Method, apparatus and computer program

Abstract

There is provided an apparatus comprising means for: determining, at a roaming intermediary, that a data quota for a user equipment has been exhausted; and based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

Description

[0001] AN APPARATUS AND A METHOD FOR CONTROLLING A PROTOCOL DATA UNIT SESSION

[0002] TECHNICAL FIELD

[0003] Various example embodiments of this disclosure relate to a method, apparatus, system and computer program, and in particular - but not exclusively to - enabling (or otherwise facilitating) a roaming intermediary to control a PDU session of a user equipment.

[0004] BACKGROUND

[0005] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. A communication device may be provided with a service by an application server.

[0006] Such communication networks operate in according with standards such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of standards are the so-called 5G (5th Generation) standards provided by 3GPP.

[0007] SUMMARY

[0008] Some example embodiments of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the various embodiments of this disclosure, nor are they intended to be used to limit the scope of thereof. Other features, aspects, and elements will be readily apparent to a person skilled in the art in view of this disclosure.

[0009] According to an aspect, there is provided an apparatus comprising means for: determining, at a roaming intermediary, that a data quota for a user equipment has been exhausted; and based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function. Determining that the data quota has been exhausted may comprise: monitoring, by the roaming intermediary, messages sent between the session management function in the first network and a charging function comprised in the second network via the roaming intermediary.

[0010] The monitoring may comprise determining, by the roaming intermediary and based on the messages sent between the session management function and the charging function, information about usage of data by the user equipment for the at least one protocol data unit session or at least one service data flow.

[0011] The means may be further for: receiving, at the roaming intermediary from the session management function, at least one request to establish the at least one protocol data unit session; based on the at least one request, storing, by the roaming intermediary, information associated with the session management function and sending, by the roaming intermediary, the at least one request to a unified data management function comprised in the second network.

[0012] Causing the session management function to terminate the protocol data unit session may comprise: sending, from the roaming intermediary to the unified data management function via a network exposure function comprised in the second network, a message to update the user equipment’s subscription data to disallow the at least one protocol data unit session or to disallow roaming for the user equipment.

[0013] The message may comprise information indicating that at least one data network name associated with the at least one protocol data unit session is not allowed.

[0014] Causing the session management function to terminate the protocol data unit session may comprise: sending, from the roaming intermediary to the session management function via a network exposure function comprised in the first network, a message to terminate the at least one protocol data unit session.

[0015] The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0016] The message may comprise an internet protocol address associated with the user equipment. According to an aspect, there is provided an apparatus comprising means for providing a network exposure function configured for: receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determining, based on the message, a unified data management function managing the subscription data of the user equipment; and sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0017] The message to update the user equipment’s subscription data may comprise information indicating that a data quota for the user equipment or for the at least one protocol data unit session has expired.

[0018] According to an aspect there is provided an apparatus comprising means for providing a network exposure function configured for: receiving, from a roaming intermediary , a message to terminate at least one protocol data unit session of a user equipment; determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

[0019] The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0020] The message to terminate the at least one protocol data unit session may comprise an internet protocol address of the user equipment, and wherein the means is for providing a network exposure function further configured for: determining, based on the internet protocol address of the user equipment, the session management function and / or policy control function.

[0021] The message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated may further comprise information indicating a cause of the termination of the at least one protocol data unit session being due to data quota expiry. According to an aspect, there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine that a data quota for a user equipment has been exhausted; and based on the determining, cause a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

[0022] The at least one processor may be configured to cause the apparatus to: monitor messages sent between the session management function in the first network and a charging function comprised in the second network via a roaming intermediary.

[0023] The at least one processor may be configured to cause the apparatus to determine, based on the messages sent between the session management function and the charging function, information about usage of data by the user equipment for the at least one protocol data unit session or at least one service data flow.

[0024] The at least one processor may be configured to cause the apparatus to: receive, from the session management function, at least one request to establish the at least one protocol data unit session; based on the at least one request, store information associated with the session management function and send the at least one request to a unified data management function comprised in the second network.

[0025] The at least one processor may be configured to cause the apparatus to: send to the unified data management function via a network exposure function comprised in the second network, a message to update the user equipment’s subscription data to disallow the at least one protocol data unit session or to disallow roaming for the user equipment.

[0026] The message may comprise information indicating that at least one data network name associated with the at least one protocol data unit session is not allowed.

[0027] The at least one processor may be configured to cause the apparatus to: send to the session management function via a network exposure function comprised in the first network, a message to terminate the at least one protocol data unit session.

[0028] The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0029] The message may comprise an internet protocol address associated with the user equipment.

[0030] According to an aspect, there is provided an apparatus for a network exposure function, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determine, based on the message, a unified data management function managing the subscription data of the user equipment; and send, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0031] The message to update the user equipment’s subscription data may comprise information indicating that a data quota for the user equipment or for the at least one protocol data unit session has expired.

[0032] According to an aspect, there is provided an apparatus for a network exposure function, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a roaming intermediary , a message to terminate at least one protocol data unit session of a user equipment; determine, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and send, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

[0033] The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0034] The message to terminate the at least one protocol data unit session may comprise an internet protocol address of the user equipment, and wherein the at least one processor may be configured to cause the apparatus to: determine, based on the internet protocol address of the user equipment, the session management function and / or policy control function.

[0035] The message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated may further comprise information indicating a cause of the termination of the at least one protocol data unit session being due to data quota expiry.

[0036] According to an aspect, there is provided a method performed by a roaming intermediary, the method comprising: determining, at the roaming intermediary, that a data quota for a user equipment has been exhausted; and based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

[0037] Determining that the data quota has been exhausted may comprise: monitoring, by the roaming intermediary, messages sent between the session management function in the first network and a charging function comprised in the second network via the roaming intermediary.

[0038] The monitoring may comprise determining, by the roaming intermediary and based on the messages sent between the session management function and the charging function, information about usage of data by the user equipment for the at least one protocol data unit session or at least one service data flow.

[0039] The method may further comprise: receiving, at the roaming intermediary from the session management function, at least one request to establish the at least one protocol data unit session; based on the at least one request, storing, by the roaming intermediary, information associated with the session management function and sending, by the roaming intermediary, the at least one request to a unified data management function comprised in the second network.

[0040] Causing the session management function to terminate the protocol data unit session may comprise: sending, from the roaming intermediary to the unified data management function via a network exposure function comprised in the second network, a message to update the user equipment’s subscription data to disallow the at least one protocol data unit session or to disallow roaming for the user equipment. The message may comprise information indicating that at least one data network name associated with the at least one protocol data unit session is not allowed.

[0041] Causing the session management function to terminate the protocol data unit session may comprise: sending, from the roaming intermediary to the session management function via a network exposure function comprised in the first network, a message to terminate the at least one protocol data unit session.

[0042] The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0043] The message may comprise an internet protocol address associated with the user equipment.

[0044] According to an aspect, there is provided a method performed by a network exposure function, the method comprising: receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determining, based on the message, a unified data management function managing the subscription data of the user equipment; and sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0045] The message to update the user equipment’s subscription data may comprise information indicating that a data quota for the user equipment or for the at least one protocol data unit session has expired.

[0046] According to an aspect, there is provided a method performed by a network exposure function, the method comprising: receiving, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment; determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated. The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0047] The message to terminate the at least one protocol data unit session may comprise an internet protocol address of the user equipment, and wherein the method may further comprise: determining, based on the internet protocol address of the user equipment, the session management function and / or policy control function.

[0048] The message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated may further comprise information indicating a cause of the termination of the at least one protocol data unit session being due to data quota expiry.

[0049] According to an aspect, there is provided a computer readable medium comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: determining that a data quota for a user equipment has been exhausted; and based on the determining, causing a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

[0050] Determining that the data quota has been exhausted may comprise: monitoring messages sent between the session management function in the first network and a charging function comprised in the second network via a roaming intermediary.

[0051] The monitoring may comprise determining, based on the messages sent between the session management function and the charging function, information about usage of data by the user equipment for the at least one protocol data unit session or at least one service data flow.

[0052] The instructions, when executed by the apparatus, may cause the apparatus to further perform: receiving, from the session management function, at least one request to establish the at least one protocol data unit session; based on the at least one request, storing information associated with the session management function and sending the at least one request to a unified data management function comprised in the second network. Causing the session management function to terminate the at least one protocol data unit session may comprise: sending, from the roaming intermediary to the unified data management function via a network exposure function comprised in the second network, a message to update the user equipment’s subscription data to disallow the at least one protocol data unit session or to disallow roaming for the user equipment.

[0053] The message may comprise information indicating that at least one data network name associated with the at least one protocol data unit session is not allowed.

[0054] Causing the session management function to terminate the at least one protocol data unit session may comprise: sending, to the session management function via a network exposure function comprised in the first network, a message to terminate the at least one protocol data unit session.

[0055] The message to terminate the at least one protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0056] The message may comprise an internet protocol address associated with the user equipment.

[0057] According to an aspect, there is provided a computer readable medium comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determining, based on the message, a unified data management function managing the subscription data of the user equipment; and sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0058] The message to update the user equipment’s subscription data may comprise information indicating that a data quota for the user equipment or for the at least one protocol data unit session has expired. According to an aspect, there is provided a computer readable medium comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment; determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

[0059] The message to terminate the protocol data unit session may comprise information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

[0060] The message to terminate the at least one protocol data unit session may comprise an internet protocol address of the user equipment, and wherein the instructions, when executed by the apparatus, may cause the apparatus to further perform: determining, based on the internet protocol address of the user equipment, the session management function and / or policy control function.

[0061] The message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated may further comprise information indicating a cause of the termination of the at least one protocol data unit session being due to data quota expiry.

[0062] According to an aspect, there is provided a non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method according to any of the preceding aspects.

[0063] In the above, many different aspects have been described. It should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above.

[0064] DESCRIPTION OF FIGURES

[0065] Some example embodiments will now be described, by way of non-limiting and illustrative example only, with reference to the accompanying FIGS, in which: FIG. 1 shows a representation of a 5thgeneration communication system;

[0066] FIG. 2 shows a representation of an apparatus for the communication system of FIG. 1 according to some example embodiments;

[0067] FIG. 3 shows a representation of an apparatus according to some example embodiments;

[0068] FIG. 4 shows methods according to some example embodiments; and

[0069] FIG. 5 shows a signalling exchange according to some example embodiments.

[0070] DETAILED DESCRIPTION

[0071] In the following, various example embodiments are explained with reference to communication devices capable of communication with a communication system. Before explaining in detail the various example embodiments of the methods and apparatuses described herein, a 5thgeneration communication system (5GS), an access network and a core network (5GC) thereof, and communication devices are briefly explained with reference to FIGS. 1 , 2 and 3.

[0072] References in this disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” “some example embodiments,” “certain example embodiments,” “various example embodiments” and the like indicate that the referenced embodiment(s) described may include a particular feature(s), structure(s), or characteristic(s), but it is not necessary that every embodiment or example embodiment described herein includes the particular feature(s), structure(s), or characteristic(s). Moreover, such phrases are not necessarily referring to the same embodiment or same example embodiment. Further, when a particular feature(s), structure(s), or characteristic(s) are described in connection with an embodiment or example embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect combine such feature(s), structure(s), or characteristic(s) in connection with any other embodiments or example embodiments described herein (whether or not such combination is explicitly described).

[0073] FIG. 1 shows a schematic representation of a 5G communication system (5GS). The 5GS may comprise a user equipment (UE), an access network such as a 5G radio access network (5G-RAN) or next generation radio access network (NG-RAN), a 5G core network (5GC), and one or more application functions. An application function may be deployed in the 5GS as trusted application function or may be deployed or host on one or more application servers of the data network. Such application functions are untrusted application functions. The 5GS connects the UE to a data network the access network and the 5GC (e.g., a UPF of the 5GC). The 5G-RAN may comprise one or more radio access nodes, such as gNodeB (GNB). A gNB may include one or more gNodeB (GNB) distributed units connected to one or more gNodeB (GNB) centralized units.

[0074] The 5GC may comprise the following network functions: Network Slice Selection Function (NSSF); Network Exposure Function; Network Repository Function (NRF); Policy Control Function (PCF); Unified Data Management (UDM); Application Function (AF); Authentication Server Function (AUSF); an Access and Mobility Management Function (AMF); and Session Management Function (SMF), and a user plane function (UPF). FIG. 1 also shows the various interfaces (N1 , N2 etc.) that may be implemented between the various elements of the system.

[0075] FIG. 2 illustrates an example of a control apparatus 200 for controlling a function of the access network (e.g., a 5G-RAN or the NG-RAN illustrated in FIG. 1 ) illustrated in FIG. 1. The control apparatus 200 may comprise at least one random access memory (RAM) 211 a, at least on read only memory (ROM) 211 b, at least one processor 212, 213 and a network interface 214. The at least one processor 212, 213 may be coupled to the RAM 211 a and the ROM 211 b. The at least one processor 212, 213 may be configured to execute an appropriate software code 215. Execution of the software code 215 may, for example, cause the apparatus to perform operations for controlling a function of the access network. The software code 215 may be stored in the ROM 211 b. The control apparatus 200 may be interconnected with another control apparatus 200 for controlling another function of the 5G-RAN or the NG-RAN. In some example embodiments, each function of the 5G-RAN or the NG-RAN is deployed or hosted on a control apparatus 200. In alternative example embodiments, two or more functions of the 5G-RAN or the NG-RAN may share a control apparatus.

[0076] FIG. 3 illustrates an example of a communication device 300, such as the UE illustrated in FIG. 1. The communication device 300 may be provided by any device capable of sending and receiving radio signals. Non-limiting and illustrative examples of a communication device 300 comprise a user equipment, a mobile station (MS) or mobile device, such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), a personal data assistant (PDA) or a tablet provided with wireless communication capabilities, a machine-type communications (MTC) device, an Internet of things (loT) type communication device or any combinations of these or the like. The communication device 300 may comprise a transceiver for transmitting and / or receiving, for example, wireless signals carrying communications, for example radio signals. The communications may be one or more of voice, electronic mail (email), text messages, multimedia data, machine data and so on. The communication device 300 may receive wireless signals (e.g., radio signals) over an air or radio interface 307 via appropriate apparatus for receiving and may transmit wireless signals via appropriate apparatus for transmitting radio signals. In FIG. 3, the transceiver is designated schematically by block 306. The transceiver 306 may comprise, for example, a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device and may comprise one or more antenna elements. The antenna arrangement may be a multi-input multi output (MIMO) antenna.

[0077] The communication device 300 may be provided with at least one processor 301 , at least one memory ROM 302a, at least one RAM 302b and other possible components 303 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access networks (e.g., the 5G-RAN or NG-RAN illustrated in FIG. 1 ) and other communication devices. The at least one processor 301 is coupled to the RAM 302b and the ROM 302a. The at least one processor 301 may be configured to execute an appropriate software code 308. The software code 308 may for example allow to perform one or more operations of the communication device. The software code 308 may be stored in the ROM 302a.

[0078] The processor, the ROM, and the RAM, the transceiver and other circuitry of the communication device (e.g., a modem) can be provided on a circuit board, in chipsets, or in a system on chip. The circuit board, chipsets or system on chip is denoted by reference 304. The communication device 300 may optionally have a user interface such as keypad 305, touch sensitive screen or pad, combinations thereof or the like. Optionally one or more of a display, a speaker and a microphone may be provided depending on the type of communication device.

[0079] A roaming intermediary may refer to a commercial entity that can be contracted by a network operator to enable optimized (e.g., quick and / or efficient) access to a wide range of roaming agreements. An example of a roaming intermediary is a roaming hub (RHLIB). A roaming intermediary may, in some examples, be as described in 3GPP TS 33.501 and / or GSMA specifications.

[0080] A roaming intermediary may have a number of roaming agreements and technical interconnections that are already fully negotiated and operational with other network operators. Contracting network operators may then “buy in” to these agreements (e.g. some or all of them). As negotiating roaming agreements with the full range of network operators in the world may take a substantial amount of time and resources, some contracting network operators use a roaming intermediary to get quick access to a wide roaming footprint.

[0081] A roaming intermediary may be acting on behalf of the contracting operators from the commercial and technical point of view and have financial liability for roaming agreements enabled through them. When a roaming intermediary is used, the commercial agreements may not be directly between the network operators, but between the roaming intermediary and the home and visited network operator. In some examples, a roaming intermediary may manage a data quota for a roaming subscriber (e.g., a UE). For example, a roaming intermediary may sell and / or manage a roaming data quota on behalf of a network operator.

[0082] Many network operators may own or have partners in one or more countries, forming a network operator group. For reasons of cost, efficiency and security, these network operator groups may have a common, centralised roaming aggregation point. This roaming aggregation point may form a network operator group roaming intermediary and may establish centralized roaming services (e.g. commercial and technical services) between all network operator group members and to all or some roaming partners of this network operator group (e.g. each roaming partner of the network operator group roaming intermediary may reach each network operator group member and vice versa).

[0083] GSMA defines the concept of hosted security edge protection proxy (SEPP), which is an SEPP that is outsourced by a network operator to a provider outside of the network (e.g. to an internet protocol exchange (IPX) provider or roaming intermediary operator). In some cases, the protocol for N32 interconnect security (PRINS) may prevent the proper working of Roaming intermediary s. While some enhanced PRINS frameworks may enable error messages to be generated at the roaming intermediary, there are still other problems to be solved.

[0084] One problem is how the control of roaming subscriber user plane can be implemented by an intermediary like such as the Roaming intermediary, in order to prevent the data consumption exceeding the the limit agreed in roaming contracts. For example, a use case is that the roaming intermediary operator wants to control the quota (e.g., internet data pack) allocated to the user in roaming, and when the data pack is expired, the roaming intermediary could send an error to the SEPP of the visited network.

[0085] In some examples, the roaming intermediary can see the message over N32-f thanks to PRINS, and when quota is exhausted, may then send an error over N32 message, so that PDU session can be terminated. However, the intorduction of an error message on the N32 PRINS protocol for the same may make PRINS more complex.

[0086] Some examples of the disclosure provide an alternative mechanism where the Roaming intermediary can control the PDU session without changing the PRINS protocol. In particular, some examples may provide mechanism(s) whereby a Roaming intermediary (which may act as a roaming intermediary but also as external Application Function) may control a PDU session for a user equipment.

[0087] Reference is made to FIG. 4, which shows methods according to some examples.

[0088] At 400, a method comprises determining, at a roaming intermediary, that a data quota for a user equipment has been exhausted.

[0089] At 402, the method comprises, based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session.

[0090] At 404, a method comprises receiving, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment.

[0091] At 406, the method comprises determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment.

[0092] At 408, the method comprises sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

[0093] At 410, a method comprises receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment.

[0094] At 412, the method comprises determining, based on the message, a unified data management function managing the subscription data of the user equipment.

[0095] At 414, the method comprises sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0096] In some examples, the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function. In some examples, steps 404- 408 may be performed at or by a NEF, which may be a NEF comprised in the first network. In some examples, steps 410-414 may be performed at or by a NEF, which may be a NEF comprised in the second network.

[0097] In some examples, the Roaming intermediary may control the PDll session for a user equipment. For example, the Roaming intermediary may control the data usage in roaming Local Breakout scenario. The Roaming intermediary may monitor messages (e.g., in N10 and N47 interfaces), and control the PDll Session based on the messages.

[0098] In some examples, the Roaming intermediary may control the PDll session by delivering corresponding messages (e.g., enforcement policies) via V-NEF to the V-SMF; or by updating UE subscription data in the UDM. For example, the Roaming intermediary may update UE subscription data, which may trigger the UDM to notify the SMF about the updates in subscription data, which may in turn trigger the SMF to terminate the PDU Session. Alternatively, the updating of UE subscription data may trigger the UDM to notify the AMF to initiate deregistration of the UE, thereby causing release of the PDU Session.

[0099] Reference is made to FIG. 5, which shows a signalling exchange according to some examples.

[0100] In particular, the example depicted in FIG. 5 represents a Local Breakout roaming scenario. It is assumed that the operators of the first and second networks have an agreement with the Roaming intermediary through which the networks are connected. While only one roaming intermediary (Rl) is depicted in FIG. 5, in some examples there could be two different roaming intermediaries, one (e.g., roaming hub 1 , RH1 ) providing connectivity to the first network (e.g., PLMN1 ) and other another one (e.g., roaming hub 2, RH2) providing connectivity to the second network (e.g., PLMN2), and both roaming intermediaries are connected.

[0101] At 500, a UE that is a subscriber of a second network (e.g., PLMN2) and that is roaming in a first network (e.g., PLMN1 ) initiates a PDU session via the SMF of the first network (i.e. the V- SMF). For example, the UE may send a request for a PDU session to the V-SMF. At 502, the V-SMF creates a registration in the UDM of the home network (i.e. the UDM of the second network) based on the request. The registration may, for example, be created based on a request sent from the V-SMF to the UDM via the roaming intermediary. The request may be sent via the N10 interface.

[0102] Since the request passes via the roaming intermediary, the roaming intermediary may determine and store information associated with the SMF for the PDU session. The information associated with the SMF may, for example, indicate the network in which the SMF is located (which in the example of FIG. 5 is the first network). While the example shown FIG. 5 includes SEPPs in each network through which messages into or out of the network may pass, it should be understood that, in some examples, the SEPPs may not be present.

[0103] At 504, the V-SMF sends, to the Charging Function (CHF) in the Second Network (H-CHF), via the roaming intermediary, information about the usage of the data. The V-SMF may for example communicate via the N47 interface.

[0104] Again, since the information is sent via the roaming intermediary, the roaming intermediary may monitor the messages related to the information about the usage of the data.

[0105] At 506, a data quota for the UE (e.g., a data quota for the UE or for the PDU session of the UE,) or a service data flow (e.g., a data flow for the UE, which may be identified by one or more filters e.g., IP tuples, FQDN etc.) is exhausted / expired. The roaming intermediary may determine that the data quota has been exhausted / expired based on monitoring the messages sent between the H-CHF and V-SMF (e.g., by the N47 interface).

[0106] Having determined that the data quota has been exhausted / expired, the roaming intermediary may cause the V-SMF to terminate the PDU session. Two different example mechanisms for causing the V-SMF to terminate the PDU session are described below with reference to steps 508-514 and 516-522.

[0107] At 508, the roaming intermediary may send, to the V-NEF (e.g., via Nnef_PDUSessionUpdate message) a message to terminate the PDU session. The message may comprise information indicating at least one of: the SMF ID; PDU session ID; or the cause of termination. For example, the message may comprise information indicating that the reason for termination is due to data quota expiry. At 510, based on the message received at 508, the NEF determines the V-SMF (e.g., based on the PDU session ID and SMF ID).

[0108] At 512, the NEF sends to the determined V-SMF a message (e.g., Nsmf_PDUSessionllpdate) to terminate the PDU session. The message sent to the V-SMF may comprise information indicating that the PDU session is to be terminated due to data quota expiry. Alternatively, NEF may send a message to the PCF and then the PCF may instruct the V-SMF to terminate the PDU Session.

[0109] At 514, based on the instruction from the NEF and / or PCF, the V-SMF may terminate the PDU session.

[0110] In some examples, the roaming intermediary may communicate using the UE IP address. The IP address may be used to identify the PDU Session and the SMF serving the PDU Session. For example, at 508 the RH may send, to the V-NEF, a message targeting an IP address. From the IP address using BSF query, the V-NEF may at 510 determine the serving PCF and at 512 may provide policies to the serving PCF. The serving PCF may then update the V-SMF and at 514 the V-SMF may terminate the PDU session accordingly.

[0111] Alternatively, to steps 508-514, at 516 the RH may send to the UDM via the NEF of the second network (e.g., via Nnef_ParameterProvision service) a message to update the UE’s subscription data.

[0112] The message may be to update the user equipment’s subscription data (stored at the UDM) to disallow a protocol data unit session (or a DNN associated with the PDU session), or to disallow roaming for the user equipment. In some examples, the message may comprise information indicating that the data quota for the UE or the PDU session has been exhausted.

[0113] Thus, in some examples, the NEF of the second network may receive the message to update the UE’s subscription data. The NEF may then determine the UDM managing the subscription data of the UE based on the message. The NEF may then send, to the determined UDM, a message comprising information indicating that roaming is not allowed for the UE or at least one DNN associated with the PDU session is not allowed for the UE.

[0114] At 518, upon receiving the message at 516, the UDM may update the Session Management subscription data to disallow roaming for the user equipment or to disallow the DNN specific to the PDU Session for the UE. At 520, the UDM may send, to the V-SMF, a message indicating that the PDU session for the UE is not allowed or that roaming is not allowed for the LIE. The message may, for example, indicate that the DNN associated with the PDU session is not allowed. The message may be sent via the SEPPs / roaming intermediary as shown in FIG. 5, for example as N32 traffic.

[0115] At 522, based on the message received at 520, the V-SMF may terminate the PDU session.

[0116] In some examples (not shown in FIG. 5), a modification of steps 516-522 may be implemented, where the roaming intermediary may send, to the UDM via the NEF of the HPLMN (e.g. via Nnef_ParameterProvision service) a message to update the UE’s subscription data. The message may comprise information for updating the UE’s subscription data to disallow roaming for the UE. Upon subscription data update, the UDM may trigger network-initiated deregistration procedure and notifies the AMF to deregister the UE. The AMF may then trigger the V-SMF to perform PDU session release and then the AMF deregisters the UE.

[0117] While FIG. 5 above is described with reference to a PDU session, it should be understood that, in some examples, there may be more than one PDU session of the UE that is managed by the V-SMF. In other words, the roaming intermediary may determine that the data quota has expired, and cause the V-SMF to terminate at least one PDU session, for example by sending a message to the V-SMF via a NEF to terminate the at least one PDU session, or by sending a message to a UDM via a NEF to update the UE’s subscription data to disallow the at least one PDU session or to disallow roaming for the UE.

[0118] Thus, in some examples, the Roaming intermediary may monitor messages associated with a UE that is registered in a second network (e.g. PLMN2) and is roaming in a first network (e.g. PLMN1 ). Based on the messages, the Roaming intermediary may determine that a data quota associated with the UE (or PDU session) has been exhausted. The Roaming intermediary may then cause the SMF of the first network (V-SMF) to terminate the PDU session for the UE. For example, the Roaming intermediary may send, to the V-NEF a message to terminate the PDU session, which is then forwarded on to the SMF accordingly. Alternatively, the Roaming intermediary may send, to the UDM in the second network, a message to update the UE’s subscription data stored at the UDM to disallow the PDU session for the UE, and the UDM may inform the SMF of the first network accordingly. Thus, mechanisms are provided whereby the Roaming intermediary can control the PDU session without changing the PRINS protocol. In some examples, there is provided an apparatus comprising means for: determining, at a roaming intermediary, that a data quota for a user equipment has been exhausted; and based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

[0119] In some examples, there is provided an apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine that a data quota for a user equipment has been exhausted; and based on the determining, cause a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

[0120] In some examples, there is provided an apparatus comprising means for providing a network exposure function configured for: receiving, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment; determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

[0121] In some examples, there is provided an apparatus for a network exposure function, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a roaming intermediary , a message to terminate at least one protocol data unit session of a user equipment; determine, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and send, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

[0122] In some examples, there is provided an apparatus comprising means for providing a network exposure function configured for: receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determining, based on the message, a unified data management function managing the subscription data of the user equipment; and sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0123] In some examples, there is provided an apparatus for a network exposure function, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determine, based on the message, a unified data management function managing the subscription data of the user equipment; and send, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

[0124] It is understood that references in the above to various network functions (e.g., to an AMF, an SMF, TNF etc.), an apparatus may be configured to operate as particular network function(s). For example, the apparatus may be configured to perform at least some of the functionality associated with the particular network function(s). By way of non-limiting and illustrative example, an apparatus configured to operate as a particular network function may be configured to implement a virtual network function instance of that particular network function.

[0125] It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and / or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

[0126] It is noted that whilst some example embodiments have been described in relation to 5G networks, similar principles can be applied in relation to other networks and communication systems. Therefore, although certain example embodiments were described above, by way of non-limiting and illustrative example with reference to certain example architectures for wireless networks, technologies and standards, example embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein. It is also noted herein that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0127] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements. As used herein, the expression “and / or” includes any and all combinations of one or more of the listed terms.

[0128] In general, the various example embodiments may be implemented in hardware or special purpose circuitry, software, logic or any combination thereof. Some aspects of the disclosure may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting and illustrative examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0129] As used herein, the term “circuitry” may refer to one or more or all of the following:

[0130] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0131] (b) combinations of hardware circuits and software, such as (as applicable):

[0132] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0133] (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[0134] I hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.”

[0135] This definition of circuitry applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0136] The various example embodiments of this disclosure may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and / or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out one or more of the various example embodiments of this disclosure. The one or more computer-executable components may be at least one software code or portions of it.

[0137] Further, in this regard, it should be noted that any blocks of the logic flow as in the FIGS, may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

[0138] The term “non-transitory,” as used herein, is a limitation of the medium itself (e.g., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0139] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting and illustrative examples.

[0140] Various example embodiments of the disclosure may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0141] The scope of protection sought for various example embodiments of the disclosure is set out by the independent claims. The example embodiments and features thereof, if any, described in this disclosure that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various example embodiments of the disclosure. The foregoing description has provided, by way of non-limiting and illustrative examples, a full and informative description of the various example embodiments of this disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the claims. However, all such and similar modifications of the teachings will still fall within the various example embodiments of the disclosure as set forth in the claims. By way of non-limiting and illustrative example, there is a further example embodiment comprising a combination of one or more example embodiments with any of the other example embodiments previously discussed.

Claims

CLAIMS1 . An apparatus comprising means for: determining, at a roaming intermediary, that a data quota for a user equipment has been exhausted; and based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

2. The apparatus of claim 1 , wherein determining that the data quota has been exhausted comprises: monitoring, by the roaming intermediary, messages sent between the session management function in the first network and a charging function comprised in the second network via the roaming intermediary.

3. The apparatus of claim 2, wherein the monitoring comprises determining, by the roaming intermediary and based on the messages sent between the session management function and the charging function, information about usage of data by the user equipment for the at least one protocol data unit session or at least one service data flow.

4. The apparatus of any preceding claim, wherein the means is further for: receiving, at the roaming intermediary from the session management function, at least one request to establish the at least one protocol data unit session; based on the at least one request, storing, by the roaming intermediary, information associated with the session management function and sending, by the roaming intermediary, the at least one request to a unified data management function comprised in the second network.

5. The apparatus of claim 4, wherein causing the session management function to terminate the protocol data unit session comprises: sending, from the roaming intermediary to the unified data management function via a network exposure function comprised in the second network, a message to update the user equipment’s subscription data to disallow the at least one protocol data unit session or to disallow roaming for the user equipment.

6. The apparatus of claim 5, wherein the message comprises information indicating that at least one data network name associated with the at least one protocol data unit session is not allowed.

7. The apparatus of any of claims 1 to 4, wherein causing the session management function to terminate the protocol data unit session comprises: sending, from the roaming intermediary to the session management function via a network exposure function comprised in the first network, a message to terminate the at least one protocol data unit session.

8. The apparatus of claim 7, wherein the message to terminate the at least one protocol data unit session comprises information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

9. The apparatus of claim 7 or 8, wherein the message comprises an internet protocol address associated with the user equipment.

10. An apparatus comprising means for providing a network exposure function configured for: receiving, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment; determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.11 . The apparatus of claim 10, wherein the message to terminate the at least one protocol data unit session comprises information indicating at least one of: the session management function identity; the at least one protocol data unit session identity; or a cause of termination of the at least one protocol data unit session being due to data quota expiry.

12. The apparatus of claim 10 or 11 , wherein the message to terminate the at least one protocol data unit session comprises an internet protocol address of the user equipment, and wherein the means is for providing a network exposure function further configured for: determining, based on the internet protocol address of the user equipment, the session management function and / or policy control function.

13. The apparatus of any of claims 10 to 12, wherein the message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated further comprises information indicating a cause of the termination of the at least one protocol data unit session being due to data quota expiry.

14. An apparatus comprising means for providing a network exposure function configured for: receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determining, based on the message, a unified data management function managing the subscription data of the user equipment; and sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

15. The apparatus of claim 14, wherein the message to update the user equipment’s subscription data comprises information indicating that a data quota for the user equipment or for the at least one protocol data unit session has expired.

16. An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine that a data quota for a user equipment has been exhausted; and based on the determining, cause a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

17. An apparatus for a network exposure function, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment; determine, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and send, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.

18. An apparatus for a network exposure function, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determine, based on the message, a unified data management function managing the subscription data of the user equipment; and send, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

19. A method performed by a roaming intermediary, the method comprising: determining, at the roaming intermediary, that a data quota for a user equipment has been exhausted; and based on the determining, causing, by the roaming intermediary, a session management function managing at least one protocol data unit session for the user equipment to terminate the at least one protocol data unit session, wherein the user equipment is a subscriber of a second network and is roaming in a first network comprising the session management function.

20. A method performed by a network exposure function, the method comprising: receiving, from a roaming intermediary, a message to terminate at least one protocol data unit session of a user equipment;determining, based on the message, a session management function managing the at least one protocol data unit session of the user equipment; and sending, to the determined session management function or to a policy control function, a message comprising information indicating that the at least one protocol data unit session of the user equipment is to be terminated.21 . A method performed by a network exposure function, the method comprising: receiving, from a roaming intermediary, a message to update a user equipment’s subscription data to disallow at least one protocol data unit session or to disallow roaming for the user equipment; determining, based on the message, a unified data management function managing the subscription data of the user equipment; and sending, to the determined unified data management function, a message comprising information indicating that the roaming is not allowed for the user equipment or at least one data network name associated with the at least one protocol data unit session is not allowed for the user equipment.

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