Network initiated slice selection in wireless communication networks

Abstract

The present disclosure provides a method and apparatus for network initiated slice selection that include receiving a first message instructing the AMF to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF); modifying an allowed network slice assistance information (NSSAI) for the UE to exclude a single-NSSAI (S-NSSAI) identifying the first network slice and include a S-NSSAI identifying a second network slice; and transmitting a second message to the UE that comprises the modified allowed NSSAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NSSAI.

Description

NETWORK INITIATED SLICE SELECTION IN WIRELESS COMMUNICATIONNETWORKSRELATED APPLICATIONS

[0001] This patent application claims the benefit of priority of Indian Provisional Patent Application No. 202441009740 filed February 13, 2024, which is hereby incorporated by reference as if reproduced in its entirety.FIELD OF TECHNOLOGY

[0002] The present disclosure relates to network initiated slice selection in a wireless communication networks.BACKGROUND

[0003] Network slicing enables network resources of a physical network to be allocated into different, independent, logical, or virtual, networks, referred to as “network slices”. Each network slice is end-to-end 5G network that may be isolated from other network slices. Each network slice can deliver one or more services. The advantage of having network slices is that each network slice may be configured to meet the particular network requirements in terms of, for example, data rates, reliability, latency, and security requirements. Rather than a one-size fit all network, the different network slices provided in a 5G network, support different use cases or serve different industries that each have different network requirements while utilizing a single physical network.

[0004] Developments in network slicing in communication networks are desirable.SUMMARY

[0005] According to one aspect of an embodiment, the present disclosure provides a method for an access management function (AMF) of a communication network to initiate network initiated slice selection, the method includes receiving a first message instructing the AMF to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF), modifying an allowed network slice assistanceinformation (NSSAI) for the UE to exclude a single-NSSAI (S-NSSAI) identifying the first network slice and include a S-NSSAI identifying a second network slice, and transmitting a second message to the UE that comprises the modified allowed NSSAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NSSAI.

[0006] In an example, the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

[0007] In an example, the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

[0008] In an example, the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

[0009] In an example, the first network slice and the second network slice are included in a bundle service.

[0010] According to another aspect of an embodiment, the present disclosure provides an apparatus that includes at least one processor, and at least one memory storing instructions of an access management function (AMF), wherein when the instructions are executed by the at least one processor, cause the apparatus to receive a first message instructing the apparatus to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF), modify an allowed network slice assistance information (NSSAI) for the UE to exclude a single-NSSAI (S-NSSAI) identifying the first network slice and include a S-NSSAI identifying a second network slice, and transmit a second message to the UE that comprises the modified allowed NSSAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NSSAI.

[0011] In an example, the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

[0012] In an example, the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

[0013] In an example, the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

[0014] In an example, the first network slice and the second network slice are included in a bundle service.

[0015] According to another aspect of an embodiment, the present disclosure provides a computer-readable medium storing instructions of an access management function (AMF), wherein when the instructions are executed by at least one processor of an apparatus, cause the apparatus to receive a first message instructing the apparatus to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF), modify an allowed network slice assistance information (NS SAI) for the UE to exclude a single-NSSAI (S-NSSAI) identifying the first network slice and include a S-NSSAI identifying a second network slice, and transmit a second message to the UE that comprises the modified allowed NSSAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NSSAI.

[0016] In an example, the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

[0017] In an example, the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

[0018] In an example, the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

[0019] In an example, the first network slice and the second network slice are included in a bundle service.

[0020] According to another aspect of an embodiment, the present disclosure provides a method for an access management function (AMF) of a communication network to initiate network initiated slice selection, the method includes receiving a first message instructing the AMF to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF), determining whether the UE is capable of network slice replacement based on UE capabilities provided by the UE during registration of the UE with the communication network, performing at least one of the following in response to determining that the UE is capable of network slice replacement, transmitting to the UE a second message that instructs the UE to perform network slice replacement of the first network slice with a second network slice, or in response to determining that the UE is not capable of network slice replacement modifying an updated allowed network slice assistance information (NS SAI) for the UE to exclude a single-NSSAI (S-NSSAI) of the first network slice and include a S-NSSAI of the second network slice, and transmitting a third message to the UE that comprises the modified allowed NS SAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NS SAI.

[0021] In an example, the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE in response to determining that the first UE is configured capable of network slice replacement includes the application information for the specific application for the UE to perform replacement of the first network slice with the second network slice for the specific application only, and the third message transmitted to theUE in response to determining that the UE is UE is not capable of network slice replacement includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

[0022] In an example, the method further includes in response to determining that the UE is configured to perform network slice replacement, transmitting a fourth message to a session management function (SMF) of the communication network that includes the application information for the specified application and instructs the SMF to perform network slice replacement for the UE for the specific application.

[0023] In an example, the method further includes in response to determining that the UE is not capable of network slice replacement, transmitting a command instructing an application function of an application server to deactivate a network initiated slice selection function for the UE.

[0024] In an example, the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

[0025] In an example, the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

[0026] In an example, the first network slice and the second network slice are included in a bundle service.

[0027] According to another aspect of an embodiment, the present disclosure provides an apparatus that includes at least one processor, and at least one memory storing instructions of an access management function (AMF), wherein when the instructions are executed by the at least one processor, cause the apparatus to receive a first message instructing the apparatus to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF), determine whether the UE is capable of network slice replacement based on UE capabilities provided by the UE during registration of the UE with the communication network, perform at least one of the following: in response to determining that the UE is capable of network slice replacement, transmit to the UE a secondmessage that instructs the UE to perform network slice replacement of the first network slice with a second network slice, or in response to determining that the UE is not capable of network slice replacement modify an updated allowed network slice assistance information (NSSAI) for the UE to exclude a single-NSSAI (S-NSSAI) of the first network slice and include a S-NSSAI of the second network slice, and transmit a third message to the UE that comprises the modified allowed NSSAI to the UE and a command instructing the UE to reevaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NSSAI.

[0028] In an example, the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE in response to determining that the first UE is configured capable of network slice replacement includes the application information for the specific application for the UE to perform replacement of the first network slice with the second network slice for the specific application only, and the third message transmitted to the UE in response to determining that the UE is UE is not capable of network slice replacement includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

[0029] In an example, when the instructions are executed by the at least one processor, further cause the apparatus to, in response to determining that the UE is configured to perform network slice replacement, transmit a fourth message to a session management function (SMF) of the communication network that includes the application information for the specified application and instructs the SMF to perform network slice replacement for the UE for the specific application.

[0030] In an example, when the instructions are executed by the at least one processor, further cause the apparatus to, in response to determining that the UE is not capable of network slice replacement, transmitting a command instructing an application function of an application server to deactivate a network initiated slice selection function for the UE.

[0031] In an example, the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

[0032] In an example, the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

[0033] In an example, the first network slice and the second network slice are included in a bundle service.

[0034] According to another aspect of an embodiment, the present disclosure provides a computer-readable medium storing instructions of an access management function (AMF), wherein when the instructions are executed by at least one processor of an apparatus, cause the apparatus to receive a first message instructing the apparatus to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF), determine whether the UE is capable of network slice replacement based on UE capabilities provided by the UE during registration of the UE with the communication network, perform at least one of the following: in response to determining that the UE is capable of network slice replacement, transmit to the UE a second message that instructs the UE to perform network slice replacement of the first network slice with a second network slice, or in response to determining that the UE is not capable of network slice replacement modify an updated allowed network slice assistance information (NS SAI) for the UE to exclude a single-NSSAI (S-NSSAI) of the first network slice and include a S-NSSAI of the second network slice, and transmit a third message to the UE that comprises the modified allowed NSSAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NSSAI.

[0035] In an example, the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE in response to determining that the first UE is configured capable of network slice replacement includes the application information for the specific application for the UE to perform replacement of the first network slice with the second network slice for the specific application only, and the third message transmitted to the UE in response to determining that the UE is UE is not capable of network slice replacement includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

[0036] In an example, when the instructions are executed by the at least one processor, further cause the apparatus to, in response to determining that the UE is configured to perform network slice replacement, transmit a fourth message to a session management function (SMF) of the communication network that includes the application information for the specified application and instructs the SMF to perform network slice replacement for the UE for the specific application.

[0037] In an example, when the instructions are executed by the at least one processor, further cause the apparatus to, in response to determining that the UE is not capable of network slice replacement, transmitting a command instructing an application function of an application server to deactivate a network initiated slice selection function for the UE.

[0038] In an example, the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

[0039] In an example, the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

[0040] In an example, the first network slice and the second network slice are included in a bundle service.

[0041] According to another aspect of an embodiment, the present disclosure provides a method for a user equipment (UE) to perform network initiated slice selection, the method including receiving from a communication network UE route selection policy (URSP) rules in which a first network slice of the communication network is prioritized over a second network slice of the communication network, wherein the UE is subscribed to the first and second network slices, receiving from an access management function (AMF) of the communication network a first allowed network slice assistance information (NS SAI) that includes a single- NSSAI (S-NSSAIA) identifying the first network slice, transmitting a request to the communication network for establishment of a first data protocol unit (PDU) session on the first network slice based on the first URSP rules and the first allowed NS SAI, receiving from the AMF a second allowed NSSAI that includes a S-NSSAI identifying the second network slice and does not include the S-NSSAI identifying the first network slice, receiving from theAMF a command to re-evaluate the URSP rules, and transmitting a request to communication network for establishing a second PDU session on the second network slice according to the URSP rules and the second allowed NSSAI.

[0042] In an example, receiving the command to re-evaluate the URSP rules further comprises receiving from the AMF application information for a specific application of the UE, and transmitting the request to the communication network for establishment of the new PDU session on the second network slice comprises transmitting a request for establishment of a new PDU session on the second slice for the specific application only.

[0043] In an example, the first network slice and the second network slice are included in a bundle service.

[0044] According to another aspect of an embodiment, the present disclosure provides an apparatus that includes at least one processor, and at least one memory storing instructions of a user equipment (UE), wherein when the instructions are executed by the at least one processor, cause the apparatus to receive from a communication network UE route selection policy (URSP) rules in which a first network slice of the communication network is prioritized over a second network slice of the communication network, wherein the apparatus is subscribed to the first and second network slices, receive from an access management function (AMF) of the communication network a first allowed network slice assistance information (NSSAI) that includes a single-NSSAI (S-NSSAIA) identifying the first network slice, transmit a request to the communication network for establishment of a first data protocol unit (PDU) session on the first network slice based on the first URSP rules and the first allowed NSSAI, receive from the AMF a second allowed NSSAI that includes a S-NSSAI identifying the second network slice and does not include the S-NSSAI identifying the first network slice, receive a command to re-evaluate the URSP rules, and transmit a request to communication network for establishing a second PDU session on the second network slice according to the URSP rules and the second allowed NSSAI.

[0045] In an example, the instructions, when executed by the at least one processor, cause the apparatus to receive the command to re-evaluate the URSP rules include instructions, when executed by the at least one processor, cause the apparatus to receive application information for a specific application of the apparatus, and the instructions, when executed by the at leastone processor, cause the apparatus to transmit the request to the communication network for establishment of the new PDU session on the second network slice include instructions, when executed by the at least one processor, cause the apparatus to transmit a request for establishment of a new PDU session on the second slice for the specific application only.

[0046] In an example, the first network slice and the second network slice are included in a bundle service.

[0047] According to another aspect of an embodiment, the present disclosure provides a computer-readable medium storing instructions of a user equipment (UE), wherein when the instructions are executed by at least one processor of an apparatus, cause the apparatus to receive from a communication network UE route selection policy (URSP) rules in which a first network slice of the communication network is prioritized over a second network slice of the communication network, wherein the apparatus is subscribed to the first and second network slices, receive from an access management function (AMF) of the communication network a first allowed network slice assistance information (NS SAI) that includes a single- NSSAI (S-NSSAIA) identifying the first network slice, transmit a request to the communication network for establishment of a first data protocol unit (PDU) session on the first network slice based on the first URSP rules and the first allowed NS SAI, receive from the AMF a second allowed NSSAI that includes a S-NSSAI identifying the second network slice and does not include the S-NSSAI identifying the first network slice, receive a command to reevaluate the URSP rules, and transmit a request to communication network for establishing a second PDU session on the second network slice according to the URSP rules and the second allowed NSSAI.

[0048] In an example, the instructions, when executed by the at least one processor, cause the apparatus to receive the command to re-evaluate the URSP rules include instructions, when executed by the at least one processor, cause the apparatus to receive application information for a specific application of the apparatus, and the instructions, when executed by the at least one processor, cause the apparatus to transmit the request to the communication network for establishment of the new PDU session on the second network slice include instructions, when executed by the at least one processor, cause the apparatus to transmit a request for establishment of a new PDU session on the second slice for the specific application only.

[0049] In an example, the first network slice and the second network slice are included in a bundle service.

[0050] The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal ) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached figures.

[0052] FIG. 1 is a schematic diagram showing a communication network in accordance with an aspect of an embodiment.

[0053] FIG. 2 is a schematic diagram showing network slices in a communication network in accordance with an aspect of an embodiment.

[0054] FIG. 3 and FIG. 5 are flowcharts showing methods in accordance with example embodiments.

[0055] FIG. 6 is a schematic diagram showing components of one or more of the example embodiments.

[0056] FIG. 7 and FIG. 8 are diagrams showing operations in a procedure in accordance with embodiments.DETAILED DESCRIPTION

[0057] For simplicity and clarity of illustration, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Numerous details are set forth to provide an understanding of the examples described herein. The examples may be practiced without these details. In other instances, well-known methods, procedures, and components are not described in detail to avoid obscuring the examples described. The description is not to be considered as limited to the scope of the examples described herein.

[0058] The present disclosure relates to network-initiated slice selection in a communicationnetwork, such as a communication network operating in accordance with the 3rd Generation Partnership Program (3GPP) technical specifications for 5G which may be referred to herein as a “5G network”. Network- initiated slice selection is performed by a policy control function (PCF) of the communication network in response to a request originating from an application function (AF) hosted on an application server to replace a first network slice with a second network slice.

[0059] Reference is first made to FIG. 1 , which shows a schematic representation of a communication network 100 that is configured to enable a user equipment (UE) 102 to communicate with one or more application servers (AS) 110 hosting third party application functions (AF) 112 via a data network 104. The communication network 100 comprises a radio access network 106 (e.g., a 5G-RAN otherwise referred to as a next generation (NG)- RAN) and a core network 108 (e.g., a 5G core network (5GC)) that operates based on the 5th generation radio access technology described in the 3rd Generation Partnership Project (3 GPP) standard for new radio, which may be referred to herein as the “3 GPP 5G standard”.

[0060] The radio access network 106 comprises one or more radio access network (RAN) nodes (otherwise referred to as base stations), such as a gNodeB (gNB). A radio access network node may comprise a central unit (e.g., gNB-CU) and one or more distributed units (e.g., one or more gNB-DUs) linked to the central unit (e.g., gNB-CU) by an Fl interface.

[0061] The core network 108 has a service-based architecture and comprises a plurality of network functions, including control plane network functions (NFs) and user plane network functions. The control plane network functions include an access and mobility function (AMF) 114, a trusted application function (AF) 116, an authentication server function (AUSF) 118, a binding support function (BSF) 120, a network exposure function (NEF) 122, a network slicing selection function (NSSF) 124, a policy control function (PCF) 126, a session management function (SMF) 128, a unified data repository (UDR) 130, and a united data repository (UDM) 134. The user plane network functions include the user plane function (UDF) 132. Other control plane network functions of the core network 108, such as a charging function (CHF), a network repository function (NRF), a network data analytics function (NWDAF), are not shown for ease of illustration. The functionalities of the network functions of the core network are well known to a person skilled in the art and hence are not described indetail. Although only one UPF 132 is shown in FIG. 1, a core network 108 may include a plurality of user plane functions (UPFs).

[0062] The AF 112 may be a non-trusted application function that must communication with the control plane network functions of the network core 108 via the NEF 122, whereas because AF 116 is a trusted AF, it is able to communicate with control plane network functions of the network core 108 directly, i.e., not via the NEF 122, and therefore is schematically shown as inside the core network 108 in FIG. 1.

[0063] Each control plane network function of the core network 108 may provide one or more services to other control plane network functions of the core network 108 and expose their one or more services through service based interfaces (SBIs) that may be implemented as application programming interfaces (APIs). Each control plane NF can also register itself and the services it supports (e.g., the services it offers to other network functions) to the NRF of the core network 108. The NRF may be used by any network function to discover other network functions (or instances of NFs) and the services the other NFs support (e.g., services the other NFs provide). Any control plane NF may consume (e.g., use) the services provided and exposed by another control plane NF. A control plane NF that consumes a service of another network function is generally referred to as a network function service consumer. A control plane network function that provides and exposes one or more of its services is referred to as a network function service producer.

[0064] In order to support different network requirements that may be desired for different third party applications or services, that may have different network requirements, multiple “network slices” may be created on the common physical infrastructure of a communication network, such as the communication network 100 described previously.

[0065] Network slices are virtualized and independent end-to-end networks that are formed by allocating resources of a communication network, such as communication network 100, to different network slices in order to customize each network slice for a particular use or service, for example.

[0066] For example, a network slice may be configured for enhanced mobile broadband (eMBB) communications (e.g., may be configured to have a relatively large bandwidth overthe air interface of the communication network to enable large data throughput), whereas another network slice may be configured for massive machine type communication (mMTC) (e.g., may be configured for communication with a large number of internet of things (loT) devices that periodically transmit data), whereas still another network slice may be configured for ultra- reliable low latency communication (URLLC) (e.g., may be configured with extremely low latency and high reliability, and potentially high security, for use in drone control or remote robotic surgery contexts).

[0067] By allocating resources of the underlying physical communication network, such as communication network 100 described previously, network slices are configured with their own security rules and performance characteristics, within the limits imposed by the underlying physical communication network to meet the network requirements related to the context for which the network slice is created to service.

[0068] Each network slice is uniquely identified by a single-network slice selection assistance information (S-NSSAI). A particular UE, such as UE 102, may be subscribed to one or more network slices of the communication network. Subscription information of a UE is stored in a UDM, such as UDM 134, and the subscription information of a UE includes one or more S- NSSAIs of the network slices to which the UE is subscribed.

[0069] Before a UE, such as UE 102, requests establishment of a data protocol unit (PDU) session in order to effect data transfers between the UE and an application function hosted or running on an application server, such as the AF 112 on the application server 110 described previously, the UE is provided with an identifier (e.g., S-NSSAI) of each respective network slice the UE is allowed to access. The identifier of each respective network slice the UE is allowed to access is provided from an AMF, such as AMF 114, as a list of identifiers (e.g., S- NSSAI) of allowed network slices, which is generally referred to as “allowed NS SAI”. The allowed NSSAI may include one or more, up to a maximum of eight, S-NSSAIs to which the UE is subscribed to, and includes at least one default S-NSSAI. In addition, UE route selection policy (URSP) rules are provided to a UE by the PCF, such as PCF 116. The URSP rules includes a set of rules that map a set of applications to one or more S-NSSAI, which inform a UE which slice and data network name (DNN) the UE should use when requesting the establishment of a PDU session for sending traffic to and for receiving traffic from acertain application. For a particular application, the UE utilizes the set of rules included in the URSP rules and the allowed NS SAI to determine a network slice that is mapped to the particular application, then requests to establish a PDU session on that network slice. If an application is mapped to multiple S-NSSAI, the URSP rules may be used by the UE to determine which S-NSSAI is highest in priority, next highest in priority, and so forth, such that the UE request establishment of a PDU session on the network slice identified by the S- NSSAI that is highest in priority, according to the URSP rules, and that is included in the allowed NSSAI. For example, if the S-NSSAI that is highest in priority is not included in the allowed NSSAI, then the UE will check if the S-NSSAI that is next highest in priority is included in the allowed NSSAI, and so forth. The URSP rules may indicate that one of the S- NSSAI is a default network slice of the bundle service and the PDU session is to be established on the network slice indicated as a default network slice, provided that that the identifier of the default network slice (e.g., the S-NSSAI of the default network slice) is included in the allowed NSSAI.

[0070] Conventionally, a network slice that a UE is to use for communicating with an application function (e.g., for transmitting data to and for receiving data from the application function) can only be changed in very limited circumstances, for example, when the network slice becomes congested or becomes unavailable. This process for changing network slices is referred to “network slice replacement” and is set out in clause 5.15.19 of VI 8.0 3GPP TS 23.501.

[0071] In network slice replacement set out in clause 5.15.19 of V18.0 3GPP TS 23.501, either a NSSF, such as NSSF 124, or a PCF, such as PCF 126, of the communication network determines that a network slice that the UE is using has become congested or unavailable based on information from an 0AM entity or analytics received from a NWDAF . In response to determining that the network slice has become congested or unavailable, the NSSF or PCF, as the case may be, sends a notification to an AMF, such as AMF 114, or the 0AM itself notifies the AMF, that instructs the AMF perform network slice replacement. In response to the notification, the AMF sends a message to the UE that includes a mapping of the S-NSSAI that the PDU session is connected to and an alternative S-NSSAI, and the UE establishes a new PDU session using the alternative S-NSSAI.

[0072] A third party application may have more than one network slice associated with it for providing a service to UEs. The plurality of network slices that are associated with a third party application for providing a service to a UE or group of UEs is referred to as a “bundle service”. Network slices of a bundle service are configured by an operation and maintenance (0AM) entity of a communication network, such as the communication network 100. The particular network slices that are to be included in a bundle service would be provided in a service level agreement (SLA) between an operator of the communication network and the operator of the third party application.

[0073] As noted above, currently network slice replacement in communication networks is limited to circumstances in which a network slice has been determined to be congested or unavailable by the NSSF, PCF, or an 0AM entity. However, when a third party application function is associated with a bundle service, it may be desirable for the third party application function hosted or running on an application server, such as the application function 112 of the application server 110 described with reference to FIG. 1, to instruct or request a UE to change from using one network slice of the bundle service to another network slice of the bundle service.

[0074] The present disclosure provides for network initiated slice selection that enables a third party application function, such as AF 112, to request that network slice replacement. In this disclosure, network initiated slice selection refers to network slice replacement that is initiated for reasons other than because a network slice is determined to be congested or unavailable as provided in clause 5.15.19 of VI 8.0 3GPP TS 23.501, for example, because the third party application function has requested network slice replacement.

[0075] FIG. 2 shows a schematic view of an example communication network 200 which includes two network slices 202 and 204 of a bundle service associated with an application function (AF) 220 hosted on an application server 218. As discussed previously, NFs of a core network 206 and RAN resources are allocated to the network slices 202 and 204 such that network slice 202 has a plurality of control plane NFs 208 and a user plane network function, UPF 210, and network slice 204 has a plurality of control plane NFs 212 and a user plane network function, UPF 214. The core network 206 shown in the example communication network 200 has a NEF 216 that is common to both network slices 202 and 204. In otherexamples, each network slice 202 and 204 may each have its own NEF. The application server (AS) 218 includes (e.g., hosts) an AF 220 and connects to the core network 106 via a data network (DN) 222. A UE 224 communicates on the control plane with the core network 206 via the RANs 226 and 228 and communicates with the AF 220 on the user plane via the RANs 226 and 228 and the UPFs 210 and 214. Although each of the network slices 202 and 204 are shown in FIG. 2 with separate NFs and RANs, it is understood that these may be virtual NFs and RANs that may be provided by allocating resources of a shared physical infrastructure of a communication network, such as communication network 100 described previously with reference to FIG. 1.

[0076] In the example shown in FIG. 2, the identifier of network slice 202 (e.g., S-NSSAI of network slice 202) is included in the allowed NS SAI as the default slice, and there is a PDU session 230 established on the default network slice 202 between the UE 224 and the service provide by the AF 220. At some point, the AF 220 determines that the PDU session 230 should be switched from network slice 202 to network slice 204 and sends a request 232 to the NEF 216, which forwards the request 234 to the control plane NFs of the network slice 202 which then sends the command 236 to the UE 224 to request establishment of a new PDU session on network slice 204.

[0077] In the example shown, the AF 220 is a non-trusted AF 220 to the core network 206, and therefore the request 232 is sent to the NEF 216, where the AF can be authenticated, before the NEF 216 sends the request to a control plane NF at 234. However, in other examples, the AF 220 may an AF trusted by the core network 206, such as AF 112 described previously, in which examples the AF 220 may send the request 232 directly to a control plane NFs 208 rather than via the NEF 216 as shown in FIG. 2.

[0078] Referring now to FIG. 3, a flow chart showing an example method or process of performing network initiated slice selection is shown. The example method or process may be performed by a AMF of a communication network such as, for example, the AMF 114 of the communication network 100 described previously.

[0079] At 302, a first message is received at the AMF instructing the AMF to initiate for a UE, such as the UE 102 of the communication network 100 described previously, replacement of a first network slice. The first message that is received at 302 may be received as a result from arequest from an AF, such as AF 112 of the communication network 100 described previously, sent to the core network, such as the 5GC core 108 of the communication network 100.

[0080] In one example, the first message may be received at 302 from a PCF, such as the PCF 126 of the communication network 100 described previously. As described in more detail later on, the first message may be received at 302 from the PCF as a result of the AF utilizing external parameter provisioning as described in clauses 4.15.6.9.2, 4.15.6.9.3, and 4.16.6 of V18.0 3GPP TS 23.502.

[0081] In other examples, the first message may be received at the AMF at 302 from a UDR, such as the UDR 130, a NEF, such as NEF 122 described previously, or directly from an AF of an application server that is a trusted AF.

[0082] The first message may identify a second network slice that is to replace the first network slice. The first message may identify the second slice by including, for example, a S- NSSAI of the second network slice.

[0083] Optionally, when the first message does not identify the second network slice to be used to replace the first network slice, a determination of the second network slice may be made at 304. The determination at 304 may be made with reference to the subscription information of the UE.

[0084] In an example, the first request may include a service quality level that a slice must have to replace the first slice. The service quality level may, for example, indicate a quality of service parameter, or set of quality of service parameters, that an alternative slice must satisfy if it is to replace the first slice. The quality of service parameter(s) may indicate that the quality of service of the alternative slice that is to replace the first slice should be greater than or, alternatively, less than the quality of service of the first slice. In this example, the determination of the second network slice that is to replace the first network slice may be made based on the service quality level that is included in the first request to determine a second slice of the slices included in the subscription information for the UE that has or meets or satisfies the service quality level.

[0085] The determination at 304 may be made by the AMF based on an internal configuration of the AMF, or by identifying a network slice in the subscription information that has or meetsor satisfies the service quality level, or may be determined by the AMF inquiring with another NF of the communication network such as, for example, the PCF, a UDR, such as UDR 130 described previously, or the NEF.

[0086] At 306, the AMF modifies an allowed NSSAI for the UE to include a S-NSSAI for the second network slice, if it is not already included, and exclude a S-NSSAI for the first network slice. The allowed NSSAI may be a subset of the network slices included in the subscription information for a UE and indicate the network slices that the UE is allowed to use in operation.

[0087] At 308, a second message is transmitted by the AMF to the UE. The second message includes the updated allowed NSSAI. Optionally, at 310, a command instructing the UE to reevaluate the URSP rules may be transmitted to the UE. The optional command transmitted at 310 may be included in, for example, the second message transmitted at 308 transmitted by the AMF, or in a separate message. In other examples, the command instructing, or otherwise causing, the UE to re-evaluate the URSP rules may be received by a network function of the communication network other than the AMF. In response to receiving the optional command from the AMF or from any other network function, the UE may re-evaluate, or apply again, the URSP rules based on the updated allowed NSSAI.

[0088] The URSP rules may prioritize the first network slice over the second network slice, which causes the UE to initially request that a PDU session over the communication network be established on the first network slice when the first network slice is included in the allowed NSSAI. However, when the UE re-evaluates the URSP rules in view of the updated allowed NSSAI in which the first network slice is not included, i.e., it is not an allowed network slice, the UE will move to the next network slice in priority according to the URSP rules and check that the next network slice is an allowed network slice in the updated allowed NSSAI, i.e., the second slice, and will request establishing a new PDU session on the second network slice. After the new PDU session is established, the UE or the AMF may request releasing the PDU session on the first network slice.

[0089] In some examples, the second message transmitted at 308 may include application information for a specific application that causes the UE re-evaluating the URSP rules for the specific application only. For example, the first network slice may be a “non-dedicated” or“non-application specific” network slice that is utilized by more than one application of the UE simultaneously. If slice replacement is desired for only a specific application, then application information may be included that identifies the specific application that the updated allowed NS SAI pertain to, and the UE will re-evaluate the URSP rules with respect to that specific application only. In these examples, the application information may be included in the first message received at 302, in which the AF indicates a particular application of the UE for which slice replacement is desired.

[0090] In some examples, it may be desirable for the AMF to determine whether the UE is configured to perform network slice replacement. This determination may be utilized to determine the action taken by the AMF to cause the UE to operate on an alternative network slice in a network initiated slice selection procedure. In the present disclosure, the phrase “network slice replacement” is utilized to refer to network slice replacement that is performed as set out in clause 5.15.19 ofV 18.0 3GPP TS 23.501.

[0091] In network slice replacement, it is the PCF or the NSSF or the 0AM that initially triggers the network slice replacement. Because the PCF, the NSSF and 0AM have access to the capabilities of the UE, the AMF does not have to determine a capability of the UE when instructed to perform network slice replacement. Rather, it is assumed that the PCF or NSSF or 0 AM that originally initiated the network slice replacement will only do so for UEs that are capable of network slice replacement.

[0092] However, network initiated slice selection is triggered by an AF of an application server that may not know the capability of the UE for which network initiated slice selection is being requested. In this case, the AMF cannot assume that the UE is capable of the network slice change that the AMF is being requested to perform. In the present disclosure the phrase “network initiated slice selection” refers to a change of the network slice of a UE based on a request that originates with a third party AF of an application server, rather than from another NF such as the PCF, the NSSF, or the 0AM.

[0093] Referring now to FIG. 4, a flow chart showing another example method or process of performing network initiated slice selection is shown that may account for different UEs having different capabilities with respect to performing network initiated slice selection. The example method or process may be performed by an AMF of a communication network suchas, for example, the AMF 114 of the communication network 100 described previously.

[0094] At 402, a first message is received at the AMF instructing the AMF to initiate for a UE replacement of a first network slice of the communication network. Optionally, at 404, a determination of the second network slice to be used to replace the first network slice may be made. 402 and 404 may be substantially similar to 302 and 304, respectively, described previously and therefore are not further described here to avoid repetition.

[0095] At 406, the AMF determines whether the UE is capable of network slice replacement. The determination at 406 may be performed utilizing the UE capabilities information that the UE provides to the communication network during UE registration with the communication network. The UE capabilities information may be stored at the UDR, such as UDR 130 of the communication network 100 described previously. In this example, the AMF may make the determination at 406 by inquiring with the UDR regarding the capabilities of the UE.

[0096] If the UE is determined at 406 to be capable of network slice replacement, indicated by “SLICE REPLACEMENT” in FIG. 4, then the method or process proceeds to 408 and the AMF transmits a second message to the UE instructing the UE to perform network slice replacement of the first network slice with the second network slice. The second message transmitted at 408 may be generated and transmitted in accordance with network slice replacement as set out in clause 5.15.19 of V 18.0 3GPP TS 23.501.

[0097] If the UE is determined at 406 to be not capable of network slice replacement, indicated by “RE-EVALUATION” in FIG. 4, then the method or process proceeds by modifying an allowed NS SAI to include the S-NSSAI of the second network slice, if it is not already included, and exclude the S-NSSAI of the first network slice at 410, and transmitting to the UE a third message that includes the modified allowed NSSAI at 412. Optionally, a command instructing the UE to re-evaluate the URSP rules is transmitted at 413. The optional command at 413 may be included in the third message transmitted at 412, or in a separate message. 410, 412, and 413 may be substantially similar to 306, 308, and 310 described previously with reference to FIG. 3 and are not further described here to avoid repetition.

[0098] As discussed previously, in some examples the network initiated slice selection may be intended only for a specific application of the UE. Similar to the application specific networkslice replacement described previously, the second message transmitted at 408 and / or the third message transmitted at 412 may include application information for a specific application of the UE to indicate to the UE that slice replacement is to be performed for a specific application of the UE only. In this example, the first message received at 402 may include the application information for the specific application of the UE. The application information may come from a network initiated slice selection request received at the core, for example at an NEF, from the AF of an application server requesting slice change at the UE for the specific application of the UE.

[0099] In this optional example in which the second message transmitted at 408 includes application information for a specific application of the UE, at 414 the application information for the specific application of the UE is transmitted to the SMF of the communication network, such as SMF 128 of the communication network 100 described previously with reference to FIG. 1. The application information is sent to the SMF to enable the SMF to facilitate the network slice replacement for only the specific application of the UE.

[0100] In some other embodiments, if the UE is determined not to be capable of network slice replacement at 406, indicated by “DEACTIVATE” in FIG. 4, then the method or process optionally moves to 416 and a request or a command directed to the AF is transmitted that requests or instructs the AF to disable a network initiated slice selection feature for the UE, or for all UEs. The request or command may be transmitted to the AF from the AMF via one or more other NFs of the communication network, such as, for example, the PCF and / or the NEF. Disabling the network initiated slice selection function at the AF may result in the AF refraining from sending further requests for network initiated slice selection for that UE or for a group of UEs that are not capable of the requested network slice change.

[0101] Referring now to FIG. 5, a flowchart illustrating a method or process for a UE to perform re-evaluation of URSP rules after updates or modifications to allowed NS SAI are received is shown. The example method or process may be performed by a UE of a communication network such as, for example, the UE 102 of the communication network 100 described previously.

[0102] At 502, URSP rules for the UE are received in which a first network slice is prioritized over a second network slice. The URSP rules may be received from the core network of thecommunication network, such as the core 108 of the communication network 100 described previously. The URSP rules may be received by the UE during the UE registration process in which the UE registers with the communication network.

[0103] At 504, the UE receives from the AMF a first allowed NSSAI that includes a S-NSSAI for or related to the first network slice. The first allowed NSSAI may be included in subscription information for the UE that is stored in, for example, a UDR, such as the example UDR 130 of communication network 100 described previously. In some examples, the first allowed NSSAI includes a S-NSSAI for the second network slice, and in other examples the first allowed NSSAI does not include the S-NSSAI for the second network slice. The first and second network slices may be included in a bundle service in which the first network slice is designated as a default or initial slice.

[0104] At 506, the UE transmits a request for establishment of a first PDU session on the first network slice. The UE identifies the first network slice based on the URSP rules, which prioritize the first network slice, and the first allowed NSSAI, which indicates that the first network slice is allowed. In general, the UE will request establishing a PDU session on the network slice that is included in the allowed NSSAI and has the highest priority according to the URSP rules.

[0105] At 508, the UE receives from the AMF a second allowed NSSAI that includes a S- NSSAI of the second network slice and does not include the S-NSSAI of the first network slice. The second allowed NSSAI received at the UE at 508 may be substantially the same as the “modified allowed NSSAI” that are generated by the AMF at, for example, 308 of FIG. 3 or 410 of FIG. 4, based on the first allowed NSSAI and in response to receiving instructions to initiate a network initiated slice selection at the UE.

[0106] At 510, the UE receives a command that instructs the UE to re-evaluate the URSP rules. The command may be received from the AMF, or any other network function of the communication network. The command received at 510 may be received by the UE after the second allowed NSSAI is received at 508. In other example, the command may be received at substantially the same time as the second allowed NSSAI received at 508. In examples in which the command is received from the AMF, the command may be received together with the second allowed NSSAI received at 508.

[0107] At 512, the UE re-evaluates the URSP rules based on the second NSSAI in response to receiving the command at 510. The URSP rules re-evaluated at 512 may be unchanged from the URSP rules received at 502 and prioritize the first network slice over the second network slice. However, because the first network slice is not an allowed network slice included in the second allowed NSSAI, the UE then selects the second network slice which is lower in priority than the first network slice according to the URSP rules but, unlike the first network slice, is included in the second allowed NSSAI.

[0108] At 514, the UE transmits a request to the communication network for the establishment of a second PDU session on the second network slice in response to the re-evaluation of the URSP rules. In some examples, the PDU session on the first network slice may be released by request from the UE. In other examples the core network (i.e., AMF via communication with SMF) may initiate the release of the PDU session related to the first network slice.

[0109] In some examples, the second allowed NSSAI received at 508 and / or the command received at 510 may include application information for a specific application at the UE in order to perform application specific network initiated slice selection, as described previously. In these examples, the request for the establishing the second PDU session may be a request to establish a second PDU session for the specific application only. In this case, the UE may continue to operate on the first network slice for applications of the UE other than the specific application after the second PDU session is established.

[0110] Referring to FIG. 6, a schematic diagram illustrating various physical and logical components of an exemplary apparatus 600 for a communication network in accordance with an embodiment is shown. Although an example embodiment of the apparatus 600 is shown and discussed below, other embodiments may be used to implement examples disclosed herein, which may include components different from those shown. Although FIG. 6 shows a single instance of each component of the apparatus 600, there may be multiple instances of each component shown.

[0111] The apparatus 600 includes one or more processors 602, such as a central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), a field- programmable gate array (FPGA), a dedicated logic circuitry, a graphics processing unit (GPU), a tensor processing unit, a neural processing unit, a dedicated artificial intelligenceprocessing unit, a hardware accelerator, or combinations thereof. The one or more processors 602 may collectively be referred to as a processor 602.

[0112] The apparatus 600 also includes one or more memories 604 (collectively referred to as "memory 604"), which may include a volatile or non-volatile memory (e.g., a flash memory, a random-access memory (RAM), and / or a read-only memory (ROM)). The non-transitory memory 604 may store instructions for execution by the processor 602. In some embodiments, instructions 606 of an AMF or a UE described herein, such as the AMF 114 and the UE 102 of the example communication network 100, may be stored in the memory 604, and the instructions 606 may be executed by the processor 602 to perform the actions or operations of the methods or processes described herein. The memory 604 may include other instructions for execution by the processor 602, such as instructions of other network functions of a communication network, such as those described above.

[0113] The apparatus 600 may also include one or more network interfaces 608 for connecting to a network, such as a data network, or other apparatuses of the core network or the access networks described herein.

[0114] In some examples, the apparatus 600 may also include one or more electronic storage units (not shown), such as a solid state drive, a hard disk drive, a magnetic disk drive and / or an optical disk drive. In some examples, one or more datasets and / or modules may be provided by an external memory (e.g., an external drive in wired or wireless communication with the computing system 600) or may be provided by a transitory or non-transitory computer- readable medium. Examples of non-transitory computer readable media include a RAM, a ROM, an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a CD-ROM, or other portable memory storage. The storage units and / or external memory may be used in conjunction with memory 604 to implement data storage, retrieval, and caching functions of the apparatus 600.

[0115] The components of the apparatus 600 may communicate with each other via a bus. In some embodiments, the apparatus 600 may be a processing system implementing functionality of the AMF or the UE described herein, such as the AMF 114 and the UE 102 of the example communication network 100 previously described with reference to FIG. 1. In some embodiments, the apparatus 600 may be distributed computing system and may includemultiple computing devices in communication with each other over a data network, as well as optionally one or more additional components. The various operations described herein may be performed by different computing devices of a distributed computing system in some embodiments. In some embodiments, the apparatus 600 a cloud computing system or may be a virtual machine provided by a cloud computing system.

[0116] In one example, the above-described methods or processes for network initiated slice selection initiated by an initial request from an AF of or hosted on an application server may be performed by the PCF using conventional external parameter provisioning procedure, for example, the external parameter provisioning procedure for cases targeting individual UE where UE address is known to the AF set out in clause 4.15.6.9.2 of V 18.0 3GPP TS 23.502, the external parameter provisioning procedure for cases targeting individual UE where UE address is not known to the AF set out in clause 4.15.6.9.3 of VI 8.0 3GPP TS 23.502, and the external parameter provisioning for cases targeting changes per slice or service set out in clause 4.16.6 of VI 8.0 3GPP TS 23.502.

[0117] Referring now to FIG. 7, operations of a procedure in accordance with an example embodiment are shown in which network initiated slice selection is initiated by an AF 112 of an application server utilizing external parameter provisioning per network slice or service as set out in clause 4.16.6 of VI 8.0 3GPP TS 23.502. Messages may be sent between the AF 112, an NEF 702, a SMF 703, a UDR 704 at which a UDM 706 stores subscription data, the UDM 706, a PCF 708, an AMF 710, a RAN 106 and a UE 712.

[0118] In the operations shown, the AMF 710 provides the UE 713 with initial allowed NSSAI at 713. The UE 712 operates on a first network slice (illustrated as slice 1) at 714 to access a service provided by the AF 112 in accordance with URSP rules and the initial allowed NSSAI. The PDU session on the first network slice (e.g., slice 1) at 714 may have been established in any suitable manner including, for example, as described previously with reference to 502, 504, and 506 of FIG. 5. For example, the PDU session associated with 714 may have been established based on, for example, URSP rules of the UE 712 that prioritize the first network slice (e.g., slice 1) over a second network slice (e.g., slice 2) and the initial allowed NSSAI of the UE 712 that includes a S-NSSAI of the first network slice (e.g., slice 1).

[0119] At 716, the AF 112 creates a slice selection request. The AF 112 then sends a sliceselection request 716 to the NEF 702 as a Nnef_Service Parameter_Create request, or Nef_Service_Update Request, or a Nef_Service_Delete Request 718. The request 718 may include a service quality level of a network slice that is to replace the first network slice. Alternatively, the request 718 may identify a second network (e.g., illustrated as slice 2) via which AF 112 is to provide the service to the UE 712. For example, the request 718 may include an identifier of a network slice (e.g., S-NSSAI of slice 2). If the request 718 includes a service quality level, the NEF 702 may optionally determine a second network slice (e.g., slice 2) based on the service quality level based on a configuration at the NEF 702 or by querying another NF such as, for example, the UDR 704 or the PCF 708 for the identifier of the second network slice (e.g., slice 2) that satisfies the service quality level.

[0120] The NEF 702 sends a slice selection request to the UDM 706 via a Nudm SDM Get message 720. The message 720 may indicate to the UDM 706 that first network slice (e.g., slice 1) is to be replaced with the second network slice (e.g., slice 2) when an identifier of the second network slice has been determined, or may be a command to replace the first network slice (e.g., slice 1) in accordance with the service quality level.

[0121] At 722, the specific parameter requested by the AF 112, in this case the network initiated slice selection request, may be authorized, i.e., the AF 112 has been determined to be authorized to request network initiated slice selection. If the message 720 includes a service quality level, the UDR 704 may optionally determine a second network slice (e.g., slice 2) based on the service quality level based on the service quality level and the bundle information of the UE.

[0122] Optionally, the UDR 704 may perform a storing, or an updating, or a removing operation 724 to log any changes made to the UE, which may include changes to the subscription information based on the request 716.

[0123] After authorization at 722, the NEF 702 sends a response 726 to the AF 112 confirming the network slice selection request is authorized using a Nnef_Service Parameter Create response if the request 718 was a Nnef Service Parameter Create request, a Nnef_Service Parameter_Update response if the request 718 was a Nnef_ServiceParameter Update request, or a Nnef Service Parameter Delete response if the request 718 was a Nnef_Service Parameter_Delete request.

[0124] The UDR 704 sends a notification (e.g., a Nudr DM Notify notification) 728 to the PCF 708. The notification 728 may indicate to the PCF 708 that the network slice (e.g., slice 1) is to be replaced with a second network slice (e.g., slice 2), or can be a command to replace the first network slice (e.g., slice 1) in accordance with the service quality level. If the notification 728 includes a service quality level, the PCF 708 may optionally determine 730 a second network slice (e.g., slice 2) that is to replace the first network slice and a configuration at the PCF 708 or by sending a query to another NF such as, for example, the UDR 704 or the NEF 702.

[0125] In response to receiving the notification 728, the PCF 708 sends a slice replacement message 732 to the AMF 710 that includes a command instructing the AMF 710 to perform network slice replacement. If the notification 728 identifies the second network slice (e.g., slice 2) (i.e., the notification includes an identifier of the second network slice (e.g., a S- NSSAI of slice 2)), or if the PCF 708 determines the second slice (e.g., slice 2) at 730, then the command instructs or requests the AMF 710 to replace the network slice (e.g., slice 1) with the second network slice (e.g., slice 2). Otherwise, the command instructs or requests the AMF 710 to perform network slice replacement of first network slice (e.g., slice 1), in which case the AMF 710 will optionally determine the second network slice (e.g., slice 2) based on the service quality level and the configuration of the AMF 710 or by querying another NF such as, for example, the UDR 704.

[0126] In examples in which the AMF 710 is configured to determine a capability of the UE 712 as described previously with reference to FIG. 4, then the AMF 710 may optionally determine the capability of the UE 712 at 734. The optional determination at 734 may include determining whether the UE is capable of network slice replacement as described previously with reference to 406 of FIG. 4.

[0127] At 736, a modified allowed NS SAI and, optionally, a re-evaluation command, as described previously with reference to 306, 308, 310 of FIG. 3 and 410, 412, 413 of FIG. 4, or a slice replacement command from the first network slice (e.g., slice 1) to the second network slice (e.g., slice 2), as described previously with reference to 408 of FIG. 4, is sent by the AMF 710 to the UE 712. Which of the two options the AMF 710 sends to the UE 712 may be determined based the AMF 710 being configured to provide one or the other, or may bedetermined based on the optional determination by the AMF 710 of the capability of the UE 712.

[0128] In examples in which application specific slice replacement is performed, as described previously, the message(s) sent by the AMF 710 to the UE 712 at 736 may also include application information for the specific application of the UE. In the specific in which the AMF 710 sends a network slice replacement from slice 1 to slice 2 command that includes the application information, the AMF 710 may also send information on the slice replacement from slice 1 to slice 2 and the application information to the SMF 703 at 737, or may send information on the affected PDU session operating on the first network (e.g., slice 1). The AMF 710 may send the information the SMF 703 at 737 as previously described with reference to 414 of FIG. 4.

[0129] At 738, a new PDU session of the UE 712 is established on slice 2. 738 may include the UE 712 requesting the establishment of a PDU session on slice 2 as described previously, for example as described with reference to 514 of FIG. 5. In application specific slice replacement examples, the PDU session established at 738 may be for the specific application only. Establishing the PDU session on the second network slice (e.g., slice 2) may include releasing the PDU session on the first network slice (e.g., slice 1), or in application specific slice replacement, the UE 712 may continue to utilize the first network slice (e.g., slice 1) for other applications. At 740, the UE 712 then communicates with the AF 112 and the AF 112 communicates with the UE 712 (e.g., provides a service to the UE 712) on the second network slice (e.g., slice 2).

[0130] Referring now to FIG. 8, operations of a procedure in accordance with an example embodiment are shown in which network initiated slice selection is initiated by an AF 112 of or hosted on an application server utilizing external parameter provisioning per slice or service as set out in clause 4.16.6 of V 18.0 3GPP TS 23.502. Portions of the operations procedure are substantially the same as in FIG. 7 and therefore reference numerals for those portions that are substantially the same are reused and are not further describe here to avoid repetition.

[0131] In the operations of the procedure in FIG. 8, the determination of UE capability is performed by the AMF 802 at 804 and determines that the UE 806 is not capable of network slice replacement. The determination at 802 may be performed as described previously withreference to 406 of FIG. 4. The determination at 804 may be performed utilizing capabilities provided to the core network by the UE 806 during, for example, registration of the UE 806 with the communication network.

[0132] In the example shown in FIG. 8, the AMF 802 sends a Deactivate slice replacement for the UE or all UEs message 808 to the PCF 708 to cause the AF to deactivate slice selection feature for the UE 806 or for all UEs. The PCF 708 sends a Deactivate slice replacement for the UE or all UEs message 810 to the NEF 702. The NEF 702 sends a Deactivate slice selection for UE or all UEs message in a Nnef_Service Parameter_Create, or Nnef_Service Parameter Update, or Nnef Service Parameter Delete response 812 sent to the AF 112, which instructs the AF 112 to deactivate slice replacement for the UE 806 or for all UEs.

[0133] Embodiments of the present disclosure enable an application function (AF) of a communicate network to initiate a change from a first network slice to a second network slice of a communication network in order to improve the quality of service that is provides to UEs via the communication network by. For example, the AF may request initiating a change of network slices to load balance when, for example, the amount of data being transmitted in providing the services to the UEs using different network slices form a bundle service is unbalanced.

[0134] Embodiments of the present invention including functions, processes, and operations, may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and / or hardware may reside on memory, or any computer media. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this application, a “memory” or “computer-readable medium” may be any non-transitory media or means that contains, stores, communicates, propagates or transports the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

[0135] Reference to, where relevant, “computer-readable medium”, “computer program product”, “tangibly embodied computer program” etc., or a “processor” or “processing circuitry” etc. should be understood to encompass not only computers having differing architectures such as single / multi-processor architectures and sequencers / parallelarchitectures, but also specialized circuits such as field programmable gate arrays FPGA, application specify circuits ASIC, signal processing devices / apparatus and other devices / apparatus. References to computer program, instructions, code etc. should be understood to express software for a programmable processor firmware such as the programmable content of a hardware device / apparatus as instructions for a processor or configured or configuration settings for a fixed function device / apparatus, gate array, programmable logic device / apparatus, etc.

[0136] As used in the present disclosure, the term “circuitry”, for example in the hardware processing circuitry that may be used to implement the UPF or the SMF in accordance with certain embodiments of the present disclosure, may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (iii) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in the present disclosure, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0137] The functions, processes, and operations described herein may be performed in a different order, or may be performed concurrently with each other, or a combination thereof. Furthermore, one or more of the functions, processes, and operations may be optional or may be combined. It will be appreciated that the flow diagram shown in FIG. 5 and the variousembodiments described with reference to FIG. 5, are examples only. Various operations and processes depicted therein may be omitted, may be reordered, may be combined, or a combination of reordered and combined.

[0138] Advantageously, embodiments of the present disclosure provide for network initiated slice selection in which an AF is able to initiate slice replacement such that slice replacement may be performed for reasons other than that a slice is congested or is unavailable. Some embodiments of the present disclosure rely on existing procedures, such as external parameter provisions of the current 3 GPP standard for 5G, and without requiring dynamic modifications of the URSPs, such that network initiated slice selection may be performed on existing UEs. Embodiments of the present disclosure enable network initiated slice selection for UEs having different capabilities, and enable network initiated slice selection for UEs that may not be capable of network slice selection.

[0139] The scope of the claims should not be limited by the preferred embodiments set forth in the examples but should be given the broadest interpretation consistent with the description as a whole.

Claims

Claims1. A method for an access management function (AMF) of a communication network to initiate network initiated slice selection, the method comprising: receiving a first message instructing the AMF to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF); modifying an allowed network slice assistance information (NS SAI) for the UE to exclude a single-NSSAI (S-NSSAI) identifying the first network slice and include a S-NSSAI identifying a second network slice; and transmitting a second message to the UE that comprises the modified allowed NS SAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NS SAI.

2. The method according to claim 1, wherein the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein the second message transmitted to the UE includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

3. A method for an access management function (AMF) of a communication network to perform network initiated slice selection, the method comprising: receiving a first message instructing the AMF to initiate for a user equipment (UE) replacement of a first network slice of the communication network, wherein the first message is associated with a request for network initiated slice selection from an application function (AF); determining whether the UE is capable of network slice replacement based on UE capabilities provided by the UE during registration of the UE with the communication network; performing at least one of the following: in response to determining that the UE is capable of network slice replacement, transmitting to the UE a second message that instructs the UE to perform network slice replacement of the first network slice with a second network slice, orin response to determining that the UE is not capable of network slice replacement: modifying an updated allowed network slice assistance information (NS SAI) for the UE to exclude a single-NSSAI (S-NSSAI) of the first network slice and include a S-NSSAI of the second network slice; and transmitting a third message to the UE that comprises the modified allowed NS SAI to the UE and a command instructing the UE to re-evaluate UE route selection policy (URSP) rules associated with the UE based on the modified allowed NS SAI.

4. The method according to claim 3, wherein the first message includes application information for a specific application for which network initiated slice selection is to be performed, and wherein: the second message transmitted to the UE in response to determining that the first UE is configured capable of network slice replacement includes the application information for the specific application for the UE to perform replacement of the first network slice with the second network slice for the specific application only, and the third message transmitted to the UE in response to determining that the UE is UE is not capable of network slice replacement includes the application information for the specific application for the UE to re-evaluate the URSP rules with respect to the specific application only.

5. The method according to claim 4, further comprising, in response to determining that the UE is configured to perform network slice replacement, transmitting a fourth message to a session management function (SMF) of the communication network that includes the application information for the specified application and instructs the SMF to perform network slice replacement for the UE for the specific application.

6. The method according to any one of claims 3-5, further comprising in response to determining that the UE is not capable of network slice replacement, transmitting a commandinstructing an application function of an application server to deactivate a network initiated slice selection function for the UE.

7. The method according to any one of claims 1-6, wherein the first message includes a service quality level that the second network slice must satisfy, the method further comprising determining the second network slice based on the service quality level.

8. The method according to claim 7, wherein the service quality level is a set of quality of service parameters that the second network slice is requested to satisfy.

9. A method for a user equipment (UE) to perform network initiated slice selection, the method comprising: receiving from a communication network UE route selection policy (URSP) rules in which a first network slice of the communication network is prioritized over a second network slice of the communication network, wherein the UE is subscribed to the first and second network slices; receiving from an access management function (AMF) of the communication network a first allowed network slice assistance information (NSSAI) that includes a single-NSSAI (S- NSSAIA) identifying the first network slice; transmitting a request to the communication network for establishment of a first data protocol unit (PDU) session on the first network slice based on the first URSP rules and the first allowed NSSAI; receiving from the AMF a second allowed NSSAI that includes a S-NSSAI identifying the second network slice and does not include the S-NSSAI identifying the first network slice; receiving a command to re-evaluate the URSP rules; and transmitting a request to communication network for establishing a second PDU session on the second network slice according to the URSP rules and the second allowed NSSAI.

10. The method according to claim 9, wherein receiving the command to re-evaluate the URSP rules further comprises receiving application information for a specific application of the UE, and wherein transmitting the request to the communication network for establishment of thenew PDU session on the second network slice comprises transmitting a request for establishment of a new PDU session on the second slice for the specific application only.

11. The method according to any of claims 1 to 10, wherein the first network slice and the second network slice are included in a bundle service.

12. An apparatus comprising: at least one processor; and at least one memory storing instructions of an access management function (AMF), wherein when the instructions are executed by the at least one processor, cause the apparatus to perform the method of any of claims 1 to 8 and 11.

13. An apparatus comprising: an access management function configured to perform the method of any of claims 1 to 8 and 11.

14. A computer program comprising instructions, wherein when the computer program is executed by at least one processor of an apparatus, the apparatus is caused to perform the method of any of claims 1 to 8 and 11.

15. A computer-readable medium comprising instructions which, when executed by at least one processor of an apparatus, cause the apparatus to perform the method of any of claims 1 to 8 and 11.

16. A user equipment comprising: at least one processor; and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus to perform the method of any of claims 9 to 11.

17. A computer program comprising instructions, wherein when the computer program is executed by at least one processor of a user equipment, the user equipment is caused to perform the method of any of claims 1 to 8 and 11.

18. A computer-readable medium comprising instructions which, when executed by at least one processor of a user equipment, cause the user equipment to perform the method of any of claims 1 to 8 and 11.

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