Patent Description:
For example, online charging is a process where charging information of a subscriber for network resource usage for a communication session in the network of a subscriber is collected concurrently with that network resource usage. Authorization for the network resource usage should be obtained by the network prior to the actual network resource usage to occur. This authorization is granted by an OCF node residing in the Online Charging System (OCS) upon request from a CTF node residing in a core network of the network.

The OCS thereby allows a telecommunication service provider to charge subscribers in real-time, based on network resource usage. The OCS can be configured for both event based charging and session based charging for various services, such as like voice, data, etc. in the network.

The CTF node generates charging events based on information from a gateway in the core network pertaining to observation of network resource usage. The charging events are forwarded to the OCF node in order for the CTF node to obtain authorization for the network resource usage requested by the subscriber.

The CTF node should be configured to delay the actual network resource usage until permission by the OCF node has been granted. Based on the service, the OCF node will rate and reserve required units (monetary or non-monetary) from the user account of the subscriber, and allow the service to be accessed by the subscriber. The reserved units are informed to the CTF node as granted units. The CTF node will request the OCF node for further reservation and granting of network resources during of the communication session. This might occur either when granted units are consumed or when any other rating parameters are changed. The CTF node should be configured to enforce termination of the subscriber's network resource usage when permission from the OCF node is not granted or expires.

The units are thus granted during each request in the communication session and the CTF node should report back the usage and obtain grant for additional units from the OCF node in order for the communication session to be continued by sending a new request to the OCF node. However, it could be that there is a communication failure between the CTF node and the OCF node, resulting in that the communication session for the subscriber cannot be rated. In this scenario, the CTF node might decide either to allow the communication session to continue toll free (i.e. without real-time charging), or to allow the communication session to continue and later post process the Charging Data Records (CDRs) in the OCS, or to terminate the communication session. All these options have drawbacks. If the session is allowed to continue toll free or with later post processing of CDRs, this can lead to revenue loss for the mobile network operator of the subscriber. Terminating the communication session will lead to negative user experience for the subscriber.

<CIT> relates to overload control handling in case of an overload state of a charging entity.

Hence, there is still a need for an improved way of handling requests for network resources for maintaining a communication session for a subscriber.

<CIT> relates to managing a shared quota for a plurality of network subscribers in a consumer telecommunications network. In use, a first usage quota reservation out of a shared quota is allocated to at least one first subscriber among a plurality of network subscribers. Further, it is determined that at least a portion of the shared quota is available. Additionally, a progressively smaller at least one second usage quota reservation out of the at least a portion of the shared quota is recursively allocated to the at least one first subscriber among the plurality of network subscribers, the smaller at least one second usage quota reservation being smaller than the first usage quota reservation out of the shared quota.

Furthermore, the embodiments of the invention are those defined by the claims. Moreover, examples and embodiments, which are not covered by the claims are presented not as embodiments of the invention, but as background art or examples useful for understanding the invention.

An object of embodiments herein is to alleviate, or at least reduce or mitigate the above disclosed issues.

<FIG> is a schematic diagram illustrating a network <NUM> where embodiments presented herein can be applied. The network <NUM> could be a third generation (<NUM>) telecommunication system, a fourth generation (<NUM>) telecommunication system, or a fifth (<NUM>) telecommunication system and support any 3GPP telecommunications standard, where applicable.

The network <NUM> comprises a radio access network (RAN) <NUM>, a core network (CN) <NUM>, and a packet based service network <NUM>, such as the Internet. The radio access network <NUM> is operatively connected to the core network <NUM>, which in turn is operatively connected to the packet based service network <NUM>. Subscribers <NUM>, such as wireless devices, are thereby, via a radio base station <NUM> in the radio access network <NUM> and at least one gateway (GW) <NUM> in the core network <NUM> access services of, and exchange data with, the service network <NUM> during a communication session of the subscriber <NUM>. As the skilled person understands, the network <NUM> might comprise further entities, functions, nodes, and devices, such as an offline charging system. The gateway <NUM> could be any of, or a combination of, a service gateway and a packet data network gateway.

Examples of radio base stations <NUM> are radio access network nodes, radio base stations, base transceiver stations, Node Bs, evolved Node Bs, g Node Bs, access points, access nodes, transmission and reception points, and backhaul nodes. Examples of subscribers <NUM> are wireless devices, terminal devices, mobile stations, mobile phones, handsets, wireless local loop phones, user equipment (UE), smartphones, laptop computers, tablet computers, network equipped sensors, network equipped vehicles, and so-called Internet of Things devices.

When the subscriber <NUM> is to access services of, and exchange data with, the service network <NUM> during the communication session, the gateway <NUM>, for example, requests network resources from a CTF node <NUM> located in the core network <NUM> for maintaining the communication session for the subscriber <NUM>. In turn, the CTF node <NUM> requests credit units corresponding to the network resources from an OCF node <NUM> located in an OCS <NUM>. Assuming that credit units are available for the subscriber <NUM>, the OCF node <NUM> responds with a grant of the credit units. The CTF node <NUM> then provides, to the gateway <NUM>, a grant for the network resources for maintaining the communication session in accordance with the obtained grant. However, as noted above, it could be that the OCF node <NUM> is unavailable when the CTF node <NUM> requests credit units from the OCF node <NUM>. Corresponding resulting disadvantages have been listed above. If possible, such disadvantages should be avoided, or at least reduced or mitigated. There is thus a need for improved handling requests for network resources for maintaining the communication session for the subscriber <NUM>.

The embodiments disclosed herein therefore relate to mechanisms for granting network resources for maintaining a communication session for a subscriber <NUM> in a network <NUM> and granting credit units for maintaining a communication session for a subscriber <NUM> in a network <NUM>. In order to obtain such mechanisms there is provided a CTF node <NUM>, a method performed by the CTF node <NUM>, a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the CTF node <NUM>, causes the CTF node <NUM> to perform the method. In order to obtain such mechanisms there is further provided an OCF node <NUM>, a method performed by the OCF node <NUM>, and a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the OCF node <NUM>, causes the OCF node <NUM> to perform the method.

Reference is now made to <FIG> illustrating a method for granting network resources for maintaining a communication session for a subscriber <NUM> in a network <NUM> as performed by the CTF node <NUM> according to an embodiment.

As disclosed above, the gateway <NUM> request network resources in order for the communication session for the subscriber is to be maintained. It is assumed that this request is obtained by the CTF node <NUM>. The CTF node <NUM> is thus configured to perform step S <NUM>:
S102: The CTF node <NUM> obtains, from the gateway <NUM> in the network <NUM>, a request for network resources for maintaining the communication session for the subscriber <NUM>.

The CTF node <NUM> then requests the corresponding credit units from the OCF node <NUM>. That is, the CTF node <NUM> is configured to perform step S104:
S104: The CTF node <NUM> requests, from the OCF node <NUM> and in response thereto (i.e., in response to having obtained the request in step S104), credit units corresponding to the network resources.

As will be further disclosed below, the OCF node <NUM> will inform the CTF node <NUM> in advance of how many such credit units can be granted to the subscriber for the same session communication session. Thus, the CTF node <NUM> is configured to perform step S106:
S106: The CTF node <NUM> obtains a grant of the credit units as well as an advance credit indication of additional credit units for the communication session from the OCF node <NUM>.

The CTF node <NUM> will, upon receiving the grant and the advance credit indication from the OCF node <NUM>, cache the advance indication (in addition to other values for the communication session). In particular, the CTF node <NUM> is configured to perform step S108:
S108: The CTF node <NUM> stores the advance credit indication for the communication session.

SThe CTF node <NUM> will, upon receiving the grant and the advance credit indication from the OCF node <NUM>, provide a grant to the gateway <NUM>. In particular, the CTF node <NUM> is configured to perform step S110:
S110: The CTF node <NUM> provides, to the gateway <NUM>, a grant for the network resources for maintaining the communication session in accordance with the obtained grant.

The advance credit indication is used when the CTF node <NUM> is not able to reach the OCF node <NUM>. By using the advance credit indication, the CTF node <NUM> ensures that the communication session can be maintained as normal even when the OCF node <NUM> is unreachable.

Embodiments relating to further details of granting network resources for maintaining a communication session for a subscriber <NUM> in a network <NUM> as performed by the CTF node <NUM> will now be disclosed.

There could be different types of network resources. Non-limiting examples include, but are not limited to the amount of resource blocks occupied by data and dedicated control signalling for the subscriber, the amounts of bits needed for communication of data and dedicated control signalling for the subscriber, the amount of memory and/or computing resources needed to be allocated in the communications network for handling communication of data and dedicated control signalling for the subscriber, etc..

There could be different types of advance credit indications. According to an embodiment, the grant of the credit units is valid for one single request for credit units for the communication session, and the advance credit indication pertains to grant of credit units for N≥<NUM> additional such requests for the same communication session. Hence, the CTF node <NUM> is thereby enabled to respond to N consecutive requests for network resources for the same communication session for the subscriber <NUM> even if the OCF node <NUM> is unreachable. In some non-limiting examples, <NUM>≤N≤<NUM>. The value of N depends on the service used by the subscriber <NUM>, the type of subscription the subscriber <NUM> has, the total amount of quota available for the subscriber <NUM>, etc..

There could be different ways for the CTF node <NUM> to act once the advance credit indication has expired, such as for examples after the CTF node <NUM> having responded to N consecutive requests for network resources for the same communication session for the subscriber <NUM> where the OCF node <NUM> is unreachable. According to an embodiment, upon expiration of the advance credit indication the CTF node <NUM> either grants the gateway <NUM> to maintain the communication session or causes the gateway <NUM> to terminate the communication session. That is, the CTF node <NUM> might decide either to allow the communication session to continue toll free (i.e. without real-time charging), or to allow the communication session to continue and later post process the CDRs in the OCS <NUM>, or to terminate the communication session.

As disclosed above, the advance credit indication can be used when the CTF node <NUM> is not able to reach the OCF node <NUM>. In more detail, when the CTF node <NUM> detects that the OCF node <NUM> is unreachable, while trying to obtain more credit units for the communication session, then CTF node <NUM> will use the stored advance credit indication and grant further network resources for that communication session. Hence, according to an embodiment, the advance credit indication is used for granting further network resources for maintaining the communication session for the subscriber <NUM> when the OCF node <NUM> is unavailable. By means of these further network resources the communication session is enabled to continue for the subscriber <NUM>.

According to an embodiment the CTF node <NUM> is configured to perform (optional) steps S112-S <NUM>:.

It is in this embodiment assumed that the the CTF node <NUM> is not able to reach the OCF node <NUM>, or in other words that the OCF node <NUM> is unreachable. Hence:
S116: The CTF node <NUM> obtains an indication of unavailability of the OCF node <NUM>.

There could be different ways for the CTF node <NUM> to determine that the OCF node <NUM> is unavailable, and thus to obtain the indication of unavailability of the OCF node <NUM>. For example, the CTF node <NUM> might use a time-out mechanism. As an example, a timer might be started when the request is provided to the OCF node <NUM> and if the CTF node <NUM> does not receive any acknowledgement from the OCF node <NUM> of the request once the timer has expired the CTF node <NUM> deems the OCF node <NUM> to be unavailable. As the skilled person understands there could be other mechanisms for the CTF node <NUM> to determine that the OCF node <NUM> is unavailable and thus to obtain the indication of unavailability of the OCF node <NUM>.

The CTF node <NUM> then determines whether to deny or grant further network resources based on the stored advance credit indication (for the same communication session for the subscriber <NUM>). Hence:
S118: The CTF node <NUM> provides, to the gateway <NUM>, a further grant of the further network resources for maintaining the communication session in accordance with the stored advance credit indication.

In some aspects the stored advance credit indication is updated when consumed by the further grant of the further network resources. In particular, according to an embodiment the CTF node <NUM> is configured to perform (optional) step S120:
S120: The CTF node <NUM> updates the stored advance credit indication for the communication session in accordance with the further network resource having been granted.

In some aspects the CTF node <NUM> informs the OCF node <NUM> about the thus updated advance credit indication. Thus, according to an embodiment the CTF node <NUM> is configured to perform (optional) step S122 when the OCF node <NUM> no longer is unavailable (i.e., when the OCF node <NUM> becomes available):
S122: The CTF node <NUM> provides information about the further granted network resources to the OCF node <NUM>.

There could be different ways for the CTF node <NUM> to inform the OCF node <NUM> about the thus updated advance credit indication.

In some aspects the CTF node <NUM> determines based on a configuration parameter, whether to initiate the account update separately or as part of a next update request for the communication session. Thus, according to an embodiment, the information is provided either upon requesting yet further credit units for the communication session, or separately from requesting yet further credit units for the communication session.

In some aspects the stored advance credit indication is updated when the CTF node <NUM> receives a new advance credit indication from the OCF node <NUM>. In particular, according to an embodiment, the advance credit indication is updated upon obtaining yet further advance credit indication of yet additional credit units for the communication session from the OCF node <NUM>.

In more detail, when requesting yet further credit units for the communication session, if the OCF node <NUM> is reachable, the CTF node <NUM> will ignore the previously stored advance credit indication and will attempt to obtain further credit units from the OCF node <NUM>. The CTF node <NUM> will then store this updated advance credit indication (thus overwriting the previously stored advance credit indication). Thus, according to an embodiment the CTF node <NUM> is configured to perform (optional) steps S124-S132:.

The stored advance credit indication is then updated based on the further advance credit indication.

Reference is now made to <FIG> illustrating a method for granting credit units for maintaining a communication session for a subscriber <NUM> in a network <NUM> as performed by the OCF node <NUM> according to an embodiment.

As disclosed above, the CTF node <NUM> requests credit units from the OCF node <NUM> for maintaining the communication session for the subscriber <NUM>. It is assumed that the OCF node <NUM> obtains this request. The OCF node <NUM> is thus configured to perform step S202:
S202: The OCF node <NUM> obtains, from the CTF node <NUM>, a request for credit units corresponding to network resources for maintaining the communication session for the subscriber <NUM>.

Assuming that credit units for the subscriber <NUM> indeed are available, the OCF node <NUM> grants service to the communication session via a grant of credits units that is provided to the CTF node <NUM>. The OCF node <NUM> will then also provide the CTF node <NUM> with an advance credit indication for the communication session. Hence, the OCF node <NUM> is thus configured to perform step S206:
S206: The OCF node <NUM> provides a grant of the credit units as well as an advance credit indication of additional credit units for the communication session to the CTF node <NUM>.

As noted above, the advance credit indication can be stored by the CTF node <NUM> and used when the CTF node <NUM> is not able to reach the OCF node <NUM>. By using the advance credit indication stored in CTF node <NUM>, the CTF node <NUM> ensures that the communication session can be maintained as normal even when the OCF node <NUM> is unreachable.

Embodiments relating to further details of granting credit units for maintaining a communication session for a subscriber <NUM> in a network <NUM> as performed by the OCF node <NUM> will now be disclosed.

As disclosed above, according to an embodiment, the grant of the credit units is valid for one single request for credit units for the communication session, and the advance credit indication pertains to grant of credit units for N≥<NUM> additional such requests.

In some aspects the OCF node <NUM> determines the amount of credit units to be represented by the advance credit indication. According to an embodiment the OCF node <NUM> is configured to perform (optional) step S204:
S204: The OCF node <NUM> determines the amount of additional credit units to be indicated to the CTF node <NUM>.

In this respect, the OCF node <NUM>, or the OCS <NUM>, might determine the advance credit indication based on a configurable set of parameters (such as the remaining balance for the subscriber <NUM>, type of subscription for the subscriber <NUM>, type of service for the communication session, previous usage pattern, etc.). Further in this respect, the OCF node <NUM>, or the OCS <NUM>, might be configured with a maximum threshold value for the advance credit indications (for example such that the advance credit indications cannot exceed x% of the total available quota for the subscriber <NUM>, where <NUM>< x <<NUM> is a configurable number, such as <NUM>< x <<NUM>).

In some aspects the OCF node <NUM>, or the OCS <NUM>, reserves the additional credit units that corresponds to the advance credit indication. Thus, according to an embodiment the OCF node <NUM> is configured to perform (optional) step S208:
S208: The OCF node <NUM> reserves the additional credit units for the communication session upon having provided the grant of the credit units to the CTF node <NUM>.

In this respect, the reserved additional credit units might only be part of the total available credit units for the subscriber <NUM>. As above, the OCF node <NUM>, or the OCS <NUM>, might be configured with a maximum threshold value for the advance credit indications such that only a small portion of the total quota for the subscriber <NUM> is reserved each time.

As disclosed above, in some aspects the CTF node <NUM> updates the stored advance credit indication and informs the OCF node <NUM> about the thus updated advance credit indication. Hence, according to an embodiment the OCF node <NUM> is configured to perform (optional) step S210:
S210: The OCF node <NUM> obtains information about further granted network resources for the communication session from the CTF node <NUM>, the further granted network resources having been granted in accordance with the advance credit indication.

As disclosed above there could be different ways for the CTF node <NUM> to inform the OCF node <NUM> about the thus updated advance credit indication, and thus different ways for the OCF node <NUM> to obtain the information in step S210. In view of the above, according to an embodiment, the information in step S210 is obtained either upon the OCF node <NUM> obtaining a request for yet further credit units for the communication session from the CTF node <NUM>, or separately from the OCF node <NUM> obtaining a request for yet further credit units for the communication session from the CTF node <NUM>.

One particular embodiment for granting network resources and for granting credit units for maintaining a communication session for a subscriber <NUM> in a network <NUM> based on at least some of the above disclosed embodiments will now be disclosed in detail with reference to the signalling diagram of <FIG>.

S301: The gateway <NUM> requests network resources for maintaining a communication session for a subscriber <NUM>. The CTF node <NUM> thus obtains the request for the network resources.

S302: The CTF node <NUM> requests, from the OCF node and in response to having obtained the request in step S301, credit units corresponding to the network resources. The OCF node <NUM> thus obtains the request for credit units.

S303: The OCF node <NUM> provides a grant of the credit units as well as an advance credit indication of additional credit units for the communication session to the CTF node <NUM>. The CTF node <NUM> thus obtains the grant of the credit units as well as the advance credit indication of additional credit units. The OCF node <NUM> also reserves the additional credit units for the communication session upon having provided the grant of the credit units to the CTF node <NUM>.

S304: The CTF node <NUM> stores the advance credit indication for the communication session.

S305: The CTF node <NUM> provides, to the gateway <NUM>, the grant for the network resources for maintaining the communication session in accordance with the obtained grant.

It is here for illustrative purposes assumed that the subscriber <NUM> consumes the thus granted network resources and is in need for more network resources in order for the communication session to be maintained.

S306: The gateway <NUM> requests further network resources for maintaining the communication session for the subscriber <NUM>. The CTF node <NUM> thus obtains the further request for the further network resources.

S307: The CTF node <NUM> requests, from the OCF node <NUM> and in response to having obtained the further request, further credit units corresponding to the further network resources. The CTF node <NUM> further obtains an indication of unavailability of the OCF node <NUM>.

S308: The CTF node <NUM> fetches the stored advance credit indication in order to determine whether to deny or grant further for the same communication session for the subscriber <NUM>.

It is here for illustrative purposes assumed that the stored advance credit indication allows the further network resources to the granted.

S309: The CTF node <NUM> provides, to the gateway <NUM>, a further grant of the further network resources for maintaining the communication session in accordance with the stored advance credit indication.

SIt is here for illustrative purposes assumed that the subscriber <NUM> consumes the thus granted further network resources and is in need for even more network resources in order for the communication session to be maintained.

S310: The gateway <NUM> requests yet further network resources for maintaining the communication session for the subscriber <NUM>. The CTF node <NUM> thus obtains the yet further request for the yet further network resources.

S311: The CTF node <NUM> requests, from the OCF node <NUM> and in response to having obtained the yet further request in step S310, yet further credit units corresponding to the yet further network resources. The OCF node <NUM> thus obtains the yet further request. The CTF node <NUM> also provides information about the further granted network resources (i.e., information about network resources granted during unavailability of the OCF node <NUM>) to the OCF node <NUM>. The OCF node <NUM> thus obtains the information.

S312: The OCF node <NUM> provides a further grant of the yet further credit units as well as a further advance credit indication of yet additional credit units for the subscriber <NUM> to the CTF node <NUM>. The CTF node <NUM> thus obtains the further grant and the further advance credit indication.

S313: The CTF node <NUM> updates the stored advance credit indication for the communication session based on the further advance credit indication.

S314: The CTF node <NUM> provides, to the gateway <NUM>, a yet further grant of the yet further network resources for maintaining the communication session in accordance with the yet further grant.

<FIG> is a flowchart illustrating an example of a request for network resources is handled by the CTF node <NUM> and the OCF node <NUM>.

S401: The CTF node <NUM> obtains, from the gateway <NUM> in the network <NUM>, a request for network resources for maintaining the communication session for the subscriber <NUM>.

S402: The CTF node <NUM> requests, from the OCF node <NUM> and in response to having obtained the request in step S401, credit units corresponding to the network resources.

S403: In case the CTF node <NUM> is able to contact the OCF node <NUM> step S404 is entered (i.e., when the OCF node <NUM> is reachable). In case the CTF node <NUM> is unable to contact the OCF node <NUM> step S407 is entered (i.e., when the OCF node <NUM> is unreachable).

S404: The OCF node <NUM> checks if there is enough credit balance for the subscriber <NUM>. If yes, step S405 is entered, and if no, step S409 is entered.

S405: The OCF node <NUM> determines the amount of additional credit units to be indicated to the CTF node <NUM>. The OCF node <NUM> provides a grant of the credit units as well as an advance credit indication of the additional credit units for the communication session to the CTF node <NUM>. The OCF node <NUM> reserves the additional credit units for the communication session upon having provided the grant of the credit units to the CTF node <NUM>.

S406: The CTF node <NUM> stores the advance credit indication for the communication session. The CTF node <NUM> provides, to the gateway <NUM>, a grant for the network resources for maintaining the communication session in accordance with the obtained grant.

S407: The CTF node <NUM> fetches stored advance credit indication in order to determine whether to deny or grant further for the same communication session for the subscriber <NUM>.

S408: In case the CTF node <NUM> is able to find the stored advance credit indication step S410 is entered. In case the CTF node <NUM> is unable to find the stored advance credit indication step S409 is entered.

S409: The CTF node <NUM> either grants the gateway <NUM> to maintain the communication session or causes the gateway <NUM> to terminate the communication session.

S410: CTF node <NUM> provides, to the gateway <NUM>, a grant of the network resources for maintaining the communication session in accordance with the stored advance credit indication.

<FIG> is a flowchart illustrating an example of how the CTF node <NUM> might update the user account of the subscriber <NUM> in a scenario where the CTF node <NUM> grants network resources based on a stored advance credit indication.

S501: The CTF node <NUM> is unable to reach the OCF node <NUM>. The connection with the OCF node <NUM> is thus deemed lost.

S502: The CTF node <NUM> checks if the connection with the OCF node <NUM> has been restored, and thus whether the CTF node <NUM> is able to contact the OCF node <NUM> or not. If yes, step S504 is entered, and if no, step S503 is entered.

S503: The CTF node <NUM> makes decisions as to whether to grant further network resources for maintaining the communication session for the subscriber <NUM> based on the stored advance credit indication, and updates the stored advance credit indication accordingly when determining to grant the further network resources.

S504: The CTF node <NUM> informs the OCF node <NUM> of any use of network resources based on the stored advance credit indication in order to update the OCF node <NUM> on credit units granted/used from the advance credit indication.

<FIG> schematically illustrates, in terms of a number of functional units, the components of a CTF node <NUM> according to an embodiment. Processing circuitry <NUM> is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110a (as in <FIG>), e.g. in the form of a storage medium <NUM>. The processing circuitry <NUM> may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry <NUM> is configured to cause the CTF node <NUM> to perform a set of operations, or steps, as disclosed above. For example, the storage medium <NUM> may store the set of operations, and the processing circuitry <NUM> may be configured to retrieve the set of operations from the storage medium <NUM> to cause the CTF node <NUM> to perform the set of operations. Thus the processing circuitry <NUM> is thereby arranged to execute methods as herein disclosed.

The CTF node <NUM> may further comprise a communications interface <NUM> for communications with other functions, entities, nodes, and devices of the network <NUM>, such as the OCF node <NUM> and the gateway <NUM>. As such the communications interface <NUM> may comprise one or more transmitters and receivers, comprising analogue and digital components.

The processing circuitry <NUM> controls the general operation of the CTF node <NUM> e.g. by sending data and control signals to the communications interface <NUM> and the storage medium <NUM>, by receiving data and reports from the communications interface <NUM>, and by retrieving data and instructions from the storage medium <NUM>. Other components, as well as the related functionality, of the CTF node <NUM> are omitted in order not to obscure the concepts presented herein.

<FIG> schematically illustrates, in terms of a number of functional modules, the components of a CTF node <NUM> according to an embodiment. The CTF node <NUM> of <FIG> comprises a number of functional modules; an obtain module 210a configured to perform step S102, a request module 210b configured to perform step S104, an obtain module 210c configured to perform step S106, a store module 210d configured to perform step S108, and a provide module 210e configured to perform step S110. The CTF node <NUM> of <FIG> may further comprise a number of optional functional modules, such as any of an obtain module 210f configured to perform step S112, a request module <NUM> configured to perform step S114, an obtain module <NUM> configured to perform step S116, a provide module 210i configured to perform step S118, an update module 210j configured to perform step S120, a provide module <NUM> configured to perform step S122, an obtain module <NUM> configured to perform step S124, a request module <NUM> configured to perform step S126, an obtain module 210n configured to perform step S128, an update module 210o configured to perform step S130, a provide module 210p configured to perform step S132.

In general terms, each functional module 210a-210p may be implemented in hardware or in software. Preferably, one or more or all functional modules 210a-210p may be implemented by the processing circuitry <NUM>, possibly in cooperation with the communications interface <NUM> and/or the storage medium <NUM>. The processing circuitry <NUM> may thus be arranged to from the storage medium <NUM> fetch instructions as provided by a functional module 210a-210p and to execute these instructions, thereby performing any steps of the CTF node <NUM> as disclosed herein.

<FIG> schematically illustrates, in terms of a number of functional units, the components of an OCF node <NUM> according to an embodiment. Processing circuitry <NUM> is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110b (as in <FIG>), e.g. in the form of a storage medium <NUM>. The processing circuitry <NUM> may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry <NUM> is configured to cause the OCF node <NUM> to perform a set of operations, or steps, as disclosed above. For example, the storage medium <NUM> may store the set of operations, and the processing circuitry <NUM> may be configured to retrieve the set of operations from the storage medium <NUM> to cause the OCF node <NUM> to perform the set of operations. Thus the processing circuitry <NUM> is thereby arranged to execute methods as herein disclosed.

The OCF node <NUM> may further comprise a communications interface <NUM> for communications with other functions, entities, nodes, and devices of the network <NUM>, such as the CTF node <NUM>. As such the communications interface <NUM> may comprise one or more transmitters and receivers, comprising analogue and digital components.

The processing circuitry <NUM> controls the general operation of the OCF node <NUM> e.g. by sending data and control signals to the communications interface <NUM> and the storage medium <NUM>, by receiving data and reports from the communications interface <NUM>, and by retrieving data and instructions from the storage medium <NUM>. Other components, as well as the related functionality, of the OCF node <NUM> are omitted in order not to obscure the concepts presented herein.

<FIG> schematically illustrates, in terms of a number of functional modules, the components of an OCF node <NUM> according to an embodiment. The OCF node <NUM> of <FIG> comprises a number of functional modules; an obtain module 310a configured to perform step S202, and a provide module 310c configured to perform step S206. The OCF node <NUM> of <FIG> may further comprise a number of optional functional modules, such as any of a determine module 310b configured to perform step S204, a reserve module 310d configured to perform step S208, and an obtain module 310e configured to perform step S210. In general terms, each functional module 310a-310e may be implemented in hardware or in software. Preferably, one or more or all functional modules 310a-310e may be implemented by the processing circuitry <NUM>, possibly in cooperation with the communications interface <NUM> and/or the storage medium <NUM>. The processing circuitry <NUM> may thus be arranged to from the storage medium <NUM> fetch instructions as provided by a functional module 310a-310e and to execute these instructions, thereby performing any steps of the OCF node <NUM> as disclosed herein.

The CTF node <NUM> and/or OCF node <NUM> may be provided as a standalone device or as a part of at least one further device. For example, the CTF node <NUM> may be provided in a node of the core network <NUM> and the OCF node <NUM> may be provided in a node of the OCS <NUM>. Alternatively, functionality of the CTF node <NUM> and/or OCF node <NUM> may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part or may be spread between at least two such network parts. Thus, a first portion of the instructions performed by the CTF node <NUM> and/or OCF node <NUM> may be executed in a first device, and a second portion of the of the instructions performed by the CTF node <NUM> and/or OCF node <NUM> may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the CTF node <NUM> and/or OCF node <NUM> may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a CTF node <NUM> and/or OCF node <NUM> residing in a cloud computational environment. Therefore, although a single processing circuitry <NUM>, <NUM> is illustrated in <FIG> and <FIG> the processing circuitry <NUM>, <NUM> may be distributed among a plurality of devices, or nodes. The same applies to the functional modules 210a-210p, 310a-310e of <FIG> and <FIG> and the computer programs 1120a, 1120b of <FIG>.

<FIG> shows one example of a computer program product 1110a, 1110b comprising computer readable means <NUM>. On this computer readable means <NUM>, a computer program 1120a can be stored, which computer program 1120a can cause the processing circuitry <NUM> and thereto operatively coupled entities and devices, such as the communications interface <NUM> and the storage medium <NUM>, to execute methods according to embodiments described herein. The computer program 1120a and/or computer program product 1110a may thus provide means for performing any steps of the CTF node <NUM> as herein disclosed. On this computer readable means <NUM>, a computer program 1120b can be stored, which computer program 1120b can cause the processing circuitry <NUM> and thereto operatively coupled entities and devices, such as the communications interface <NUM> and the storage medium <NUM>, to execute methods according to embodiments described herein. The computer program 1120b and/or computer program product 1110b may thus provide means for performing any steps of the OCF node <NUM> as herein disclosed.

In the example of <FIG>, the computer program product 1110a, 1110b is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 1110a, 1110b could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 1120a, 1120b is here schematically shown as a track on the depicted optical disk, the computer program 1120a, 1120b can be stored in any way which is suitable for the computer program product 1110a, 1110b.

Claim 1:
A method for granting network resources for maintaining a communication session for a subscriber (<NUM>) in a network (<NUM>), the method being performed by a Charging Trigger Function, CTF, node (<NUM>), the method comprising:
obtaining (S102), from a gateway (<NUM>) in the network (<NUM>), a request for network resources for maintaining the communication session for the subscriber (<NUM>);
requesting (S104), from an Online Charging Function, OCF, node (<NUM>) and in response thereto, credit units corresponding to the network resources;
obtaining (S106) a grant of the credit units for immediate use and an advance credit indication of additional credit units for future use in case where the OCF node (<NUM>) becomes unavailable, wherein the grant of the credit units is valid for one single request for credit units for the communication session, and wherein the advance credit indication pertains to grant of credit units for N≥<NUM> additional such requests for the same communication session, and wherein the advance credit indication is used for granting further network resources for maintaining the communication session for the subscriber (<NUM>) when the OCF node (<NUM>) is unavailable, and wherein N indicates number of services used by the subscriber (<NUM>);
storing (S108) the advance credit indication for the communication session; and
providing (S110), to the gateway (<NUM>), a grant for the network resources for maintaining the communication session in accordance with the obtained grant.