Network entities and methods for controlling a UE network slice transfer

Abstract

A network entity (110a; 110), in particular Enforcement Network Function, ENF, is disclosed for controlling a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b) of a mobile network (100). The network entity, in particular ENF, (110a; 110) is configured to send a Network Slice Replacement, NSR, notification message to an application function, AF, (140) associated with an application running on the plurality of UEs (120a-n), wherein the NSR notification message comprises a respective identifier of the one or more UEs transferred to the further network slice (130b), an identifier of the network slice (130a), and / or an identifier of the further network slice (130b).

Description

[0001] NETWORK ENTITIES AND METHODS FOR CONTROLLING A UE NETWORK SLICE TRANSFER

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to wireless communications. More specifically, the present disclosure relates to network entities and methods for controlling and supporting a transfer of selected user equipments, UEs, from a network slice to a further network slice of a mobile network, in particular a 3GPP mobile network.

[0004] BACKGROUND

[0005] The 5thgeneration (5G) mobile telecommunication technology with Network Slice Replacement (NSR) feature enables service continuity of a UE by allocating to an alternative network slice (i.e., alternative S-NSSAI), if a current network slice is unavailable to support the required service. A network slice unavailability for supporting the required service may occur, for instance, due to the current network slice being overloaded, i.e. congested (which can be considered as a no mobility case) and / or due to the current network slice being not available in a new service area one or more UEs are moving into (which can be considered a mobility case).

[0006] The 3GPP specification TS23.501 defines how the network detects and triggers NSR procedure by CN entities. In particular, an Access and Mobility Management Function (AMF) detects an S-NSSAI becoming unavailable or congested together with other CN NFs, such as a Network Slice Selection Function (NSSF), Policy Control Function (PCF) and / or Operation and Management (OAM). It is assumed that an alternative S-NSSAI is available in the Network Slice Area of Service (NS-AoS), e.g., based on OAM or Network Data Analytics Function (NWDAF) analytics output.

[0007] The identified mechanisms consider that the network can detect which S-NSSAI (or UEs) is congested and can select an alternative S-NSSAI to initiate the NSR procedure. On one hand, there is no option for the NSR being triggered by other entities, e.g., Application Function (AF). For example, an NSR trigger may be initiated by AF to the network when a UE or group of UEs changes UE SLA temporarily, e.g., UE asks for a specific service (e.g., a higher throughput) when it needs for a specific application for a specific time period with the associated higher cost. The application provider (e.g., AF) in return may trigger NSR for UE(s) to the network temporarily. On the other hand, it is assumed that all UEs from the current network slice can obtain services in the alternative network slice. In case of transferring UEs to the alternative network slice, it is also important to support a mechanism for a proper selection of UEs based on UE’s requirements and the performance fulfilment by the network, e.g., UE SLA.

[0008] Network triggered NSR does not allow other conditions requiring NSR events by other entities, for example, when the UE or UEs needs a temporary change of SLA with an Application provider (e.g., AF) due to its requirements. Another example is that the application provider detects that the requirements of UE or UEs (e.g., QoS or QoE) are not being fulfilled, hence, it triggers the NSR event for the specific UE or UEs.

[0009] If the UE or UEs to be migrated to the alternative S-NSSAI are unknown or not considered by the NSR triggered by the Network, there is no mechanism which UEs to be migrated to which alternative S-NSSAI. With a proper selection of the right UEs in the right S-NSSAI, the network may increase overall UE satisfaction and can improve the efficient use of available resources. SUMMARY

[0010] It is an objective of the present disclosure to provide improved entities and methods for controlling and supporting a transfer of selected user equipments, UEs, from a network slice to a further network slice of a mobile network, in particular a 3GPP mobile network, such as a 5G or 6G network.

[0011] The foregoing and other objectives are achieved by the subject matter of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

[0012] According to a first aspect a network entity, in particular an Enforcement Network Function, ENF, is provided for controlling a transfer of one or more user equipments, UEs, of a plurality of UEs from a network slice, S-NSSAI, to a further network slice, Alt-S-NSSAI, of a mobile network. The network entity, in particular ENF, according to the first aspect is configured to send a Network Slice Replacement, NSR, notification message to an application function, AF, associated with an application running on the plurality of UEs, wherein the NSR notification message comprises a respective identifier of the one or more UEs transferred to the further network slice, an identifier of the network slice, and / or an identifier of the further network slice. This allows AF the awareness of new S-NSSAI association with the application running on which one or more UEs associated to the new S-NSSAI. Thus, the network entity according to the first aspect allows to be triggered by an AF for controlling the transfer of one or more UEs from a network slice to a further network slice in a mobile network.

[0013] In a further possible implementation form, the AF is configured to associate the one or more UEs running the application with a further network slice, Alt-S-NSSAI, of the mobile network. Based on that, AF can check the QoS, QoE or SLA of a particular UE or UEs associated with a further network slice, Alt-S-NSSAI, and may trigger (e.g., QoS or SLA requirement is not fulfilled) a request to the network for controlling the transfer of the UEs of the plurality of UEs from the network slice to the further network slice.

[0014] In a further possible implementation form, the network entity is configured to receive a NSR request from the AF for transferring one or more UEs of the plurality of UEs from a network slice to a further network slice of the mobile network, wherein the NSR request comprises a respective identifier of the one or more UEs, an identifier of the network slice, an identifier of the further network slice, an identifier of the application associated with the AF, and / or an indication of a network slice replacement for the one or more UEs from the network slice. This allows the network entity to control the transfer of one or more UEs from a network slice to a further network slice in a mobile network in response to a request from the AF.

[0015] In a further possible implementation form, in response to receiving the NSR request from the AF, the network entity is configured to select the one or more UEs of the plurality of UEs and to trigger, i.e. initiate the requested transfer of the one or more UEs of the plurality of UEs from the network slice to the further network slice of the mobile network. Thus, the network entity is configured to select the UEs most suitable to be transferred.

[0016] In a further possible implementation form, the network entity, in particular ENF, is configured to receive the NSR request from the AF, in response to sending the NSR notification message to the AF. This allows to adjust the transfer of one or more UEs from a network slice to a further network slice in a mobile network in response to a request from the AF.

[0017] In a further possible implementation form, in response to receiving the NSR request from the AF, the network entity is configured to trigger, i.e. initiate the requested transfer of the one or more UEs of the plurality of UEs from the further network slice back to the original network slice of the mobile network. This allows to undo a transfer of one or more UEs from a network slice to a further network slice in a mobile network, if the transfer does not lead to the desired result(s). In a further possible implementation form, the network entity is configured to receive a NSR request from a core network, CN, network function of the mobile network for transferring one or more UEs of the plurality of UEs from the network slice to the further network slice of the mobile network, wherein the NSR request comprises an identifier of the network slice, and / or an identifier of the further network slice. This allows the network entity to control the transfer of one or more UEs from a network slice to a further network slice in a mobile network in response to a request from a CN NF of the mobile network.

[0018] In a further possible implementation form, in response to receiving the NSR request from the CN network function of the mobile network, the network entity is configured to select the one or more UEs of the plurality of UEs and to trigger, i.e. to i.e. initiate the transfer of the one or more selected UEs of the plurality of UEs from the network slice to the further network slice of the mobile network. Thus, the network entity is configured to select the UEs most suitable to be transferred.

[0019] In a further possible implementation form, each of the plurality of UEs is associated with a Service Level Agreement, SLA, wherein each SLA defines one or more Service Level Objects, SLOs, for one or more SLA attributes of the SLA, and wherein the network entity is configured to determine or to obtain from a further network entity, in particular Tracking and Evaluation Network Function, TENF, for each of the plurality of UEs monitoring data, i.e. stateful information of each of the plurality of UEs and to select, i.e. prioritize the one or more UEs of the plurality of UEs based on the monitoring data of each of the plurality of UEs. This allows the network entity to perform the selection of the UEs based on the monitoring data provided by the TENF.

[0020] In a further possible implementation form, the network entity is configured to select, i.e. prioritize the one or more UEs of the plurality of UEs based on the monitoring data of each of the plurality of UEs, wherein the monitoring data is related to the status of the SLA or SLA fulfilment of each UE of the plurality of UEs. This allows the network entity to perform the selection of the UEs based on the status of the SLA fulfilment of each UE.

[0021] In a further possible implementation form, the monitoring data determined by the network entity or obtained from the further network entity comprises a stateful evaluation of each UE of the plurality of UEs. This allows the network entity to perform the selection of the UEs based on a stateful evaluation of each UE.

[0022] In a further possible implementation form, the mobile network is a 3GPP network, wherein the network entity is a Policy Control Function or Network Data Analytics Function of the mobile network. This allows to seamlessly implement the network entity according to the first aspect in the existing 3GPP network architecture.

[0023] According to a second aspect a further network entity, in particular Tracking and Evaluation Network Function, TENF, is provided for supporting a transfer of one or more user equipments, UEs, of a plurality of UEs from a network slice to a further network slice controlled by a network entity of a mobile network. The further network entity according to the second aspect is configured to determine a stateful evaluation of each UE of the plurality of UEs and send the stateful evaluation of each UE of the plurality of UEs as monitoring data to the network entity for controlling the transfer of the UEs of the plurality of UEs from the network slice to the further network slice. Thus, the network entity allows providing information for selecting the most appropriate UEs for a transfer from a first network slice to a further network slice.

[0024] In a further possible implementation form, the further network entity, in particular TENF, is configured to determine the stateful evaluation of each UE of the plurality of UEs based on one or more service level agreement, SLA, attributes and one or more associated service level objectives, SLOs, of each SLA attribute, one or more tolerances of each SLO upholding and / or a specific time window associated with the tolerance of each SLO upholding related to each UE of the plurality of UEs. According to a third aspect a method is provided for operating a network entity, in particular Enforcement Network Function, ENF, for controlling a transfer of one or more user equipments, UEs, of a plurality of UEs from a network slice to a further network slice of a mobile network. The method according to the third aspect comprises: sending a Network Slice Replacement, NSR, notification message to an application function, AF, associated with an application running on the plurality of UEs, wherein the NSR notification message comprises a respective identifier of the one or more UEs, an identifier of the network slice, and / or an identifier of the further network slice.

[0025] The method according to the third aspect can be performed by the network entity according to the first aspect. Thus, further features of the method according to the third aspect result from the functionality of the network entity according to the first aspect as well as the different implementation forms and embodiments thereof described above and below.

[0026] According to a fourth aspect a method is provided for operating a further network entity, in particular Tracking and Evaluation Network Function, TENF, for supporting a transfer of one or more user equipments, UEs, of a plurality of UEs from a network slice to a further network slice controlled by a network entity of a mobile network. The method according to a fourth aspect comprises: determining a stateful evaluation of each UE of the plurality of UEs; and sending the stateful evaluation of each UE of the plurality of UEs as monitoring data to the network entity for controlling the transfer of the UEs of the plurality of UEs from the network slice to the further network slice.

[0027] The method according to the fourth aspect can be performed by the further network entity according to the third aspect. Thus, further features of the method according to the fourth aspect result from the functionality of the further network entity according to the third aspect as well as the different implementation forms and embodiments thereof described above and below.

[0028] According to a fifth aspect, a computer program product is provided, comprising a computer-readable storage medium for storing a program code which causes a computer or a processor to perform the method according to the third aspect, or the method according to the fourth aspect, when the program code is executed by the computer or the processor.

[0029] Details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the following, embodiments of the present disclosure are described in more detail with reference to the attached figures and drawings, in which:

[0032] Figs, la and lb show schematic diagrams illustrating a core network of a mobile network including a network entity and a further network entity according to an embodiment for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0033] Figs. 2a and 2b show schematic diagrams illustrating a transfer of one or more UEs from a network slice to a further network slice of a mobile network controlled by a network entity according to an embodiment;

[0034] Figs. 3a and 3b show signalling diagrams illustrating the exchange of messages between a network entity and a further network entity according to the embodiment of figures la and lb for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network; Figs. 4a and 4b show signalling diagrams illustrating the exchange of messages between a network entity and a further network entity according to the embodiment of figures la and lb for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0035] Fig. 5 shows a schematic diagram illustrating a core network of a mobile network including a network entity and a further network entity according to a further embodiment for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0036] Figs. 6a and 6b show signalling diagrams illustrating the exchange of messages between a network entity and a further network entity according to the embodiment of figure 5 for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0037] Figs. 7a and 7b show signalling diagrams illustrating the exchange of messages between a network entity and a further network entity according to the embodiment of figure 5 for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0038] Figs. 8a and 8b show signalling diagrams illustrating the exchange of messages between a network entity and a further network entity according to the embodiment of figure 5 for controlling and supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0039] Fig. 9 shows a table illustrating information used by a network entity according to an embodiment for implementing a UE selection policy for a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0040] Fig. 10 shows a schematic diagram illustrating processing stages implemented by a further network entity according to an embodiment for supporting a transfer of one or more UEs from a network slice to a further network slice of the mobile network;

[0041] Figs. I la and 1 lb show algorithms implemented by a network entity according to an embodiment for controlling a transfer of one or more UEs from a network slice to a further network slice of a mobile network;

[0042] Figs. 12a-f show tables illustrating exemplary values determined by a network entity according to an embodiment for controlling a transfer of one or more UEs from a network slice to a further network slice of a mobile network;

[0043] Fig. 13 is a flow diagram illustrating a method for operating a network entity according to an embodiment for controlling a transfer of one or more UEs from a network slice to a further network slice of a mobile network; and

[0044] Fig. 14 is a flow diagram illustrating a method for operating a further network entity according to an embodiment for supporting a transfer of one or more UEs from a network slice to a further network slice of a mobile network.

[0045] In the following, identical reference signs refer to identical or at least functionally equivalent features.

[0046] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] In the following description, reference is made to the accompanying figures, which form part of the disclosure, and which show, by way of illustration, specific aspects of embodiments of the present disclosure or specific aspects in which embodiments of the present disclosure may be used. It is understood that embodiments of the present disclosure may be used in other aspects and comprise structural or logical changes not depicted in the figures. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

[0048] For instance, it is to be understood that a disclosure in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if one or a plurality of specific method steps are described, a corresponding device may include one or a plurality of units, e.g. functional units, to perform the described one or plurality of method steps (e.g. one unit performing the one or plurality of steps, or a plurality of units each performing one or more of the plurality of steps), even if such one or more units are not explicitly described or illustrated in the figures. Moreover, if a specific apparatus is described based on one or a plurality of units, e.g. functional units, a corresponding method may include one step to perform the functionality of the one or plurality of units (e.g. one step performing the functionality of the one or plurality of units, or a plurality of steps each performing the functionality of one or more of the plurality of units), even if such one or plurality of steps are not explicitly described or illustrated in the figures. Further, it is understood that the features of the various exemplary embodiments and / or aspects described herein may be combined with each other, unless specifically noted otherwise.

[0049] Figure la shows a schematic diagram illustrating a portion of a mobile network 100, in particular a 3GPP mobile network 100, such as a 5G or 6G network. More specifically, figure la shows network function entities of a core network, CN, of a mobile network 100, which may further comprise a radio access network, RAN. As illustrated in figures 2a and 2b, the RAN of the mobile network 100 may comprise a plurality of base stations or access points 115a,b configured to provide communication access to a plurality of user equipments, UEs, 120a-n.

[0050] As will be described in more detail below, the CN of the mobile network 100 illustrated in figure la comprises a network entity 110a, in particular an Enforcement Network Function, ENF, 110a configured to control a transfer of one or more UEs of a plurality of UEs 120a-n from a network slice, S-NSSAI, 130a (illustrated in figures 2a and 2b) to a further network slice, Alt- S-NSSAI, 130b of the mobile network 100. The network entity 110a, in particular ENF 110a is configured to send a Network Slice Replacement, NSR, notification message to an application function, AF, 140 associated with an application running on the plurality of UEs 120a-n. The NSR notification message comprises a respective identifier of the one or more UEs transferred to the further network slice 130b, an identifier of the network slice 130a, and / or an identifier of the further network slice 130b. As will be described in more detail below, the network entity 110a, in particular ENF 110a may receive a trigger for the transfer of the one or more UEs of the plurality of UEs 120a-n from the network slice, S-NSSAI, 130a to the further network slice, Alt- S-NSSAI, 130b from the AF 140 or other CN network functions 150, 151.

[0051] As will be described in more detail below, the CN of the mobile network 100 illustrated in figure 1 a comprises a further network entity 110b, in particular a Tracking and Evaluation Network Function, TENF 110b configured to support the transfer of the one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b controlled by the network entity 110a, e.g. the ENF 110a. The further network entity 110b, in particular TENF 110b is configured to determine a stateful evaluation of each UE of the plurality of UEs 120a-n and to provide the stateful evaluation of each UE of the plurality of UEs 120a-n as monitoring data to the network entity 110a, in particular ENF 110a for controlling the transfer of the one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130a. As illustrated in figure la, in an embodiment, the network entity 110a, in particular ENF 110a, and the further network entity 110b, in particular TENF 110b may be components of a single network entity function 110.

[0052] Figure lb shows different processes and interactions between core network entities and AF for controlling and supporting a transfer of one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. As will be described in more detail below, based on the network triggered NSR request (step Oa), the ENF 110a interacts with the TENF 110b for a stateful SLA based UE selection (step Ob) and supports NSR enforcement, i.e., determines the transfer of one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b (step 0c). The change of the association of the one or more UEs from the network slice 130a to the further network slice 130b is notified to the AF 140 (step la). If the requirement of QoS, QoE or SLA of the one or more UEs associated with the further network slice 130b is not fulfilled or the adjustment of QoS, QoE or SLA of one or more UEs associated with the network slice 130a is required, the AF 140 may trigger a request to the ENF 110a for controlling the transfer of the one or more UEs associated with the further network slice 130b back to the (original) network slice 130a or the UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b (step lb). Based on the NSR triggered request from the AF 140, the ENF 110a performs NSR controlling (step 2a-2c) where the ENF 110a optionally is configured to obtain Alt-S- NSSAI information from a core network entity (step 2a) and performs transfer of one or more UEs from the S-NSSAI 130a to the Alt-S-NSSAI 130b. Optionally, the ENF 110a may perform (stateful) SLA based UE selection for the requested UEs from the AF 140 similar to steps 0a and 0b (steps 2b-2c) if the capacity of the Alt-S-NSSAI 130b is limited. Then, the ENF 110a sends an acknowledgement response to the AF 140 (step 3a) whether the request is successful, partially successful or unsuccessful.

[0053] Before describing more detailed embodiments of the network entity 110a, in particular ENF 110a, and the further network entity 110b, in particular TENF 110b in the following some technical background as well as terminology will be introduced making use of one or more of the following acronyms and abbreviations:

[0054] 5G The fifth-generation technology standard for mobile network

[0055] 5G-A The advanced fifth-generation technology standard for mobile network

[0056] 6G The sixth-generation technology standard for mobile network

[0057] CN Core Network

[0058] AN Access Network

[0059] AF Application Function

[0060] SMF Session Management Function

[0061] PCF Policy Control Function

[0062] NWDAF Network Data Analytics Function

[0063] NS Network Function

[0064] NS_AoS Network Slice Area of Service

[0065] As used herein, “UE SLA” is a Service Level Agreement (SLA) between a subscriber (UE) and service provider (e.g., network operator or application provider). The UE SLA may include one or more UE specific / related attribute(s) and its service level objectives (SLO). Examples for UE specific or related attributes are defined in GSMA - Generic Network Slice Template, Version 9.0 such as, maximum downlink throughput per UE, maximum uplink throughput per UE, service availability, packet delay budget (PDB). Other types of UE SLA include the information related to the subscription plan, e.g., data volume limit (maximum downlink bit rate or maximum uplink bit rate or maximum downlink data volume or maximum uplink data volume). Another example of UE SLA includes a service (e.g., V2X service) requirements and promised SLO for the performance KPIs (SLO of guaranteed downlink throughput, guaranteed uplink throughput and service availability associated with tolerance and time window). The tolerances of each SLO upholding can be defined as the percentage value with respect to the time window. For example, 1% of tolerance of service availability for the time window 30 days means that the maximum service unavailability is acceptable for 1% of 30 days (i.e., 7.2 hours) within 30 days. As used herein, “stateful SLA” means that a UE SLA may be evaluated based on the SLA attribute and its service level objectives (SLO), the tolerances of each SLO upholding and a specific time windows for the tolerance of each SLO upholding.

[0066] As used herein, “Network Slice Replacement, NSR” is defined as a feature of a 3GPP mobile network for replacing an S- NSSAI with an Alternative S-NSSAI when an S-NSSAI becomes unavailable or congested, as defined in TS23.501. The term Network Slice and S-NSSAI are used herein interchangeably. The term further network slice, alternative S-NSSAI and Alt-S- NSSAI are used herein interchangeably. The term monitoring data, stateful information, stateful evaluation and stateful evaluation result are used herein interchangeably.

[0067] Embodiments disclosed herein are based on a Stateful SLA Evaluation for determining the proper UE(s) selection by the network entity 110a, in particular ENF 110a during the NSR procedure. In an embodiment, based on the history of SLA (i.e., how UEs have been served by the network with respect to the agreed SLA) each UE is evaluated and selected. As will be described in more detail below, in an embodiment the plurality of UEs 120a-n are prioritized based on its stateful SLA evaluation or stateful information. A UE selection policy is defined based on the prioritized UEs and an NSR scenario. The UE selection policy defines the rules for the UE(s) 120a-n to be continued in the current S-NSSAI 130a and the rules for UEs 120a- n to be migrated to the Alternative S-NSSAI 130b. For example, UEs may be identified as low priority UEs, if the respective UE has no SLA breach, and UEs may be identified as high priority UEs, if the SLA is breached soon based on stateful SLA evaluation. In an embodiment, the UE selection policy may be to migrate low priority UEs to the Alternative S-NSSAI 130b in no mobility NSR scenario. In the mobility scenario, the UE selection policy may be to migrate high priority UEs to the Alternative S-NSSAI 130b.

[0068] As alreadv described above in the context of figure la, according to an embodiment a NSR may be triggered based on UE SLA adaptation by the AF 140. This allows the AF 140 to trigger the NSR procedure and to interact with the network 100 for the NSR procedure when UE / UEs adapts the SLA. An example of UE SLA adaptation is temporarily upgrading a data plan. Another example is the change of UE SLA requirements with respect to application requirements, e.g., QoS or QoE requirements.

[0069] For a NSR event in the no mobility scenario illustrated in figure 2a, when the network 100 detects congestion of the S-NSSAI 130a (e.g., S-NSSAI #1), the Alternative S-NSSAI 130b may be selected. Some UE(s) from the congested / overloaded S-NSSAI 130a need to be migrated to the Alternative S-NSSAI 130b. The UEs of the congested / overloaded S-NSSAI 130a are associated with a UE SLA. As will be described in more detail in the following, embodiments disclosed herein allow to select UEs to be migrated from the congested slice 130a to the alternative S-NSSAI 130b.

[0070] For an NSR event in the mobility scenario illustrated in figure 2b, when the network 100 detects the unavailability of the network slice 130a (e.g., S-NSSAI #1) at a new service area (e.g., service area 2), the Alternative S-NSSAI 130b (e.g., S- NSSAI #2) may be selected. For UEs of S-NSSAI #1 from Service Area 1 moved to the Service Area 2 are allocated to S- NSSAI #2. However, the alternative S-NSSAI 130b (i.e., S-NSSAI#2) cannot serve all incoming UEs. The UEs already admitted to the S-NSSAI #1 from Service Area 1 is associated with UE SLA. With the Network Slice admission control (NSAC) mechanism, the UEs can be admitted to the Alternative S-NSSAI 130b up to maximum number of allowed UEs. However, this mechanism does not consider which UEs are admitted to the Alternative S-NSSAI 130b. As will be described in more detail in the following, embodiments disclosed herein allow to select UEs to be admitted to the alternative S-NSSAI 130b in Service Area 2.

[0071] Embodiments disclosed herein provide a UE priority-based Network Slice Replacement (NSR) based on stateful UE SLA evaluation, for both no mobility and mobility scenarios. The NSR procedure may be triggered: 1) for UEs in the no mobility scenario when the current network slice 130a is congested or overloaded; 2) for UEs in the mobility scenario, when the current network slice 130a in the new service area is unavailable to serve all incoming UEs; and 3) based on the application’s requirement. In an embodiment, the NSR may be triggered either by the network 150 or the AF 140. As will be described in more detail below, in an embodiment, the UE priority-based NSR procedure disclosed herein consists of the following main elements: a stateful SLA Evaluation, where UE SLA is evaluated based on the SLA attribute and its SLO, the tolerances of each SLO upholding and a specific time windows for the tolerance of each SLO upholding; a UE Selection Policy, where UEs are prioritized based on their stateful evaluation. UE selection policy is defined based on the prioritized UEs & NSR scenario. For e.g., UEs are identified as low priority UEs if UE has no SLA breach and UEs are identified as high priority UEs if SLA is breached soon. An example of UE Selection Policy is to migrate low priority UEs to the alternative S-NSSAI 130b in no mobility NSR scenario.

[0072] As already described above, the TENF 110b is configured to determine a stateful evaluation of each UE of the plurality of UEs 120a-n and to provide the stateful evaluation of each UE of the plurality of UEs 120a-n as monitoring data to the ENF 110a for controlling the transfer of the one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130a. In an embodiment, the TENF 110b may be configured to monitor UE SLA information including but not limited to the parameter related to S-NSSAI, UE ID, UE SLA Attribute, SLO, Tolerance, Time window, Time instance, and Requested Service Level by UE or application function 140 and provided service level by the network.

[0073] Moreover, in an embodiment, the TENF 110b may be configured to monitor adaptive changes of the UE SLA information, for example, specific UE SLA information including but not limited to data volume credit limit, max. downlink / uplink throughput, guaranteed downlink / uplink throughput, E2E delay, QoS or QoE related parameters. Basically, the adaptive changes of the UE SLA may be considered as temporary conditions or time (e.g., hours, days). However, the UE(s) 120a-n may require the alternative S-NSSAI 130b to fulfil its UE SLA change, e.g., upgrading data plan or QoS requirements does not fulfil with the congested S-NSSAI 130a.

[0074] As will be described in more detail below, in an embodiment, the network entity 110a, e.g. ENF 110a is configured to support a UE selection policy to perform enforcement actions. The action includes migrating UE(s) to a further, i.e. alternative S- NSSAI 130b, admitting UEs to the alternative S-NSSAI in the NSR procedure. In an embodiment, the network entity 110a, e.g. ENF 110a may be configured to determine priority of UEs based on the stateful evaluation results, i.e. the monitoring data provided by the TENF 110b and apply the UE selection policy to the prioritized UE according to the NSR scenario. In an embodiment, the network entity 110a, e.g. ENF 110a may be configured to provide a UE ranking to a requesting network entity to initiate a NSR procedure for one or more UEs of the plurality of UEs 120a-n.

[0075] Figures 3a and 3b show signalling diagrams illustrating the exchange of messages between the ENF 110a according to an embodiment, the TENF 110b according to the embodiment as well as further network entities for controlling and supporting a transfer of one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. The embodiment shown in figure 3b differs from the embodiment of figure 3a in that the ENF 110a and the TENF 110b are collocated and implemented as components of a NWDAF 110.

[0076] In step 0 of figures 3a and 3b, the exemplary UE 120a is registered in the S-NSSAI 130a and a PDU session is established, for instance, according to the procedure defined in TS23.502.

[0077] In step 1 of figures 3a and 3b, the TENF 110b monitors the UE SLA parameters per UE per S-NSSAI. The monitoring and tracking of UE SLA related information for the UEs 120a-n by the TENF 110b may already have been initiated, i.e. ongoing or will be initiated when the request from ENF 110a is received. In step 2a of figures 3a and 3b, the network, i.e., CN NF 150 initiates an NSR event and triggers UE selection for NSR event to the ENF 110a with the input parameters including identifications of one or more UEs, the identification of S-NSSAI 130a, the identification of further network slice (i.e., Alt-S-NSSAI) 130b and the indication of UE selection (e.g., a percentage of the total number of UEs to be selected for Alt-S-NSSAI).

[0078] In step 3 of figures 3a and 3b, in response to the received NSR event triggering request from CN NF 150, the ENF 110a sends a request to the TENF 110b for the (stateful) SLA evaluation of UEs running on the network slice S-NSSAI 130a.

[0079] In step 4 of figures 3a and 3b, based on the monitored UE SLA information from step 2a and the request from step 3, the TENF 110b determines the requested stateful SLA evaluation of the plurality of UEs 120a-n (further details are described below in the context of Figure 10).

[0080] In step 5 of figures 3a and 3b, the TENF 110b provides the requested stateful SLA evaluation, i.e. monitoring data of the plurality of UEs 120a-n of the indicated S-NSSAI 130a to the ENF 110a.

[0081] In step 6 of figures 3a and 3b, the ENF 110a determines the selection priority of the plurality of UEs 120a-n based on the stateful evaluation results, i.e. the monitoring data provided by TENF 110b in step 5 and applies a UE selection policy to the prioritized UEs 120a-n according to the indication of UE selection in NSR event request received in step 2a.

[0082] In step 7 of figures 3a and 3b, the ENF 110a provides the selected UEs of the plurality of UEs 120a-n for the Alt-S-NSSAI 130b with the mapping of each UE with its ranking or priority to the requesting CN NF 150. If multiple Alt-S-NSSAIs are provided, multiple mappings may be provided. If the request from step 2a does not include an indication of the number of UEs to be transferred to the alternative S-NSSAI 130b, the mapping of all UEs 120a-n with their corresponding ranking may be provided to the NSR triggering CN NF 150.

[0083] In step 8 of figures 3a and 3b, for each UE to be transferred to the Alt-S-NSSAI 130b, the CN NF 150 performs the enforcement of the NSR procedure and communicates with the UE 120a for the alternative S-NSSAI 130b.

[0084] In step 9 of figures 3a and 3b, independent from step 7, the ENF 110a notifies NSR notification message to the AF 140 for the selected UEs of the plurality of UEs 120a-n for the Alt-S-NSSAI 130b. The message includes the identifications of migrated UE(s) to the Alt-S-NSSAI, the identification s) of the associated Alt-S-NSSAI(s).

[0085] In step 10 of figures 3a and 3b, the AF 140 acknowledges the NSR notification message to the ENF 110a.

[0086] In step 11 of figures 3a and 3b, the AF 140 monitors the SLA of the migrated UEs or application requirements (e.g., QoS) running on the Alt-S-NSSAI 130b, i.e. whether the migrated UEs or the application is fulfilling SLA or QoS / QoE requirements.

[0087] In step 12 of figures 3a and 3b, the AF 140 detects the SLA or QoS / QoE unfulfillment and determines to trigger NSR event for restoring the original S-NSSAI 130a to fulfil the requirements.

[0088] In step 13 of figures 3a and 3b, the AF 140 initiates an NSR event to the ENF 110a with the input parameters including identifications of one or more UEs, the identification of current S-NSSAI (i.e., Alt-S-NSSAI) 130b, the identification of further network slice (i.e., old S-NSSAI) 130a and the indication of NSR event (e.g., SLA / QoS / QoE reason). In step 14 of figures 3a and 3b, the ENF 110a may perform the NSR control procedure as defined in steps 3-8 for the one or more UEs associated with the S-NSSAI (i.e., current S-NSSAI) received in step 13. Alternatively, the ENF 110a may perform a transfer of one or more UEs from S-NSSAI (current S-NSSAI) to Alt-S-NSSAI (old S-NSSAI). If the capacity of Alt-S- NSSAI is limited, the ENF may perform (stateful) SLA based UE selection for the requested UEs from AF similar to steps 3- 8.

[0089] Figures 4a and 4b show signalling diagrams illustrating the exchange of messages between the ENF 110a according to an embodiment, the TENF 110b according to an embodiment as well as further network entities for controlling and supporting a transfer of one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. The embodiment shown in figure 4b differs from the embodiment of figure 4a in that the ENF 110a is implemented as a PCF 110a and the TENF 110b is implemented as a NWDAF 110b. The embodiments shown in figures 4a and 4b differ from the embodiments shown in figures 3a and 3b primarily in the NSR triggering condition by the AF 140. While in the embodiments of figures 3a and 3b the AF 140 triggers the NSR event for restoring of the original S-NSSAI for the migrated UEs, the embodiments of figures 4a and 4b concern an individual NSR trigger, e.g., due to SLA adjustment.

[0090] In step 0 of figures 4a and 4b, the exemplary UE 120a is registered in the S-NSSAI 130a and a PDU session is established, for instance, according to the procedure defined in TS23.502.

[0091] In step 1 of figures 4a and 4b, the AF 140 monitors the UE SLA parameters per UE per S-NSSAI for the application.

[0092] In step 2 of figures 4a and 4b, the AF 140 determines to trigger NSR event for one or more of UEs running application on the S-NSSAI, e.g., due to SLA / QoS or QoE adjustment or requirements.

[0093] In step 3 of figures 4a and 4b, the AF 140 triggers NSR event to the ENF 110a with the input parameters including identifications of one or more UEs, the identification of S-NSSAI 130a, the identification of further network slice (optional) 130b, the identification of the application and the indication of NSR trigger event (e.g., SLA / QoS or QoE adjustment).

[0094] In step 4 of figures 4a and 4b, the ENF 110a is configured to obtain the alternative S-NSSAI information for the requested NSR event from step 3.

[0095] Steps 5 to 11 of the embodiments shown in figures 4a and 4b are identical to steps 3 to 9 of the embodiments shown in figures 3a and 3b.

[0096] A further example of the UE priority based N SR procedure is illustrated in the embodiment of figure 5. In a stage 1 , the ENF 110a receives an NSR event from the NSR triggering NF 150, e.g., a 5GC NF, such as a NSSF, AMF, PCF, or NWDAF 150, or (as alreadv described in the context of the embodiment shown in figures la and lb) for the network triggering NSR event and from a 5GC NF, such as a PCF or NWDAF, for the 3rdparty (e.g., AF 140) triggering NSR event. In an embodiment, the triggering request may include an identifier of the replaced, i.e. current S-NSSAI 130a, an identifier of the alternative, i.e. further S-NSSAI 130b, an indication of the number of UEs from the current S-NSSAI 130a to be transferred to the alternative S-NSSAI 130b (e.g., in the form of integer value or percentage value), an indication of a mobility scenario, and the like.

[0097] Based on the NSR event, the ENF 110a requests in stage 2 of figure 5 the stateful SLA information, i.e. the monitoring data of the plurality of UEs 120a-n of the indicated S-NSSAI 130a from the TENF 110b. In response to the request from the ENF 110a, in stage 3 of figure 5 the TENF 110b determines the stateful information based on the monitored UE SLA information. The monitoring and tracking of UE SLA related information may already have been initiated or is already initiated when the request from the ENF 110a is received in stage 2 of figure 5.

[0098] In stage 4 of figure 5, the TENF 110b provides the requested stateful SLA evaluation, i.e. the monitoring data / information of the plurality of UEs 120a-n of the indicated S-NSSAI 130a to the ENF 110a.

[0099] Based on the stateful evaluation results provided by the TENF 110b in stage 4 of figure 5, the ENF 110a in stage 5 of figure 5 determines the priority of UEs and applies UE selection policy to the prioritized UE according to the NSR scenario for selecting the one or more UEs of the plurality of UEs 120a-n to be transferred to the further S-NSSAI 130b.

[0100] In stage 6 of figure 5, the ENF 110a provides the selected UEs if the request from stage 1 of figure 5 includes the number of UEs to be transferred to the alternative S-NSSAI 130b together with the ranking of UEs to the NSR triggering NF 150.

[0101] Figures 6a and 6b show signalling diagrams illustrating the exchange of messages between the ENF 110a and the TENF 110b as well as further network entities for the embodiment of figure 5 for controlling and supporting the transfer of one or more UEs of the plurality of UE 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. The embodiment shown in figure 6b differs from the embodiment of figure 6a in that the ENF 110a is implemented as a NWDAF 110a and the TENF 110b is implemented as a NSSF 110b.

[0102] In step 0.1 of figures 6a and 6b, the exemplary UE 120a is registered in the S-NSSAI 130a and a PDU session is established, for instance, according to the procedure defined in TS23.502.

[0103] In step 0.2 of figures 6a and 6b, the network, e.g. a CN NF 150, detects an NSR event of the S-NSSAI 130a and determines the S-NSSAI of the S-NSSAI 130a. The CN NF 150 determines to interact with the ENF 110a for UE prioritization request of UEs from the S-NSSAI 130a.

[0104] In steps 1 and l.l offigures 6a and 6b, the ENF 110a receives the NSR event from the NSR triggering NF, e.g., CN NF 150 (or the OAM) for the network triggering NSR event. As already described above, the triggering request may include an identifier of the current S-NSSAI 130a, an identifier of the further, i.e. alternative S-NSSAI 130b, an indication of the number of UEs 120a-b of the current S-NSSAI 130a to be transferred to the alternative S-NSSAI 130b (e.g., in the form of a integer value or percentage value), an indication of mobility scenario, and the like.

[0105] In step 2.1 offigures 6a and 6b, based on the NSR event, the ENF 110a requests the stateful SLA information, i.e. the monitoring data of the plurality of UEs 120a-n of the current S-NSSAI 130a from the TENF 110b. The request may include the S-NSSAI 130a and UE IDs. In addition, the request may include the information received by the ENF 110a in step 1.1.

[0106] In step 2.2 of figures 6a and 6b, the TENF 110b monitors the UE SLA information, as will be described in more detail further below. The monitoring and tracking of UE SLA related information for the UEs 120a-n by the TENF 110b may already have been initiated, i.e. ongoing or will be initiated when the request from ENF 110a is received.

[0107] In step 2.3 of figures 6a and 6b, based on the monitored UE SLA information, the TENF 110b may determine a stateful SLA evaluation of the plurality of UEs 120a-n, as will be described in more detail further below. In step 2.4 of figures 6a and 6b, the TE NF 110b provides the requested stateful SLA evaluation, i.e. monitoring data of the plurality of UEs 120a-b of the indicated S-NSSAI 130a to the ENF 110a.

[0108] In step 2.5 of figures 6a and 6b, the ENF 110a determines the selection priority of the plurality of UEs 120a-n based on the stateful evaluation results, i.e. the monitoring data provided by TENF 110b in step 2.4 and applies a UE selection policy to the prioritized UEs 120a-n according to the NSR scenario, as will be described in more detail further below.

[0109] In step 3.1 of figures 6a and 6b, the ENF 110a provides the selected UEs of the plurality of UEs 120a-n with the mapping of each UE with its ranking or priority to the requesting CN NF 150. If multiple S-NSSAIs are provided, multiple mappings may be provided. If the request from step 1 does not include an indication of the number of UEs to be transferred to the alternative S-NSSAI 130b, the mapping of all UEs 120a-n with their corresponding ranking may be provided to the NSR triggering CN NF 150.

[0110] In step 3.2 of figures 6a and 6b, the CN NF 150 communicates with the UE 120a for the alternative S-NSSAI 130b.

[0111] In step 3.3 of figures 6a and 6b, the UE 120a is registered with the alternative S-NSSAI 130b and a PDU session is established, for instance, in accordance with the procedure defined in TS23.502.

[0112] Figures 7a and 7b show signalling diagrams illustrating the exchange of messages between the ENF 110a and the TENF 110b as well as further network entities for the embodiment of figure 5 for supporting the transfer of one or more UEs of the plurality ofUE 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. The embodiment shown in figure 7b differs from the embodiment of figure 7a in that the ENF 110a is implemented as a NWDAF 110a and the TENF 110b is implemented as a NSSF 110b.

[0113] In step 1 of figures 7a and 7b, the TENF 110b receives a request for the stateful SLA information of the UEs 120a-n of the indicated S-NSSAI 130a. The request may include the S-NSSAI information and the UE IDs (similar to step 2.1 of figures 6a and 6b).

[0114] In step 2 of figures 7a and 7b, the TENF 110b checks that the UE IDs are in the stateful SLA table. If not, the TENF 110b creates an entry for the requested UE(s). The following steps are skipped, if the UE IDs are already created in the stateful SLA table.

[0115] In step 3 of figures 7a and 7b, the TENF 110b requests UE SLA information from the network entity, e.g., AF / OAM 140.

[0116] In step 4 of figures 7a and 7b, the network entity, e.g., AF / OAM 140 provides UE SLA information. The information may include SLA parameters with SLO, associated tolerance and time window.

[0117] In step 5 of figures 7a and 7b, the TENF 110b subscribes the provided service to the UE 120a by the network to the corresponding CNNFs (e.g., SMF, AMF). The subscription request may include UE identifications and the UE SLA parameter, e.g., performance KPIs, reporting information, for instance, periodic or event-based reporting.

[0118] In step 6 of figures 7a and 7b, the TENF 110b receives the acknowledgement from the CNNFs 150.

[0119] In step 7 of figures 7a and 7b, when the event occurs, the CN NFs 150 notify the provided service level to the TENF 110b. In step 8 of figures 7a and 7b, the notifications of the provided service level for the corresponding UE SLA parameter and corresponding UE identification is updated to the stateful SLA table.

[0120] The monitored provided service level (SL) of each SLA parameter is used to determine the stateful SLA information of UE as described further below.

[0121] Figures 8a and 8b show signalling diagrams illustrating the exchange of messages between the ENF 110a and the TENF 110b as well as further network entities for the embodiment of figure 5 for supporting the transfer of one or more UEs of the plurality of UE 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100, more specifically for UE SLA adaptation monitoring and NSR event triggering. The embodiment shown in figure 8b differs from the embodiment of figure 8a in that the ENF 110a is implemented as a NWDAF 110a and the TENF 110b is implemented as a NSSF 110b.

[0122] In step 1 of figures 8a and 8b, the TENF 110b receives an NSR event subscription from the ENF. The subscription request includes the S-NSSAI, UE IDs or App ID. The request may include the reporting information, e.g., notify if UE SLA adaptation happens. Three types of UE SLA adaptation are illustrated in figures 8a and 8b.

[0123] For a first type A, in step A.O of figures 8a and 8b, based on the subscription request, the TENF 110b monitors the UE SLA and determines if the negotiation of UE SLA is recommended. For example, UE’s downlink data volume has crossed a threshold (e.g., 80% of the maximum downlink data volume has been reached) or UE’s maximum downlink bit rate is not fulfilling the service’s requirement, the TENF 110b (i.e., AF) determines to negotiate or recommend using a better UE SLA scheme. In step A.l of figures 8a and 8b the TENF 110b negotiates the UE SLA adaptation with the UE 120a. In step A.2 the UE 120a accepts the negotiation or recommended request.

[0124] For a further type B, in step B.O of figures 8a and 8b, based on the subscription request, the TENF 110b monitors the UE SLA related to the QoS of UEs or QoS requirement related to the indicated S-NSSAI.

[0125] For a further type C, in step C.O of figures 8a and 8b, based on the subscription request, the TENF 110b monitors the UE SLA related to the QoE of UEs or QoS requirement related to the Application.

[0126] In step 2 of figures 8a and 8b, the TENF 110b detects the subscribed event by monitoring the UE SLA adaptation.

[0127] In step 3 of figures 8a and 8b, when the event occurs, the TENF 110b notifies the NSR event to the ENF 110a.

[0128] In the following the concept of stateful SLA, which according to an embodiment is generated by the TENF 100b and used by the ENF 110a for the UE selection, i.e. the NSR procedure is described. In an embodiment, stateful UE SLA information indicates how the services or service level requested by a respective UE 120a-n is provided by the network 100 in comparison with the stateful SLA evaluation as agreed UE SLA information. In an embodiment, the UE SLA is evaluated over a specific time periodic, e.g., monthly basis. The SLA violation and evaluation is justified by the end of each month. In the proposed stateful SLA evaluation, UE SLA violation and evaluation is measured, monitored and actions are taken to avoid overall SLA violation in timely manner or in advanced, in particular, for NSR service operation procedures. Based on the stateful SLA evaluation results, the UE(s) 120a-n to be migrated or to be admitted to the alternative S-NSSAI 130b are selected properly and the network 100 may improve overall UE SLA violation in NSR procedure.

[0129] In an embodiment, stateful UE SLA information is based on historical data of UE SLA information such as the required or requested SLA related information and the provided SLA associated with one or more specific time periods. Based on the stateful UE SLA information collected, the stateful UE SLA may be evaluated over a specific time window, e.g., from a start of every calendar month to the time of evaluation. The algorithm of determination of stateful SLA evaluation and some examples are described in the following.

[0130] In addition to the UE related performance attributes and SLOs, the UE SLA information may include QoS and QoE related information. In the case of QoS related UE SLA information, a respective UE may be evaluated based on the QoS parameters and its requirements, the tolerances of each QoS requirement upholding and a specific time windows for the tolerance of each QoS requirement upholding. In the case of QoE related UE SLA information, UE is evaluated based on the QoE (e.g., MOS) performance, the tolerances of QoE requirement upholding and a specific time window for the tolerance of QoE requirement upholding.

[0131] In an embodiment, a UE selection policy is identified for selecting UE / UEs to perform the enforcement actions. According to an embodiment information to identify the UE selection policy for an NSR event is provided in the table shown in figure 9. The priority information indicates low or high priority UEs. To determine the priority, UE stateful evaluation results are considered. For example, a UE is identified as a low priority UE, if UE has no UE SLA breach in history, and a UE is identified as a high priority UE, if UE SLA is breached soon in order to avoid potential UE SLA violation. Low or high priority UEs may be ranked so that the specific amount of UEs to be replaced or to be admitted to Alternative S_NSSAI 130b may be selected in order.

[0132] Using the information defined for the NSR selection policy, the NSR selection policy may be enforced. Different enforcement actions may be identified based on the NSR scenario and operator’s requirements. Examples of enforcement actions include migration of low priority UEs 120a-n to the alternative S-NSSAI 130b in the no mobility scenario and / or admission of high priority UEs 120a-n to the alternative S-NSSAI 130b in the mobility scenario.

[0133] As already described above, in addition to a Network triggered NSR service operation, according to embodiments disclosed herein NSR events may be triggered by a 3rdparty application service provider, e.g., the AF 140. The 3rdparty application provider, e.g., the AF 140 may interact with the network 100 for NSR events, for instance, when one or more of the following conditions are met: UE SLA adaptation for the UE / UEs 120a-n: QoS requirements adaptation for the UE / UEs 120a-n: and / or QoE requirement adaptation for the UE / UEs 120a-n.

[0134] In an embodiment, the UE SLA adaptation may be initiated by the UE 120a-n to the application service provider for a specific period time or temporarily in addition to the current UE SLA. Exemplary use cases include Application related subscription plan upgrade or downgrade which might be associated with cost or charging. Based on the requirement from the UE 120a-n the application service provider may determine to trigger an NSR event, e.g., if the current S-NSSAI 130a of the UE / UEs 120a- n cannot fulfil the new requirement of the UE / UEs 120a-n. In addition, an NSR event trigger may be initiated directly by the AF 140, if the requirement of UE SLA adaptation is decided by the Application service provider, e.g., based on UE behavior, energy saving or efficiency related decision.

[0135] In a further embodiment, the QoS requirement adaptation may be initiated by the application service provider, e.g., the AF 140. Exemplary use cases include QoS adaptation for UE / UEs or Applications with a granularity of Network Slice level. The cause of QoS adaptation may include poor radio coverage or radio quality UEs at the current S-NSSAI 130a (i.e., per Slice per App) or the need of dynamic and temporary QoS requirements per Slice per Application. A Network Slice Replacement notification may be triggered to the network (5GS, 5G-A, 6G) for UEs 120a-n, e.g., temporarily. The granularity can be per UE or per Slice or per Application or any combination. In a further embodiment, the QoE requirement adaptation may initiated by the application service provider, e.g., the AF 140. Exemplary use cases include service Experience (QoE) for an Application related to UE / UEs in an Application. The cause of QoE adaptation may include poor radio coverage or radio quality UEs 120a-n at the current S-NSSAI 130a (i.e., per Slice per App). A Network Slice Replacement notification due to QoE requirement adaptation per slice per application may be triggered to the network (5GS, 5G-A, 6G) for UEs, e.g., temporarily.

[0136] Figure 10 shows a schematic diagram illustrating processing stages implemented by the TENF 110b according to an embodiment for supporting the transfer of one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. More specifically, figure 10 illustrates how the TENF 110b may determine a Stateful Evaluation Result until time instant t based on the following phases. Given the promised SLO, requested and provided SL info, tolerance and time window, the TENF 110b computes in phase 1 the provided stateful tolerance, PST, according to the algorithm illustrated in figure I la. Using the tolerance and stateful tolerance, the TENF 110b determines in phase 2 the level of prioritization of the UEs 120a-b based on a ranking system. Using the determined level of prioritization, the TENF 110b computes in phase 3 the overall Stateful Evaluation Result (SER), which may be provided as the monitoring data to the ENF 110a.

[0137] In an embodiment, the level of prioritization of UEs may be determined in phase 2 of figure 10 based on a two-dimensional ranking system, wherein the first dimension (i.e. Dimension 1) is based on whether the PST has been violated or not and the second dimension (i.e. Dimension 2) is based on the type of the UE attribute. In a first step the TENF 110b may determine the ranking based on the first dimension (Provided Stateful Tolerance). To this end, in an embodiment, the TENF 110b may implement the algorithm illustrated in figure 1 lb. In a second step the TENF 110b may determine the ranking based on the second dimension (Attribute Type). Based on the type of UE Attribute, the ranking may be recorded. An exemplary attribute ranking is illustrated in the table shown in figure 12a.

[0138] In phase 3 (i.e. the computation of the Overall Stateful Evaluation Result (SER) for a UE), for a given UE ID and its attribute, its ranking along the first and second dimensions are known from phase 2. According to an embodiment, the SER may be computed by the TENF 110b in two steps. In a first step, the TENF 110b may compute the Per UE Per Attribute SER = second step, the TENF 110b may compute Per UE SER = SER of Attribute 1 + SER of Attribute 2 + ...

[0139] In this embodiment, the UE with the highest SER has the highest priority.

[0140] In the following a simple example for computing the overall SER by the TENF 110b is described.

[0141] Phase 1: Computation of Provided Stateful Tolerance (PST)

[0142] In this example, three UE attributes are considered: 1 ) Availability of CS, 2) PDB and 3) Throughput. Considering UE#1 and Attribute “Availability of CS” and arbitrary time stamp t = 10 / 06 / 2020 16:20:51, according to Algorithm 1 (illustrated in figure I la).

[0143] 1. At = 30 + 60 + 60 = 150s

[0144] 2. L = 24 x 60 x 60 - 100 = 864s

[0145] 3. PST until t = 150 - 864 = 0.17%

[0146] In this example, PST is within the tolerance limit I as illustrated by the table shown in figure 12b. Phase 2: Determination of level of prioritization

[0147] Step 1: Determine ranking based on Dimension 1 (Provided Stateful Tolerance). Threshold value of the tolerance is C = 50%. Step 2: Determine ranking based on Dimension 2 (Attribute Type).

[0148] The attribute ranking policy along Dimension 1 is considered as shown in the table of figure 12c. The attribute ranking policy along Dimension 2 is considered as shown in the table of figure 12d. Therefore, combining the tables of figures 12c and 12d and applying Algorithm 2 shown in figure 11b, the level of prioritization of UE#1 for the current example is as shown in the table of figure 12e.

[0149] Phase 3: Computation of Overall Stateful Evaluation Result (SER) for a UE

[0150] According to the steps described earlier for Phase 3, the Per UE Per attribute SER and Per UE SER are computed as shown in the table of figure 12f. The SER per UE is computed for all other UEs and the UE with the highest SER has the highest priority.

[0151] Figure 13 is a flow diagram illustrating a method 1300 for operating the network entity 110a, in particular ENF 110a, for controlling a transfer of one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b of the mobile network 100. The method 1300 comprises a step 1301 of sending by the network entity 110a, in particular ENF 110a, a Network Slice Replacement, NSR, notification message to the application function, AF, 140 associated with an application running on the plurality of UEs 120a-n. As already described above, the NSR notification message comprises a respective identifier of the one or more UEs of the plurality of UEs 120a-n, an identifier of the network slice 130a, and / or an identifier of the further network slice 130b.

[0152] The method 1300 can be performed by the network entity 110a, in particular ENF 110a. Thus, further features of the method 1300 result from the functionality of the network entity 110a, in particular ENF 110a, as well as the different implementation forms and embodiments thereof described above and below.

[0153] Figure 14 is a flow diagram illustrating a method 1400 for operating the further network entity 110b, in particular TENF 110b, for supporting a transfer of one or more UEs of a plurality of UEs 120a-n from a network slice 130a to a further network slice 130b controlled by a network entity 110a, in particular ENF 110a, of a mobile network 100. The method 1400 comprises a step 1401 of determining a stateful evaluation of each UE of the plurality of UEs 120a-n. Moreover, the method 1400 comprises a step 1403 of sending the stateful evaluation of each UE of the plurality of UEs 120a-n as monitoring data to the network entity 110a, in particular ENF 110a, for controlling the transfer of the one or more UEs of the plurality of UEs 120a-n from the network slice 130a to the further network slice 130b.

[0154] The method 1400 can be performed by the further network entity 110b, in particular TENF 110b. Thus, further features of the method 1400 result from the functionality of the further network entity 110b, in particular TENF 110b, as well as the different implementation forms and embodiments thereof described above and below.

[0155] The person skilled in the art will understand that the "blocks" ("units") of the various figures (method and apparatus) represent or describe functionalities of embodiments of the present disclosure (rather than necessarily individual "units" in hardware or software) and thus describe equally functions or features of apparatus embodiments as well as method embodiments (unit = step).

[0156] In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described embodiment of an apparatus is merely exemplary. For example, the unit division is merely a logical function division and may be another division in an actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented by using some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

[0157] In addition, functional units in the embodiments of the disclosure may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units may be integrated into one unit.

Claims

CLAIMS1. A network entity (110a; 110) for controlling a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b) of a mobile network (100), wherein the network entity (110a; 110) is configured to: send a notification message to an application function, AF, (140) for a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b), wherein the notification message comprises a respective identifier of the one or more UEs of the plurality of UEs (120a-n), an identifier of the network slice (130a), and / or an identifier of the further network slice (130b).

2. The network entity (110a; 110) of claim 1, wherein the network entity (110a; 110) is configured to receive a request from the AF (140) for transferring one or more UEs of the plurality of UEs (120a-n) from the network slice (130a) to the further network slice (130b) of the mobile network (100), wherein the request comprises a respective identifier of the one or more UEs transferred to the further network slice (130b), an identifier of the network slice (130a), an identifier of the further network slice (130b), an identifier of an application running on the plurality of UEs (120a-n) and associated with the AF (140), and / or an indication of a network slice replacement for the one or more UEs from the network slice (130a).

3. The network entity (110a; 110) of claim 2, wherein, in response to receiving the request from the AF (140), the network entity (110a; 110) is configured to select the one or more UEs of the plurality of UEs (120a-n) and to trigger the transfer of the one or more UEs of the plurality of UEs (120a-n) from the network slice (130a) to the further network slice (130b) of the mobile network (100).

4. The network entity (110a; 110) of claim 2, wherein the network entity (110a; 110) is configured to receive the request from the AF (140), in response to sending the notification message to the AF (140).

5. The network entity (110a; 110) of claim 4, wherein, in response to receiving the request from the AF (140), the network entity (110a; 110) is configured to trigger the transfer of the one or more UEs of the plurality of UEs (120a-n) from the further network slice (130b) back to the network slice (130a) of the mobile network (100).

6. The network entity (110a; 110) of claim 1, wherein the network entity (110a; 110) is configured to receive a request from a network function (150) of the mobile network (100) for transferring one or more UEs of the plurality of UEs (120a-n) from the network slice (130a) to the further network slice (130b) of the mobile network (100), wherein the request comprises an identifier of the network slice (130a), and / or an identifier of the further network slice (130b).

7. The network entity (110a; 110) of claim 6, wherein, in response to receiving the request from the network function (150) of the mobile network (100), the network entity (110a; 110) is configured to select the one or more UEs of the plurality of UEs (120a-n) and to trigger [the transfer of the one or more selected UEs of the plurality of UEs (120a-n) from the network slice (130a) to the further network slice (130b) of the mobile network (100).

8. The network entity (110a; 110) of claim 7, wherein each of the plurality of UEs (120a-n) is associated with a Service Level Agreement, SLA, wherein each SLA defines one or more Service Level Objects, SLOs, for one or more SLA attributes of the SLA, and wherein the network entity (110a; 110) is configured to determine or to obtain from a further network entity (110b) for each of the plurality of UEs (120a-n) monitoring data of each of the plurality of UEs (120a-n) and to select the one or more UEs of the plurality of UEs (120a-n) based on the monitoring data of each of the plurality of UEs (120a-n).

9. The network entity (110a; 110) of claim 8, wherein the network entity (110a; 110) is configured to select the one or more UEs of the plurality of UEs (120a-n) based on the monitoring data of each of the plurality of UEs (120a-n), wherein the monitoring data is related to the status of the SLA or SLA fulfilment of each UE of the plurality of UEs (120a-n).

10. The network entity (110a; 110) of claim 9, wherein the monitoring data determined by the network entity (110) or obtained from the further network entity (110b) comprises a stateful evaluation of each UE of the plurality of UEs (120a-n).

11. The network entity (110a; 110) of any one of the preceding claims, wherein the mobile network (100) is a 3GPP network (100) and wherein the network entity (110a; 100) is a Policy Control Function (110a; 110) or Network Data Analytics Function of the mobile network (100).

12. A further network entity (110b) for supporting a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b) controlled by a network entity (110a) of a mobile network (100), wherein the further network entity (110b) is configured to determine a stateful evaluation of each UE of the plurality of UEs (120a-n) and to send the stateful evaluation of each UE of the plurality of UEs (120a-n) as monitoring data to the network entity (110a).

13. The further network entity ( 110b) of claim 12, wherein the further network entity ( 110b) is configured to determine the stateful evaluation of each UE of the plurality of UEs (120a-n) based on one or more service level agreement, SLA, attributes and one or more associated service level objectives, SLOs, of each SLA attribute, one or more tolerances of each SLO upholding and / or a specific time window associated with the tolerance of each SLO upholding related to the each UE of the plurality of UEs (120a-n).

14. A method (1300) for operating a network entity (110a; 110) for controlling a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b) of a mobile network (100), wherein the method (1300) comprises: sending (1301) a notification message to an application function, AF, (140) for a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b), wherein the notification message comprises a respective identifier of the one or more UEs of the plurality of UEs (120a-n), an identifier of the network slice (130a), and / or an identifier of the further network slice (130b).

15. A method (1400) for operating a further network entity (110b) for supporting a transfer of one or more user equipments, UEs, of a plurality of UEs (120a-n) from a network slice (130a) to a further network slice (130b) controlled by a network entity (110a) of a mobile network (100), wherein the method (1400) comprises: determining (1401) a stateful evaluation of each UE of the plurality of UEs (120a-n); and sending (1403) the stateful evaluation of each UE of the plurality of UEs (120a-n) as monitoring data to the network entity (110a).

Images