distributed across the processing nodes 1000 and the control system 902.

[0105] 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., a CPU, an ASIC, an 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 radio front-end circuitry connected to the antenna 1212 configured to condition signals communicated between the antenna 1212 and the processor 1202, as will be understood by those skilled in the art. The processor 1202 is sometimes referred to herein as a processing circuit. The transceiver 1206 is also sometimes referred to herein as a radio circuit. In some embodiments, the functionality of the wireless communication device 1200 described above may be implemented, fully or partially, in software, for example, stored in the memory 1204 and executed by the processor(s) 1202. It should be noted that wireless communication device 1200 may include additional components not shown in FIG. 12 , such as, for example, one or more user interface components (e.g., an input / output interface including a display, buttons, a touchscreen, a microphone, a speaker, etc., and / or any other components for enabling input of information into wireless communication device 1200 and / or output of information from wireless communication device 1200, a power source (e.g., a battery and associated power circuitry), etc.

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

[0107] 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 functionality of the wireless communication device 1200 described herein.

[0108] 14, according to one embodiment, a communications system includes a telecommunications network 1400, such as a 3GPP-type cellular network, comprising 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 Bs, eNBs, gNBs, or other types of wireless access points (APs), each defining a corresponding coverage area 1408A, 1408B, 1408C. Each base station 1406A, 1406B, 1406C can be connected to the core network 1404 via a wired or wireless connection 1410. A first UE 1412 located in the coverage area 1408C is configured to wirelessly connect to or be paged by the corresponding base station 1406C. A second UE 1414 within the coverage area 1408A can wirelessly connect to the corresponding base station 1406A. Although multiple UEs 1412, 1414 are shown in this example, the disclosed embodiments are equally applicable to situations where a single UE is within the coverage area or where a single UE is connected to a corresponding base station 1406.

[0109] The telecommunications network 1400 is itself connected to a host computer 1416, which may be embodied in 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 under the ownership or control of a service provider, or may be operated by or on behalf of the 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 may go through an optional intermediate network 1422. The intermediate network 1422 may be one of a public, private, or hosted network, or a combination of two or more thereof; the intermediate network 1422, if present, may be a backbone network or the Internet; in particular, the intermediate network 1422 may comprise two or more subnetworks (not shown).

[0110] The communication system of FIG. 14 , as a whole, enables connectivity between the connected UEs 1412, 1414 and a host computer 1416. The connectivity may 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 via the OTT connection 1424 using the access network 1402, the core network 1404, any intermediate networks 1422, and possible additional infrastructure (not shown) as intermediaries. The OTT connection 1424 may be transparent, in the sense that the participating communication devices through which the OTT connection 1424 passes are unaware of the routing of the uplink and downlink communications. For example, the base station 1406 does not need to be informed or aware of the past routing of incoming downlink communications with data originating from the host computer 1416 to be forwarded (e.g., handed over) to the connected UE 1412. Similarly, the base station 1406 does not need to be aware of the future routing of outgoing uplink communications from the UE 1412 to the host computer 1416 .

[0111] Referring now to FIG. 15 , an exemplary embodiment will be described in accordance with the embodiments of the UE, base station, and host computer discussed in the previous paragraphs. In communication system 1500, host computer 1502 comprises hardware 1504 including communication interface 1506 configured to establish and maintain wired or wireless connections with interfaces of different communication devices of communication system 1500. Host computer 1502 further comprises processing circuitry 1508, which may have storage and / or processing capabilities. In particular, processing circuitry 1508 may comprise one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. Host computer 1502 further comprises software 1510 stored on or accessible by host computer 1502 and executable by processing circuitry 1508. Software 1510 includes host application 1512. The host application 1512 may be operable to provide services to a remote user, such as the UE 1514, connecting via an OTT connection 1516 that terminates at the UE 1514 and the host computer 1502. In providing services to the remote user, the host application 1512 may provide user data that is transmitted using the OTT connection 1516.

[0112] The communications system 1500 further includes a base station 1518 provided within the telecommunications system and comprising hardware 1520 that enables communication with the host computer 1502 and the UE 1514. The hardware 1520 may include a communications interface 1522 for setting up and maintaining wired or wireless connections with interfaces of different communications devices of the communications 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 FIG. 15 ) served by the base station 1518. The communications interface 1522 may be configured to facilitate a connection 1528 to the host computer 1502. The connection 1528 may be direct or may pass through a core network of the telecommunications system (not shown in FIG. 15 ) and / or one or more intermediate networks external to the telecommunications system. In the illustrated embodiment, the hardware 1520 of the base station 1518 further includes processing circuitry 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 has software 1532 stored internally or accessible via an external connection.

[0113] The communications system 1500 further includes the previously 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 a 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 combinations thereof (not shown) adapted to execute instructions. The UE 1514 further includes software 1540 stored on 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, with the support of the host computer 1502, may be operable to provide services to a human or non-human user via the UE 1514. In the host computer 1502, a running host application 1512 can communicate with a running client application 1542 via an OTT connection 1516 that terminates at the UE 1514 and the host computer 1502. In providing a service 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 request data and user data. The client application 1542 can interact with the user to generate the user data that it provides.

[0114] It should be noted 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, 1406C, and one of the UEs 1412, 1414 of Figure 14, respectively. That is, 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] 15, the OTT connection 1516 is depicted abstractly to show communication between the host computer 1502 and the UE 1514 via a base station 1518 and the precise routing of messages through these devices without explicitly referencing any intermediate devices. The network infrastructure can determine the routing, which can be configured to be hidden from the UE 1514, the service provider operating the host computer 1502, or both. While the OTT connection 1516 is active, the network infrastructure can further decide to dynamically change the routing (e.g., based on load balancing considerations or network reconfiguration).

[0116] The wireless 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 service provided to the UE 1514 using the OTT connection 1516 of which the wireless connection 1526 forms the last segment.

[0117] Measurement procedures may be provided for the purpose of monitoring data rates, latency, and other factors that one or more embodiments improve. There may further be optional network functionality for reconfiguring the OTT connection 1516 between the host computer 1502 and the UE 1514 in response to fluctuations in the measurement results. The measurement procedures and / or network functionality 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 communication devices through which the OTT connection 1516 passes, and the sensors may participate in the measurement procedures by providing values ​​of the monitored quantities exemplified above, or by providing values ​​of other physical quantities from which the software 1510, 1540 can calculate or estimate the monitored quantities. Reconfiguration of the OTT connection 1516 can include message formats, retransmission settings, preferred routing, etc., and the reconfiguration need not affect the base station 1518 and may be unknown or imperceptible to the base station 1518. Such procedures and functions are known in the art and may be practiced. In particular embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation time, latency, etc., at the host computer 1502. Measurements may be implemented in that the OTT connection 1516 is used to send messages, particularly empty or “dummy” messages, while the software 1510 and 1540 monitors propagation times, 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, logic processing circuits, and other digital hardware, such as digital signal processors (DSPs), dedicated digital logic, etc. The processing circuits may be configured to execute program code stored in memory, which may include one or several types of memory, such as read-only memory (ROM), random access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. The program code stored in memory includes program instructions for implementing one or more telecommunications and / or data communication protocols and instructions for performing one or more of the techniques described herein. In some embodiments, the processing circuits may be used to cause each functional unit to perform corresponding functions according to one or more embodiments of the present disclosure.

[0119] Although the processes in the figures may indicate a particular order of operations performed by some embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform operations in a different order, combine some operations, overlap some operations, etc.).

[0120] Embodiment

[0121] Group A Embodiments

[0122] Embodiment 1: A method performed by a user equipment (UE) (312) for accessing a network slice, the method including one or more of: requesting network slice assistance (702) during registration with a network node (900); receiving network slice assistance from the network node (900) indicating access to a first network slice in a first tracking area (TA) that is not an entire registration area (RA); and accessing the first network slice in the first TA (706).

[0123]

[0023] Embodiment 2: The method of embodiment 1, wherein requesting network slice assistance (702) includes including a requested network slice selection assistance information (NSSAI) information element (IE) in a registration request message, and receiving network slice assistance (704) from the network node (900) includes receiving an allowed NSSAI IE, a rejected NSSAI IE, or both the allowed NSSAI IE and the rejected NSSAI IE in a registration accept message from the network node.

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

[0125] Embodiment 4: The method of any one of embodiments 1 to 3, wherein receiving network slicing support from the network node (704) includes receiving an indication of which network slicing is allowed in each TA of the RA.

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

[0127] Embodiment 6: The method of embodiment 4 or 5, wherein an indication of which network slices are allowed in each TA of the RA is received in an NSSAI IE allowed per TA.

[0128] Embodiment 7: The method of 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 allowed in the second TA.

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

[0130]

[0023] Embodiment 9: The method of any one of embodiments 1 to 8, wherein receiving network slicing support from the network node (704) includes receiving an indication of which network slicing is not allowed in each TA of the RA.

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

[0132] Embodiment 11: The method of embodiment 9 or 10, wherein an indication of which network slices are not allowed in each TA of the RA is received in a rejected NSSAI per TA IE.

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

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

[0135]

[0033] Embodiment 14: The method of any one of embodiments 1 to 13, wherein receiving network slice assistance from a network node (704) includes receiving an indication that the first network slice is not available in the current TA.

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

[0137]

[0033] Embodiment 16: A user equipment (UE) (312) configured to communicate with a network node (900) and comprising a radio interface and processing circuitry configured to perform the method of any of the previous embodiments.

[0138] Group B Embodiments

[0139] Embodiment 17: A method performed by a network node (900) for heterogeneous slice deployment in a registration area (RA), comprising one or more of: receiving a request for network slice assistance from a user equipment (UE) (312) (802); determining that the UE is authorized 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 accessing the first network slice in the first TA that is not the entire RA (806).

[0140]

[0022] Embodiment 18: The method of embodiment 17, wherein receiving a request for network slicing assistance (802) comprises receiving a requested network slice selection assistance information (NSSAI) information element (IE) in a registration request message, and providing network slicing assistance to the UE (312) (806) comprises including an allowed NSSAI IE, a rejected NSSAI IE, or both the allowed NSSAI IE and the rejected NSSAI IE in a registration accept message to the UE.

[0141]

[0082] Embodiment 19: The method of embodiment 17 or 18, further comprising receiving (800) from the UE (312) an indication that the UE is capable of supporting a slice deployment that is not available across the RA.

[0142] Embodiment 20: The method of embodiment 17 or 18, wherein if the network node does not have an indication that the UE is capable of supporting a slice deployment that is not available throughout the RA, providing network slice support to the UE (806) comprises indicating that the UE is not authorized to access the first network slice in the RA.

[0143] Embodiment 21: The method of any one of embodiments 17 to 20, wherein determining (804) that the UE is permitted to access a first network slice in a first TA that is not the entire RA includes 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.

[0144]

[0082] Embodiment 22: The method of any one of embodiments 17 to 21, wherein providing network slice assistance to the UE (806) includes providing an indication of which network slices are allowed in each TA of the RA.

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

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

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

[0148]

[0082] Embodiment 26: The method of embodiment 22 or 23, wherein the UE is allowed access to the first network slice in the second TA with a reduced quality of service (QoS) when the first network slice is not indicated as allowed in the second TA.

[0149]

[0082] Embodiment 27: The method of any one of embodiments 17 to 26, wherein providing network slice assistance to the UE (806) includes providing an indication of which network slices are not allowed in each TA of the RA.

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

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

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

[0153] Embodiment 31: The method of any one of embodiments 27 to 29, wherein the UE is allowed access to the first network slice in the second TA with a reduced quality of service (QoS) when the first network slice is indicated as not being allowed in the second TA.

[0154]

[0039] Embodiment 32: The method of any one of embodiments 17 to 31, wherein providing network slice assistance to the UE (806) includes providing an indication that the first network slice is not available in the current TA.

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

[0156]

[0033] Embodiment 34: A network node (900) configured to communicate with a user equipment (UE) (312), the network node comprising processing circuitry configured to perform the method of any of the preceding embodiments.

[0157] At least some of the following abbreviations may be used in this disclosure: In case of conflict between abbreviations, the usage above shall prevail. If listed multiple times below, the first listing shall prevail over subsequent listings. 3GPP 3rd 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 Features 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 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 Elements 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-Access Tier NEF network publishing function NF Network Function NG Next generation NG-RAN Next Generation Radio 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 Exposure Function SMF Session Management Facility S-NSSAI Single Network Slice Selection Assistance Information TA Tracking Area TAI Tracking Area Information TCI Transmit Configuration 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 Function

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

Claims

1. A method performed by a user equipment (UE) (312) for accessing a network slice, comprising: Requesting network slicing support (702) during registration with a network node (900); Receiving network slice assistance from the network node indicating access to a first network slice in a first tracking area (TA) other than the entire registration area (RA) (704); Accessing the first network slice in the first TA (706); A method comprising:

2. 10. The method of claim 1, Requesting network slice assistance (702) includes including a requested network slice selection assistance information (NSSAI) information element (IE) in a registration request message; receiving (704) network slicing assistance from the network node (900) includes receiving at least one of an allowed NSSAI IE and a rejected NSSAI IE in a registration accept message from the network node.

3. 3. The method of claim 1 or 2, further comprising the UE indicating to the network node that it is capable of supporting slice deployments that are not available across the RA.

4. 4. The method according to claim 1, wherein receiving network slicing assistance from the network node (704) comprises receiving an indication of which network slicing is allowed in which target area (TA) of the RA.

5. 5. The method of claim 4, wherein the indication of which network slices are allowed in which TAs of the RA is received in the allowed NSSAI IE.

6. 5. The method of claim 4, wherein the indication of which network slices are allowed in which TAs of the RA is received in an Allowed NSSAI IE per TA IE for slices that are not available in all TAs of the RA.

7. 7. The method according to claim 4, further comprising: not accessing the first network slice in the second TA if the first network slice is not indicated as allowed in the second TA.

8. 8. The method according to claim 1, wherein receiving (704) network slicing assistance from the network node comprises receiving an indication of which network slicing is not allowed in which TA of the RA.

9. 9. The method of claim 8, wherein the indication of which network slices are not allowed in which TAs of the RA is received in one or more of 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.

10. 10. The method of claim 1, wherein receiving (704) network slice assistance from the network node comprises receiving an indication that the first network slice is not available in a current TA.

11. 11. The method of claim 10, wherein accessing (706) the first network slice in the first TA comprises: entering the first TA; Requesting a service provided by the first network slice; receiving a rejection with a cause value of "S-NSSAI not available in current tracking area"; A method comprising:

12. 12. A user equipment (UE) (312) configured to communicate with a network node (900), the UE comprising a radio interface and processing circuitry configured to perform the method of any one of claims 1 to 11.

13. A method performed by a network node (900) for heterogeneous slice deployment in a registration area (RA), comprising: Receiving a request for network slicing support from a user equipment (UE) (312) (802); Determining (804) that the UE is authorized to access a first network slice in a first tracking area (TA), which is not an entire RA; providing network slice support to the UE according to accessing the first network slice in the first TA, which is not the entire RA (806); A method comprising:

14. 14. The method of claim 13, Receiving (802) the request for network slice assistance includes receiving a requested network slice selection assistance information (NSSAI) information element (IE) in a registration request message; providing (806) network slicing assistance to the UE (312) includes including at least one of an allowed NSSAI IE and a rejected NSSAI IE in a registration accept message to the UE.

15. 15. The method of claim 13 or 14, further comprising receiving (800) an indication from the UE (312) that the UE is capable of supporting slice deployment that is not available across the RA.

16. 15. The method of claim 13 or 14, wherein, when the network node does not have an indication that the UE is capable of supporting a slice deployment that is not available across the RA, providing network slice assistance to the UE (806) comprises indicating that the UE is not authorized to access the first network slice in the RA.

17. 17. The method according to claim 13, wherein determining (804) that the UE is allowed to access the first network slice in the first TA that is not the entire RA comprises: determining that an area covered by the first network slice is smaller than the entire RA; configuring the first TA to coincide with the area covered by the first network slice; A method comprising:

18. 18. The method of claim 13, wherein providing network slice assistance to the UE (806) comprises providing an indication of which network slices are allowed in which target assignments of the RA.

19. 19. The method of claim 18, wherein the indication of which network slices are allowed in which TAs of the RA is provided in the allowed NSSAI IE.

20. 19. The method of claim 18, wherein the indication of which network slices are allowed in which TAs of the RA is provided in an Allowed NSSAI IE per TA IE for slices that are not available in all TAs of the RA.

21. 20. The method of claim 18 or 19, wherein if the 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.

22. 22. The method of claim 13, wherein providing network slicing assistance to the UE (806) comprises providing an indication of which network slicing is not allowed in which target area (TA) of the RA.

23. 23. The method of claim 22, wherein the indication of which network slices are not allowed in which TAs of the RA is provided in one or more of 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.

24. 24. The method of claim 13, wherein providing network slice assistance to the UE (806) comprises providing an indication that the first network slice is not available in a current TA.

25. 25. The method of claim 24, receiving, from the UE, a request for a service provided by the first network slice; providing a rejection with a cause value of "S-NSSAI not available in current tracking area" to the UE; A method comprising:

26. A network node (900) configured to communicate with a user equipment (UE) (312), the network node comprising processing circuitry configured to perform the method of any one of claims 13 to 25.

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