Methods for enhanced QOS setup with NWDAF assistance

Abstract

A method of Network Data Analytics Function (NWDAF) assisted Quality of Service (QoS) setup for a User Equipment (UE) in a telecommunications network is disclosed. A session management function (SMF) or Policy control function (PCF) subscribes to NWDAF QoS sustainability analytics which predict whether the UE is likely to request a different QoS in a particular time window or area. At or during establishment or modification of a Protocol Data Unit (PDU) session, the SMF or PCF uses a QoS value for a default QoS that is different from a subscribed default QoS value for the UE, to anticipate the future requirement of the UE and avoid signalling associated with requesting QoS change. In an alternative, the SMF or PCF returns at least two QoS flows.

Description

The present invention relates to QoS setup, for example in 5GC. Background to the invention 3GPP SA2 Rel-19 Study in AIML The 3GPP has agreed a study item for Rel-19 AIML topic in SP-231800 - “Study on Core Network Enhanced Support for Artificial Intelligence (Al) / Machine Learning (ML), 3GPP TSG SA Meeting #102, 11-15 December 2023, Edinburgh, UK”. The study lists so called work tasks (WT) which define specific aspects that are to be investigated, where WT3 is described as follows: WT3: Study enhancements to support NWDAF-assisted policy control and address network abnormal behaviour WT3.1 - Study whether and what additionally needs to be supported in order to enhance 5GC NF operations (i.e. policy control and QoS) assisted by NWDAF. The work will firstly identify the specific use cases to be considered, in order to identify the appropriate scope. The work will analyse the result impacts on NWDAF (e.g. the need to understand specific NF functionality), and the compatibility of new solutions wrt existing analytics, in order to determine the need and benefits of new solutions. WT3.2 - Study prediction, detection, prevention, and mitigation of network abnormal behaviours i.e. signalling storm with the assistance of NWDAF. The Network Data Analytics Function framework is defined in 3GPP TS 23.288. The specification describes how the NWDAF can be used to obtain analytics (and / or predictions) for well-defined set of parameters. For example, section 6.9 defines the QoS Sustainability Analytics as follows: The consumer of QoS Sustainability analytics may request the NWDAF analytics information regarding the QoS change statistics for an Analytics target period in the past in a certain area or the likelihood of a QoS change for an Analytics target period in the future in a certain area. The consumer can request either to subscribe to notifications (i.e. a Subscribe-Notify model) or to a single notification (i.e. a Request-Response model). The inputs and outputs of the analytics are further defined in aforementioned 3GPP specification. Summary of the Invention According to a first aspect of the invention, there is provided a method of Network Data Analytics Function (NWDAF) assisted Quality of Service (QoS) setup for a User Equipment (UE) in a telecommunications network, the method comprising: using, at and / or during establishment or modification of a Protocol Data Unit (PDU) session, a QoS value for a default QoS that is different from a subscribed default QoS value for the UE; and / or returning, by the Session Management Function (SMF) and / or the Policy Control Function (PCF), at least two QoS flows; and / or subscribing, by the SMF and / or the PCF, to and / or with the NWDAF for at least one defined analytics. In an embodiment, the method further comprises the step of: defining, by the PCF and / or the SMF, the default QoS value for the UE, for example based on analytics information. In an embodiment, the method further comprises the step of: obtaining, by the SMF and / or the PCF, analytics for the UE, and / or other information related to network performance. In an embodiment, the method further comprises the step of: verifying, by the SMF and / or the PCF, the frequency of QoS changes that were made by the UE. In an embodiment, the method further comprises the step of: determining, by the SMF and / or the PCF, to use a default QoS value for the default QoS flow that is different from the subscribed QoS value. In an embodiment, the method further comprises the step of: informing, by the SMF, the PCF that at least one QoS value has been modified, based on analytics. In an embodiment, the method further comprises the step of: obtaining, by the SMF and / or the PCF analytics for the UE, where the analytics relates to QoS sustainability analytics. In an embodiment, the method further comprises the step of: performing, by the NWDAF, analytics for the UE in a certain area of interest. In an embodiment, the method further comprises the step of: verifying, by the SMF and / or the PCF, the frequency of QoS changes that were made by the UE. In an embodiment, the method further comprises the step of: determining, by the SMF and / or the PCF, that QoS change statistics indicate that the UE may request a change of QoS. In an embodiment, the method further comprises the step of: creating and / or establishing, by the SMF and / or the PCF, at least one additional QoS rule or QoS flow with a QoS value that is different from the QoS value associated with the default QoS flow. In an embodiment, the method further comprises the step of: choosing, by the SMF and / or the PCF, a QoS value for an additional QoS flow such that the chosen value is similar to, or better than in terms of QoS characteristics, what the UE would have normally requested for a QoS flow which is not a default QoS flow. In an embodiment, the method further comprises the step of: ensuring, by the SMF and / or the PCF, that an “Authorized QoS rules" Information Element (IE) of a PDU Session Establishment Accept message contains at least one additional QoS rule which is not a default QoS rule, and / or the QoS value that is indicated is associated with, or maps to, the chosen QoS value. In an embodiment, the method further comprises the step of: informing, by the SMF, the PCF that at least one QoS value has been modified based on analytics. In an embodiment, the method further comprises the step of: triggering, by the PCF and / or the PCF, storage / retrieval of analytics from the ADRF. In an embodiment, the method further comprises the step of: retrieving, by the PCF, the stored analytics for the UE, when the SMF contacts the PCF to obtain policy rules. In an embodiment, the method further comprises the step of: determining, by the PCF and / or the SMF, a modified QoS value based on the analytics obtained from the ADRF and / or the NWDAF and providing, by the PCF, a policy rule such that the determined QoS value is then provided. In an embodiment, the method further comprises the step of: determining, by the PCF and / or the SMF, to provide a second rule such that the second rule is associated with a non-default QoS rule and determining the QoS value for this rule based on the analytics that is received. In an embodiment, the method further comprises the step of: providing, by the PCF to the SMF: the determined QoS value for the default QoS rule or QoS flow; and / or at least two rules where the second rule is for a non-default QoS rule with a QoS value that has been determined. In an embodiment, the method further comprises the step of: determining, by the SMF and / or PCF, to establish at least two QoS rules during a PDU session establishment procedure, if SMF and / or PCF receives at least two policy rules where at least one of these are for a non-default QoS rule. In an embodiment, the method further comprises the step of: providing, by the PCF to the SMF, an indication that the QoS value has been determined based on analytics; and establishing, by the SMF, at least one non-default QoS rule based on the indication. According to a second aspect of the invention, there is provided a telecommunications network configured to implement the method according to the first aspect. Detailed Description of the Invention According to the present invention there is provided a method, as set forth in the appended claims. Also provided is a network. Other features of the invention will be apparent from the dependent claims, and the description that follows. Lack of solutions for enhanced QoS setup with NWDAF assistance There are no current solutions which have been proposed for the WT indicated above, in particular one that can be used as an enhancement for QoS flow setup. The following is one example of a scenario that can be used to describe a use case which can benefit from further enhancements. A UE may setup a PDU session after it registers with the 5GS. Each PDU session is necessarily associated with a so called default QoS rule which in turn provides a default QoS treatment for data flows. The characteristics of the default QoS is determined by the so called subscribed default values (for parameters such as 5QI, ARP) which the SMF may obtain from the UDM. The characteristics of a default QoS rule, and hence default QoS flow, may not be able to support requirements for applications like video streaming or video conferencing, etc. The default values may be sufficient for basic browsing or instant messaging over IP whereas video streaming applications will then require better QoS treatment e.g. using QoS flows which are for Guaranteed Bit Rate (GBR) or which are characterized by certain 5QI values even for the case of non-GBR QoS flows. Further parameters and details related to QoS can be found in 3GPP TS 23.501. When such flows are required due to the use of an application in the UE, the UE would normally send a NAS message to modify the PDU session and thereby request to establish a new QoS with the required characteristics. This results in a few NAS signalling messages between the UE and the SMF, and also requires signalling between the SMF, UPF, RAN, and eventually results in RRC messages between the RAN and the UE. As such a modification of a PDU session can indeed result in system-wide signalling. Figure 1, taken from 3GPP TS 23.502 shows the overall signalling that can be associated with a PDU session modification procedure. Figure 1 shows overall signalling based on a prior art procedure for session modification from 3GPP TS 23.502. It is possible that the UE’s requests for establishing a PDU session and subsequent modification of the session in order to request a new QoS flow with particular treatment are driven by a user (of the device or UE) who demonstrates some pattern in terms of frequency of use of a service, place of use of a service, and the QoS requirements that emerge from the UE as a result. For example, a UE may request a PDU session and later modify that such that a new GBR QoS flow is established for a particular time window. This may be a recurring pattern for the UE. As such, it can be expected that a PDU session will be modified eventually (at some time) and, hence, system-wide signalling is expected to be generated as explained above. If the NAS procedures can be predictable, then the system may benefit from analytics and predictions that would help the SMF establish the necessary QoS flows as part of one procedure instead of having multiple procedures and hence more signalling. Embodiments of the present invention seek to provide NWDAF assistance for enhancing QoS setup and reduction of signalling. Solutions The first aspect provides a method of Network Data Analytics Function (NWDAF) assisted Quality of Service (QoS) setup for a User Equipment (UE) in a telecommunications network, for example a 5G network, the method comprising: using, for example at and / or during establishment of a Protocol Data Unit (PDU) session, a 5QI for a default QoS that is different from a subscribed default 5QI for the UE; and / or returning, by the Session Management Function (SMF), for example at and / or during establishment of the PDU session, at least two QoS flows; and / or subscribing, by the Policy Control Function (PCF), to and / or with the NWDAF for the QoS sustainability analytics. The second aspect provides a telecommunications network configured to implement the method according to the first aspect. Note that, herein, the term “analytics” may refer to any combination of: analytics, statistics, prediction, recommendation, information, and in any order. For all the nodes that are proposed to use analytics, the nodes may aggregate analytics from one or more source analytics entities. Although the solutions herein are set out using an example analytics (i.e. QoS sustainability analytics), the details can be applied with / to any other existing analytics, or new analytics, which may be used to provide similar information, statistics, predictions, etc. As such the embodiments herein are not necessarily limited to one type of analytics only. Moreover, embodiments may find utility with any existing analytics that may be enhanced in the future. For all the embodiments herein, steps described can be applied in any order or combination. The SMF subscribes to the QoS sustainability analytics with the NWDAF. Alternatively, or additionally, the PCF subscribes to the QoS sustainability analytics with the NWDAF The following assumptions, which are to be considered as solutions, are set out: • For at least one UE in question, the SMF and / or the PCF should subscribe to or request the NWDAF for obtaining analytics (predictions) related to QoS sustainability analytics o Note that the solutions described may also apply to all UEs or group of UEs or a list of UEs, as appropriate. • QoS sustainability analytics might be provided by the NWDAF at UE level, i.e. average value of multiple UEs in an area, or for specific UEs. • QoS sustainability analytics might be the analytics for the Applicable Area that the UE belongs to. • SMF and / or PCF subscribes to or requests the QoS related parameters, e.g. QoS sustainability analytics, with the NWDAF. • The SMF and / or PCF should trigger the storage of analytics in the Analytics Data Repository Function (ADRF) as described in 3GPP TS 23.228. The SMF and / or PCF should maintain in context the ADRF address which was used to store analytics for a (group of) UE in question. Upon a NAS 5GSM procedure, e.g. during a PDU session establishment procedure or PDU session modification procedure, the SMF and / or PCF may verify if there is an ADRF address stored for the (group of) UE in question. If yes, the SMF and / or PCF may retrieve the analytics from the ADRF optionally before the completion of the procedure (e.g. before the SMF and / or PCF responds with a NAS message to the UE, etc). How the SMF and / or PCF uses this information will be described subsequently. o The SMF and / or PCF may be configured to operate as explained above e.g. based on local policies or OAM. Alternatively, new subscription information may be defined such that the SMF and / or PCF can behave as described above for a UE in question. For example, the subscription information may indicate that the SMF and / or PCF can behave as described above for a UE. This new subscription information may be obtained from the UDM. For all the embodiments described herein, the details can apply to a single UE or a group or list of UEs. At establishment of a PDU session, use a 5QI for the default QoS such that it is different from the subscribed default 5QI The SMF and / or PCF may be configured to operate as explained below for any combination of steps or SMF and / or PCF actions. Alternatively, new subscription information may be defined such that the SMF and / or PCF can behave as described below for a UE in question. For example, this new subscription information may indicate that the SMF and / or PCF can use the method below to proactively modify the default 5QI for a UE in question, where for example the updated value is different from the subscribed default value (and optionally based on NWDAF assistance as will be described). This new subscription information may be obtained from the UDM. The default 5QI for a UE might be also defined by the PCF and / or the SMF based on analytics information, i.e. the PCF or SMF determine the default 5QI value by considering the QoS sustainability analytics from NWDAF, optionally with the potential and existing services the UE may have, any other information related to network condition and / or performance. Therefore, to reduce the potential modification of the established QoS flow, if there are new service flow or traffic for the UE. The signalling and modification procedures within the 5GS can be reduced or optimized correspondingly. In one example, during the establishment of a PDU session (or modification of a PDU session), the SMF and / or PCF should obtain analytics for the UE in question, where the analytics is for QoS sustainability analytics, any other potential information related to the UE (e.g. UE performance, UE traffic, mobility, UE service experience), other potential information related to network performance. In one example, the SMF and / or PCF may verify the frequency of QoS changes that were made by the UE. For example, the SMF and / or PCF may verify Crossed Reporting Threshold parameter as described in 'Table 6.9.3-1: "QoS Sustainability" statistics’ in 3GPP TS23.228. If the SMF and / or PCF determines that the QoS change statistics (optionally for an Analytics target period in the past in a certain area or the likelihood of a QoS change for an Analytics target period in the future in a certain area) indicates that the UE may request a change of QoS, then the SMF and / or PCF may determine to use a default 5QI value for the default QoS flow that is different from the subscribed 5QI value. With the above, the SMF and / or PCF is using modified default 5QI value such that this value is applicable to different services that the UE may request and hence the UE will not need to request this 5QI value subsequently as part of PDU session modification for creating a new QoS flow with this 5QI. Therefore, advantageously, overall signaling can be reduced in the system. Figure 2 shows an example procedure to establish a PDU session using a modified default 5QI value based on analytics. Note that all the details set out above apply to other QoS parameters such as ARP, etc. In other words, the SMF and / or PCF may modify the ARP value, for example, when the SMF and / or PCF determines to modify the 5QI value for the default QoS flow. The determined I modified ARP value may be based on local policies. Note that the SMF may have different suggestion for using a modified default 5QI value e.g. based on OAM, or indication from the subscription that this value can be changed, or based on a policy rule from the PCF (Policy Control Function), or based on NWDAF assistance as explained herein. The SMF and / or PCF may be configured with a method to prioritize one of these values or sources e.g. the SMF and / or PCF may prioritize the information which is based on NWDAF over other methods for determining a modified value for the default 5QI. Note that although the details herein are set out based on the QoS sustainability analytics, embodiments can also relate to other analytics that can provide similar information to the consumer of the analytics. Therefore, the proposals are not to be considered limited to just the QoS sustainability analytics. Moreover, specific examples are given based around the SMF, but embodiments of the invention may apply or relate to other network functions such as, particularly, the PCF. As such, references to the use of the SMF should be considered as examples only, and not a limitation. As such, all the embodiments herein can be applied for other NFs such as the PCF. In this case, the PCF may in turn provide any determined values (as will be described below) to another NF such as the SMF. The SMF may inform the PCF that at least one 5QI value (for the default QoS rule or a nondefault QoS rule) has been modified based on analytics (although not shown in Figure 2). At established of a PDU session, the SMF returns at least two QoS Hows The SMF and / or PCF may be configured to operate as explained below for any combination of steps or SMF and / or PCF actions. Alternatively, new subscription information may be defined such that the SMF and / or PCF can behave as described below for a UE in question. For example, this new subscription information may indicate that the SMF and / or PCF can use the method below to proactively modify the default 5QI for a UE in question, where for example the updated value is different from the subscribed default value (and optionally based on NWDAF assistance as will be described). This new subscription information may be obtained from the UDM. In one example, during the establishment of a PDU session (or modification of a PDU session), the SMF and / or PCF should obtain analytics for the UE in question, where the analytics is for QoS sustainability analytics. Alternatively, the NWDAF may perform analytics for a particular UE in question, optionally in a certain area of interest. Note that this may apply to all solutions herein. In one example, the SMF and / or PCF should verify the frequency of QoS changes that were made by the UE. For example, the SMF may verify Crossed Reporting Threshold parameter as described in ‘Table 6.9.3-1: "QoS Sustainability" statistics’ in 3GPP TS23.228. If the SMF and / or PCF determines that the QoS change statistics (optionally for an Analytics target period in the past in a certain area or the likelihood of a QoS change for an Analytics target period in the future in a certain area) indicates that the UE may request a change of QoS, then the SMF may determine to behave as follows: • In addition to the default QoS that is established with the PDU session, the SMF and / or PCF should create or establish at least one additional QoS rule (or QoS flow) with a 5QI value that is different (and expected to be better in terms of QoS treatment) from the value of the 5QI associated with the default QoS flow. • The SMF and / or PCF should choose a 5QI value for the additional (at least one) QoS flow such that the chosen value is similar to (or better than in terms of QoS characteristics) what the UE would have normally requested for a QoS flow which is not a default QoS flow. This information (i.e. what the UE would have normally requested) may be based on the assistance information from the NWDAF (or ARDF) that the SMF and / or PCF should verify and use to make this determination. • In one example for the details provided above, the SMF and / or PCF should ensure that the Authorized QoS rules IE (of the PDU Session Establishment Accept message) contains at least one additional QoS rule which is not a default QoS rule, and the QFI that is indicated is associated with (or maps to) the chosen 5QI as described above. Therefore the outcome of the NAS procedure (i.e. the PDU session establishment procedure) is that the UE will receive the IE (and NAS message) such that this leads to the creation of at least two QoS rules where one is a default QoS rule (associated with a subscribed QFI / 5QI value) and at least one nondefault QoS rule which is associated with a QFI / 5QI that the SMF and / or PCF has determined as explained above. Figure 3 shows an example procedure to establish non-default QoS rule based with 5QI based on analytics. Note that although the details herein are provided based on the QoS sustainability analytics, embodiments can also apply to other analytics that can provide similar information to the consumer of the analytics. Therefore, the examples are not to be considered limited to just the QoS sustainability analytics. Moreover, the details may apply to other network functions such as the PCF, in particular, and so the use of the SMF should be considered as an example and not a limitation. As such, all the details herein can be applied for other NFs such as the PCF. In this case, the PCF may in turn provide any determined values (as will be described below) to another NF such as the SMF. The SMF may inform the PCF that at least one 5QI value (for the default QoS rule or a nondefault QoS rule) has been modified based on analytics (although not shown in Figure 3). PCF subscribes to QoS sustainability analytics In this solution option, the PCF (Policy Control Function) subscribes to the (or with the) NWDAF for the QoS sustainability analytics. Moreover, the PCF can also trigger the storage / retrieval of analytics from the ADRF as set out above for the SMF. As such all the details above in terms of subscribing to the NWDAF, and triggering storage / retrieval of analytics into / from the ADRF would apply for the PCF. Furthermore, this solution option sets out that when the SMF contacts the PCF to obtain policy rules (e.g. when the SMF requests to establish an SM Policy Association with the PCF by invoking Npcf_SMPolicyControl_Create operation), the PCF may retrieve the stored analytics for a UE in question. The PCF may then behave in any of the following manners: • The PCF determines a modified 5QI value based on the analytics obtained from the ADRF (or NWDAF) and the PCF provides a policy rule such that the determined 5QI value is then provided (where this value is based on the analytics received) • The PCF may determine to provide a second rule such that the second rule is associated with a non-default QoS rule and also determines the 5QI for this rule based on the analytics that is received. The PCF may provide to the SMF either: • The determined 5QI for the default QoS rule (or QoS flow) as described above, • At least two rules where the second rule is for a non-default QoS rule with a 5QI that has been determined as described above. If the SMF receives at least two policy rules where at least one of these are for a non-default QoS rule, then the SMF may determine to establish at least two QoS rules during the PDU session establishment procedure as has been described in previous solution options. In this case, the SMF uses the 5QI which has been received from the PCF per policy rule. Figure 4 shows an example of how the solutions above can be used. Figure 4 shows an example procedure for PCF determination of 5QI values based on analytics. Note that although not shown in the Figure 4, the PCF may, based on the determined 5QI using analytics, provide an explicit indication to the SMF that the 5QI value(s) have been determined based on analytics. The SMF may use this indication to in turn establish at least one non-default QoS rule using the 5QI obtained from the PCF. The term “consisting of” or “consists of means including the components specified but excluding other components. Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to include the meaning “consists essentially of or “consisting essentially of, and also may also be taken to include the meaning “consists of" or “consisting of”. The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments. Brief description of the drawings For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which: Figure 1 shows overall signalling based on a prior art procedure for session modification from 3GPP TS 23.502; Figure 2 shows an example procedure to establish a PDU session using a modified default 5QI value based on analytics; Figure 3 shows an example procedure to establish non-default QoS rule based with 5QI based on analytics; and Figure 4 shows an example procedure for PCF determination of 5QI values based on analytics. Detailed Description of the Drawings At establishment of a PDU session, use a 5QI for the default QoS such that it is different from the subscribed default 5QI The SMF and / or PCF may be configured to operate as explained below for any combination of steps or SMF and / or PCF actions. Alternatively, new subscription information may be defined such that the SMF and / or PCF can behave as described below for a UE in question. For example, this new subscription information may indicate that the SMF and / or PCF can use the method below to proactively modify the default 5QI for a UE in question, where for example the updated value is different from the subscribed default value (and optionally based on NWDAF assistance as will be described). This new subscription information may be obtained from the UDM. The default 5QI for a UE might be also defined by the PCF and / or the SMF based on analytics information, i.e. the PCF or SMF determine the default 5QI value by considering the QoS sustainability analytics from NWDAF, optionally with the potential and existing services the UE may have, any other information related to network condition and / or performance. Therefore, to reduce the potential modification of the established QoS flow, if there are new service flow or traffic for the UE. The signalling and modification procedures within the 5GS can be reduced or optimized correspondingly. In one example, during the establishment of a PDU session (or modification of a PDU session), the SMF and / or PCF should obtain analytics for the UE in question, where the analytics is for QoS sustainability analytics, any other potential information related to the UE (e.g. UE performance, UE traffic, mobility, UE service experience), other potential information related to network performance. In one example, the SMF and / or PCF should verify the frequency of QoS changes that were made by the UE. For example, the SMF and / or PCF may verify Crossed Reporting Threshold parameter as described in ‘Table 6.9.3-1: "QoS Sustainability" statistics’ in 3GPP TS 23.228. If the SMF and / or PCF determines that the QoS change statistics (optionally for an Analytics target period in the past in a certain area or the likelihood of a QoS change for an Analytics target period in the future in a certain area) indicates that the UE may request a change of QoS, then the SMF and / or PCF may determine to use a default 5QI value for the default QoS flow that is different from the subscribed 5QI value. With the above, the SMF and / or PCF is using modified default 5QI value such that this value is applicable to different services that the UE may request and hence the UE will not need to request this 5QI value subsequently as part of PDU session modification for creating a new QoS flow with this 5QI. Therefore, advantageously, overall signaling can be reduced in the system. Figure 2 shows an example procedure to establish a PDU session using a modified default 5QI value based on analytics. Note that all the details above apply to other QoS parameters such as ARP, etc. In other words, the SMF and / or PCF may modify the ARP value, for example, when the SMF and / or PCF determines to modify the 5QI value for the default QoS flow. The determined / modified ARP value may be based on local policies. Note that the SMF and / or PCF may have different suggestion for using a modified default 5QI value e.g. based on QAM, or indication from the subscription that this value can be changed, or based on a policy rule from the PCF (Policy Control Function), or based on NWDAF assistance as explained herein. The SMF and / or PCF may be configured with a method to prioritize one of these values or sources e.g. the SMF and / or PCF may prioritize the information which is based on NWDAF over other methods for determining a modified value for the default 5QI. Note that although the solutions herein are described based on the QoS sustainability analytics, the solutions can also apply to / with other analytics that can provide similar information to the consumer of the analytics. Therefore, the details are not to be considered limited to just the QoS sustainability analytics. Moreover, the techniques may apply to other network functions such as the PCF and so the use of the SMF should be considered as an example proposal and not a limitation. As such, all the techniques herein can be applied to other NFs such as the PCF. In this case, the PCF may in turn provide any determined values (as will be described below) to another NF such as the SMF. The SMF may inform the PCF that at least one 5QI value (for the default QoS rule or a nondefault QoS rule) has been modified based on analytics (although not shown in Figure 2). At establishment of a PDU session, the SMF and / or PCF returns at least two QoS flows The SMF and / or PCF may be configured to operate as explained below for any combination of steps or SMF and / or PCF actions. Alternatively, new subscription information may be defined such that the SMF and / or PCF can behave as described below for a UE in question. For example, this new subscription information may indicate that the SMF and / or PCF can use the proposed method below to proactively modify the default 5QI for a UE in question, where for example the updated value is different from the subscribed default value (and optionally based on NWDAF assistance as will be described). This new subscription information may be obtained from the UDM. In one example, during the establishment of a PDU session (or modification of a PDU session), the SMF and / or PCF should obtain analytics for the UE in question, where the analytics is for QoS sustainability analytics. Alternatively, the NWDAF may perform analytics for a particular UE in question, optionally in a certain area of interest. Note that this may apply to all solutions herein. In one example, the SMF and / or PCF should verify the frequency of QoS changes that were made by the UE. For example, the SMF may verify Crossed Reporting Threshold parameter as described in ‘Table 6.9.3-1: "QoS Sustainability" statistics’ in 3GPP TS 23.228. If the SMF and / or PCF determines that the QoS change statistics (optionally for an Analytics target period in the past in a certain area or the likelihood of a QoS change for an Analytics target period in the future in a certain area) indicates that the UE may request a change of QoS, then the SMF and / or PCF may determine to behave as follows: • In addition to the default QoS that is established with the PDU session, the SMF and / or PCF should create or establish at least one additional QoS rule (or QoS flow) with a 5QI value that is different (and expected to be better in terms of QoS treatment) from the value of the 5QI associated with the default QoS flow. • The SMF and / or PCF should choose a 5QI value for the additional (at least one) QoS flow such that the chosen value is similar to (or better than in terms of QoS characteristics) what the UE would have normally requested for a QoS flow which is not a default QoS flow. This information (i.e. what the UE would have normally requested) may be based on the assistance information from the NWDAF (or ARDF) that the SMF and / or PCF should verity and use to make this determination. • In one example for the above, the SMF and / or PCF should ensure that the Authorized QoS rules IE (of the PDU Session Establishment Accept message) contains at least one additional QoS rule which is not a default QoS rule, and the QFI that is indicated is associated with (or maps to) the chosen 5QI as described above. Therefore the outcome of the NAS procedure (i.e. the PDU session establishment procedure) is that the UE will receive the IE (and NAS message) such that this leads to the creation of at least two QoS rules where one is a default QoS rule (associated with a subscribed QFI / 5QI value) and at least one non-default QoS rule which is associated with a QFI / 5QI that the SMF has determined as explained above. Figure 3 shows an example procedure to establish non-default QoS rule based with 5QI based on analytics. Note that although the details provided herein are based on the QoS sustainability analytics, embodiments can also apply to other analytics that can provide similar information to the consumer of the analytics. Therefore, the embodiments are not to be considered limited to just the QoS sustainability analytics. Moreover, the techniques may apply to other network functions such as the PCF and, so, the use of the SMF should be considered as an example proposal and not a limitation. As such, all the details herein can be applied to other NFs such as, in particular, the PCF. In this case, the PCF may in turn provide any determined values (as will be described below) to another NF such as the SMF. The SMF may inform the PCF that at least one 5QI value (for the default QoS rule or a nondefault QoS rule) has been modified based on analytics (although not shown in Figure 3). PCF subscribes to QoS sustainability analytics In this solution option, the PCF (Policy Control Function) subscribes to the (or with the) NWDAF for the QoS sustainability analytics. Moreover, the PCF can also trigger the storage / retrieval of analytics from the ADRF as set out above for the SMF. As such all the details above in terms of subscribing to the NWDAF, and triggering storage / retrieval of analytics into / from the ADRF apply for the PCF. Furthermore, this solution option sets out that when the SMF contacts the PCF to obtain policy rules (e.g. when the SMF requests to establish an SM Policy Association with the PCF by invoking Npcf_SMPolicyControl_Create operation), the PCF may retrieve the stored analytics for a UE in question. The PCF may then behave in any of the following manner: • The PCF determines a modified 5QI value based on the analytics obtained from the ADRF (or NWDAF) and the PCF provides a policy rule such that the determined 5QI value is then provided (where this value is based on the analytics received) • The PCF may determine to provide a second rule such that the second rule is associated with a non-default QoS rule and also determines the 5QI for this rule based on the analytics that is received. The PCF may provide to the SMF either: • The determined 5QI for the default QoS rule (or QoS flow) as described above, • At least two rules where the second rule is for a non-default QoS rule with a 5QI that has been determined as described above. If the SMF receives at least two policy rules where at least one of these are for a non-default QoS rule, then the SMF may determine to establish at least two QoS rules during the PDU session establishment procedure as has been described in previous solution options. In this case, the SMF uses the 5QI which has been received from the PCF per policy rule. Figure 4 shows an example of how the above can be used. Figure 4 shows an example procedure for PCF determination of 5QI values based on analytics. Note that although not shown in the Figure 4, the PCF may, based on the determined 5QI using analytics, provide an explicit indication to the SMF that the 5QI value(s) have been determined based on analytics. The SMF may use this indication to in turn establish at least one non-default QoS rule using the 5QI obtained from the PCF. Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above. Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at most some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A method of Network Data Analytics Function (NWDAF) assisted Quality of Service (QoS) setup for a User Equipment (UE) in a telecommunications network, the method comprising:using, at and / or during establishment or modification of a Protocol Data Unit (PDU) session, a QoS value for a default QoS that is different from a subscribed default QoS value for the UE; and / orreturning, by the Session Management Function (SMF) and / or the Policy Control Function (PCF), at least two QoS flows; and / orsubscribing, by the SMF and / or the PCF, to and / or with the NWDAF for at least one defined analytics.

2. A method according to claim 1, the method further comprising the step of:defining, by the PCF and / or the SMF, the default QoS value for the UE, for example based on analytics information.

3. The method according to any previous claim, comprising:obtaining, by the SMF and / or the PCF, analytics for the UE, and / or other information related to network performance.

4. The method according to any previous claim, comprising:verifying, by the SMF and / or the PCF, the frequency of QoS changes that were made by the UE.

5. The method according to any previous claim, comprising:determining, by the SMF and / or the PCF, to use a default QoS value for the default QoS flow that is different from the subscribed QoS value.

6. The method according to any previous claim, comprising:informing, by the SMF, the PCF that at least one QoS value has been modified, based on analytics.

7. The method according to any previous claim, comprising:obtaining, by the SMF and / or the PCF analytics for the UE, where the analytics relates to QoS sustainability analytics.

8. The method according to any previous claim, comprising:performing, by the NWDAF, analytics for the UE in a certain area of interest9. The method according to any previous claim, comprising:verifying, by the SMF and / or the PCF, the frequency of QoS changes that were made by the UE.

10. The method according to any previous claim, comprising:determining, by the SMF and / or the PCF, that QoS change statistics indicate that the UE may request a change of QoS.

11. The method according to any previous claim, comprising:creating and / or establishing, by the SMF and / or the PCF, at least one additional QoS rule or QoS flow with a QoS value that is different from the QoS value associated with the default QoS flow.

12. The method according to any previous claim, comprising:choosing, by the SMF and / or the PCF, a QoS value for an additional QoS flow such that the chosen value is similar to, or better than in terms of QoS characteristics, what the UE would have normally requested for a QoS flow which is not a default QoS flow.

13. The method according to claim 12, comprising:ensuring, by the SMF and / or the PCF, that an “Authorized QoS rules" Information Element (IE) of a PDU Session Establishment Accept message contains at least one additional QoS rule which is not a default QoS rule, and / or the QoS value that is indicated is associated with, or maps to, the chosen QoS value.

14. The method according to any previous claim, comprising:informing, by the SMF, the PCF that at least one QoS value has been modified based on analytics.

15. The method according to any previous claim, comprising:triggering, by the PCF and / or the PCF, storage / retrieval of analytics from the ADRF.

16. The method according to any previous claim, comprising:retrieving, by the PCF, the stored analytics for the UE, when the SMF contacts the PCF to obtain policy rules.

17. The method according to any previous claim, comprising:determining, by the PCF and / or the SMF, a modified QoS value based on the analytics obtained from the ADRF and / or the NWDAF and providing, by the PCF, a policy rule such that the determined QoS value is then provided.

18. The method according to claim 17, comprising:determining, by the PCF and / or the SMF, to provide a second rule such that the second rule is associated with a non-default QoS rule and determining the QoS value for this rule based on the analytics that is received.

19. The method according to any previous claim, comprising:providing, by the PCF to the SMF: the determined QoS value for the default QoS rule or QoS flow; and / or at least two rules where the second rule is for a non-default QoS rule with a QoS value that has been determined.

20. The method according to any previous claim, comprising:determining, by the SMF and / or PCF, to establish at least two QoS rules during a PDU session establishment procedure, if SMF and / or PCF receives at least two policy rules where at least one of these are for a non-default QoS rule.

21. The method according to any previous claim, comprising:providing, by the PCF to the SMF, an indication that the QoS value has been determined based on analytics; andestablishing, by the SMF, at least one non-default QoS rule based on the indication.

22. A telecommunications network configured to implement the method according to any previous claim.

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