Methods and apparatuses for charging in a communications network

Abstract

Disclosed methods and apparatuses embody an approach to charging for service in a communications network that avoids premature deductions or reservations against subscriber accounts, while providing the network operator with the information needed to reconcile charging upon service delivery. As a further advantage, the approach in one or more embodiments relies on a repurposing of charging-related or authorization-related parameters normally included in the signaling going between network charging trigger functions (CTFs) and charging functions (CHFs).

Description

[0001] P112015W001

[0002] METHODS AND APPARATUSES FOR CHARGING IN A COMMUNICATIONS

[0003] NETWORK

[0004] TECHNICAL FIELD

[0005] Disclosed methods and apparatuses relate to communications networks and, particularly, to charging operations involving charging trigger functions (CTFs) and charging functions (CHFs).

[0006] BACKGROUND

[0007] The Third Generation Partnership Project (3GPP) Technical Specification (TS) 32.290 specifies different approaches to event-based charging. Specified approaches include Immediate Event Charging (IEC), post event charging (PEC), and event-based charging with unit reservation (ECUR).

[0008] With IEC, the charge for a service or event is processed in real-time. When a subscriber initiates an action that incurs a charge (e.g., downloading content or initiating a one-time service), the charging system immediately deducts the cost from one or more account balances associated with the subscriber. If the account(s) do not have sufficient funds, the service request may be denied. IEC is useful for small, one-time events that require instant feedback on whether the charge was successful. IEC is commonly used in prepaid services where immediate balance checking and deduction are essential. One issue with IEC is that a subscriber may be charged, even if service delivery fails.

[0009] PEC, in contrast, occurs after the event or service has been completed. With PEC, the service provider allows the subscriber to use the service and charges the subscriber only after service usage. Among the various issues that arise with PEC, the account(s) to be charged may or may not have sufficient funds to cover the service delivered.

[0010] ECUR offers something of a hybrid approach, based on reserving a certain amount of credit or units before the service is provided, and the network may determine whether the subscriber account includes a sufficient balance. One challenge with the use of the ECUR approach is that the charging session is opened responsive to the service request and it must remain open until the involved service is delivered or otherwise used. In some instances, there is a potentially lengthy interval between the service request and the service delivery.

[0011] For example, an originating subscriber initiates the sending of a Short Messaging Service (SMS) message, but delivery is delayed. With ECUR in this scenario, the associated charging session remains open until delivery succeeds. P112015W001

[0012] SUMMARY

[0013] Disclosed methods and apparatuses embody an approach to charging for service in a communications network that avoids premature deductions or reservations against subscriber accounts, while providing the network operator with the information needed to reconcile charging upon service delivery. As a further advantage, the approach in one or more embodiments relies on a repurposing of charging-related or authorization-related parameters normally included in the signaling going between network charging trigger functions (CTFs) and charging functions (CHFs).

[0014] An example embodiment comprises a method of operation by a CTF in a communications network. The method includes the CTF sending message pairs to a charging function (CHF), each message pair comprising a service authorization request message for obtaining authorization for delivery of a corresponding communication service and a later charging request message confirming delivery of the corresponding communication service, for prompting the CHF to reconcile charging for the delivered communication service. Further, the method includes the CTF enabling the CHF to detect the message pairs by including in each service authorization request message an identification of correlation terms. Here, each correlation term is a particular authorization or charging related parameter that is predefined for inclusion in all authorization request and charging request messages but reused for correlationbased detection at the CHF of the message pairs. Each such particular authorization or charging related parameter necessarily has a same context-specific value for both messages in each message pair.

[0015] A related embodiment comprises a CTF configured for operation in a communications network. The CTF includes a communications interface and processing circuitry. The processing circuitry is configured to send, via the communications interface, message pairs to a CHF. Each message pair comprises a service authorization request message for obtaining authorization for delivery of a corresponding communication service and a later charging request message confirming delivery of the corresponding communication service, for prompting the CHF to reconcile charging for the delivered communication service. Further, the processing circuitry of the CTF is configured to enable the CHF to detect the message pairs by including in each service authorization request message an identification of correlation terms. Each correlation term is a particular authorization or charging related parameter that is predefined for inclusion in all authorization request and charging request messages but reused for correlation-based detection at the CHF of the message pairs. To that end, each such particular authorization or charging related parameter necessarily has a same context-specific value for both messages in each message pair. P112015W001

[0016] Another example embodiment comprises a method of operation by a CHF in a communications network. The method includes the CHF receiving a service authorization request message from a CTF in the communications network, and interpreting the service authorization request message as a request for authorization of delivery of a corresponding communication service. The interpretation is based on the CHF determining that the service authorization request message includes an identification of correlation terms to be used by CHF in determining that a later charging request message received from the CTF is paired to the service authorization request message. Each such correlation term is a particular authorization or charging related parameter that is commonly included in all service authorization request and charging request messages, and for each pairing of service authorization and charging request messages, will have a same context-specific parameter value. The method further includes the CHF reconciling charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message.

[0017] A related embodiment comprises a CHF configured for operation in a communications network. The CHF includes a communications interface and processing circuitry. The processing circuitry is configured to receive, via the communications interface, a service authorization request message from a CTF in the communications network. Further, the processing circuitry is configured to interpret the service authorization request message as a request for authorization of delivery of a corresponding communication service, based on determining that the service authorization request message includes an identification of correlation terms to be used by CHF in determining that a later charging request message received from the CTF is paired to the service authorization request message. Each such correlation term is a particular authorization or charging related parameter that is commonly included in all service authorization request and charging request messages, and for each pairing of service authorization and charging request messages, will have a same context-specific parameter value. Still further, the processing circuitry is configured to reconcile charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message.

[0018] Of course, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings. P112015W001

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a block diagram of a communications network according to an example embodiment.

[0021] Figure 2 is a block diagram of a charging trigger function (CTF) according to an example embodiment.

[0022] Figure 3 is a logic flow diagram of a method of operation by a CTF according to an example embodiment.

[0023] Figure 4 is a block diagram of a charging function (CHF) according to an example embodiment.

[0024] Figure 5 is a logic flow diagram of a method of operation by a CHF according to an example embodiment.

[0025] Figure 6 is a signal flow diagram depicting example signaling exchanged between a CTF and a CHF according to an example embodiment.

[0026] DETAILED DESCRIPTION

[0027] Figure 1 illustrates a communications network 10 according to an example embodiment, where the example network 10 comprises a wireless communications network configured according to Third Generation Partnership Project (3GPP) specifications. Depiction of the network 10 is simplified to focus on charging- and billing-related entities and there may be multiple network functions (NFs) that are not illustrated, nor does the diagram illustrate radio access network (RAN) portions of the network 10.

[0028] Depicted entities include a session management function (SMF) 12, which manages user (subscriber) sessions, e.g., by interfacing with user plane functions (UPFs) in the network 10. In particular, the SMF 12 establishes and manages data sessions for user equipment (UE), including allocating IP addresses and selecting network paths. It controls the data flows between a UE and one or more data network (DNs) through respective UPFs.

[0029] Of particular interest herein, the SMF 12 includes one or more charging trigger functions (CTFs) 14. Via the CTF 14, the SMF 12 monitors and reports on user activities that have billing implications. The CTF 14 detects and records charging events, such as data volume usage, session duration, and QoS requirements. The CTF 14 cooperates with a charging function (CHF) 16 of the network 10, for such operations, with CTF-CHF signaling conducted via aNchf interface.

[0030] The example CHF 16 itself includes various functions, including a charging data function (CDF) 20, and a charging gateway function (CGF) 22. The CDF 20 is responsible for generating, storing, and managing Charging Data Records (CDRs), which contain detailed information about P112015W001 the usage of network services by individual subscribers. The CGF 22 is responsible for collecting and consolidating charging data records (CDRs) generated by different network functions (NFs) in the network 10.

[0031] Figure 1 further illustrates a business operations support system (BOSS) 24 sometimes referred to as a Converged Charging System (CCS). The BOSS 24 includes a rating function (RF) 26, a billing system (BS) 28, and an account balance management function (ABMF) 30. Communications between the CHF 16 and the BOSS 24 involve a number of interfaces, including the Nchf* interface and the Bx interface.

[0032] Figure 2 illustrates example implementation details for the CTF 14, which includes a communications interface 40, comprising physical-layer circuitry for wired or wireless exchange of input / output signaling over a physical medium, along with protocol processing circuitry, e.g., for exchanging charging-related messages as described herein.

[0033] The CTF 14 further includes processing circuitry 42 that is configured to carry out overall CTF functionality and is particularly configured to carry out the CTF operations described herein. In one or more embodiments, the processing circuitry 42 comprises one or more computer processors 44, e.g., microprocessors, that is / are specially adapted based on the execution of computer program instructions (CPI) 48 held in associated storage 46.

[0034] The storage 46 comprises one or more types of computer readable media, such as a mix of volatile and non-volatile storage. The storage 46 may further store data 50. As detailed below, such data 50 comprises, for example, configuration information regarding which authorization / charging parameters to use as correlation values for pairing service authorization request messages with corresponding subsequent charging request messages.

[0035] With reference to Figure 2, in one or more embodiments, a CTF 14 is configured for operation in a communications network 10, and it includes a communications interface 40 and processing circuitry 42. The processing circuitry 42 is configured to send, via the communications interface 40, message pairs to a CHF 16. Each message pair comprises a service authorization request message for obtaining authorization for delivery of a corresponding communication service and a later charging request message confirming delivery of the corresponding communication service, for prompting the CHF 16 to reconcile charging for the delivered communication service. Further, the processing circuitry 42 is configured to enable the CHF 16 to detect the message pairs by including in each service authorization request message an identification of correlation terms. Each such correlation term is a particular authorization or charging related parameter that is predefined for inclusion in all authorization request and charging request messages but reused for correlation-based detection at the CHF of the message pairs. Each such particular authorization or charging related parameter necessarily has a same P112015W001 context-specific value for both messages in each message pair. That is, for a given communication session and corresponding charging session, the parameter(s) indicated for use as correlation terms will match between the service authorization request message and the corresponding charging request message.

[0036] In one or more embodiments, the processing circuitry 42 is configured to identify at least two particular authorization or charging related parameters to be used as correlation terms. In an example case, the at least two particular authorization or charging related parameters comprise at least one of an originator subscription permanent identifier (SUPI) and a recipient SUPI, corresponding to originator and recipient user equipments (UEs) associated with delivery of the communication service. In another example case, the at least two particular authorization or charging related parameters comprise an originator SUPI of an originating UE associated with the corresponding communication service, and a data network name (DNN) associated with the corresponding communication service.

[0037] In one or more example contexts, all service authorization request messages and all charging request messages are defined to carry certain information elements (IES), and at least some such IEs are used to convey respective authorization or charging related parameter values. Further, at least some such IEs are common to both message types. In one or more embodiments, the processing circuitry 42 is configured to include, for each service authorization request message, an identification that one or more of the common IEs are to be used as correlation terms by the CHF 16 for correlation-based detection of the message pairs.

[0038] In one or more embodiments, at least three of the common IEs are identified for use as the correlation terms. That is, the correlation identifiers comprise three or more IEs that are commonly included in service authorization request messages and in charging request messages, where these three or more commonly included IEs will have the same (matching) values as between a corresponding pair of authorization request and charging request messages.

[0039] In one or more embodiments, the processing circuitry 42 is configured to include in each service authorization request message an indication of a maximum delay for receiving the corresponding charging request message, to bound a historical message window searched by the CHF 16 in relation to receiving one of the charging request messages. As further advantages, the maximum delay can be understood as indicating to the CHF 16 for how long it should store the service authorization request information for correlation use, before migrating such information to longer term storage. Still further, at least in cases where the CHF 16 reserves a quota against the request, the maximum delay can be used by the CHF 16 to limit the reservation time.

[0040] In one or more embodiments, the processing circuitry 42 is configured to set the maximum delay in dependence on at least one of: policy information provided to the CTF 14; the P112015W001 communication service associated with the corresponding service authorization request message, wherein different types of communication services have different maximum delays associated therewith; or stored user preferences associated with the corresponding authorization request. For example, the network 10 stores subscriber profiles, with such profiles at least optionally including maximum delay information.

[0041] In one or more example embodiments or in one or more operational scenarios, for one or more of the message pairs going between the CTF 14 and CHF 16, the corresponding communication service is a short messaging service. As one advantage here, there may be a meaningful delay between an originating user attempting to send a SMS and the successful delivery of the SMS, e.g., in dependence on the corresponding service coverage conditions of the originating and targeted users. In such cases, a service authorization request message corresponds to the sending attempt, while a later corresponding charging request message corresponds to successful delivery. Use of the message pair approach in such cases allows the CHF 16 to accurately and efficiently determine whether a later corresponding charging request message is received in relation to the earlier service authorization request message.

[0042] In one or more embodiments, each service authorization request message is a modified version of the immediate event charging (IEC) message defined by 3GPP TS 32.290 and 3GPP TS 32.291 and each charging request message is a post event charging (PEC) message, as defined in those same TSs. Unlike the conventional IEC message, the IEC message used herein is modified to indicate which inherently included authorization or charging related parameters are to be reused by the CHF 16 as correlation terms for identifying the corresponding PEC message that is later sent from the CTF 14 to the CHF 16, as said charging request message.

[0043] Figure 3 illustrates a method 300 of operation by a CTF according to an example embodiment. As one example, the computer program instructions (CPI) 48 retained in the storage 46 include instructions that, when executed by the one or more computer processors 44 comprised in the processing circuitry 42, configure the CTF to carry out the operations shown as method 300, or variations or extensions thereof.

[0044] The method 300 includes the CTF 14: sending (Block 302) message pairs to a CHF 16, each message pair comprising a service authorization request message for obtaining authorization for delivery of a corresponding communication service and a later charging request message confirming delivery of the corresponding communication service, for prompting the CHF 16 to reconcile charging for the delivered communication service; and enabling (Block 304) the CHF 16 to detect the message pairs by including in each service authorization request message an identification of correlation terms, each correlation term being a particular authorization or charging related parameter that is predefined for inclusion in all authorization P112015W001 request and charging request messages but reused for correlation-based detection at the CHF 16 of the message pairs, each such particular authorization or charging related parameter necessarily having a same context-specific value for both messages in each message pair.

[0045] In one or more embodiments, the CTF 14 identifies at least two particular authorization or charging related parameters to be used as correlation terms. The at least two particular authorization or charging related parameters include at least one of an originator SUPI and a recipient SUPI, corresponding to originator and recipient UEs associated with delivery of the communication service. As another example, the at least two particular authorization or charging related parameters comprise an originator SUPI of an originating UE associated with the corresponding communication service, and a DNN associated with the corresponding communication service.

[0046] In the context of the method 300, all service authorization request messages and all charging request messages are defined to carry certain IES, at least some such IES are used to convey respective authorization or charging related parameter values, and at least some such IEs are common to both message types. Correspondingly, in one or more embodiments, the method 300 includes, for each service authorization request message it sends to the CHF 16, an identification that one or more of the common IEs are to be used as correlation terms by the CHF 16 for correlation-based detection of the message pairs.

[0047] In at least one embodiment of the method 300, the CTF includes in each service authorization request message an indication of a maximum delay for receiving the corresponding charging request message, to bound a historical message window searched by the CHF 16 in relation to receiving one of the charging request messages. For example, the CTF 14 sets the maximum delay in dependence on at least one of: policy information provided to the CTF; the communication service associated with the corresponding service authorization request message, wherein different types of communication services have different maximum delays associated therewith; or stored user preferences associated with the corresponding authorization request.

[0048] In one or more embodiments of the method 300, each service authorization request message is a modified version of an IEC message as defined by the 3GPP for converged eventbased charging. Correspondingly, each charging request message is a PEC as defined by the 3GPP for converged event-based charging. The particular modification of the IEC message is that it carries an indication of which inherently included authorization or charging related parameters are to be reused by the CHF 16 as correlation terms for identifying the corresponding PEC message that is later sent from the CTF 14 to the CHF 16, or at least later sent if service delivery succeeds. P112015W001

[0049] Figure 4 illustrates example implementation details for a CHF 16, which includes a communications interface 60, comprising physical-layer circuitry for wired or wireless exchange of input / output signaling over a physical medium, along with protocol processing circuitry, e.g., for exchanging charging-related messages as described herein.

[0050] The CHF 16 further includes processing circuitry 62 that is configured to carry out overall CHF functionality and is particularly configured to carry out the CHF operations described herein. In one or more embodiments, the processing circuitry 62 comprises one or more computer processors 64, e.g., microprocessors, that is / are specially adapted based on the execution of CPI 68 held in associated storage 66.

[0051] The storage 66 comprises one or more types of computer readable media, such as a mix of volatile and non-volatile storage. The storage 66 may further store data 70. Such data 70 comprises, for example, a running record of received service authorization request messages from one or more CTFs 14, for pair-wise matching (correlation) with any charging request messages incoming from those same one or more CTFs 14. That is, to the extent that the CHF 16 supports multiple CTFs 14, in one or more embodiments, it performs message correlation processing on a per CTF basis, such that the CHF 16 maintains a running message record with respect to each supported CTF 14.

[0052] With reference to Figure 4, in one or more embodiments, a CHF 16 is configured for operation in a communications network 10, and it includes a communications interface 60 and processing circuitry 62. The processing circuitry 62 is configured to receive, via the communications interface 60, a service authorization request message from a CTF 14 in the communications network 10. Further, the processing circuitry 62 is configured to interpret the service authorization request message as a request for authorization of delivery of a corresponding communication service. This interpretation is based on the processing circuitry 62 determining that the service authorization request message includes an identification of correlation terms to be used by CHF 16 in determining that a later charging request message received from the CTF 14 is paired to the service authorization request message. Here, each correlation term is a particular authorization or charging related parameter that is commonly included in all service authorization request and charging request messages, and for each pairing of service authorization and charging request messages, will have a same context-specific parameter value.

[0053] Still further, the processing circuitry 62 of the CHF 16 is configured to reconcile charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message. For example, for reconciling charging for the corresponding communication service P112015W001 responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message, the processing circuitry 62 is configured to charge or initiate charging for the delivered communication service.

[0054] In one or more embodiments, the processing circuitry 62 is configured to include in a charging data record (CDR) or include in information sent from the CHF for generation of the CDR, an indication that the charging request message was detected as a paired message. Additionally, or alternatively, the processing circuitry 62 in one or more embodiments is configured to include in the CDR or the information sent from the CHF for generation of the CDR, the service authorization request message or parts thereof.

[0055] The charging request message is one among multiple charging request messages incoming to the CHF 16 and wherein, for any charging request message for which the CHF 16 does not identify a paired service authorization request message, the processing circuitry 62 is configured to reconcile charging for any such charging request message by one of: declining to assess charges for the communication service indicated as having been delivered; or charging for the delivered communication service and correspondingly recording or transmitting for recordation an indication of the failure to identify a paired service authorization request message.

[0056] In the above examples, a service authorization request message and a corresponding charging request message are one message pair, and the CHF 16 in operation may receive a plurality of message pairs received from a CTF 14, for respective instances of corresponding communication services being requested and delivered. Correspondingly, in one or more embodiments, the processing circuitry 62 of the CHF is configured to maintain a running record of received service authorization request messages and, for each received charging request message, perform correlation processing against the running record, in an attempt to identify the paired service authorization request message. For each received charging request message for which no paired service authorization request message was found in the running record, referred to as a correlation failure, the processing circuitry 62 is configured to store or transmit for storage an indication of the correlation failure, for compiling correlation failure statistics.

[0057] In at least one embodiment, each service authorization request message incoming to the CHF 16 from a CTF 14 includes an indication of a maximum delay for receiving the paired charging request message. Here, the processing circuitry 62 of the CHF 16 is configured to limit the length of time that each service authorization request message remains in the running record according to the maximum delay indicated in the service authorization request message. In at least one such embodiment, the processing circuitry 62 is configured to create a retained record corresponding to each service authorization request message that is removed from the running P112015W001 record as a consequence of reaching the indicated maximum delay without reception of the corresponding charging request message.

[0058] Figure 5 illustrates an example method 500 of operation by a CHF 16 in a communications network 10. The method 500 includes the CHF 16: receiving (Block 502) a service authorization request message from a CTF 14 in the communications network 10; interpreting (Block 504) the service authorization request message as a request for authorization of delivery of a corresponding communication service, based on determining that the service authorization request message includes an identification of correlation terms to be used by CHF 16 in determining that a later charging request message received from the CTF 14 is paired to the service authorization request message, each correlation term being a particular authorization or charging related parameter that is commonly included in all service authorization request and charging request messages, and for each pairing of service authorization and charging request messages, will have a same context-specific parameter value; and reconcile (Block 506) charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message.

[0059] Reconciling charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message comprises, for example, charging for the delivered communication service. The method 500 may also include the CHF 16 including in a charging data record (CDR) or including in information sent from the CHF 16 for generation of the CDR, an indication that the charging request message was detected as a paired message. Additionally or alternatively, the CHF 16 may include in the CDR or the information sent from the CHF 16 for generation of the CDR, the service authorization request message or parts thereof.

[0060] In a practical example, the charging request message is one among multiple charging request messages incoming to the CHF 16 and, for any charging request message for which the CHF 16 does not identify a paired service authorization request message, the method 500 may include the CHF 16 reconciling charging for any such charging request message by one of: declining to assess charges for the communication service indicated as having been delivered; or charging for the delivered communication service and correspondingly recording, or transmitting for recordation, an indication of the failure to identify a paired service authorization request message.

[0061] The method 500 in one or more embodiments includes the CHF 16 maintaining a running record of received service authorization request messages and, for each received charging request message, performing correlation processing against the running record, in an attempt to identify the paired service authorization request message. For example, for each received P112015W001 charging request message for which no paired service authorization request message was found in the running record, referred to as a correlation failure, the method 500 may include the CHF 16 storing or transmitting for storage an indication of the correlation failure, for compiling correlation failure statistics.

[0062] In at least one embodiment, an example service authorization request message includes an indication of a maximum delay for receiving the paired charging request message. The method 500 in such embodiments may further include the CHF 16 limiting the length of time that each service authorization request message remains in the running record according to the maximum delay indicated in the service authorization request message. Further, in at least one embodiment, the method 500 includes the CHF 16 creating a retained record corresponding to each service authorization request message that is removed from the running record as a consequence of reaching the indicated maximum delay without reception of the corresponding charging request message.

[0063] The disclosed message pairing has a number of particular advantages in the context of using IEC messages for requesting service authorization and using corresponding PEC messages for confirming service delivery / usage. As one advantage, very little “new” information need be added to the IEC messages; namely, the indication of which normally included parameters are to be used for correlating the IEC messages with subsequent PEC messages. Optionally, the IEC message format may be modified to further include the aforementioned indication of maximum duration or delay for which the CHF should expect the corresponding PEC message.

[0064] However, the technique is not limited to IEC / PEC message pairing. A CTF may send essentially any type of request message that includes correlation indicators that “point to” or otherwise identify the normally included message information that will also appear in any corresponding charging request message, which also may be thought of as a service delivery confirmation message.

[0065] A CHF operating in this context receives a service authorization request message and stores the correlation information contained in it, and may decide to either charge the implicated account(s) immediately or defer charging until reception of the corresponding charging request message. Such deferral may be condition on the maximum duration indicated in the service authorization request message. Among other things, this approach reduces the computer resources need as compared to using ECUR, while retaining visibility into whether the service in question was delivered successfully. Such visibility protects not only the interests of the subscribers, but also the interests of the network operator. At a minimum, the operator can detect revenue loss or use the information collected over sufficiently long monitoring intervals to identify possible equipment configuration or deployment problems. P112015W001

[0066] Having the CTF set the maximum duration that the CHF should wait from reception of a service authorization request message to subsequent reception of a corresponding charging request message, allows it to influence operation at the CHF in view of realistic service-delivery scenarios. For example, as noted, there may be significant delays between initiation of SMS transmission from the originating UE and eventual delivery of the SMS to the targeted terminating UE. In most operational scenarios, the CTF has better knowledge regarding how long it may take to consummate service delivery.

[0067] Further, not adding dedicated correlation identifiers but instead using existing information Elements (IES) that are already present in CTF / CHF messaging offers numerous advantages. For example, the CTF does not need to keep or store any extra information which it does not already maintain. Further, the reuse of existing IEs as correlation terms minimizes changes to standardized message structure.

[0068] Figure 6 illustrates an example signal flow between a CTF in a network function (NF), such as a SMF, and a CHF. Item (1) indicates the transmission of an IEC message from the CTF to the CHF. As compared to an existing standardized IEC message, the message sent by the CTF contains two additional attributes: (a) a list of IEs, e.g., originator SUPI, to be used for correlation with a later PEC; and the time that it may take until that later PEC is sent by the CTF, which is shown in the diagram as “PEC timeout.” In the depicted example, the PEC timeout is set to one week (604,800 seconds).

[0069] The CHF stores such information and, at Item (2), sends a response that grants / allows the service event delivery to start. Item (3) indicates delivery of the service, and Item (4) indicates transmission of the corresponding PEC from the CTF to the CHF, as confirmation of service delivery. The PEC contains information on the service delivered and, as noted earlier herein, contains a number of IEs that are common with the earlier IEC, e.g., originator SUPI. Item (5) indicates acknowledgement of the PEC, and Item (6) indicates IEC / PEC correlation processing.

[0070] Although the diagram indicates such processing at the CHF, the correlation processing in one or more embodiments is performed in a billing system, such as the BOSS 24 of Figure 1. In an example of correlation processing, as lECs arrive at the CHF from a given CTF, the CHF creates corresponding entries in a running set of records, which may be referred to as a running correlation table. Periodically, or as part of ongoing processing, the CHF removes stale entries from the running correlation table. A stale entry is any IEC record that has hit its PEC timeout — i.e., the CHF did not receive a PEC corresponding to the IEC within the maximum duration indicated in the IEC.

[0071] In at least one embodiment, the CHF is configured to consider stale lECs as indicating failed service event deliveries, with charging reconciliation by the CHF configured to account P112015W001 for that failure. For example, charging is nulled or the CHF includes the failure indication in charging records generated for downstream billings systems.

[0072] With respect to individual PECs incoming to the CHF from that same given CTF, the CHF compares the IES included in each PEC to corresponding IES saved for respective IEC entries in the running correlation table, to determine whether the PEC matches (pairs with) one of the IEC entries. In one or more embodiments, the CHF is configured to consider any PEC message that matches one of the IEC messages represented in the running correlation table as confirmation of service event delivery, with that confirmation used in charging reconciliation operations. As an example, Table 1 below shows the standardized SMS charging information defined in Table 6.5.2.1 in 3GPP TS 32.274. One or more of these standardized IEs may be designated for reuse as correlation identifiers, for IEC / PEC message correlation.

[0073] Table 1. P112015W001 P112015W001 P112015W001 P112015W001

[0074] In an example case where the IES used as correlation terms are Originator SUPI, Recipient SUPI, and Submission Time, the correlation identifier information in JSON may look as follows:

[0075] “correlationinformation”: { P112015W001

[0076] “informationElements”: [

[0077] “originatorSUPI”,

[0078] “recipientSUPI”,

[0079] “submissionTime”

[0080] Of course, there are other alternatives, in dependence on which IES are available in both IEC and PEC. Notably, which IEs are available for correlation use depends on operator settings as well as the particulars of the communication service(s). For example, SMS function (SMSF) capabilities, SMS vendor, or SMS type all may influence which IEs are available for use in IEC / PEC correlation in cases where the communication service in question is SMS.

[0081] Further, there may be information items that are common for all service types, such as the unique identifier of the involved network function(s) (e.g., UUIDs ) or the type of network function (e.g., SMSF). One or more such information items could be used as correlation terms, particularly in scenarios where there is a need or benefit to have correlation between network functions. For example, consider an example scenario where a CHF receives charging requests from a SMSF and from a short message service center (SMSC) for the same SMS. In such cases, it is beneficial if the correlation terms identified in both requests are the same, to simplify the charging associated with both such entities.

[0082] Notably, modifications and other embodiments of the disclosed invention(s) will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention(s) is / are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of this disclosure. Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

P112015W001CLAIMSWhat is claimed is:

1. A method of operation by a charging trigger function (CTF) in a communications network, the method comprising: sending message pairs to a charging function (CHF), each message pair comprising a service authorization request message for obtaining authorization for delivery of a corresponding communication service and a later charging request message confirming delivery of the corresponding communication service, for prompting the CHF to reconcile charging for the delivered communication service; and enabling the CHF to detect the message pairs by including in each service authorization request message an identification of correlation terms, each correlation term being a particular authorization or charging related parameter that is predefined for inclusion in all authorization request and charging request messages but reused for correlation-based detection at the CHF of the message pairs, each such particular authorization or charging related parameter necessarily having a same context-specific value for both messages in each message pair.

2. The method according to claim 1, wherein the method includes the CTF identifying at least two particular authorization or charging related parameters to be used as correlation terms.

3. The method according to claim 2, wherein the at least two particular authorization or charging related parameters comprise at least one of an originator subscription permanent identifier (SUP I) and a recipient SUPI, corresponding to originator and recipient user equipment associated with delivery of the communication service.

4. The method according to claim 2 or 3, wherein the at least two particular authorization or charging related parameters comprise an originator subscription permanent identifier (SUPI) of an originating user equipment (UE) associated with the corresponding communication service, and a data network name (DNN) associated with the corresponding communication service.Page 20 of 29P112015W0015. The method according to any one of claims 1-4, wherein all service authorization request messages and all charging request messages are defined to carry certain information elements (IES), at least some such IES are used to convey respective authorization or charging related parameter values, and at least some such IEs are common to both message types, and wherein the method includes, for each service authorization request message, an identification that one or more of the common IEs are to be used as correlation terms by the CHF for correlation-based detection of the message pairs.

6. The method according to claim 5, wherein at least three of the common IEs are identified for use as the correlation terms.

7. The method according to any one of claims 1-6, further comprising the CTF including in each service authorization request message an indication of a maximum delay for receiving the corresponding charging request message, to bound a historical message window searched by the CHF in relation to receiving one of the charging request messages.

8. The method according to claim 7, further comprising setting the maximum delay in dependence on at least one of: policy information provided to the CTF; the communication service associated with the corresponding service authorization request message, wherein different types of communication services have different maximum delays associated therewith; or stored user preferences associated with the corresponding authorization request.

9. The method according to any one of claims 1-8, wherein for one or more of the message pairs, the corresponding communication service is a short messaging service.

10. The method according to any one of claims 1-9, wherein each service authorization request message is an immediate event charging (IEC) message and each charging request message is a post event charging (PEC) message, as defined by the Third Generation Partnership Project (3 GPP) for converged event based charging, except that each IEC message is modified by the CTF to indicate which inherently included authorization or charging related parameters are to be reused by the CHF as correlation terms for identifying the corresponding PEC message that is later sent from the CTF to the CHF.Page 21 of 29P112015W00111. A method of operation by a charging function (CHF) in a communications network, the method comprising: receiving a service authorization request message from a charging trigger function (CTF) in the communications network; interpreting the service authorization request message as a request for authorization of delivery of a corresponding communication service, based on determining that the service authorization request message includes an identification of correlation terms to be used by CHF in determining that a later charging request message received from the CTF is paired to the service authorization request message, each correlation term being a particular authorization or charging related parameter that is commonly included in all service authorization request and charging request messages, and for each pairing of service authorization and charging request messages, will have a same context-specific parameter value; and reconciling charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message.

12. The method according to claim 11, wherein reconciling charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message comprises charging for the delivered communication service.

13. The method according to claim 12, further comprising including in a charging data record (CDR) or including in information sent from the CHF for generation of the CDR, an indication that the charging request message was detected as a paired message.

14. The method according to claim 12 or 13, further comprising including in the CDR or the information sent from the CHF for generation of the CDR, the service authorization request message or parts thereof.

15. The method according to any one of claims 11-14, wherein the charging request message is one among multiple charging request messages incoming to the CHF and wherein, for any charging request message for which the CHF does not identify a paired service authorizationPage 22 of 29P112015W001 request message, the method includes reconciling charging for any such charging request message by one of: declining to assess charges for the communication service indicated as having been delivered; or charging for the delivered communication service and correspondingly recording or transmitting for recordation an indication of the failure to identify a paired service authorization request message.

16. The method according to any one of claims 11-15, wherein the service authorization request message and the corresponding charging request message are one message pair among a plurality of message pairs received from CTF for respective instances of corresponding communication services being requested and delivered, and wherein the method includes the CHF maintaining a running record of received service authorization request messages and, for each received charging request message, performing correlation processing against the running record, in an attempt to identify the paired service authorization request message.

17. The method according to claim 16, wherein, for each received charging request message for which no paired service authorization request message was found in the running record, referred to as a correlation failure, the method includes the CHF storing or transmitting for storage an indication of the correlation failure, for compiling correlation failure statistics.

18. The method according to claim 16 or 17, wherein each service authorization request message includes an indication of a maximum delay for receiving the paired charging request message, and wherein the method further includes the CHF limiting the length of time that each service authorization request message remains in the running record according to the maximum delay indicated in the service authorization request message.

19. The method according to claim 18, wherein the method further includes the CHF creating a retained record corresponding to each service authorization request message that is removed from the running record as a consequence of reaching the indicated maximum delay without reception of the corresponding charging request message.

20. The method according to any one of claims 11-19, wherein the service authorization request message is an immediate event charging (IEC) message and the later charging request message is a post event charging (PEC) message, as defined by the Third Generation PartnershipPage 23 of 29P112015W001Project (3 GPP) for converged event based charging, except that each IEC message is modified by the CTF to indicate which inherently included authorization or charging related parameters are to be reused by the CHF as correlation terms for identifying the later PEC message as corresponding with the PEC message.

21. A charging trigger function (CTF) configured for operation in a communications network, the CTF comprising: a communications interface; and processing circuitry configured to: send, via the communications interface, message pairs to a charging function (CHF), each message pair comprising a service authorization request message for obtaining authorization for delivery of a corresponding communication service and a later charging request message confirming delivery of the corresponding communication service, for prompting the CHF to reconcile charging for the delivered communication service; and enable the CHF to detect the message pairs by including in each service authorization request message an identification of correlation terms, each correlation term being a particular authorization or charging related parameter that is predefined for inclusion in all authorization request and charging request messages but reused for correlation-based detection at the CHF of the message pairs, each such particular authorization or charging related parameter necessarily having a same context-specific value for both messages in each message pair.

22. The CTF according to claim 21, wherein the processing circuitry is configured to identify at least two particular authorization or charging related parameters to be used as correlation terms.

23. The CTF according to claim 22, wherein the at least two particular authorization or charging related parameters comprise at least one of an originator subscription permanent identifier (SUP I) and a recipient SUPI, corresponding to originator and recipient user equipment associated with delivery of the communication service.

24. The CTF according to claim 22 or 23, wherein the at least two particular authorization or charging related parameters comprise an originator subscription permanent identifier (SUPI) ofPage 24 of 29P112015W001 an originating user equipment (UE) associated with the corresponding communication service, and a data network name (DNN) associated with the corresponding communication service.

25. The CTF according to any one of claims 21-24, wherein all service authorization request messages and all charging request messages are defined to carry certain information elements (IES), at least some such IES are used to convey respective authorization or charging related parameter values, and at least some such IEs are common to both message types, and wherein the processing circuitry is configured to include, for each service authorization request message, an identification that one or more of the common IEs are to be used as correlation terms by the CHF for correlation-based detection of the message pairs.

26. The CTF according to claim 25, wherein at least three of the common IEs are identified for use as the correlation terms.

27. The CTF according to any one of claims 21-26, wherein the processing circuitry is configured to include in each service authorization request message an indication of a maximum delay for receiving the corresponding charging request message, to bound a historical message window searched by the CHF in relation to receiving one of the charging request messages.

28. The CTF according to claim 27, wherein the processing circuitry is configured to set the maximum delay in dependence on at least one of: policy information provided to the CTF; the communication service associated with the corresponding service authorization request message, wherein different types of communication services have different maximum delays associated therewith; or stored user preferences associated with the corresponding authorization request.

29. The CTF according to any one of claims 21-28, wherein for one or more of the message pairs, the corresponding communication service is a short messaging service.

30. The CTF according to any one of claims 21-29, wherein each service authorization request message is an immediate event charging (IEC) message and each charging request message is a post event charging (PEC) message, as defined by the Third Generation Partnership Project (3 GPP) for converged event based charging, except that each IEC message is modified by the CTF to indicate which inherently included authorization or charging related parametersPage 25 of 29P112015W001 are to be reused by the CHF as correlation terms for identifying the corresponding PEC message that is later sent from the CTF to the CHF.

31. A charging function (CHF) configured for operation in a communications network, the CHF comprising: a communications interface; and processing circuitry configured to: receive, via the communications interface, a service authorization request message from a charging trigger function (CTF) in the communications network; interpret the service authorization request message as a request for authorization of delivery of a corresponding communication service, based on determining that the service authorization request message includes an identification of correlation terms to be used by CHF in determining that a later charging request message received from the CTF is paired to the service authorization request message, each correlation term being a particular authorization or charging related parameter that is commonly included in all service authorization request and charging request messages, and for each pairing of service authorization and charging request messages, will have a same context-specific parameter value; and reconcile charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message.

32. The CHF according to claim 31, wherein, for reconciling charging for the corresponding communication service responsive to correlation-based detection of the later charging request message as being paired with the service authorization request message, the processing circuitry is configured to charge or initiate charging for the delivered communication service.

33. The CHF according to claim 32, wherein the processing circuitry is configured to include in a charging data record (CDR) or include in information sent from the CHF for generation of the CDR, an indication that the charging request message was detected as a paired message.Page 26 of 29P112015W00134. The CHF according to claim 32 or 33, wherein the processing circuitry is configured to include in the CDR or the information sent from the CHF for generation of the CDR, the service authorization request message or parts thereof.

35. The CHF according to any one of claims 31-34, wherein the charging request message is one among multiple charging request messages incoming to the CHF and wherein, for any charging request message for which the CHF does not identify a paired service authorization request message, the processing circuitry is configured to reconcile charging for any such charging request message by one of: declining to assess charges for the communication service indicated as having been delivered; or charging for the delivered communication service and correspondingly recording or transmitting for recordation an indication of the failure to identify a paired service authorization request message.

36. The CHF according to any one of claims 31-35, wherein the service authorization request message and the corresponding charging request message are one message pair among a plurality of message pairs received from CTF for respective instances of corresponding communication services being requested and delivered, and wherein the processing circuitry is configured to maintain a running record of received service authorization request messages and, for each received charging request message, perform correlation processing against the running record, in an attempt to identify the paired service authorization request message.

37. The CHF according to claim 36, wherein, for each received charging request message for which no paired service authorization request message was found in the running record, referred to as a correlation failure, the processing circuitry is configured to store or transmit for storage an indication of the correlation failure, for compiling correlation failure statistics.

38. The CHF according to claim 36 or 37, wherein each service authorization request message includes an indication of a maximum delay for receiving the paired charging request message, and wherein the processing circuitry is configured to limit the length of time that each service authorization request remains in the running record according to the maximum delay indicated in the service authorization request.Page 27 of 29P112015W00139. The CHF according to claim 38, wherein the processing circuitry is configured to create a retained record corresponding to each service authorization request message that is removed from the running record as a consequence of reaching the indicated maximum delay without reception of the corresponding charging request message.

40. The CHF according to any one of claims 31-39, wherein the service authorization request message is an immediate event charging (IEC) message and the later charging request message is a post event charging (PEC) message, as defined by the Third Generation Partnership Project(3 GPP) for converged event based charging, except that each IEC message is modified by the CTF to indicate which inherently included authorization or charging related parameters are to be reused by the CHF as correlation terms for identifying the later PEC message as corresponding with the PEC message.Page 28 of 29

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