Flow based charging in communication networks

Abstract

A method for supporting flow-based application traffic data reporting, performed by a User Plane Function (UPF) node, is provided. The method includes receiving an indication to enable flow level reporting. The method includes receiving application traffic data from a user equipment (UE). The method includes analyzing the application traffic data to determine that the application traffic data matches a Packet Data Rule (PDR) for which reporting per application traffic flow is enabled. The method includes retrieving and storing information about the application traffic data per said flow. The method includes forwarding the application traffic data to an application server.

Description

FLOW BASED CHARGING IN COMMUNICATION NETWORKSTECHNICAL FIELD

[0001] Disclosed are embodiments related to flow-based charging in communication networks (e.g., a Third Generation Partnership Project (3 GPP) Fifth Generation (5G) network).BACKGROUND

[0002] FIG. 1 illustrates a 5G reference architecture as defined by 3 GPP. This includes a number of nodes, such as a Network Slice Selection Function (NSSF) node 102, a Network Exposure Function (NEF) node 104, a Network Repository Function (NRF) node 106, a Policy Control Function (PCF) node 108, a Unified Data Management (UDM) node 110, and a Application Function (AF) node 112. Other nodes include an Edge Application Server Discovery Function (EASDF) node 114, a Network Slice Specific Authentication and Authorization Function (NSSAAF) node 116, an Authentication Server Function (AUSF) node 118, an Access and Mobility Function (AMF) 120, and a Session Management Function (SMF) 122. Other nodes include a Service Communication Proxy (SCP) node 124, a Network Slice Access Control Function (NSACF) node 126, a user equipment (UE) 128, a (Radio) Access Network ((R)AN) node 130, a User Plane Function (UPF) node 132, and a Data Network (DN) node 134. The figure illustrates some communication pathways between these nodes.

[0003] FIG. 2 illustrates a 5G reference architecture of a policy and charging control framework using a service-based representation. A Unified Data Repository (UDR) node 202, a a Network Data Analytics Function (NWDAF) node 204, and a Charging Function (CHF) node 206 are illustrated, among some of the other nodes shown in FIG. 1. The figure illustrates some communication pathways between these nodes.

[0004] FIG. 3 illustrates a 5G reference architecture of a policy and charging control framework using a reference point representation. The figure illustrates some communication pathways between these nodes.

[0005] Some relevant architectural aspects for disclosed embodiments herein include the CHF 206, the PCF 108, the SMF 122, the UPF 132, the NRF 106, described further below.

[0006] The Charging Function (CHF) 206 supports offline and online charging functionality and exposes the Nchf interface towards the consumers (e.g. SMF 122).

[0007] The Policy Control Function (PCF) 108 supports a unified policy framework to govern the network behavior. Specifically, the PCF 108 provides Policy and Charging Control (PCC) rules to the Policy and Charging Enforcement Function (PCEF), i.e. the SMF 122 / UPF 132 that enforces policy and charging decisions according to provisioned PCC rules.

[0008] The Session Management function (SMF) 122 supports different functionalities, e.g., SMF 122 receives PCC rules from the PCF 108 and configures the UPF 132 accordingly.

[0009] The User Plane function (UPF) 132 supports handling of user plane traffic, including packet inspection, packet routing and forwarding, traffic usage reporting, and Quality of Service (QoS) handling.

[0010] The Network Repository Function (NRF) 106 is the network entity in the 5G Core Network (5GC) supporting the following functionality:Maintains the Network Function (NF) profile of available NF instances and their supported services;Maintains the SCP profile of available SCP instances;Maintains the Security Edge Protection Proxy (SEPP) profile of available SEPP instances;Allows other NF or SCP instances to subscribe to, and get notified about, the registration in NRF of new NF instances of a given type or of SEPP instances. It also allows SCP instances to subscribe to, and get notified about, the registration in NRF of new SCP instances;Supports service discovery function. It receives NF Discovery Requests from NF or SCP instances, and provides the information of the available NF instances fulfilling certain criteria (e.g., supporting a given service);Support SCP discovery function. It receives NF Discovery Requests for SCP profiles from other SCP instances, and provides the information of the available SCP instances fulfilling certain criteria (e.g., serving a given NF set);Support SEPP discovery function. It receives NF Discovery Requests for SEPP profiles from other NF or SCP instances, and provides the information of the available SEPP instances fulfilling certain criteria (e.g. supporting connectivity with a remote Public Land Mobile Network (PLMN)).

[0011] Based on 3GPP Technical Specification (“TS”) 23.501 (Sections 6.3.3.3 and 6.3.3.2), UPF selection for a Packet Data Unit (PDU) session is based on the following information. The following parameter(s) and information may be considered by the SMF for UPF selection and re-selection:UPF's dynamic load.UPF's relative static capacity among UPFs supporting the same Data Network Name (DNN).UPF location available at the SMF.UE location information.Capability of the UPF and the functionality required for the particular UE session: An appropriate UPF can be selected by matching the functionality and features required for an UE.Data Network Name (DNN).PDU Session Type (i.e. IPv4, IPv6, IPv4v6, Ethernet Type or Unstructured Type) and if applicable, the static IP address / prefix.Session and Service Continuity (SSC) mode selected for the PDU Session.UE subscription profile in UDM.Data Network Access Identifier (DNAI) as included in the PCC RulesLocal operator policies.Single Network Slice Selection Assistance Information (S-NSSAI).Access technology being used by the UE.Information related to user plane topology and user plane terminations, that may be deduced from:AN-provided identities (e.g. CelllD, Tracking Area Identity (TAI)), available UPF(s) and DNAI(s);Information regarding the user plane interfaces of UPF(s).This information may be acquired by the SMF using N4;Information regarding the N3 User Plane termination(s) of the AN serving the UE. This may be deduced from AN-provided identities (e.g. CelllD, TAI);Information regarding the N9 User Plane termination(s) of UPF(s) if needed;Information regarding the User plane termination(s) corresponding to DNAI(s).

[0012] In 3GPP TS 29.510 Section 6.1.6.2.2, it is defined the NF profile that is composed of several attributes like IP address and / or FQDN of the NF, name of the NF and specific info depending of each NF. For example, upfinfo is defined in 3GPP TS 29.510 at Section 6.1.6.2.13.

[0013] References:

[0014] 3GPP TS 29.244 vl 8.2.1 (June 2023) “Interface between the Control Plane and the User Plane nodes”

[0015] 3GPP TS 29.512 vl8.2.0 (June 2023) ”5G System; Session Management Policy Control Service; Stage 3

[0016] 3GPP TS 29.510 vl8.3.0 (June 2023) “5G System; Network function repository services; Stage 3”SUMMARY

[0017] The current mechanism for Usage Reporting Rule (URR) reporting [1] does not have per flow granularity.

[0018] Network operators (e.g. SKT) require detailed reports, differentiating among the different services with a per flow granularity, e.g. for charging purposes, for revenue creation from new business based on big data analysis, to provide faster and more proactive response tocustomer complaints, and / or abnormal behavior analysis (including malicious UE and / or virus UE).

[0019] Embodiments disclosed herein provide a mechanism which allows the network operator to support flow-based charging. This provides at least the following advantages:Allows the network operator to differentiate user application traffic on a per IP flow basis, which can be used for reporting and / or charging purposes, for revenue creation from new business based on big data analysis, to provide faster and more proactive response to customer complaints, abnormal behavior analysis (including malicious UE and / or virus UE), and so on.Allows the network operator to differentiate user traffic that is not known in advance (i.e. traffic classified into the default catch all rule), which can be used for reporting and / or charging purposes.Allows the network operator to simplify the provisioning and to reduce the number of the rules to classify the traffic, which results in a significant performance improvement.

[0020] According to a first aspect, a method for supporting flow-based application traffic data reporting, performed by a User Plane Function (UPF) node is provided. The method includes receiving an indication to enable flow level reporting. The method includes receiving application traffic data from a user equipment (UE). The method includes analyzing the application traffic data to determine that the application traffic data matches a Packet Data Rule (PDR) for which reporting per application traffic flow is enabled. The method includes retrieving and storing information about the application traffic data per said flow. The method includes forwarding the application traffic data to an application server.

[0021] In some embodiments, the method further includes determining that a Usage Reporting Rule (URR) threshold is met. In some embodiments, the method further includes sending a PFCP Session Report Request message comprising a report on a per-flow-level basis, said report comprising information about the application traffic data per said flow. In some embodiments, the indication to enable flow level reporting is received from a Session Management Function (SMF) node. In some embodiments, the indication to enable flow level reporting specifies a granularity for the flow level reporting. In some embodiments, thegranularity for the flow level reporting is one of (i) a per-Packet Forwarding Control Protocol (PF CP) session granularity and (ii) a per-application granularity. In some embodiments, the indication to enable flow level reporting is comprised in in a Packet Forwarding Control Protocol (PFCP) Session Establishment Request message or a PFCP Session Modification Request message received from a Session Management Function (SMF) node. In some embodiments, the information about the application traffic flow includes a source IP address, a source port, a destination IP address, a destination port, and an IP protocol, accumulated uplink and downlink volume for the application traffic flow, and timestamp when the application traffic flow was created.

[0022] According to a second aspect, a method for User Plane Function (UPF) Registration performed by a UPF node is provided. The method includes determining to register a Network Function (NF) Profile with a Network Repository Function (NRF) node. The method includes sending towards the NRF node a request to register the NF Profile. The NF Profile indicates support for flow-based reporting. The method includes receiving a response from the NRF node to the request to register the NF Profile.

[0023] According to a third aspect, a method for User Plane Function (UPF) Registration performed by a Network Repository Function (NRF) node is provided. The method includes receiving from a UPF node a request to register a Network Function (NF) Profile. The NF Profile indicates support for flow-based reporting. The method includes storing the NF Profile for the UPF node. The method includes sending towards the UPF node a response to the request to register the NF Profile.

[0024] According to a fourth aspect, a method for User Plane Function (UPF) discovery performed by a Session Management Function (SMF) node is provided. The method includes determining to trigger UPF discovery procedure with a Network Repository Function (NRF) node. The method includes sending towards the NRF node a request to initiate UPF discovery. The request includes an indication of support for flow-based reporting. The method includes receiving a response from the NRF node to the request to initiate UPF discovery. The response includes a list of UPF instances. The method includes selecting a UPF instance from among the list of UPF instances.

[0025] According to a fifth aspect, a method for User Plane Function (UPF) discovery performed by a Network Repository Function (NRF) node is provided. The method includes receiving from a Session Management Function (SMF) node a request to initiate UPF discovery. The request includes an indication of support for flow-based reporting. The method includes determining a list of UPF instances matching criteria included in the request to initiate UPF discovery. The method includes sending towards the SMF node a response to the request to initiate UPF discovery. The response includes the list of UPF instances.

[0026] According to a sixth aspect, a method for Packet Forwarding Control Protocol (PFCP) association performed by a User Plane Function (UPF) node is provided. The method includes sending a PFCP association setup request towards a Session Management Function (SMF) node. The PFCP association setup request includes an indication of support for flowbased reporting. The method includes receiving a response from the SMF node to the PFCP association setup request.

[0027] According to a seventh aspect, a method for Packet Forwarding Control Protocol (PFCP) association performed by a Session Management Function (SMF) node is provided. The method includes receiving a PFCP association setup request from a User Plane Function (UPF) node. The PFCP association setup request includes an indication of support for flow-based reporting. The method includes sending a response towards the UPF node to the PFCP association setup request. The method includes triggering UPF selection for a packet data unit (PDU) session taking into account UPF capabilities indicated by the request, including support for flow-based reporting.

[0028] According to an eighth aspect, a User Plane Function (UPF) node is provided. The UPF node includes processing circuitry; and a memory. The memory contains instructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to receive an indication to enable flow level reporting. The processing circuitry is further configured to receive application traffic data from a user equipment (UE). The processing circuitry is further configured to analyze the application traffic data to determine that the application traffic data matches a Packet Data Rule (PDR) for which reporting per application traffic flow is enabled. The processing circuitry is further configured to retrieve andstore information about the application traffic data per said flow. The processing circuitry is further configured to forward the application traffic data to an application server.

[0029] According to a ninth aspect, a User Plane Function (UPF) node is provided. The UPF node includes processing circuitry; and a memory. The memory contains instructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to determine to register a Network Function (NF) Profile with a Network Repository Function (NRF) node. The processing circuitry is further configured to send towards the NRF node a request to register the NF Profile. The NF Profile indicates support for flow-based reporting. The processing circuitry is further configured to receive a response from the NRF node to the request to register the NF Profile.

[0030] According to a tenth aspect, a Network Repository Function (NRF) node is provided. The NRF node includes processing circuitry; and a memory. The memory contains instructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to receive from a UPF node a request to register a Network Function (NF) Profile. The NF Profile indicates support for flow-based reporting. The processing circuitry is further configured to store the NF Profile for the UPF node. The processing circuitry is further configured to send towards the UPF node a response to the request to register the NF Profile.

[0031] According to an eleventh aspect, a User Plane Function (UPF) node is provided. The UPF node includes processing circuitry; and a memory. The memory contains instructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to determine to trigger UPF discovery procedure with a Network Repository Function (NRF) node. The processing circuitry is further configured to send towards the NRF node a request to initiate UPF discovery. The request includes an indication of support for flow-based reporting. The processing circuitry is further configured to receive a response from the NRF node to the request to initiate UPF discovery. The response includes a list of UPF instances. The processing circuitry is further configured to select a UPF instance from among the list of UPF instances.

[0032] According to a twelfth aspect, a Network Repository Function (NRF) node is provided. The NRF node includes processing circuitry; and a memory. The memory containsinstructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to receive from a Session Management Function (SMF) node a request to initiate UPF discovery. The request includes an indication of support for flow-based reporting. The processing circuitry is further configured to determine a list of UPF instances matching criteria included in the request to initiate UPF discovery. The processing circuitry is further configured to send towards the SMF node a response to the request to initiate UPF discovery. The response includes the list of UPF instances.

[0033] According to a thirteenth aspect, a User Plane Function (UPF) node is provided. The UPF node includes processing circuitry; and a memory. The memory contains instructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to send a PFCP association setup request towards a Session Management Function (SMF) node. The PFCP association setup request includes an indication of support for flowbased reporting. The processing circuitry is further configured to receive a response from the SMF node to the PFCP association setup request.

[0034] According to a fourteenth aspect, a Session Management Function (SMF) node is provided. The SMF node includes processing circuitry; and a memory. The memory contains instructions executable by the processing circuitry, whereby when executed the processing circuitry is configured to receive a PFCP association setup request from a User Plane Function (UPF) node. The PFCP association setup request includes an indication of support for flowbased reporting. The processing circuitry is further configured to send a response towards the UPF node to the PFCP association setup request. The processing circuitry is further configured to trigger UPF selection for a packet data unit (PDU) session taking into account UPF capabilities indicated by the request, including support for flow-based reporting.

[0035] According to a fifteenth aspect, a computer program is provided, comprising instructions which when executed by the processing circuitry of a node cause the node to perform the method of any of the embodiments of the first, second, third, fourth, fifth, sixth, and seventh aspects.

[0036] According to a sixteenth aspect, a carrier is provided, containing the computer program of the fifteenth aspect. The carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium.BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments.

[0038] FIG. 1 illustrates a 5G reference architecture as defined by 3GPP.

[0039] FIG. 2 illustrates a 5G reference architecture of a policy and charging control framework using a service-based representation.

[0040] FIG. 3 illustrates a 5G reference architecture of a policy and charging control framework using a reference point representation.

[0041] FIG. 4 illustrates a sequence diagram according to some embodiments.

[0042] FIG. 5 illustrates a sequence diagram according to some embodiments.

[0043] FIG. 6 illustrates a sequence diagram according to some embodiments.

[0044] FIG. 7 illustrates a sequence diagram according to some embodiments.

[0045] FIG. 8 illustrates a sequence diagram according to some embodiments.

[0046] FIG. 9 illustrates a sequence diagram according to some embodiments.

[0047] FIG. 10 illustrates a flowchart according to an embodiment.

[0048] FIG. 11 illustrates a flowchart according to an embodiment.

[0049] FIG. 12 illustrates a flowchart according to an embodiment.

[0050] FIG. 13 illustrates a flowchart according to an embodiment.

[0051] FIG. 14 illustrates a flowchart according to an embodiment.

[0052] FIG. 15 illustrates a flowchart according to an embodiment.

[0053] FIG. 16 illustrates a flowchart according to an embodiment.

[0054] FIG. 17 is a block diagram of an apparatus according to an embodiment.DETAILED DESCRIPTION

[0055] FIG. 4 illustrates a flow diagram according to an embodiment.

[0056] According to some embodiments, at an operator's network, a new feature referred to as “IP flow level reporting” can be enabled / disabled on a per subscriber basis, on a per group of subscribers basis, and / or on a per node basis. Additionally, this feature can also be enabled / disabled on a per PCC rule basis.

[0057] The following extensions related to UPF registration and discovery are proposed. First, UPF registration and discovery via NRF including the support for a new feature “IP flow level reporting”. Second, in the Packet Forwarding Control Protocol (PFCP) Association procedure, UPF reports to SMF a new capability (IP flow level reporting). This allows SMF to select a UPF supporting this capability on a per PFCP session basis.

[0058] FIG. 4 illustrates a flow diagram according to an embodiment. For each PDU session, the following steps (as shown in FIG. 4) may be performed:

[0059] Step 1. PCF 108 retrieves from UDR 202 a subscriber policy profile, which is proposed to be extended with an indication to enable “IP flow level reporting,” e.g., on a per PDU session basis or on a per application basis.

[0060] Step 2. PCF 108 indicates to SMF 122 to enable “IP flow level reporting,” e.g., on a per PDU session basis or on a per application basis. It is proposed to extend the N7 interface with an indication, e.g. as a new attribute in the PCC rule.

[0061] Step 3. Based on the above, SMF 122 indicates to UPF 132 to enable “IP flow level reporting.” It is proposed to extend the N4 interface (PFCP protocol) by provisioning URR(s) extended to request IP flow level reporting. Different granularity levels are proposed, including, for example:On a per PFCP session basis, i.e. for all the IP flows in the PFCP session.On a more granular basis, e.g. only for the IP flows corresponding to traffic matching a certain application (e.g. Netflix). This can be enabled on a per subscriber and on a per Packet Data Rule (PDR) basis (in the above example, for the PDR corresponding to the Netflix application).

[0062] Steps 4 and 5. UPF 132 analyzes traffic for the PFCP session and for the traffic matching a PDR associated to a URR extended to request IP flow level reporting, it detects the presence of every single IP flow. Such traffic may travel between the UE 128, UPF 132, and an application server 402. When the URR report associated to the PDR is triggered, the URR is extended to report IP flow level information, specifically, for example, volume and timestamps on a per flow basis.

[0063] Step 6. SMF 122 receives the URR report from UPF 132 and applies the corresponding logic, specifically, for example, reporting the volume and timestamps on a per flow basis, which can be used for reporting and / or charging purposes, e.g. by forwarding this information to the CHF 206 (e.g. by extending the Nchf interface).

[0064] As mentioned, IP flow level reporting can be enabled on a per PCC rule basis. A couple of examples below:Default PCC rule. This can be useful as a significant part of the user traffic gets classified in the default PCC rule. Enabling IP flow level reporting for this default PCC rule allows an operator to differentiate this traffic (e.g., by reporting the volume and timestamps for each detected flow).Any other PCC rule, e.g. a PCC rule for a certain Video application (e.g. Netflix) traffic. Enabling IP flow level reporting for this PCC rule allows an operator to differentiate this traffic (e.g., by reporting the volume and timestamps for each detected flow). Based on the volume, an operator would be able to differentiate video flows (which carry a relevant amount of volume) from non-video flows (e.g. browsing through a Netflix movie catalogue), and to apply differentiated charging based on that.

[0065] FIG. 5 illustrates a sequence diagram describing a proposed mechanism for UPF 132 registration in NRF 106 including support for the flow-based reporting feature. This procedure is optional as UPF selection by SMF 122 does not need to be based on NRF 106. Flow-based reporting may be used to enable flow-based charging, and the feature may also be referred to as flow-based charging in this description. Steps are detailed below:

[0066] Steps 1 and 2. UPF 132 registers in NRF 106 its NFProfile indicating support for the flow-based reporting feature. To do this, it is proposed that UPF 132 triggers a Nnrf_NFManagement NFRegister Request message including the following parameters:NFType=UPFNFInstanceldNFProfile including upflnfo extended with an indication of support for flow-based reporting. For example, it is proposed to update 3GPP TS 29.510 Table 6.1.6.2.13-1 (changes in bold).

[0067] Table 6.1.6.2.13-1: Definition of type Upflnfo

[0068] Steps 3 and 4. NRF 106 stores the NFProfile for UPF 132 (including upflnfo extended with the above information) and answers UPF 132 with a Nnrf_NFManagement NFRegister Response message indicating a successful operation.

[0069] FIG. 6 illustrates a sequence diagram describing a proposed mechanism when SMF 122 selects a UPF 132 assisted by NRF 106 and issues a Nnrf_NFDiscovery request (if a previous response for a similar request has been received and that is still within the validity period, SMF 122 uses the information in that previous response). This procedure is optional as UPF selection by SMF 122 does not need to be based on NRF 106. Steps are detailed below:

[0070] Steps 1 and 2. SMF 122 triggers UPF discovery procedure assisted by NRF 106. To do this, it is proposed that SMF 122 triggers a Nnrf_NFDiscovery Request message including the following parameters:NFType=UPFNFProfile including upflnfo extended with the requested feature flow-based reporting.

[0071] Steps 3, 4 and 5. NRF 106 returns to SMF 122 a list of UPF instances matching the requested criteria (i.e. supporting the feature flow-based reporting).

[0072] FIG. 7 illustrates a sequence diagram showing an extension of the PF CP Association Setup procedure including the support for the flow-based reporting feature. Steps are detailed below:

[0073] Step 1. At PCFP Association Setup procedure between UPF 132 and SMF 122 entities, UPF 132 indicates support for the flow-based reporting feature (FBCU in the table below) in the User Plane (UP) Function Features (see table below in bold as modified from 3GPP TS 29.244). SMF 122 might select a UPF instance based on this capability.

[0074] Table 8.2.25-1: UP Function Features

[0075] Step 2. SMF 122 answers UPF 132 with a PFCP Association Setup Response message indicating successful operation.

[0076] Step 3. SMF 122 triggers UPF selection for the PDU session having into account the UPF reported capabilities.

[0077] FIG. 8 and FIG. 9 illustrate a sequence diagram showing a proposed solution for flow-based reporting for the example use case of IP flow-based level reporting enabled for traffic matching the default rule. FIG. 9 is a continuation of the sequent diagram begun in FIG. 8.Steps are detailed below:

[0078] In this example, IP flow-based level reporting policy for default traffic is preconfigured in UDR as subscriber policy data.

[0079] Steps 1 and 2. UE 128 triggers PDU session establishment, by sending a PDU Session Establishment Request to AMF 120. AMF 120 selects an SMF 122 to manage the PDU session (the SMF selection function in the AMF 120 selects an SMF instance based on the available SMF instances obtained from NRF 106 or on the configured SMF information in the AMF 120 ) and triggers Nsmf PDU Session Create. Note the sequence diagram in FIG. 8 and FIG. 9does not include all the signaling messages involved in the PDU Session Establishment procedure. The relevant signaling messages for disclosed embodiments are described in subsequent steps.

[0080] Step 3. SMF 122 triggers a Npcf SMPolicyControl Create Request message to retrieve Session Management (SM) policies for the user PDU session.

[0081] Step 4. PCF 108 triggers a Nudr Query Request message including the subscriber identifier to retrieve the policy data for this subscriber's PDU session.

[0082] Step 5. UDR 202 answers with a Nudr Query Response message including the Subscriber Policy Data, which includes an IP flow-based level reporting policy for default traffic. In the example of the sequence diagram in FIG. 8 and FIG. 9, flow-based level reporting is enabled on a per subscriber basis (specifically for this subscriber's PDU session) and on a per PCC rule basis (specifically for the default PCC rule, and not for the other PCC rules). Other flow-based reporting bases are available, such as described herein.

[0083] Step 6. PCF 108 generates the corresponding PCC rule(s) based on Subscriber Policy Data, specifically a default PCC rule with IP flow-based level reporting enabled. In this example, the subscriber policy data (retrieved by PCF 108 from UDR 202), might include an indication (e.g. a flag) to enable flow-based reporting only for the default PCC rule. In order to minimize the impacts on PCF 108, it is proposed to use pre-defined PCC rules, as follows:PCC rule #X is the default pre-defined PCC rule when flow-based reporting is disabled.PCC rule #Y is the default pre-defined PCC rule when flow-based reporting is enabled.

[0084] In the example shown in FIG. 8 and FIG. 9, PCF 108 will activate the PCC rule #Y (based on the UDR flag described above).

[0085] Steps 7 and 8. SMF 122 triggers PFCP Session Establishment procedure towards UPF 132 to provision the PDRs (and the corresponding enforcement actions: Forwarding Action Rules (FARs), URRs, and so on) for the PDU session. Specifically, when SMF 122 receives from PCF 108 the default pre-defined PCC rule #Y, SMF 122 has locally configured that this rule #Y refers to enabling flow-based reporting, and according to that, SMF 122 will provision a default (uplink (UL) / downlink (DL)) PDR (with lowest precedence and to match all traffic) associated to a URR with IP flow-based level reporting enabled. To do this, it is proposed extend the PFCP protocol by adding a new flag (bit) in Measurement Information IE at “PFCP Session Establishment / Modification Request” in “Create / Update URR IE”, as shown below in bold:

[0086] Table 7.5.2.4-1 : Create URR IE within PFCP Session Establishment Request

[0087] As a PDR might be associated to several URRs, SMF 122 only needs to add the new IP flow measurement flag (in Measurement Information IE) for the URRs that need to report the IP flow information.

[0088] Step 9. After the PDU session is established, UE 128 sends application traffic, e.g a Transmission Control Protocol (TCP) Synchronize (SYN) message to open a certain IP flow (Flow #1) towards the application server 402. This flow may be identified through a 5-tuple (including source IP address, source TCP port, destination IP address, destination TCP port, and IP protocol set to TCP). (In this example, TCP information is used in the 5-tuple, but other protocols, e.g., User Datagram Protocol (UDP), may be used, in which case, information related to the other protocols, e.g., UDP, may be used in the 5-tuple.)

[0089] Steps 10 and 11. UPF 132 classifies this traffic in the default (UL) PDR (in this example this traffic does not match in any other UL PDR with higher precedence) and retrieves and stores the flow information (e.g., 5-tuple) value and a timestamp (e.g., to record the start time when the flow was created). Traffic is forwarded (according to the associated FAR rule) towards its destination.

[0090] Step 12. UE 128 continues sending application traffic, e.g. a TCP SYN message to open another IP flow (Flow #2), towards the application server 402 via UPF 132.

[0091] Steps 13 and 14. UPF 132 classifies this traffic in the default (UL) PDR (in this example this traffic does not match in any other UL PDR with higher precedence) and retrieves and stores the flow information (e.g., 5-tuple) value, the (accumulated) volume for this flow and a timestamp (e.g., to record the start time when the flow was created). Traffic is forwarded (according to the associated FAR rule) towards its destination.

[0092] Steps 15 to 17. When the URR threshold (e.g. a periodic or volume threshold) is reached, UPF 132 triggers a URR report including the volume (and timestamp) on a per IP flow basis, if the URR includes the IP flow measurement flag in Step 7 above. Specifically, for example, it is proposed to extend the PF CP protocol by adding an IP Flow Information IE (see tables below in bold) in the Usage Report IE within PFCP Session Report Request message.

[0093] Table 7.5.8.3-1: Usage Report IE within PFCP Session Report Request

[0094] Table X: IP Flow Information IE within Usage Report IE

[0095] Steps 18 to 20. SMF 122 triggers online / offline charging including volume (and timestamp) on a per IP flow basis. Specifically, SMF 122 triggers a Nchf Charging Request including all the information in IP Flow Information IE (e.g. Flow-Information (5-tuple corresponding to Flow #1), Volume A, Start Time=Tl; Flow-Information (5-tuple corresponding to Flow #2), Volume B, Start Time=T2).

[0096] Step 21. CHF 206 applies the corresponding logic, e.g. to reflect the IP flow volumes (and timestamps) in the charging record for the subscriber. For example, in Charging Data Records (CDRs) the following format is proposed:IP FLOW ::= SEQUENCEcount

[0001] INTEGER OPTIONAL,flowinformation [2] String OPTIONAL, dataVolumeUplink [3] INTEGER OPTIONAL, dataVolumeDownlink [4] INTEGER OPTIONAL, listOfTimeStamps [5] SEQUENCE OF TimeStamp OPTIONAL

[0097] As mentioned, the sequence diagram in FIG. 8 and FIG. 9 shows an example of IP flow-based level reporting enabled for the default PCC rule. However, IP flow-based level reporting can also be enabled for any PCC rule (other than the default PCC rule).

[0098] Finally, embodiments disclosed herein do not only apply to a 5G network architecture, but the same mechanisms can be applied to other communication networks. For example, embodiments may be applied to 4G network by replacing:PCF by Policy and Charging Rules Function (PCRF)SMF by Packet Data Network Gateway Control Plane (PGW-C) or Traffic Detection Function Control Plane (TDF-C)UPF by Packet Data Network Gateway User Plane (PGW-U) or Traffic Detection Function User Plane (TDF-U)

[0099] Exemplary Technical Specification Impact

[0100] Some embodiments may have the following impact on 5G technical specifications. These impacts are shown below specifically for Stage 3 specs (3GPP TS 29.510, 3GPP TS 29.512, and 3GPP TS 29.244). Stage 2 specs (Architecture) might also be impacted (3GPP TS 23.501, 3GPP TS 23.502 and 3GPP TS 23.503), mostly to include the extensions for flow-based charging.

[0101] 3GPP TS 29.510: Extension of the NF profile for a UPF in the NRF, specifically to extend upflnfo type with a new attribute (Flow-based charging) to indicate support of a new capability (i.e. feature) related to flow-based charging. This implies updates in Table 6.1.6.2.13- 1.

[0102] 3GPP TS 29.512: PCF to request SMF on flow-based charging.

[0103] 3GPP TS 29.244: At PFCP Association Setup procedure, UPF indicates its support of a new capability (i.e. feature) indicating UPF support for flow-based charging. This implies updates in Table 7.4.4.1-1: Information Elements in a PFCP Association Setup Request. Define a new procedure for SMF to request UPF on flow-based charging.

[0104] FIG. 10 is a flowchart illustrating a process 1000 for supporting flow-based application traffic data reporting, according to an embodiment, performed by a User Plane Function (UPF) node (132). Process 1000 may begin in step sl002.

[0105] Step sl002 comprises receiving (sl002) an indication to enable flow level reporting.

[0106] Step sl004 comprises receiving (sl004) application traffic data from a user equipment (UE) (128).

[0107] Step sl006 comprises analyzing (sl006) the application traffic data to determine that the application traffic data matches a Packet Data Rule (PDR) for which reporting per application traffic flow is enabled.

[0108] Step sl008 comprises retrieving and storing (sl008) information about the application traffic data per said flow.

[0109] Step slOlO comprises forwarding (slOlO) the application traffic data to an application server (402).

[0110] In some embodiments, the method further includes determining that a Usage Reporting Rule (URR) threshold is met; and sending a PFCP Session Report Request message comprising a report on a per-flow-level basis, said report comprising information about the application traffic data per said flow. In some embodiments, the indication to enable flow level reporting is received from a Session Management Function (SMF) node (122). In some embodiments, the indication to enable flow level reporting specifies a granularity for the flow level reporting. In some embodiments, the granularity for the flow level reporting is one of (i) a per-Packet Forwarding Control Protocol (PFCP) session granularity and (ii) a per-application granularity. In some embodiments, the indication to enable flow level reporting is comprised in in a Packet Forwarding Control Protocol (PFCP) Session Establishment Request message or aPFCP Session Modification Request message received from a Session Management Function (SMF) node. In some embodiments, the information about the application traffic flow includes a source IP address, a source port, a destination IP address, a destination port, and an IP protocol, accumulated uplink and downlink volume for the application traffic flow, and timestamp when the application traffic flow was created.

[0111] FIG. 11 is a flowchart illustrating a process 1100 for User Plane Function (UPF) Registration, according to an embodiment, performed by a User Plane Function (UPF) node (132). Process 1100 may begin in step si 102.

[0112] Step si 102 comprises determining (si 102) to register a Network Function (NF) Profile with a Network Repository Function (NRF) node (106).

[0113] Step si 104 comprises sending (si 104) towards the NRF node (106) a request to register the NF Profile, wherein the NF Profile indicates support for flow-based reporting.

[0114] Step si 106 comprises receiving (si 106) a response from the NRF node (106) to the request to register the NF Profile.

[0115] FIG. 12 is a flowchart illustrating a process 1200 for User Plane Function (UPF) Registration, according to an embodiment, performed by a Network Repository Function (NRF) node (106). Process 1200 may begin in step si 202.

[0116] Step sl202 comprises receiving (sl202) from a UPF node (132) a request to register a Network Function (NF) Profile. The NF Profile indicates support for flow-based reporting.

[0117] Step sl204 comprises storing (sl204) the NF Profile for the UPF node (132).

[0118] Step sl206 comprises sending (sl206) towards the UPF node (132) a response to the request to register the NF Profile.

[0119] FIG. 13 is a flowchart illustrating a process 1300 for User Plane Function (UPF) discovery, according to an embodiment, performed by a Session Management Function (SMF) node (122). Process 1300 may begin in step si 302.

[0120] Step si 302 comprises determining (si 302) to trigger UPF discovery procedure with a Network Repository Function (NRF) node (106).

[0121] Step si 304 comprises sending (si 304) towards the NRF node (106) a request to initiate UPF discovery. The request includes an indication of support for flow-based reporting.

[0122] Step si 306 comprises receiving (si 306) a response from the NRF node (106) to the request to initiate UPF discovery. The response includes a list of UPF instances.

[0123] Step si 308 comprises selecting (si 308) a UPF instance from among the list ofUPF instances.

[0124] FIG. 14 is a flowchart illustrating a process 1400 for User Plane Function (UPF) discovery, according to an embodiment, performed by a Network Repository Function (NRF) node (106). Process 1400 may begin in step si 402.

[0125] Step sl402 comprises receiving (sl402) from a Session Management Function (SMF) node (122) a request to initiate UPF discovery. The request includes an indication of support for flow-based reporting.

[0126] Step si 404 comprises determining (si 404) a list of UPF instances matching criteria included in the request to initiate UPF discovery.

[0127] Step si 406 comprises sending (si 406) towards the SMF node (122) a response to the request to initiate UPF discovery. The response includes the list of UPF instances.

[0128] FIG. 15 is a flowchart illustrating a process 1500 for Packet Forwarding Control Protocol (PFCP) association, according to an embodiment, performed by a User Plane Function (UPF) node (132). Process 1500 may begin in step s5002.

[0129] Step si 502 comprises sending (si 502) a PFCP association setup request towards aSession Management Function (SMF) node (122). The PFCP association setup request includes an indication of support for flow-based reporting.

[0130] Step si 504 comprises receiving (si 504) a response from the SMF node (122) to the PFCP association setup request.

[0131] FIG. 16 is a flowchart illustrating a process 1600 for Packet Forwarding Control Protocol (PFCP) association, according to an embodiment, performed by a Session Management Function (SMF) node (122). Process 1600 may begin in step sl602.

[0132] Step si 602 comprises receiving (si 602) a PF CP association setup request from a User Plane Function (UPF) node (132). The PFCP association setup request includes an indication of support for flow-based reporting.

[0133] Step si 604 comprises sending (si 604) a response towards the UPF node (132) to the PFCP association setup request.

[0134] Step si 606 comprises triggering (si 606) UPF selection for a packet data unit (PDU) session taking into account UPF capabilities indicated by the request, including support for flow-based reporting.

[0135] FIG. 17 is a block diagram of apparatus 1700 (e.g., UPF node 132, NRF node 106, SMF node 122, and other nodes shown in FIGS. 1-9), according to some embodiments, for performing the methods disclosed herein. As shown in FIG. 17, apparatus 1700 may comprise: processing circuitry (PC) 1702, which may include one or more processors (P) 1755 (e.g., a general purpose microprocessor and / or one or more other processors, such as an application specific integrated circuit (ASIC), field-programmable gate arrays (FPGAs), and the like), which processors may be co-located in a single housing or in a single data center or may be geographically distributed (i.e., apparatus 1700 may be a distributed computing apparatus); at least one network interface 1748 comprising a transmitter (Tx) 1745 and a receiver (Rx) 1747 for enabling apparatus 1700 to transmit data to and receive data from other nodes connected to a network 1710 (e.g., an Internet Protocol (IP) network) to which network interface 1748 is connected (directly or indirectly) (e.g., network interface 1748 may be wirelessly connected to the network 1710, in which case network interface 1748 is connected to an antenna arrangement); and a storage unit (a.k.a., “data storage system”) 1708, which may include one or more non-volatile storage devices and / or one or more volatile storage devices. Interface 1760 may connect PC 1702 and storage unit 1708, interface 1762 may connect PC 1702 and network interface 1748, and interface 1764 may connect network interface 1748 and network 1710. In embodiments where PC 1702 includes a programmable processor, a computer program product (CPP) 1741 may be provided. CPP 1741 includes a computer readable medium (CRM) 1742 storing a computer program (CP) 1743 comprising computer readable instructions (CRI) 1744. CRM 1742 may be a non-transitory computer readable medium, such as, magnetic media (e.g., a hard disk), optical media, memory devices (e.g., random access memory, flash memory), and thelike. In some embodiments, the CRI 1744 of computer program 1743 is configured such that when executed by PC 1702, the CRI causes apparatus 1700 to perform steps described herein (e.g., steps described herein with reference to the flow charts). In other embodiments, apparatus 1700 may be configured to perform steps described herein without the need for code. That is, for example, PC 1702 may consist merely of one or more ASICs. Hence, the features of the embodiments described herein may be implemented in hardware and / or software.

[0136] While various embodiments are described herein, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of this disclosure should not be limited by any of the above described exemplary embodiments. Moreover, any combination of the above-described embodiments in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[0137] Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, and some steps may be performed in parallel.

Claims

CLAIMS1. A method for supporting flow-based application traffic data reporting, performed by a User Plane Function (UPF) node (132), the method comprising: receiving (si 002) an indication to enable flow level reporting; receiving (si 004) application traffic data from a user equipment (UE) (128); analyzing (si 006) the application traffic data to determine that the application traffic data matches a Packet Data Rule (PDR) for which reporting per application traffic flow is enabled; retrieving and storing (si 008) information about the application traffic data per said flow; and forwarding (si 010) the application traffic data to an application server (402).

2. The method of claim 1, further comprising: determining that a Usage Reporting Rule (URR) threshold is met; and sending a PFCP Session Report Request message comprising a report on a per-flow-level basis, said report comprising information about the application traffic data per said flow.

3. The method of any one of claims 1-2, wherein the indication to enable flow level reporting is received from a Session Management Function (SMF) node (122).

4. The method of any one of claims 1-3, wherein the indication to enable flow level reporting specifies a granularity for the flow level reporting.

5. The method of claim 4, wherein the granularity for the flow level reporting is one of (i) a per-Packet Forwarding Control Protocol (PF CP) session granularity and (ii) a per- application granularity.

6. The method of any one of claims 1-5, wherein the indication to enable flow level reporting is comprised in in a Packet Forwarding Control Protocol (PFCP) Session Establishment Request message or a PFCP Session Modification Request message received from a Session Management Function (SMF) node.

7. The method of any one of claims 1 -6, wherein the information about the application traffic flow includes a source IP address, a source port, a destination IP address, a destination port, and an IP protocol, accumulated uplink and downlink volume for the application traffic flow, and timestamp when the application traffic flow was created.

8. A method for User Plane Function (UPF) Registration performed by a UPF node (132), the method comprising: determining (si 102) to register a Network Function (NF) Profile with a Network Repository Function (NRF) node (106); sending (si 104) towards the NRF node (106) a request to register the NF Profile, wherein the NF Profile indicates support for flow-based reporting; and receiving (si 106) a response from the NRF node (106) to the request to register the NF Profile.

9. A method for User Plane Function (UPF) Registration performed by a Network Repository Function (NRF) node (106), the method comprising:receiving (si 202) from a UPF node (132) a request to register a Network Function (NF) Profile, wherein the NF Profile indicates support for flow-based reporting; storing (sl204) the NF Profile for the UPF node (132); and sending (si 206) towards the UPF node (132) a response to the request to register the NF Profile.

10. A method for User Plane Function (UPF) discovery performed by a Session Management Function (SMF) node (122), the method comprising: determining (sl302) to trigger UPF discovery procedure with a Network Repository Function (NRF) node (106); sending (si 304) towards the NRF node (106) a request to initiate UPF discovery, wherein the request includes an indication of support for flow-based reporting; receiving (si 306) a response from the NRF node (106) to the request to initiate UPF discovery, wherein the response includes a list of UPF instances; and selecting (sl308) a UPF instance from among the list of UPF instances.

11. A method for User Plane Function (UPF) discovery performed by a Network Repository Function (NRF) node (106), the method comprising: receiving (sl402) from a Session Management Function (SMF) node (122) a request to initiate UPF discovery, wherein the request includes an indication of support for flow-based reporting; determining (si 404) a list of UPF instances matching criteria included in the request to initiate UPF discovery; andsending (si 406) towards the SMF node (122) a response to the request to initiate UPF discovery, wherein the response includes the list of UPF instances.

12. A method for Packet Forwarding Control Protocol (PFCP) association performed by a User Plane Function (UPF) node (132), the method comprising: sending (si 502) a PFCP association setup request towards a Session Management Function (SMF) node (122), wherein the PFCP association setup request includes an indication of support for flow-based reporting; and receiving (si 504) a response from the SMF node (122) to the PFCP association setup request.

13. A method for Packet Forwarding Control Protocol (PFCP) association performed by a Session Management Function (SMF) node (122), the method comprising: receiving (sl602) a PFCP association setup request from a User Plane Function (UPF) node (132), wherein the PFCP association setup request includes an indication of support for flow-based reporting; sending (si 604) a response towards the UPF node (132) to the PFCP association setup request; and triggering (si 606) UPF selection for a packet data unit (PDU) session taking into account UPF capabilities indicated by the request, including support for flow-based reporting.

14. A User Plane Function (UPF) node (132) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to:receive an indication to enable flow level reporting; receive application traffic data from a user equipment (UE) (128); analyze the application traffic data to determine that the application traffic data matches a Packet Data Rule (PDR) for which reporting per application traffic flow is enabled; retrieve and store information about the application traffic data per said flow; and forward the application traffic data to an application server (402).

15. The UPF node 132 of claim 14, wherein the processing circuitry is further configured to perform the method of any one of claims 2-7.

16. A User Plane Function (UPF) node (132) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to: determine to register a Network Function (NF) Profile with a Network Repository Function (NRF) node (106); send towards the NRF node (106) a request to register the NF Profile, wherein the NF Profile indicates support for flow-based reporting; and receive a response from the NRF node (106) to the request to register the NF Profile.

17. A Network Repository Function (NRF) node (106) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to:receive from a UPF node (132) a request to register a Network Function (NF) Profile, wherein the NF Profile indicates support for flow-based reporting; store the NF Profile for the UPF node (132); and send towards the UPF node (132) a response to the request to register the NF Profile.

18. A Session Management Function (SMF) node (122) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to: determine to trigger UPF discovery procedure with a Network Repository Function (NRF) node (106); send towards the NRF node (106) a request to initiate UPF discovery, wherein the request includes an indication of support for flow-based reporting; receive a response from the NRF node (106) to the request to initiate UPF discovery, wherein the response includes a list of UPF instances; and select a UPF instance from among the list of UPF instances.

19. A Network Repository Function (NRF) node (106) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to: receive from a Session Management Function (SMF) node (122) a request to initiate UPF discovery, wherein the request includes an indication of support for flow-based reporting; determine a list of UPF instances matching criteria included in the request to initiate UPF discovery; andsend towards the SMF node (122) a response to the request to initiate UPF discovery, wherein the response includes the list of UPF instances.

20. A User Plane Function (UPF) node (132) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to: send a PFCP association setup request towards a Session Management Function (SMF) node (122), wherein the PFCP association setup request includes an indication of support for flow-based reporting; and receive a response from the SMF node (122) to the PFCP association setup request.

21. A Session Management Function (SMF) node (122) comprising: processing circuitry (1702); and a memory, the memory containing instructions (1744) executable by the processing circuitry (1702), whereby when executed the processing circuitry (1702) is configured to: receive a PFCP association setup request from a User Plane Function (UPF) node (132), wherein the PFCP association setup request includes an indication of support for flow-based reporting; send a response towards the UPF node (132) to the PFCP association setup request; and trigger UPF selection for a packet data unit (PDU) session taking into account UPF capabilities indicated by the request, including support for flow-based reporting.

22. A computer program (1743) comprising instructions which when executed by processing circuitry (1702) of a node (1700), causes the node (1700) to perform the method of any one of claims 1-13.

23. A carrier containing the computer program (1743) of claim 22, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium (1742).

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