Method, apparatus, and computer-readable medium for implementing rules related to traffic routing

Abstract

Embodiments of the present disclosure relate to methods, apparatuses, and computer program products for implementing rules related to service routing. The method implemented at a terminal device includes: receiving rules related to service routing for a service and implementation information for the rules; and controlling the implementation of the rules based on the implementation information. The implementation information indicates whether a modification of a PDU session associated with the service is allowed due to the implementation of the rule.

Description

Technical Field

[0001] Non-limiting and exemplary embodiments of the present disclosure relate generally to the field of communication technology, and in particular to methods, apparatuses, and computer program products for implementing rules related to traffic routing. Background Art

[0002] This section introduces various aspects that may help to better understand the present disclosure. Therefore, the statements in this section should be read from this perspective and should not be understood as an admission that there is content in the prior art or that there is content that does not exist in the prior art.

[0003] With the development of communication technology, more and more services / applications and more and more methods for accessing networks are provided to users. In order to improve resource utilization efficiency, meet quality requirements for various services, and / or allow flexible operator configuration of UE, the concept of User Equipment (UE) policy has been proposed.

[0004] For example, with the introduction of fifth generation (5G) communication technology, UE policies have been defined in technical specifications such as TS 23.503 vf10 developed by the 3rd Generation Partnership Project (3GPP). According to the 3GPP specification, the 5G core network (5GC) should be able to provide policy information to the UE from the policy control function (PCF). Such UE policy information may include access network discovery and selection policy (ANDSP) and UE routing selection policy (URSP).

[0005] ANDSP is used by the UE to select a non-3GPP access and determine how to route traffic between the selected 3GPP and non-3GPP accesses. URSP is used by the UE to determine how to route outgoing traffic. For example, based on the URSP, the UE can route traffic to an established protocol data unit (PDU) session, offload traffic to a non-3GPP access outside of a PDU session, or trigger the establishment of a new PDU session for the traffic. Summary of the invention

[0006] Various embodiments of the present disclosure are generally directed to providing methods, apparatus, and computer program products for implementing rules related to traffic routing in a communication network.

[0007] In a first aspect of the present disclosure, a method implemented at a terminal device is provided. The method includes: receiving a rule for a service; receiving implementation information for the rule; and controlling the implementation of the rule based on the implementation information. The implementation information indicates whether modification of a protocol data unit (PDU) session associated with the service is allowed due to the implementation of the rule;

[0008] In one embodiment, controlling the implementation of rules based on implementation information may include: in response to a current PDU session associated with a service failing to satisfy the rule, determining based on the implementation information whether modification of the current PDU session associated with the service due to the implementation of the rule is allowed; and in response to determining that the modification is allowed, implementing the rule by one of the following: modifying the current PDU session to satisfy the rule; associating the service with another PDU session selected from existing PDU sessions that satisfy the rule; and creating a new PDU session that satisfies the rule for the service.

[0009] In another embodiment, controlling the implementation of rules based on implementation information may include: in response to the current PDU session failing to satisfy the rules, determining based on the implementation information whether modification of the current PDU session associated with the service due to the implementation of the rules is allowed, and determining whether switching the service from the current PDU session to another PDU session is allowed; and controlling the implementation of the rules based on the determination.

[0010] In some embodiments, controlling the implementation of rules based on implementation information may include: in response to the current PDU session failing to satisfy the rule, checking whether switching the service from the current PDU session to another PDU session is allowed; and in response to the switching being not allowed, determining based on the implementation information whether modification of the current PDU session associated with the service due to the implementation of the rule is allowed; and controlling the implementation of the rule based on the determination.

[0011] In another embodiment, controlling the implementation of rules based on whether modification and switching are allowed may include: in response to determining that modification is not allowed and switching is allowed, implementing the rules by one of the following: associating the service with an additional PDU session selected from existing PDU sessions that satisfy the rules, and creating a new PDU session that satisfies the rules for the service.

[0012] In some embodiments, controlling enforcement of the rule based on whether modification and switching are allowed may include, in response to determining that modification is allowed and switching is not allowed, enforcing the rule by modifying the current PDU session to satisfy the rule.

[0013] In some embodiments, controlling the implementation of rules based on whether modification and switching are allowed may include: in response to determining that modification is allowed and switching is not allowed, determining whether routing-related parameters for the service match the rules; and in response to determining that the routing parameters match the rules, implementing the rules by modifying the current PDU session to satisfy the rules.

[0014] In another embodiment, determining whether routing-related parameters for a service match a rule may include: determining whether routing-related parameters for each service in the services associated with the current PDU session match the rule; and if routing-related parameters for each service in the services associated with the current PDU session match the rule, determining that the routing-related parameters match the rule.

[0015] In some embodiments, controlling enforcement of the rule based on the enforcement information may include rejecting the rule in response to determining that neither modification nor switching is permitted.

[0016] In some embodiments, controlling the implementation of rules based on implementation information may include: in response to determining that both modification and switching are allowed, implementing the rules by one of the following: modifying the current PDU session to satisfy the rules; associating the service with another PDU session selected from existing PDU sessions that satisfy the rules; and creating a new PDU session that satisfies the rules for the service.

[0017] In some embodiments, multiple services are associated with a current PDU session, and implementation information is configured for each of the multiple services, and determining whether modification of the current PDU session associated with the service due to implementation of the rule may also include: checking the implementation information for all multiple services; and determining that the modification is allowed only if the implementation information for all multiple services indicates that modification of the current PDU session is allowed.

[0018] In some embodiments, determining whether switching a service from a current PDU session to another PDU session is allowed may include: checking whether the switching is allowed by previously implemented rules and received rules respectively; and if the switching is not allowed by previously implemented rules and received rules, determining that the switching is not allowed.

[0019] In some embodiments, rejecting the rule may include sending a reject message to the network device from which the rule was received.

[0020] In some embodiments, the implementation information may further include verification conditions for the rules, and the implementation of the control rules may also be based on the verification conditions. In some embodiments, the verification conditions may include at least one of the following: the time to implement the rule; the implementation delay allowed for the rule.

[0021] In some embodiments, the terminal device may receive a message including rules and implementation information from a policy control function (PCF).

[0022] In some other embodiments, the method may also include: receiving a notification that establishment of a new PDU session failed due to implementation of the rule; and determining whether to implement the rule by modifying the existing PDU session based on the implementation information and routing-related parameters for each of the services associated with the existing PDU session.

[0023] In a second aspect of the present disclosure, a method at a network device (e.g., a PCF) is provided. The method includes: obtaining a rule for a service of a terminal device; determining implementation information for the rule, the implementation information indicating whether a modification of a protocol data unit (PDU) session associated with the service is allowed due to the implementation of the rule; and sending the rule and the implementation information to the terminal device.

[0024] In a third aspect of the present disclosure, a terminal device is provided. The terminal device includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, enable the terminal device to at least perform the method according to the first aspect of the present disclosure.

[0025] In a fourth aspect of the present disclosure, a network device is provided. The network device includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to at least perform the method according to the second aspect of the present disclosure.

[0026] In a fifth aspect of the present disclosure, a computer program is provided, wherein the computer program comprises instructions, and when the instructions are executed by a device, the device is caused to perform the method according to the first aspect of the present disclosure.

[0027] In a sixth aspect of the present disclosure, a computer program is provided, wherein the computer program comprises instructions, and when the instructions are executed by a device, the device executes the method according to the second aspect of the present disclosure.

[0028] In a seventh aspect of the present disclosure, there is provided a computer readable medium having stored thereon a computer program, which, when executed by an apparatus, causes the apparatus to perform the method of the first aspect of the present disclosure.

[0029] In an eighth aspect of the present disclosure, there is provided a computer readable medium having stored thereon a computer program, which, when executed by an apparatus, causes the apparatus to perform the method of the second aspect of the present disclosure.

[0030] In a ninth aspect of the present disclosure, a terminal device is provided. The terminal device includes: a component for receiving rules related to service routing for a service and implementation information for the rules; and a component for controlling the implementation of the rules based on the implementation information. The implementation information indicates whether modification of a protocol data unit (PDU) session associated with the service is allowed due to the implementation of the rules.

[0031] In a tenth aspect of the present disclosure, a network device is provided. The network device includes: a component for obtaining a rule for a service of a terminal device; a component for determining implementation information for the rule, the implementation information indicating whether modification of a PDU session associated with the service is allowed due to implementation of the rule; and a component for sending the rule and the implementation information to the terminal device. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other aspects, features and benefits of various embodiments of the present disclosure will become more fully apparent from the following detailed description with reference to the accompanying drawings, in which like reference numerals are used to represent similar or equivalent elements. The accompanying drawings are shown to facilitate a better understanding of the embodiments of the present disclosure and are not necessarily drawn to scale, in which:

[0033] Figure 1 shows an example communication network in which embodiments of the present disclosure may be implemented;

[0034] Figure 2 A flowchart of a method at a terminal device according to an embodiment of the present disclosure is shown;

[0035] Figures 3 to 6 The embodiment according to the present disclosure is shown Figure 2 Different example implementations of block 220 and conventional methods;

[0036] Figure 7 A flowchart showing a method in a network device according to an embodiment of the present disclosure; and

[0037] Figure 8 A simplified block diagram of an apparatus that may be embodied as / in a network device or a terminal device is shown. DETAILED DESCRIPTION

[0038] Hereinafter, the principles and spirit of the present disclosure will be described with reference to illustrative embodiments. It should be understood that all these embodiments are given only to enable those skilled in the art to better understand and further practice the present disclosure, rather than to limit the scope of the present disclosure. For example, a feature shown or described as part of one embodiment can be used together with another embodiment to produce yet another embodiment. For the sake of clarity, all features of the actual implementation are not described in this specification.

[0039] References in the specification to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is considered to be within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0040] It should be understood that although the terms "first" and "second" etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the exemplary embodiment, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0041] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments. As used herein, the singular forms of "a", "an", and "the" are also intended to include plural forms unless the context clearly indicates otherwise. It should be further understood that when used herein, the terms "include", "comprise", "include", "have", "include", and / or "include" specify the presence of the features, elements, and / or components, etc., but do not exclude the presence or increase of one or more other features, elements, components, and / or combinations thereof.

[0042] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0043] (a) hardware circuit implementation only (such as implementation only in analog and / or digital circuitry); and

[0044] (b) a combination of hardware circuitry and software such as (where applicable):

[0045] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0046] (ii) any portion of hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device such as a mobile phone or server to perform various functions; and

[0047] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), which requires software (e.g., firmware)

[0048] However, when the software is not needed, the software may not exist.

[0049] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term "circuitry" also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers (for example and if applicable to a particular claim element) a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0050] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as 5G, new radio (NR), long term evolution (LTE), advanced LTE (LTE-A), wideband code division multiple access (WCDMA), high speed packet access (HSPA), etc. "Communication network" may also be referred to as a "communication system". In addition, communication between network devices, between network devices and terminal devices, or between terminal devices in a communication network may be performed according to any suitable communication protocol, including but not limited to Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), New Radio (NR), 5G, Wireless Local Area Network (WLAN) standards (such as IEEE 802.11 standards), and / or any other suitable communication standard currently known or to be developed in the future.

[0051] As used herein, the term "network device" refers to a node in a communication network via which a terminal device receives services and / or information related to services. For example, a network device may include a network node in a core network (CN) such as a PCF or a gateway.

[0052] The term "terminal device" refers to any terminal device that can communicate. As an example and not limitation, the terminal device may also be referred to as a communication device, UE, subscriber station (SS), portable subscriber station, mobile station (MS) or access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0053] As another example, in an Internet of Things (IOT) scenario, a terminal device may represent a machine and / or other device that performs monitoring and / or measurement and transmits the results of such monitoring and / or measurement to another terminal device and / or network device. In this case, the terminal device may be a machine-to-machine (M2M) device, which may be referred to as a machine type communication (MTC) device in the 3GPP context. As a specific example, a terminal device may be a UE that implements the 3GPP Narrowband Internet of Things (NB-IoT) standard. Examples of such machines or devices are sensors, metering devices (such as electric meters), industrial machinery, or household or personal devices (e.g., refrigerators, televisions, personal wearable devices (such as watches), etc.). In other cases, a terminal device may represent a vehicle or other device that is capable of monitoring and / or reporting its operating status or other functions associated with its operation.

[0054] Figure 1 An example communication network 100 is shown in which embodiments of the present disclosure may be implemented. As shown, the communication network 100 may include an access network 110 and a core network (CN) 120. A UE 111 may receive services from the core network 120 via a base station (BS) 112 in the access network 110. The core network 120 may include one or more network devices, such as a PCT 121, a gateway (GW) 122, a unified data repository (UDR) 123, and an application server (AS) 124. Note that the communication network 100 may include a plurality of network devices, such as a UE 111, a base station (BS) 112, and a core network (CN) 120. Figure 1 Other access networks, terminal devices and / or core network devices not shown.

[0055] Various services may be provided to UEs in a communication network, which may have different quality of service (QoS) requirements with respect to delay or packet error rate. In order to improve resource utilization efficiency and / or meet quality requirements for various services, UE policy information may be provided to the UE from the CN (e.g., a PCF in the CN). Such UE policy information may include ANDSP and URSP.

[0056] According to current 3GPP technical specifications, such as TS 23.503 vf10, each URSP contains multiple URSP rules. The structure of URSP rules is described in Table 6.6.2.1-2 and Table 6.6.2.1-3 of 3GPP TS 23.503 vf10, which are reproduced below.

[0057] Table 6.6.2.1-2: UE routing policy rules

[0058]

[0059] Table 6.6.2.1-3: Routing Descriptor

[0060]

[0061] As shown in these tables, the URSP rules for a UE include a traffic descriptor that specifies matching criteria and one or more of the following components:

[0062] a) SSC Mode Selection Policy (SSCMSP): This is used by the UE to associate matching applications with SSC modes.

[0063] b) Network Slice Selection Policy (NSSP): This is used by the UE to associate matching applications with the S-NSSAI.

[0064] c) DNN selection strategy: UE uses this to associate matching applications with DNNs.

[0065] d) Non-seamless offload policy: This is used by the UE to determine that matching applications should be offloaded non-seamlessly to non-3GPP access (ie outside of a PDU session).

[0066] e) Access type preference: If the UE needs to establish a PDU session for a matching application, this indicates the preferred access type (3GPP or non-3GPP).

[0067] Additionally, each URSP rule may contain multiple routing descriptors (RSDs), which are selected in an order based on their priority values.

[0068] The PCF may select the URSP applicable to each UE based on local configuration and operator policy, taking into account, for example, accumulated usage, load level information for each network slice instance, UE location, etc. When valid URSP rules are available, the UE performs association with the PDU session based on user preferences and these URSP rules.

[0069] When the operator policy is changed or any condition that triggers URSP reselection is met, the PCF can reselect URSP rules for the UE. In response to receiving new / updated URSP rules from the PCF, the UE can modify the existing PDU session, associate the service with another existing PDU session matching the updated rules, or establish a new PDU session for the service.

[0070] For example, the original URSP rules may be successfully implemented by the UE, and then the original URSP rules associated with the UE's service may be modified by the PCF, or new URSP rules may be generated by the PCF for the UE's service. In both cases, the PCF may send new / updated rules to the UE for implementation on the UE side.

[0071] However, currently, the implementation of new / updated URSP rules at the UE may cause several problems. For example, the implementation of new / updated URSP rules at the UE may cause changes to the current PDU session. This means that the IP address of the PDU session may also be changed; therefore, application services may be interrupted. In addition, the implementation of new / updated URSP rules may cause modifications to the current PDU session. If the current PDU session is shared by multiple application services, the modification of the PDU session may have a negative impact on certain application services to which the new URSP rules do not apply. The implementation of new / updated URSP rules may also result in an increase in the total number of PDU sessions. In addition, if the network rejects the establishment of a new PDU session, modifications to the existing PDU session must be considered.

[0072] The inventors of the present disclosure have observed that different applications / services may have different tolerances for the negative impact caused by URSP rule updates. For example, some applications are able to maintain service continuity at the application level. In addition, for some applications, service interruption may not affect the user experience. Therefore, for such applications, the UE can move services from one PDU session to another PDU session without negatively affecting the UE experience. However, for applications that are sensitive to service interruption, it is critical to keep the running services unaffected.

[0073] In addition, the operator of the network may have some specific requirements for the enhancement of URSP rules. For example, depending on the nature of the URSP rules to be implemented, the operator may require that the rules be applied at any time determined by the UE or at a preset exact time point (e.g., a billing cycle). In some cases, it may be critical that the new URSP rules are implemented immediately by the UE, and in this case, the operator may expect the rules to be implemented within a predefined time period. However, some ongoing services (e.g., mobile monitoring services) cannot be stopped at / within the predefined time.

[0074] Therefore, in order to determine the appropriate time point for implementing the URSP rules to avoid negative impact on ongoing services / user experience, or to reduce the negative impact to a tolerable level, the UE may need knowledge about the requirements for application and / or network preferences. However, such information is currently not available to the UE.

[0075] On the other hand, operators / applications may expect new / updated URSP rules to be effectively implemented by UEs. However, operators / applications currently have no way to inform UEs of their requirements / expectations.

[0076] 3GPP TS 23.402 specifies the validity conditions for the WLAN Selection Policy (WLANSP) in section 4.8.2.1.6, which is reproduced below.

[0077] "Validity conditions, i.e., conditions that indicate when a provided rule is valid. Validity conditions may include time of day, geographic location, network location (e.g., PLMN, location area), etc."

[0078] However, this verification condition fails to take into account the application-specific requirements.

[0079] In the current technical specifications for 5G systems (e.g., TS 23.503 vf10), no validity conditions are defined for URSP. Instead, the implementation of the updated URSP is completely handed over to the UE implementation without considering any operator / application requirements. In other words, the issue of interrupting ongoing services is not considered.

[0080] To address at least some of the above-mentioned problems and other potential problems, methods, apparatuses, and computer-readable media for implementing rules related to traffic routing have been proposed in the present disclosure.

[0081] In some embodiments, the information required to derive the URSP rules may be configured or updated by an application service provider (ASP). For example, the ASP may indicate verification time and UE address continuity requirements. The URSP rules associated with the service may be derived and stored, for example, in the UDR. In some embodiments, implementation information for the URSP rules that specifies when and / or how to implement the URSP rules on the UE side is also maintained in the UDR. Alternatively, in some embodiments, the implementation information for the URSP rules may be dynamically generated by the PCF.

[0082] In some embodiments, implementation information for URSP rules may include one or both of: a verification condition; and an indication of whether modifications to the PDU session associated with the UE's ongoing service due to implementation of the rules are allowed due to updates to the URSP rules for the current service or other application services sharing the same PDU session.

[0083] In particular, the validation condition may specify one or more of the following: the implementation time of the URSP rule and the implementation delay allowed for the URSP rule. For illustration and not limitation, the implementation time may include a time of day, or indicate to the UE that the implementation of the rule may be implemented at any time before the service is restarted, etc. In some embodiments, the absence of a validation condition means that the URSP may be installed at any time before the service is restarted.

[0084] The indication of whether modification of the PDU session due to the implementation of the rule is allowed can be used by the UE to decide whether to modify the current PDU session associated with the application service or to associate the application service with another PDU session. In some embodiments, when associating the application service with another PDU session is not allowed and when the verification condition for the URSP rule is met (for example, when the implementation time of the URSP rule is approaching), the indication can be used by the UE to determine whether and / or how to implement the URSP rule.

[0085] In some embodiments, the UE may determine whether associating the application service with another PDU session is allowed based on the UE address continuity requirement for the application associated with the service. In some embodiments, the UE may determine whether associating the application service with another PDU session is allowed based on the SSC mode specified in the URSP rule received by the UE. For example, the URSP rule may include the information shown in Table 6.6.2.1-3 of 3GPP TS 23.503 vf10, and if the "SSC Mode Selection" field in Table 6.6.2.1-3 is set to "SSC Mode 1", the UE determines that associating the application service with another PDU session is not allowed. If the "SSC Mode Selection" field in Table 6.6.2.1-3 is set to "SSC Mode 2" or "SSC Mode 3", the UE determines that associating the application service with another PDU session is allowed.

[0086] In some embodiments, the proposed implementation information and optionally together with the information about whether associating the application service with another PDU session is allowed can be used by the UE to determine whether / how to implement the URSP rule. For example, when the verification condition for the URSP rule is met, for example, when the time point of the day specified by the verification condition or the time point of the allowed implementation delay specified by the verification condition is approaching, the UE may also check the indication of whether the modification of the PDU session associated with the ongoing service of the UE due to the implementation of the rule is allowed, and may also check the information about whether associating the application service with another PDU session is allowed to determine the solution for implementation.

[0087] The implementation information of the URSP rules is sent to the UE by a network device (such as but not limited to the PCF). In this way, the UE acquires knowledge about the requirements from the operator and / or the application, and this enables a more efficient implementation of the URSP rules on the UE side.

[0088] As an example but not limitation, in some embodiments, the implementation information of the URSP rule may be sent to the UE as part of the URSP rule. For example, the URSP rule may include the information shown in Table 1.

[0089] Table 1 URSP rules

[0090]

[0091]

[0092] In the embodiment shown in Table 1, the URSP rule includes implementation information, namely, an information element (IE) of "verification condition" and an IE of "PDU session modification allowed". The IE of "verification condition" indicates when the URSP rule should be implemented, and the IE of "PDU session modification allowed" indicates whether modification of the current PDU session of the service is allowed due to the implementation of the URSP rule. Other IEs included in the URSP rule shown in Table 1 may be the same as the IEs specified in Table 6.6.2.1-2 of 3GPP TS23.503 Vf10 (the contents of which are incorporated herein by reference).

[0093] It should be understood that embodiments of URSP rules are not limited to the exact content shown in Table 1, but may include more, fewer or different IEs.

[0094] In some embodiments, the implementation information (e.g., the new IEs of "verification conditions" and "PDU session modification allowed" in Table 1) may be optionally included in the URSP rules sent to the UE. For example, the two IEs shown in Table 1 may not be included in the original URSP rules sent to the UE. Then, when the PCF reselects or generates other URSP rules after the original URSP rules have been successfully implemented at the UE, the PCF may send the reselected URSP rules to the UE, wherein one or both of the new IEs are included in the reselected URSP rules.

[0095] In some embodiments, after receiving an updated URSP rule for an ongoing service and determining that the rule priority value of the updated rule is higher than the rule priority value of the current URSP rule for the ongoing service, the UE may also check implementation information, such as a verification condition (if any) of the updated URSP rule. The UE may then implement the updated URSP rule based on the implementation information (e.g., an implementation time specified by the verification condition). For example, based on the verification condition, the UE may implement the updated URSP rule at a predefined time, within an allowed implementation delay (if the updated URSP rule needs to be installed immediately, its value may be set to 0), or at any time before the service is restarted.

[0096] In some embodiments, based on the implementation information, the updated URSP rules received by the UE may need to be implemented before the ongoing service ends, and in such embodiments, if the current PDU session associated with the ongoing service fails to satisfy the updated URSP rules, the UE may implement the updated URSP rules, for example, via one of the following solutions A to C:

[0097] Solution A: If there is an existing PDU session that matches the updated URSP rule, reselect the existing PDU session that matches the updated URSP rule for the service;

[0098] Solution B: If no existing PDU Session matches the updated URSP rule, create a new PDU Session;

[0099] Solution C: Modify the PDU session to which the service is currently bound to match the updated URSP rules.

[0100] Alternatively or additionally, in some embodiments, the UE may also check whether the association of the ongoing service is allowed to be changed to another PDU session to decide a solution for the implementation of the updated URSP rule. For example, if the updated URSP rule indicates SSC mode 2 or SSC mode 3, which means that the UE is allowed to switch the PDU session associated with the service from the current PDU session to another PDU session, the UE may decide to associate the ongoing service with another PDU session through the above solution A or solution B, or modify the existing PDU session associated with the ongoing service via the above solution C. However, if both the original URSP rule and the updated URSP rule indicate SSC mode 1, which means that PDU session switching of the service is prohibited, the UE may adopt the above solution C to implement the updated URSP rule, that is, modify the current PDU session associated with the service.

[0101] However, for some applications, modifying the PDU Session associated with the service may be unacceptable. Therefore, in some embodiments, it is proposed to send implementation information to the UE indicating whether modification of the current PDU Session associated with the service is allowed due to the implementation of the rule.

[0102] In some embodiments, the URSP rule may indicate that PDU session switching of the service is not allowed (e.g., SSC mode 1 is selected), and at the same time, the implementation information of the URSP rule indicates that modification of the current PDU session is also prohibited, and in this case, the UE may decide to reject the URSP rule.

[0103] In some embodiments, there may be multiple application services bound to the current PDU session, and in such embodiments, when selecting the above solution C for implementing the updated URSP rule, the UE may also check whether the modification of the PDU session is allowed for all application services currently bound to the PDU session. If the modification of the PDU session is not allowed for any application service in the multiple application services, the UE may determine that the modification is not allowed (or prohibited) and decide not to use solution C.

[0104] In some embodiments, if the UE receives any notification that the new PDU session establishment fails due to the implementation of the updated URSP rules, the UE may adopt solution C to implement the URSP rules. For example, in this case, the UE may evaluate whether modification of the existing PDU session is possible taking into account the "Allow PDU session modification" field in Table 1 and the RSD value of each service currently associated with the PDU session. In some embodiments, the UE may only evaluate the modification of the PDU session having the same SSC mode selection value as the SSC mode selection value configured in the updated URSP rules.

[0105] It should be understood that although some embodiments are described using URSP rules as examples of rules related to traffic routing, embodiments of the present disclosure are not limited to the implementation of URSP rules. Instead, embodiments of the present disclosure can be used to improve the implementation of any rules related to traffic routing in any communication network where similar problems exist.

[0106] In the following, in order to facilitate a better understanding of the proposed solution, reference will be made to Figures 2 to 8 Some embodiments are described.

[0107] Figure 2 1 is a flow chart showing a method 200 implemented at a terminal device for implementing rules related to traffic routing. The terminal device may be, for example, Figure 1 For ease of discussion, reference will be made to UE 111. Figure 1 The method 200 is described with reference to the UE 111 and the communication network 100. However, the embodiments of the present disclosure are not limited thereto.

[0108] At block 210, UE 111 receives rules for its service and enforcement information for the rules. The enforcement information indicates whether modification of a protocol data unit (PDU) session associated with the service is allowed due to enforcement of the rules.

[0109] By way of example and not limitation, the rules received at block 210 may include URSP rules. For example, the URSP rules may include the information shown in Table 6.6.2.1-2 in 3GPP TS 23.503 vf10. The rules may be application service specific, and the application service may be identified by, for example, a service descriptor specified by the rules.

[0110] Alternatively or additionally, in block 210, UE 111 may receive a request from a PCF (e.g., Figure 1121) to receive rules and implementation information. However, the embodiments are not limited thereto. In some embodiments, depending on the network architecture involved, UE 111 can receive rules and implementation information from different network devices.

[0111] At block 220, UE 111 implements or rejects the rule based on the implementation information.

[0112] Method 200 enables UE 111 to consider the requirements for the application when determining whether / how to implement rules related to traffic routing by checking the implementation information. Therefore, using method 200 can improve the implementation efficiency.

[0113] For purposes of illustration and not limitation, Figures 3 to 6 Some example implementations of block 220 are shown in FIG. Figure 3 In the illustrated example implementation 300, after receiving the rule at block 210, UE 111 checks at block 310 whether the current PDU session associated with the service satisfies the received rule. If the current PDU session fails to satisfy the rule, then at block 320, UE 111 determines whether modification of the current PDU session associated with the service is allowed due to the implementation of the rule based on the implementation information (e.g., the "Allow PDU Session Modification" field in Table 1 above). If modification of the current PDU session associated with the service is allowed, then at block 330, UE 111 may implement the rule through one of solutions A to C. That is, UE 111 may modify the current PDU session to satisfy the rule, associate the service with another PDU session selected from the existing PDU sessions that satisfy the rule; or create a new PDU session that satisfies the rule for the service.

[0114] In some embodiments, in addition to the implementation information, UE 111 may also consider whether switching the service from the current PDU session to another PDU session is allowed, so as to make a better decision about the implementation. That is, UE 111 may implement or reject the rule based on whether the modification of the current PDU session is allowed and whether the switching is allowed.

[0115] In some embodiments, UE 111 may check whether switching is allowed according to previously implemented rules (e.g., initial URSP rules) and received rules (e.g., updated URSP rules), respectively; and if both rules do not allow switching (e.g., SSC mode 1 is selected in both the initial URSP rules and the updated URSP rules), UE 111 determines that switching is not allowed.

[0116] exist Figure 4In the illustrated example implementation 400, the UE 111 checks at box 410 whether the current PDU session associated with the service satisfies the received rule. If the current PDU session fails to satisfy the rule, then at box 420, the UE 111 determines whether modification of the current PDU session associated with the service due to the implementation of the rule is allowed based on the implementation information. In addition, at box 430, the UE checks whether switching the service from the current PDU session to another PDU session is allowed. If the modification is not allowed, but the switching is allowed, then at box 440, the UE 111 can implement the rule via solution A or B, that is, associate the service with another PDU session selected from the existing PDU sessions that satisfy the rule; or create a new PDU session that satisfies the rule for the service. On the other hand, if both the modification and the switching are allowed, the UE 111 can implement the rule through any of solutions A to C at box 450.

[0117] Figure 2 Another example implementation 500 of block 220 is Figure 5 Similar to Figure 4 , at box 510, UE 111 checks whether the current PDU session associated with the service satisfies the received rules. If the current PDU session fails to satisfy the rules, at box 520, UE 111 determines whether modification of the current PDU session associated with the service due to the implementation of the rules is allowed based on the implementation information. In addition, at box 530, the UE checks whether switching the service from the current PDU session to another PDU session is allowed. Box 530 can be performed before or after box 520. If the modification is allowed but the switching is not allowed, at box 540, UE 111 can implement the rules by modifying the current PDU session. On the other hand, at box 550, if neither the modification nor the switching is allowed, the rule can be rejected.

[0118] In some embodiments, when UE 111 decides to reject a rule, it may send a notification to the network device (e.g., Figure 1 Or, in other words, the rejection rule may include sending a rejection message to the network device.

[0119] It should be understood that in some embodiments, UE 111 may check whether a PDU session switch is allowed before checking whether a modification of the current PDU session due to the implementation of the rule is allowed, or vice versa. Figure 6In the illustrated implementation 600, if it is determined at block 610 that the current PDU session cannot satisfy the received rule, the UE 111 checks at block 630 whether PDU session switching is allowed, and if switching is not allowed, the UE 111 checks at block 620 whether modification of the current PDU session due to implementation of the rule is allowed. Then, if modification is allowed but switching is not allowed, at block 640, the UE 111 may implement the rule by modifying the current PDU session. On the other hand, if neither modification nor switching is allowed, the UE 111 may reject the rule at block 650. However, it should be understood that embodiments are not limited to performing block 630 before block 620.

[0120] In some embodiments, UE 111 may check whether switching is allowed by previously implemented rules and received rules, respectively, at block 630. If switching is prohibited by both rules (e.g., SSC mode 1 is selected in both rules), UE 111 may determine that switching is not allowed.

[0121] In some embodiments, if modification is allowed but switching is not allowed, UE111 may also check another factor, for example, whether a routing-related parameter of the service (for example, an RSD priority included in the URSP rule, as shown in Table 6.6.2.1-3) matches the rule; and in response to determining that the routing parameter matches the rule, UE 111 may implement the rule by modifying the current PDU session to satisfy the rule.

[0122] Note that in some embodiments, multiple services may be associated with the current PDU session, and in these embodiments, the UE may determine whether the routing-related parameters for each of the multiple services associated with the current PDU session match the rule; and if the routing-related parameters for each of the multiple services match the rule, the UE 111 may determine that the routing-related parameters match the rule. As an example, in some embodiments, if modification is allowed but switching is not allowed (e.g., SSC mode 1 is selected in both the initial URSP rule and the received updated URSP rule), the UE checks for each service whether the corresponding RSD matches the updated URSP rule. If the RSD for each service matches the updated URSP rule, the UE 111 modifies the PDU session; otherwise, the updated URSP rule may be rejected.

[0123] In an embodiment where multiple services may be associated with a current PDU session and implementation information may be configured for each of the multiple services, Figure 3 Frame 320, Figure 4 In the frame 420, Figure 5 520 in the box, or Figure 6 At block 620 in the UE, the UE may determine whether modification of the current PDU session associated with the service due to the implementation of the rule is allowed by considering the implementation information configured for all multiple services. For example, at blocks 320, 420, 520, or 620, the UE 111 may check the implementation information for all multiple services, and only if the implementation information for all multiple services indicates that modification of the current PDU session is allowed, the UE 111 determines that the modification is allowed.

[0124] Now refer to it again Figure 2 In some embodiments, the implementation information received at block 210 may also include a validation condition against the rule, and at block 220, UE 111 may also implement or reject the rule based on the validation condition. As an example, UE 111 may perform block 220 when the validation condition is met.

[0125] The verification condition may include at least one of the following: the time to implement the rule, the implementation delay allowed for the rule, and the location where the rule applies. In some embodiments, the time to implement the rule may indicate an exact point in time. Alternatively, in some embodiments, the time to implement the rule may allow UE 111 to implement the rule at any time before the service is restarted.

[0126] like Figure 2As shown, in some embodiments, UE 111 may receive a notification at block 215 that a new PDU session establishment has failed due to implementation of an updated URSP rule, and in this case, UE 111 may determine at block 218 whether to implement the rule by modifying the existing PDU session based on implementation information (e.g., “PDU session modification allowed”) and optionally based on routing-related parameters (e.g., RSD priority values) for each service associated with the existing PDU session. For example, upon receiving the failure notification, UE 111 may evaluate whether it is possible to implement the updated URSP rule by modifying the existing PDU session. During the evaluation, UE 11 may consider implementation information (e.g., the “PDU session modification allowed” field included in Table 1) and the RSD value of each service currently associated with the existing PDU session. In some embodiments, UE 111 may only evaluate modifications to PDU sessions having the same SSC mode selection value as the SSC mode selection value configured in the updated URSP rule. Then at block 220, UE 111 may implement or reject the rule based on the implementation information and the determination at block 218. For example, if UE 111 determines at block 218 that modification of an existing PDU session is not possible, UE 111 may reject the rule at block 220; otherwise, UE 111 may implement the rule by modifying the existing PDU session.

[0127] Figure 7 A flow chart of a method 700 implemented at a network device for implementing rules related to traffic routing (eg, URSP rules) is shown. The network device may be, for example, Figure 1 For ease of discussion, reference will be made to the PCF 121. Figure 1 The method 700 is described with reference to the PCF 121 and the communication network 100 shown. However, the embodiments of the present disclosure are not limited thereto.

[0128] like Figure 7 As shown, at block 710, PCF 121 obtains a request for a terminal device (eg, Figure 1 In some embodiments, the rules may be obtained by PCF 121 based on, for example but not limited to, at least one of the following: information from UDR 123, operator preferences, requirements for applications associated with the services, local configuration of each network slice instance at the load level, and the location of the terminal device. For example, PCF 121 may obtain the initial URSP rules from UDR 123, and obtain the URSP rules for UE 111 based on the initial URSP rules and the location of UE 111.

[0129] At block 720, PCF 121 determines implementation information for the rules obtained at block 710. Figures 2 to 6 As described in method 200 of the present invention, the implementation information may indicate whether modification of a PDU session associated with a service is allowed due to the implementation of a rule, and / or a verification condition of the rule. All descriptions of the implementation information provided above also apply here, and therefore, the details of the implementation information (e.g., verification conditions and indication of whether modification of a PDU session associated with a service is allowed due to the implementation of a rule) will not be repeated.

[0130] In some embodiments, the implementation information may be determined by PCF 121 based on, for example but not limited to, at least one of: operator preferences and requirements for applications associated with the service. In some embodiments, the requirements for applications associated with the service may include user equipment address continuity requirements for the applications.

[0131] At block 730, PCF 121 sends the rule and implementation information to UE 111. The implementation information enables UE 111 to better decide whether / how to implement the received rule. In some embodiments, the implementation information may be sent to UE 111 as part of the rule. For example, and not limitation, the rule may include the information shown in Table 6.6.2.1-2 of 3GPP TS 23.503 vf10. In some embodiments, the rule may be extended to include the implementation information, and the extended rule may include, for example, the information shown in Table 1 of the present disclosure.

[0132] It should be understood that the implementation information included in the extended rules may be optional. For example, at block 730, PCF 121 may send the updated URSP rules with the implementation information to UE 111. However, before sending the updated URSP rules, PCF 121 may have provided UE 111 with UE access selection and PDU session related policy information during the initial registration process, and the rules sent to the UE during the initial registration may not include the implementation information.

[0133] In some embodiments, as described with reference to method 200, UE 111 may reject the rule. In such embodiments, PCF 111 may receive a message indicating the rejection of the rule from UE 111 at block 740. However, it should be understood that when UE 111 rejects the rule, it does not necessarily send a rejection message. That is, the operation at block 740 may be optional.

[0134] Figure 8 A simplified block diagram of an apparatus 800 is shown, which may be embodied in a terminal device (eg, Figure 1UE 111 shown) is / is embodied as a terminal device, or is embodied in a network device (eg, Figure 1 The PDF 121) shown is / embodied as a network device.

[0135] like Figure 8 As shown in the example of , the device 800 includes a processor 810 that controls the operation and functions of the device 800. For example, in some embodiments, the processor 810 can implement various operations with the help of instructions 830 stored in a memory (MEM) 820 coupled thereto. The memory 820 can be of any suitable type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as semiconductor-based memory terminal devices, magnetic memory terminal devices and systems, optical memory terminal devices and systems, fixed memory, and removable memory, as non-limiting examples. Although in Figure 8 Only one memory unit is shown in FIG. 8 , however, multiple physically different memory units may exist in device 800 .

[0136] Processor 810 may be of any suitable type suitable for the local technical environment, and may include, as non-limiting examples, one or more of: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor DSP, and a processor based on a multi-core processor architecture. Apparatus 800 may also include multiple processors 810 .

[0137] The processor 810 may also be coupled to a transceiver 840 that enables the reception and transmission of information. For example, the processor 810 and the memory 820 may operate in conjunction to implement a reference Figures 2 to 7 It should be understood that the above references Figures 2 to 7 All features described are also applicable to the device 800 and therefore will not be described in detail here.

[0138] Various embodiments of the present disclosure may be implemented by a computer program or a computer program product, which may be executed by one or more of the following: a processor (e.g., Figure 8 processor 810 in), software, firmware, hardware, or a combination thereof.

[0139] Although some of the above descriptions are Figure 1 The present invention is carried out in the context of the communication network shown, but it should not be interpreted as limiting the spirit and scope of the present disclosure. The principles and concepts of the present disclosure can be more generally applied to other scenarios.

[0140] In addition, the present disclosure may also provide a carrier (for example, Figure 8The computer instructions in the embodiment of the present invention are shown in Figure 830). The carrier includes a computer-readable storage medium and a transmission medium. The computer-readable storage medium may include, for example, an optical disk or an electronic storage device such as a RAM (random access memory), a ROM (read-only memory), a flash memory, a magnetic tape, a CD-ROM, a DVD, a Blu-ray disk, etc. The transmission medium may include, for example, electrical, optical, radio, acoustic or other forms of propagation signals, such as carrier waves, infrared signals, etc.

[0141] The techniques described herein may be implemented by various means, so that the device implementing one or more functions of the corresponding device described by the embodiment includes not only prior art components, but also components for implementing one or more functions of the corresponding device, and the device may include separate components for each separate function, or components that can be configured to perform two or more functions. For example, these techniques may be implemented in hardware (e.g., circuits or processors), firmware, software, or a combination thereof. For firmware or software, implementation may be performed by modules (e.g., processes, functions, etc.) that perform the functions described herein.

[0142] Some example embodiments herein have been described above with reference to block diagrams and flow diagrams of methods and apparatus. It should be understood that each block of the block diagrams and flow diagrams and combinations of blocks of the block diagrams and flow diagrams can be implemented by various components including computer program instructions, respectively. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed on the computer or other programmable data processing device create components for implementing the functions specified in one or more flow diagram blocks.

[0143] Although this specification contains many specific implementation details, these should not be interpreted as limitations on any implementation or possible scope of protection, but should be interpreted as descriptions of features specific to a particular embodiment of a particular implementation. Certain features described in this specification in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments or in any suitable sub-combination, respectively. In addition, although the features may be described above as working in certain combinations and even initially claimed as such, in some cases, one or more features in the claimed combination may be excluded from the combination, and the claimed combination may involve a sub-combination or a variant of the sub-combination.

[0144] It is clear to those skilled in the art that, with the advancement of technology, the inventive concept can be implemented in various ways. The above embodiments are given for describing rather than limiting the present disclosure, and it should be understood that, as those skilled in the art will readily appreciate, modifications and changes can be made without departing from the spirit and scope of the present disclosure. Such modifications and changes are considered to be within the scope of the present disclosure and the appended claims. The scope of protection of the present disclosure is defined by the appended claims.

Claims

1. A method for business routing, include: receiving a rule for a service, the rule specifying a routing strategy for the service; receiving implementation information for the rule, wherein the implementation information includes a validation condition for the rule, and the validation condition includes at least a location to which the rule applies, and the implementation information also includes an indication of whether modification of a current protocol data unit (PDU) session associated with the service is allowed as a result of the implementation of the rule; and In response to determining that the modification is allowed, controlling implementation of the rule based on the implementation information by performing at least one of the following: Modify the current PDU session to satisfy the rule; associating the service with a further PDU session selected from the existing PDU sessions satisfying the rule; or A new PDU session satisfying the rule is created for the service.

2. The method according to claim 1, wherein the implementation of the rule is controlled based on the implementation information include: In response to the current PDU session failing to satisfy the rule, determining, based on the implementation information, whether modification of the current PDU session associated with the service is permitted due to implementation of the rule; as well as Determining whether switching the service from the current PDU session to another PDU session is allowed; as well as Implementation of the rule is controlled based on the modification and whether the switching is allowed.

3. The method according to claim 2, wherein the implementation of the rule is controlled based on whether the modification and the switching are allowed. include: In response to determining that the modification is not allowed and the switching is allowed, implementing the rule by one of: associating the service with a further PDU session selected from among the existing PDU sessions satisfying the rule; and A new PDU session satisfying the rule is created for the service.

4. The method according to claim 2, wherein the implementation of the rule is controlled based on whether the modification and the switching are allowed. include: In response to determining that the modification is allowed and the switching is not allowed, implementing the rule by: The current PDU session is modified to satisfy the rule.

5. The method according to claim 2, wherein the implementation of the rule is controlled based on whether the modification and the switching are allowed. include: In response to determining that the modification is allowed and the switching is not allowed, determining whether a routing-related parameter for the service matches the rule; as well as In response to determining that the routing parameter matches the rule, the rule is implemented by modifying the current PDU session to satisfy the rule.

6. The method according to claim 5, determining whether the routing selection related parameters for the service match the rule include: determining whether a routing-related parameter for each of the services associated with the current PDU session matches the rule; as well as If the routing-related parameter for each of the services associated with the current PDU session matches the rule, it is determined that the routing-related parameter matches the rule.

7. The method of claim 2, wherein the implementation of the rule is controlled based on the implementation information include: In response to determining that neither the modifying nor the switching is permitted, rejecting the rule.

8. The method of claim 2, wherein the implementation of the rule is controlled based on the implementation information include: In response to the current PDU session failing to satisfy the rule, checking whether switching the service from the current PDU session to another PDU session is allowed; as well as In response to the switching being not allowed, determining based on the implementation information whether modification of the current PDU session associated with the service is allowed due to implementation of the rule; as well as Implementation of the rule is controlled based on the determination.

9. The method according to any one of claims 1 to 9, wherein a plurality of services are associated with the current PDU session, and implementation information is configured for each of the plurality of services, and wherein determining whether modification of the current PDU session associated with the service due to the implementation of the rule is allowed or not include: Checking implementation information for all of the multiple services; as well as If the implementation information for all of the plurality of services indicates that modification of the current PDU session is permitted, it is determined that the modification is permitted.

10. The method according to any one of claims 2 to 8, wherein determining whether switching the service from the current PDU session to another PDU session is allowed include: checking whether the switching is allowed by the previously implemented rules and the received rules respectively; If the switching is not permitted by the previously implemented rule and the received rule, it is determined that the switching is not permitted.

11. The method according to claim 1, wherein controlling the implementation include: The rule is rejected by sending a reject message to the network device from which the rule was received.

12. The method according to claim 1, wherein the receiving include: A message comprising said rule and said implementation information is received from a policy control function PCF.

13. The method according to claim 1, further comprising: include: receiving a notification that a new PDU session establishment failed due to implementation of said rule; determining whether to implement the rule by modifying the existing PDU session based on the implementation information and a routing-related parameter for each service associated with the existing PDU session; as well as Implementation of the rule is controlled based on the determination.

14. The method according to claim 1, wherein the verification condition further comprises at least one of the following: the time at which the rule will come into effect; or Delays in implementation are permitted under the rules.

15. A method for implementing rules related to traffic routing, include: Acquire the rule for the service of the terminal device; determining implementation information for the rule, wherein the implementation information includes a validation condition for the rule, and the validation condition includes at least a location to which the rule applies, and the implementation information also includes an indication of whether modification of a current protocol data unit (PDU) session associated with the service is permitted as a result of implementation of the rule; and The rule and the implementation information are sent to the terminal device.

16. The method according to claim 15, wherein obtaining the rule include: The rule is obtained based on at least one of the following: Information from the Unified Data Repository (UDR), Operator preferences; Requirements for applications associated with the service; Local configuration of each network slice instance at the load level; and The location of the terminal device.

17. The method of claim 15, wherein determining implementation information include: The implementation information is determined based on at least one of the following: Operator preferences; as well as Requirements for applications associated with the service.

18. The method of claim 17, wherein the requirement for an application associated with the service comprises a user equipment address continuity requirement for the application.

19. The method according to claim 15, further comprising: include: A message is received from the terminal device, the message indicating a rejection of the rule.

20. The method according to claim 15, wherein the verification condition further comprises at least one of the following: the time at which the rule will come into effect; or Delays in implementation are permitted under the rules.

21. The method according to any one of claims 15 to 20, wherein the rules comprise UE Routing Policy (URSP) rules.

22. A terminal device, include: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to at least perform the method according to any one of claims 1 to 14.

23. A network device in a core network, include: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to at least perform the method according to any one of claims 15 to 21.

24. A computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to any one of claims 1 to 14.

25. A computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform the method according to any one of claims 15 to 20.

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