Method for providing charging attributes

The invention relates to communication networks, specifically to service provisioning and authorization of service usage in different networks. The invention provides a method and a system for authorizing services for visiting subscribers and for obtaining the necessary charging profile information from the subscribers' home networks on a per-service basis.

FIELD OF INVENTION

The invention relates to communication networks, specifically to provision of charging attributes.

List of abbreviations3GPP3rd Generation Partnership ProjectAAAAuthentication, Authorization and AccountingCDRCall Detail RecordDCCADiameter Credit-Control ApplicationGGSNGateway GPRS Support NodeGPRSGeneral Packet Radio ServiceGSMGroupe Spéciale MobileGUPGeneric User ProfileHLRHome Location RegisterHPLMNHome Public Land Mobile NetworkIMSIInternational Mobile Subscriber IdentifierIPSCIP Session Control nodeMCCMobile Commerce and ChargingMOMobile OperatorMTMobile TerminalOSCOnline Service ControllerPDGPacket Data GatewayPDPPacket Data ProtocolSPService ProviderTPSPThird Party Service ProviderTRTechnical ReportVPLMNVisited Public Land Mobile NetworkWSIWeb Service Interface

TECHNICAL BACKGROUND

Current cellular telecommunication systems employ mechanisms that enable a mobile user to be authorised to use services provided within his or her home network. Certain mechanisms that authorise network access in home and visited networks are also known by a man skilled in the art.

However, current solutions are lacking in that a generic, service-based mechanism is however needed to authorise the use of services offered by a network to visiting subscribers. Such a mechanism would need to obtain certain subscriber attributes from the home network in order to perform authorisation. This authorisation can be only partially provided by existing mechanisms such as AAA, or VPLMN access attributes defined in the GSM/GPRS HLR.

The 3GPP standards define various control mechanisms and parameters (e.g. in 3GPP TS 23.060) that are stored within an HLR (Home Location Register) dictating whether a subscriber may utilise visited network services, and what charging characteristics (e.g. normal, prepaid, flat-rate, and/or hot billing subscription) apply to the subscriber or PDP context. These known mechanisms however are bearer specific and do not support per-service charging well. In particular, these known mechanisms do not support on a per-service basis for a given subscriber determination of service authorisation, charging method or charging system address.

Further, certain authentication protocols such as RADIUS and Diameter are typically used for network access authorisation. Adapting them for performing service-based authorisation would require the use of non-standard extensions to the protocol; thereby not offering a standardised solution.

Current solutions do not provide a generic mechanism that would allow a visiting subscriber to use a specific service, resolve how the subscriber should be charged, and would resolve the charging server or the balance server to which credit control messages should be directed.

SUMMARY OF THE INVENTION

The invention provides a method for providing charging attributes in a communication system. The method comprises at least the steps of

receiving a service authorization request by a service authorization node in a first network,

transmitting of a charging attribute request to a request receiver in a second network,

determining which charging attribute storage node can satisfy said charging attribute request,

transmitting charging attribute information from a charging attribute storage node, and

transmitting a service authorization reply by said service authorization node.

The charging attributes may be service and subscriber-specific attributes. Advantageously, said step of transmitting a charging attribute request is performed as a response to said step receiving a service authorization request, whereby said charging attribute request is related to said service authorization request.

In a further advantageous embodiment of the invention, the method further comprises the steps of

transmitting a charging attribute request by said request receiver to a charging attribute storage node,

receiving charging attribute information by said request receiver from said charging attribute storage node, and

transmitting charging attribute information by said request receiver to said service authorization node.

The method may also further comprise the steps of

transmitting information identifying a charging attribute storage node from said request receiver to said service authorization node, and

transmitting a charging attribute request by said service authorization node to said charging attribute storage node.

The request receiver node may also transmit information identifying said authorization node to a charging attribute storage node, whereafter the charging attribute storage node can transmit charging attribute information directly to said service authorization node.

In a further advantageous embodiment of the invention, the method further comprises the steps of

determining the home network of the subscriber identified in said service authorization request, and

determining address information of a request receiver in said home network of the subscriber.

The invention also provides a system for providing charging attributes in a communication system having a plurality of networks. The system comprises

a service authorization node in a first network for receiving service authorization requests and transmitting charging attribute requests to request receivers in other networks,

a request receiver in a second network for receiving a charging attribute request and for determining which charging attribute storage node in said second network can satisfy said charging attribute request, and

at least one charging attribute storage node in said second network for storing charging attributes and for responding to charging attribute requests.

The service authorization node may as well be responsible for transmitting such charging attribute requests to a request receiver within the same network. This may happen especially when the service authorization node receives a service authorization request concerning a subscriber whose home network is the network in which the service authorization node is located.

The invention also provides a service authorization node for a communications network. According to this aspect of the invention, the system comprises at least

means for receiving service authorization requests,

means for transmitting charging attribute requests,

means for determining the request receiver of the home network of a subscriber identified in an authorization request, and

means for receiving charging attribute information.

In an advantageous embodiment of this aspect of the invention, the service authorization node further comprises

means for transmitting charging attribute requests to a request receiver in a home network of a subscriber identified in an authorization request,

means for receiving charging attribute information from a request receiver, and

means for replying to service authorization requests.

The service authorization node may also comprise

means for transmitting charging attribute requests to a charging attribute storage node,

means for receiving charging attribute information from a charging attribute storage node, and

means for replying to service authorization requests.

The invention also provides a service authorization node for a communications network comprising at least

a receiver configured to receive service authorization requests,

a transmitter configured to transmit charging attribute requests,

a controller configured to determine the request receiver of the home network of a subscriber identified in an authorization request, and

a receiver configured to receive charging attribute information.

According to an advantageous embodiment of this aspect of the invention, the service authorization node further comprises

a transmitter configured to transmit charging attribute requests to a request receiver in a home network of a subscriber identified in an authorization request,

a receiver configured to receive charging attribute information from a request receiver, and

a controller configured to reply to service authorization requests.

According to a further advantageous embodiment of this aspect of the invention, the service authorization node further comprises

a transmitter configured to transmit charging attribute requests to a charging attribute storage node,

a receiver configured to receive charging attribute information from a charging attribute storage node, and

a controller configured to reply to service authorization requests.

The invention also provides a charging attribute request receiver node for a communication system. According to this aspect of the invention, the charging attribute request receiver node comprises at least

means for receiving charging attribute requests, and

means for determining which charging attribute storage node of a plurality of storage nodes can satisfy a received charging attribute request.

The invention also provides a method for authorizing charging in a communication system. According to this aspect of the invention, the method comprises at least the steps of

receiving a service authorization request from a service node,

determining of a request receiver in a home network of a subscriber identified in a service authorization request,

transmitting a charging attribute request to said request receiver,

receiving charging attribute information, and

transmitting a reply to said service authorization request.

According to an advantageous embodiment of this aspect of the invention, the method further comprises at least the steps of

receiving information identifying a charging attribute storage node,

transmitting a charging attribute request to said charging attribute storage node, and

receiving charging attribute information from said charging attribute storage node.

The invention also provides a method for managing charging attribute requests in a communication system. According to this aspect of the invention, the method comprises at least the steps of

receiving a charging attribute request,

determining which charging attribute storage node can satisfy said charging attribute request,

transmitting said charging attribute request to a charging attribute storage node which can satisfy said charging attribute request,

receiving charging attribute information from selected charging attribute storage node, and

transmitting charging attribute information to the node which sent said charging attribute request.

The invention also concerns a method for managing charging attribute requests in a communication system. According to this aspect of the invention, the method comprises at least the steps of

receiving a charging attribute request from a node within a second network,

determining which charging attribute storage node can satisfy said charging attribute request, and

transmitting information identifying a charging attribute storage node which can satisfy said charging attribute request to said second network node.

According to a still further aspect of the invention, there is provided a method for managing charging attribute requests in a communication system in a network node within a first network of said cellular telecommunication system. According to this aspect of the invention, the method comprises at least the steps of

receiving a charging attribute request from a node within a second network,

determining which charging attribute storage node can satisfy said charging attribute request,

transmitting said charging attribute request to a charging attribute storage node that can satisfy said charging attribute request, and

transmitting information identifying said second network node to said charging attribute storage node that can satisfy said charging attribute request.

These inventive methods can also be implemented in software, by implementing the method steps using computer program code means which may be executed on a processor of a network element of a communication system.

Many communication systems consist of a plurality of networks connected to a core network, each network covering a specific geographical area, which areas may or may not overlap. Further, different networks connected to the same core network may also use different technologies. For example, a single GSM network may cover a large region, while a smaller WLAN network may cover a part of a city within the same region. The invention is not limited to any particular radio access network technology or type.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

FIG. 1illustrates signalling according to an advantageous embodiment of the invention.FIG. 1shows signalling between a network node10providing services for subscribers, a service authorization node20, a charging attribute request receiver node30, and a charging attribute storage node40.FIG. 1indicates signalling after a roaming subscriber has initiated the use of a service provided by the visited network. The network node10providing the service (e.g. a service flow aware GGSN network node) requests110authorisation for the use of the specific service by the visiting subscriber.

In an actual implementation of the invention in a cellular telecommunication system, the service authorization node (in 3GPP standards, the function providing the services of a service authorization node is generally called a Service Authorisation Function) may be the same that provides authorisation of the network's own subscribers, or may be different for visiting users. The network node10providing the service may or may not know that the user is a visiting subscriber from another network.

If is not already previously established that the subscriber is a visiting subscriber the authorisation function will establish this (e.g. via IMSI analysis) and also determine the network to which the user belongs (not depicted inFIG. 1).

The service authorization node transmits120a charging attribute request to a charging attribute request receiver node30in the subscriber's home network. In 3GPP standards, the charging attribute request receiver node30may be denoted as an External Profile Gateway. The requested profile attributes may for example include service authorisation, subscriber's charging method, and charging server address(es). The network address of the charging attribute request receiver node30may for example be statically configured between cooperating networks, or may for example be dynamically discovered e.g. using a mechanism such as the mechanism known to a man skilled in the art as Liberty Discovery.

The charging attribute request receiver node30determines140which charging attribute storage node (or nodes)40can satisfy the request received, and transmits150the request to that storage node.

In various implementations of the invention in various cellular networks, the request may need to be reformatted or otherwise modified by the charging attribute request receiver node30, before it can be sent to the storage node40. This may happen e.g. if the cellular telecommunication system is comprised of a variety of differing networks implemented using different standards. In such a case, the attribute request receiver node30may advantageously perform any needed attribute mapping, protocol translation, or other changes as may be necessary.

Next, the charging attribute storage node40returns160the results of the request, i.e. charging attribute information back to the attribute request receiver node30, which transmits170the charging attribute information back to the service authorization node20.

Finally, the service authorization node20returns180a service authorisation response to the network node10providing the requested service. The service authorisation response may advantageously include the charging method applicable to the subscriber and service and, if required due to online charging the address of the charging server to which the charging information should be directed.

After receiving the authorization reply, in the event that the reply allows the service to be provided, the network node10providing the service can start providing the requested service to the subscriber.

FIG. 2illustrates signalling according to a further advantageous embodiment of the invention.FIG. 2shows signalling between a network node10providing services for subscribers, a service authorization node20, a charging attribute request receiver node30, and a charging attribute storage node40.FIG. 2indicates signalling after a roaming subscriber has initiated the use of a service provided by the visited network. The network node10providing the service (e.g. a service flow aware GGSN network node) requests110authorization for the use of the specific service by the visiting subscriber.

If is not already previously established that the subscriber is a visiting subscriber the authorisation function will establish this (e.g. via IMSI analysis) and also determine the network to which the user belongs (not depicted inFIG. 2).

The service authorization node transmits120a charging attribute request to a charging attribute request receiver node30in the subscriber's home network. The charging attribute request receiver node30determines140which charging attribute storage node (or nodes)40can satisfy the request received, and transmits210information about such a charging attribute storage node (or nodes) to the service authorization node20. Such information may advantageously include e.g. the network address, domain name, or other identifying information about the charging attribute storage node.

Next, the service authorization node20transmits220a charging attribute request to the indicated charging attribute storage node40. The charging attribute storage node40returns230the results of the request, i.e. charging attribute information back to the service authorization node20.

Finally, the service authorization node20returns240a service authorisation response to the network node10providing the requested service. The service authorisation response may advantageously include the charging method applicable to the subscriber and service and, if required due to online charging the address of the charging server to which the charging information should be directed.

After receiving the authorization reply, in the event that the reply allows the service to be provided, the network node10providing the service can start providing the requested service to the subscriber.

FIG. 3illustrates signalling according to a further advantageous embodiment of the invention.FIG. 3shows signalling between a network node10providing services for subscribers, a service authorization node20, a charging attribute request receiver node30, and a charging attribute storage node40.FIG. 3indicates signalling after a roaming subscriber has initiated the use of a service provided by the visited network. The network node10providing the service (e.g. a service flow aware GGSN network node) requests110authorization for the use of the specific service by the visiting subscriber.

If is not already previously established that the subscriber is a visiting subscriber the authorisation function will establish this (e.g. via IMSI analysis) and also determine the network to which the user belongs (not depicted inFIG. 3).

The service authorization node transmits120a charging attribute request to a charging attribute request receiver node30in the subscriber's home network. The charging attribute request receiver node30determines140which charging attribute storage node (or nodes)40can satisfy the request received, and transmits310the request to that storage node. In the current embodiment of the invention, the charging attribute request receiver node30also transmits310information identifying the service authorization node20to the charging attribute storage node40.

Next, the charging attribute storage node40returns320the results of the request, i.e. charging attribute information back to the charging attribute information back to the service authorization node20.

Finally, the service authorization node20returns330a service authorisation response to the network node10providing the requested service. The service authorisation response may advantageously include the charging method applicable to the subscriber and service and, if required due to online charging the address of the charging server to which the charging information should be directed.

After receiving the authorization reply, in the event that the reply allows the service to be provided, the network node10providing the service can start providing the requested service to the subscriber.

In an advantageous embodiment of the invention the charging attribute request receiver node is implemented within a 3GPP GUP Server and the Subscriber Charging Profile as a GUP Component. The GUP is, at the time of writing of this patent application, currently being defined within 3GPP TS 29.240.

FIG. 4illustrates a system according to an advantageous embodiment of the invention. The system provides charging attributes in a cellular telecommunication system400having a plurality of networks402,404.FIG. 4shows a mobile station460communicating with a first network402via a base station452,452′.FIG. 4also shows a network node450providing services to subscribers, a service authorization node410, a request receiver420, and a charging attribute storage node430. The service authorization node410in the first network402is configured to receive authorization requests and to transmit charging attribute requests to request receivers420in other networks404. The request receiver420in a second network404is configured to receive charging attribute requests and to determine which charging attribute storage node430,430′ in said second network404can satisfy said charging attribute request. The second network404has charging attribute storage nodes430,430′ for storing charging attributes and for responding to charging attribute requests. In this description of the example ofFIG. 4it is assumed that the mobile station460is roaming outside its home network404, and requesting a service from a network node450providing services. The network node450providing services transmits a service authorization request to service authorization node410as a response to receiving a service request from the mobile station460. The service authorization node410observes that the service request concerns a roaming subscriber from another network, and sends a charging attribute request to a request receiver420in the home network404of the subscriber. The request receiver420determines which charging attribute storage node430,430′ can satisfy the charging attribute request, and forwards the request to such a storage node. The storage node responds with the requested attributes, which the request receiver420transmits to the service authorization node410. Upon examining the received attribute information, the service authorization node410transmits a reply to the network node450providing services, which is then able to continue negotiation and/or providing services to the mobile station460.

The request receiver420may perform the determination of which charging attribute storage node430,430′ can satisfy the charging attribute request using the type of attribute information requested (such as charging attributes, subscribed services, or for example personal preferences) and the subscriber identity. The request receiver node420may for example comprise a configuration database or a configuration file indicating, which storage nodes store which types of attribute information, and for which groups of subscribers.

FIG. 5illustrates in more detail a service authorization node410for a cellular telecommunications network according to an advantageous embodiment of the invention. In the example ofFIG. 5, the service authorization node410comprises a receiver510configured to receive service authorization requests, a transmitter520configured to transmit charging attribute requests, a controller530configured to determine the request receiver of the home network of a subscriber identified in an authorization request, and a receiver540configured to receive charging attribute information.

In a further advantageous embodiment of the invention, the transmitter520may transmit charging attribute requests to a request receiver in a home network of a subscriber identified in an authorization request. Further, the receiver540for receiving charging attribute information may receive the information from such a request receiver. Further, the service authorization node410may comprise a controller550for replying to service authorization requests.

In a still further advantageous embodiment of the invention, the transmitter520for transmitting charging attribute requests may transmit charging attribute requests directly to a charging attribute storage node, and the receiver540for receiving charging attribute information may receive such information directly from a charging attribute storage node.

The components510,520,530,540, and550of the service authorization node can be implemented in many different ways. For example, they can be implemented using software, and functionalities of said components may be combined in various ways.

FIG. 6illustrates in more detail a charging attribute request receiver node420. In the example ofFIG. 6, the request receiver node420comprises at least a receiver610configured to receive charging attribute requests, and a controller620configured to determine which charging attribute storage node of a plurality of storage nodes can satisfy a received charging attribute request.

According to a further advantageous embodiment of the invention, the request receiver node420further comprises at least a transmitter630configured to transmit a charging attribute request to a charging attribute storage node, a receiver640configured to receive charging attribute information from a charging attribute storage node, and a transmitter650configured to transmit charging attribute information to a service authorization node.

According to a still further advantageous embodiment of the invention, the charging attribute request receiver node420further comprises at least a transmitter660configured to transmit information identifying a charging attribute storage node to a service authorization node. The information identifying the charging attribute storage node may be for example a network address or a domain name.

According to an even further advantageous embodiment of the invention, the charging attribute request receiver node420further comprises at least a transmitter670configured to transmit a charging attribute request to a charging attribute storage node, and a transmitter680configured to transmit information identifying a service authorization node to a charging attribute storage node. This identifying information allows a charging attribute storage node to send the reply comprising the desired charging attribute information directly to the service authorization node.

The components610,620,630,640,650,660,670, and680of the charging attribute request receiver node420can be implemented in many different ways. For example, they can be implemented using software, and functionalities of said components may be combined in various ways.

The inventive method can also be implemented in software. Appropriately adapted computer program code may be used for implementing embodiments of the invention described in this specification as well as their various variations. The program code product for providing the operation may be stored on and provided by means of a carrier medium such as a carrier disc, card, or tape. A possibility is to download the program code product via a data network. Implementation of various embodiments may be provided with appropriate software in a server.

A second aspect of the invention provides mechanisms and methods for locating a subscriber directory storing subscription profiles or components of subscription profiles, based on a user identifier. These mechanisms and methods may be used for example in relation with IP based services, where an IPSC (IP Session Control node) node may need to check whether a service requested by a mobile station can be provided, and related subscriber information needs to be obtained from a subscriber directory. These mechanisms and methods may advantageously be used for finding a subscriber directory in cases, where the subscriber is roaming outside his/her home network.

According to an advantageous embodiment of the second aspect of the invention, the IPSC is used to store information linking user groups to corresponding subscriber directory identifying information. The identifying information can be for example the name or address of the subscriber directory.

The IPSC analyses the user identifier which is received when a GGSN/PDG (Gateway GPRS Support Node/Packet Data Gateway) contacts the IPSC, which contacting can happen e.g. during bearer establishment. The IPSC first determines the user group on the basis of the received user identifier, and thereafter obtains the corresponding subscriber directory identifying information.

More than one Subscriber Directory may be configured per user group. This is the case e.g. if a subscription profile consists of components. As an example, the name and/or address of the Subscriber Directory storing subscription info for service authorization may be different than the name and/or address of the Subscriber Directory storing subscription info for rule creation.

According to a further advantageous embodiment of the invention, an address resolver function is provided. In this embodiment, the IPSC may advantageously store information about which address resolver function correspond to which user group.

In this embodiment, the locating of a subscriber directory proceeds as follows. The IPSC first determines the user group information on the basis of a received user identifier, and then the name or address of the address resolver function. Subsequently, the IPSC sends a request to the address resolver function, which replies with the name or address of the subscriber directory having the information particular to the user or the user group, whereafter IPSC may obtain the information from the identified subscriber directory. The request may contain the user identifier or information identifying the user group. The request may also contain information about which type of information is sought from a subscriber directory, as different subscriber directories may provide different types of information, whereby the type of subscriber information sought may affect the choice of subscriber directory. Such different subscriber information types can be for example information on whether a user or a user group is entitled to use a specific access point or access network; whether subscription information related to roaming is needed; or for example if subscription information related to a particular service is needed.

In the following we describe certain advantageous embodiments related to a third aspect of the invention. These embodiments are related to co-operation of an online charging method with an offline charging method.

These embodiments relate to online charging of services provided by third party service providers utilizing bearer services offered by a mobile operator. Scenarios related to these embodiments have three stakeholders: an end-user using a mobile terminal (MT), a mobile operator (MO) and a third party service provider (TPSP).

A TPSP provides services for the end-users. The end-users are subscribers of a MO and use their access network of their operator to contact the service portal of the TSPS. The embodiments are related to an online charging interface between a TSPS and a MO. The TSPS uses the charging interface to charge the end-users via operator billing for the services the end-users are using.

A first of these embodiments of the third aspect of the invention describes how traditional offline charging subscription methods can be supported via an online charging interface.

Although online based charging such as prepaid services is becoming more revalent, much of the charging of subscribers is still based on traditional offline charging methods where the subscription is typically a post-paid or a monthly contract subscription. One main reason for this is that offline charging (e.g. via call detail records, CDRs) generally requires a more detailed set of charging information than that permitted within a purely offline mechanism.

Nevertheless, service providers want to sell their products or services in a way that the end-user is able to use his mobile phone to buy a product or a service. There exists also a need to use the end-user's user account (operator bill) in order to charge the end-user for the product or the service.

While most of the currently known solutions try to solve the situation by debiting the end user's prepaid account, this embodiment describes a solution, wherein end-users having subscriptions that rely on an off-line charging mechanisms, can be charged via an on-line charging interface.

This embodiment has the advantage that it will increase the potential customer base of the service provider and reduce complexity in implementing a charging interface; and also make the services of the mobile network operator more attractive for the service providers. As there exists also a need for the network operator to be able to provide converged online/offline charging solutions, in this way the network operator only needs to implement one charging interface towards the third party service providers.

The core idea for this embodiment is the use of an online charging web service interface for support of offline charging. This embodiment involves a new method being introduced to the online interface whereby the TPSP charging client informs the MO charging server that it will transmit the charging data—which is actually offline charging data—e.g. in a pre-negotiated CDR format. The offline charging can be supported for example via a special request over the same online charging interface that the TPSP is using for charging the subscribers having a subscription with an online charging method.

An example of how service provision can proceed according to the current embodiment is presented in the following.

This example assumes that an end-user is browsing a web portal of the TPSP. The end-user selects a game to download to his mobile phone. As a response to the selection, the system of TPSP providing the web portal services transmits through the charging web service interface of the mobile operator (MO) a request to check if the end user has enough credits for the game download. The MO answers via the service interface that the subscription of the end-user supports only an off-line charging method, and that it can be used for charging. After receiving the answer, the TPSP begins to deliver the service and gather information related to the service. After the service is successfully delivered the TPSP sends the charging information over the charging web service interface in a predetermined format (e.g. as a Charging Data Record, CDR). The MO adds the charges to the phone bill of the end user based on the charging information received from the TPSP.

A second embodiment of the third aspect of the invention describes how the TPSP can resolve the charging method of an end-user that is a subscriber of a MO. Before the TPSP can charge the end-user for a service requested by the end-user, it needs to resolve the end-user's charging method, e.g. if the charging method is an on-line or an off-line method.

The inventors envision that the service provider will in most cases not be able to access the end-user's service profile, as maintained by the operator, in order to discover the subscriber's charging method. The second embodiment of the third aspect of the invention provides a mechanism to check the end-user's charging method, via the charging interface used between the TPSP and the operator.

Such a mechanism can be implemented in an existing query method. For example, a charging interface typically provides a method for checking the balance of the subscriber's account for online charging. The charging server can indicate that a subscriber has an off-line charged account by returning a specific value or a range of values. The TPSP can then check the returned balance information, and determine from that whether off-line charging should be used instead of online charging. Other query methods than checking of balance can also be used for checking and indicating whether offline charging should be used. Examples of other suitable query methods include methods for credit check, credit reservation or credit deduction.

It is also possible to implement a dedicated method within the interface for querying the subscriber's charging method.

This second embodiment of the third aspect of the invention has several advantages. In earlier solutions, the service providers have generally been unable to resolve the end-user's charging method before allowing a service. This has meant that, in most cases, many third party services have not been made available to pre-paying subscribers, as it is often impracticable for a TPSP to directly query a subscriber database of a MO or maintain its own database of the subscriber profiles of the MO.

This embodiment makes it easier for TPSPs to get new customers. The TPSP only needs to be able resolve the MO whose subscriber the end-user is. The TPSP does not need to maintain a database of the end-users charging methods, because a request over a charging interface can be used to determine the charging method.

FIG. 7illustrates signalling flow according to an exemplary embodiment.FIG. 7illustrates signalling between a mobile station710, a service node10, and a request receiver node30. In step720, the mobile station transmits720a request for a service to the service node10. The service node wishes to receive credits for the service and delivery of the service, and sends725a charging request to the request receiver for example via an online charging interface. The request receiver processes the request and determines730the charging methods of the subscriber based on the received information, observing that the only offline charging can be used with this subscriber. In step735, the request receiver node transmits charging method information to the service node. In step740, the service node delivers the requested service. After delivering the service, the service node transmits745the off-line charging data for example using the same online charging interface to the request receiver.

According to a third embodiment of the third aspect of the invention the TPSP can initiate a change to an ongoing charging session as well as to an ongoing service. This could, for example, be used to change the way a related access session is charged.

The TPSP may want to effect a change to the charging of an ongoing service session for various reasons, when some event in the session occurs. For example during a gaming session the end-user may enter a new game level in an online playing session, which may require changing of the charging of the user. For example, the game could give the player free playing time as a bonus. Depending on the service being provided, changing of charging parameters may need to be applied by the charging server not only to the charging session between the TPSP and the MO, but also to a concurrent related charging session towards the access network.

This embodiment can be realized for example via a dedicated request within an ongoing charging session that provides a trigger to modify the session and/or related charging sessions.

FIG. 8illustrates an example of signalling flow between a service node10and request receiver30. In this example, a service delivery is proceeding810with an ongoing charging session. In step820, an event occurs in the service, an event which requires changes in the ongoing charging session. In step830, the service node transmits a charging modification request to the request receiver for example via an online charging interface. In step840, the request receiver modifies the charging attributes and possibly also the service delivery attributes. In step850, the request receiver informs the service node about which modifications in the charging attributes were made. In step860, delivery of the service is continued with the new charging attributes.

In this specification, the term charging attribute refers to information related to control of charging of a subscriber. Examples of charging attributes include information on which services a subscriber is allowed to access, which methods can be used to charge a subscriber, and which network node or nodes are the charging servers for this subscriber.

In this specification, the term node refers to a logical entity, i.e. set of functionalities, which can be implemented in many different ways. For example, each node can be implemented in a separate physical network device. As a further example, a plurality of various nodes can be implemented in a single hardware device.

The invention has several advantages. The invention provides a generic, bearer independent solution for the problems present in the prior art. The invention also offers a generic mechanism able to uniquely define a charging server address, for all servers (including those in the home network of a subscriber), which solves problems currently identified e.g. where GPRS and IMS systems do not share a common mechanism for providing such information.

It is noted that while the preceding description illustrates various embodiments of the invention within a 3G cellular telecommunications system, the invention is not limited to a so called 3G cellular system, but can be implemented in different types of communication systems as well.

It is also noted herein that while the above describes exemplifying embodiments of the invention, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention as defined in the appended claims.