A method for providing on-line charging and a device and a system thereof

[0001] The present invention relates to field communication technology, in particular a method, device and system providing online toll collection.

Background of the invention [0002] Since the publication of the 3rd Generation Partnership Project Release 5 (3GPP R5) document, the backbone network of the Universal Mobile Telecommunications System (UMTS) has been divided into three subsystems including the switched circuit domain (CS), switched packet domain (PS) and the subsystem multimedia IP (IMS). The CS domain is used to provide users with connections to switched circuit services, the PS domain is used to provide users with connections with switched packet services, and IMS is a subsystem superimposed on an existing PS domain in the 3GPP R5 standard. The IMS subsystem uses the PS domain as a transfer channel for the transmission of signaling and multimedia data of a higher layer, introducing a session initiation protocol (SIP) in the form of a service control protocol and provides users with numerous multimedia services, separating service control and transfer control and using the characteristics of the SIP protocol, i.e. simple, extensible and convenient media connection.

[0003] The main functions of the IMS subsystem include: connection session control function (CSCF), configured to perform user registration control, session control, etc., an application server (AS) configured to provide control logic for various services; Central User Database (HSS) configured to centrally manage subscriber data and Media Gateway Control (MGCF) / IMS Media Gateway (IM-MGW) configured to enable interoperability with a switched circuit network. The user can connect to the IMS subsystem through a proxy-CSCF (P-CSCF) controller in the visited network, and then session control, service trigger control and service interaction control with AS are performed by the SCSCF of the home network.

[0004] The architecture of the IMS multimedia subsystem, defined by 3GPP, solves all key operational problems required to provide multimedia services by IP transfer, such as charging roaming charges, quality of service (QoS) and ensuring security, and it has been widely accepted in industry. Both the 3GPP2 standard and the Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN) standard define multimedia IP network architectures and service systems based on the 3GPP model. In addition, 3GPP has begun research into how wireless local area network (WLAN) access works with IMS broadband access

- 2 (FBI) 3GPP (I-WLAN) system and fully Internet networks (AIPN) supporting various access technologies. The user has the option of connecting to the IMS subsystem according to his subscription, through network access of various access technologies through a single multi-mode terminal or through various types of terminals to access permanent multimedia services, including Voice over IP (VoIP) services. The above tests may be related to the service related to both the CS domain and the IMS subsystem.

[0005] In particular, the 3GPP Release 7 standard confirms the research on the issue of continuity service between the CS connection and the VoIP transfer service implemented by the IMS subsystem, when the IMS subsystem can be accessed via WLAN or other networks with IP access, e.g. research on voice continuity (VCC), including research on the method of supporting domain transfer between a CS cell and the VoIP service, implemented by the IMS subsystem so that VCC can be achieved and meet the requirements arising from network and service development. The VCC service is an example of services related to both the CS domain and IMS subsystem.

[0006] In the development of 3GPP VCC, there is a proposal for static anchoring and a method of central IMS control for domain transfer. The basic idea u is based on the fact that in the IMS home domain the user of the VCC service is assigned to the AS, because the connection continuity control function (CCCF) and the control signals of the correlated CS cells and the IMS session of the user of the VCC service are routed to the AS for anchoring. CCCF, controlling the above communication connection between the VCC service user and the corresponding opposite user in the third party connection control mode (3PCC) and completing the domain transfer as requested by the VCC user. In other words, the communication connection between the VCC user and the opposite user is divided into two segments in the AS. When the VCC user decides to transfer the domain, the VCC user initiates the establishment of a connection to the AS in the destination network domain. After establishing a new connection, the AS controls the renegotiation of the connection to the opposite user to cause the opposite user to continue voice communication with the VCC user through the new connection. As shown in Figure 1, CCCF controls the exchange of two connections with a VCC user.

[0007] Figure 2A, Figure 2B and Figure 2C show procedures for signaling and connection transfer setup during the domain transfer procedure from the CS domain to the IMS subsystem and further the procedure for transferring the domain from IMS to the CS domain for the CS caller in the prior art. According to the procedure, you may be presented with problems encountered by the online toll mode (also called real-time toll collection) and the prepaid service that uses the online toll mode when processing the service for both the CS domain and the IMS subsystem simultaneously.

[0008] In particular, Figure 2A illustrates the procedure for setting up signaling and merging connection transfer originating from the CS domain before transferring the VCC service domain from the CS domain to the IMS subsystem. In this procedure, the connection originating from the VCC user CS is routed to CCCF

- 3 home user IMS for anchoring, and the transfer connection including the CS transfer segment and the IP transfer segment, created by the IM-MGW, is established between the VCC user and the opposite user (in Figure 2A it is assumed that the opposite side is in the IMS and the user the opposite is the PSTN network, and the connection from CCCF to the opposite side may continue to pass through MGCF) as follows.

[0009] 1. A user of the VCC service initiates a connection in the CS domino in the VMSC switchboard of the guest mobile system in which the user of the VCC service is currently registered.

[0010] 2. VSMC triggers the intelligent home page service according to the VCC user subscription data and sends a primary detection point (IDP) message towards the function of the GSM service controller (gsmSCF) responsible for controlling the home side routing.

[0011] 3. The gsmSCF controller responsible for controlling the routing on the initial side returns a virtual roaming number pointing to the home IMS of the VCC user, i.e. multimedia routing IP (IMRN), through the Connect message and in accordance with the Connect VMSC message routes the CS connection call to the CCCF assigned to the VCC user through other network elements in the CS domain, MGCF gateway communicating CS / IMS and network elements related to IMS and MGCF implementing CS-IMS communication and transforming the CS connection into an IMS session, and finally establishes a CSIMS communication session (depending on IMRN, other processing may be performed in IMS, but this is not the focus of the present invention; according to the block diagram in Figure 2, the IMRN includes the public service identifier (PSI), pointing to CCCF and network elements associated with the IMS subsystem, including the polling CSCF (ICSCF)).

[0012] 4. CCCF sets up the received connection as the last called element, communicates with HSS to acquire the S-CSCF function assigned to the VCC user (not illustrated), and then according to the information transferred in the received session set-up request, re-initiates another session segment through the S-CSCF to the original opposite user on behalf of the VCC user and interdependently controls the establishment of two session segments on the 3PCC track (also known as user agent symmetrical routing, i.e. B2BUA routing).

[0013] 5. Finally, a CS-IMS communication session is established between the VCC service user and CCCF of the home domain of the IMS user of the VCC service through the CS domain and the CS-IMS communication gateway, and the session from CCCF to the opposite user, and CCCF interdependent controls two session segments to establish a transfer connection including a CS transfer segment and an IP transfer segment created by IMMGW.

[0014] Figure 2A shows only one embodiment of the anchoring of an induced CS connection to CCCF in the user's home IMS. Alternatively, the user can

- 4 directly enter the prefix into the connection number or use a specific number indicating the user's home IMS, because the dialed number in the calling connection and the VMSC control the routing according to the prefix or specific number. Meanwhile, the number or IMRN as described above may directly point to the CCCF as illustrated in Figure 2, or may point to another AS. If the number or IMRN points to another AS, the AS works with HSS to obtain the S-CSCF currently assigned to the user and re-initiates the session to the initial opposite user on behalf of the supported user assigned according to the information transferred in the received session setup request, followed by S- CSCF triggers a session to CCCF according to the initial filter criterion (iFC) in the user's IMS subscription data, etc. The present invention is not focused on these mechanisms and they will not be further described.

[0015] Furthermore, Figure 2A illustrates the procedure for anchoring the caller of the initial CS to the user's CCCF in the prior art. Furthermore, the procedure for anchoring the set-up CS calling connection to the user's CCCF is also proposed in the prior art. As an alternative, the GMSC control panel of the mobile gate system in the home PLMN network of the user called receives a user connection request, communicates with the own subscriber register (HLR) to acquire CAMEL subscription data on the connection setting side, triggers an intelligent service the party setting up the connection in accordance with the data and communicates with gsmSCF responsible for controlling the routing on the side setting up the connection, for IMRN indication for home IMS. The GMSC, CS / IMS MGCF communication gateway and IMS-related network elements route the CS-IMS communication session to the CCCF assigned to the user for anchoring according to the above information. Then by various processing methods known in the art, e.g. by domain selection, connection communication, and CS connection delivery, the connection is delivered to the user's VCC service terminal, followed by a CS-IMS communication session between the VCC user and CCCF in the IMS home domain of the VCC user through the CS domain and CS- communication gateway IMS, and a CS-IMS communication session between CCCF and the opposite user through network elements related to the IMS subsystem, CS-IMS MGCF communication gate and CS domain, and CCCF interdependently controls the two session segments to establish a transfer connection comprising two CS transfer segments and an IP transfer segment respectively divided by IMMGW on both sides. As before, these mechanisms are not focused on the present invention and will not be further described.

[0016] According to Figure 2B, after anchoring the caller's initial CS or uplink to CCCF, the user initiates the domain transfer from the CS to the IMS subsystem according to the following procedure.

[0017] 1. After deciding to perform the domain transfer to the IMS subsystem, if no registration has been performed in the IMS subsystem, the terminal first registers the IMS (which is not illustrated) and then initiates the request to establish the calling session

- IMS to CCCF containing caller session information, wherein the transferred CCCF PSI is used as an indication of domain transfer requesting from the CCCF to perform domain transfer operations for the currently established CS domain connection to the IMS subsystem.

[0018] 2. The S-CSCF assigned to the user routes the session set up request to the CCCF in accordance with the iFC in the user subscription data.

[0019] 3. CCCF performs the SIP session transfer procedure to replace the user's CS access stage with the IMS access stage, it redirects the interaction of the media stream with the UPDATE or re-INVITE message through the session segment with the opposite side, thus the end connection is established -to-end IP transfer between the opposite user and the user of the VCC service.

[0020] 4. After the SIP session transfer has been successfully completed, the signaling connection and the transfer connection corresponding to the CS access step of the VCC user are released.

[0021] According to figure 2C, the procedure for setting up the signaling connection and transfer connection during the next domain transfer back to the CS domain is carried out as follows.

[0022] 1. After deciding that the VCC domain should be transferred back to the CS domain, if no registration has been performed at the VMSC, the terminal first registers at the VMSC (performs CS domain location update, which was not illustrated), and then initiates the CS calling call to CCCF, with the transferred CCCF PSI used as the domain transfer indication requesting from the CCCF to perform the domain transfer operation back to the CS. The CS calling connection is routed to CCCF via MGCF and I-CSCF or S-CSCF.

[0023] 2. CCCF implements a SIP session transfer procedure similar to that described above to replace the user's IMS access step with the CS access step.

[0024] 3. After successful transfer of the SIP session replacing the IMS access stage with the CS access stage, the signaling connection and the transfer connection assigned to the IMS access stage of the VCC user are released.

[0025] It should be noted that the subsequent transfer of the VVC domain from the IMS subsystem to the CS domain has been described as an example of the above descriptions, but in reality the procedure of initial domain transfer from the IMS subsystem to the CS domain is the same as the procedure of the subsequent domain transfer back to the CS domain and in other words, the domain transfer history must be mastered to control CCCF.

[0026] In addition, as with the CS calling call setup procedure of Figure 2A, various alternatives are possible for the VCC terminal to assemble new CS access steps between the VCC terminal and CCCF including: terminal directly initiating connection with a specific number, IMRN, which indicates the user's home IMS and is indicated as a domain transfer request or terminal initiating connection with a specific number indicated as a domain transfer request

- 6 VMSC in which the terminal is located triggers the intelligent service on the initial side according to the user's subscription data and communicates with the gsmSCF responsible on the initial side for the routing control to obtain an IMRN pointing to the home IMS; where the VMSC exchange, other network elements in the CS domain, CS / IMS MGCF communication gateway and network elements related to the IMS subsystem route the CS-IMS communication session to the CCCF assigned to the user in accordance with the above information. Figure 2C shows only one of the simplest and most efficient methods. As before, the present invention does not focus on these mechanisms and they will not be further described.

[0027] In such an embodiment of the voice connection continuity, it may seem that a significant improvement can be made in charging for the connection according to the connection: for the calling CS with the VCC user as the calling user or the called user, since it must be routed to the user's home IMS, the voice call will be set up by both the CS domain and the IMS subsystem before the domain transfer, which results in repeated charging of fees including period of time; and for communication with the opposite user, during the domain transfer procedure, the user will initiate a voice connection setup with CCCF either in the IMS subsystem or in the IMS subsystem and in the CS domain, which will cause difficulties in forming a complete record of fees. In addition, according to the current charging criterion, charging for several connections in a short period of time is usually different than charging for one connection for a long period of time, even if the total connection time is the same. As a consequence, even without considering recurring charging during domain transfers, it is difficult to separate charging in the CS domain and IMS subsystem in this way to guarantee the completeness and accuracy of charging. In addition, since differences can usually occur when establishing a voice call in different network domains and depending on whether the user is making or receiving a call, a more flexible charging criterion for such a scenario in which two network domains are used dynamically and flexibly to set up and maintain a voice connection. In addition, in a voice continuity service solution, regardless of whether the VCC user has previously made or received the call to set up the initial connection with the opposite user, the voice connection between the VCC user and the CCCF newly established during the domain transfer is always set up by the user initial VCC services. For this reason, to guarantee the completeness and accuracy of the fees charged, you must first confirm the correct direction of connection, and the collection of fees will be carried out in accordance with the correct direction of connection. Of course, based on the above, during such processing of the service, which simultaneously applies to the CS domain and the IMS subsystem to implement the correct collection of fees, the entire procedure of charging can be very complicated. In particular, if the separation of CS and IMS charging is still applicable, the key need for complete and accurate charging is that the correlation of charging in the domain

- 7 CS and IMS were guaranteed and, in addition, assigned processing should be guaranteed in accordance with the information on two correlated parts.

[0028] In addition, there are real-time charging modes or online charging modes, and services that use this mode include the commonly used prepay service. The main feature of the prepayment service is that there is no long-term credit relationship between the user and the network. The user prepays certain fees, and the network performs online credit control during the service. In other words, the required fees are deducted in real time, and when the prepayment is depleted, the service will be terminated.

[0029] In the current CS domain, the prepayment service is usually based on the CAMEL (Customized Application of Mobile Network Enhanced Logic) architecture, whose main procedure is as follows: when the user initiates or sets up a CS connection as gsmSCF, the VMSC control panel in which the user is currently located (in case the user initiates the connection) or the GMSC control panel (in case the user sets up the connection) triggers the intelligent service in accordance with the user's CAMEL subscription data and then the VMSC exchange or GMSC exchange sets up the control connection with gsmSCF, which provides the logic of controlling the prepaid service. In contrast, gsmSSF provides connection-related information, monitors the connection setup procedure and connection continuity in accordance with the gsmSCF instruction and the duration of the connection granted, as well as informs about the BSCM (Basic Call Status Model) event assigned and reports of charging fees used during connection establishment and connection continuity. gsmSCF performs real-time deduction of units based on the information provided and decides whether to allow the user to continue the call based on the remaining unit so as to perform CS domain credit control. According to the specific implementations described above, before the VSMC or GMSC exchanges the routing to the user's home IMS CCCF, the prepayment service based on the CAMEL architecture is called according to the user's subscription data and the assigned gsmSCF performs real-time deduction of units during the call and based on the other units decide whether to enable the connection or instruct the controller, for this to release the connection so as to perform CS domain credit control.

[0030] In IMS, because both the service and the charging criterion are more complicated, the online charging system (OCS) shown in figure 3 is introduced, which takes into account significantly different aspects related to the transfer, session, event, etc. The prepayment service in IMS can also be implemented in architecture, as shown in Figure 3. OCS in IMS includes the function of charging fees for transferring (BCF), the function of collecting fees for event (ECF), the function of charging fees for session (SCF), the indicator function (RF) and the function of managing the business account (ABMF). In accordance with the above functions, it is possible to provide the following three charging modes:

[0031] Immediate event-based charging (IEC): upon receipt of the assigned request, the OSC assigns units to the IMS network element in a single operation, which also includes deducting the assigned monetary units from the user account.

[0032] Fee-based event collection (ECUR): Fee-based event collection involves the process of requesting, reserving, disconnecting, and returning unused units for an event. The deduction of assigned monetary units takes place after the end of the ECUR transaction.

[0033] Collection of fees based on sessions with unit reservation (SCUR): Collection of fees based on sessions with unit reservation is configured to control credit during the session, which includes the process of requesting, reserving, disconnecting and returning unused monetary units for the session and deducting the assigned units currency. During SIP sessions unit booking and debit operations can be repeated.

[0034] An IMS network element may choose to use the various modes described above based on the service or the operator's regulations. In the VCC service, since the charging applies to voice communication, the SCUR mode is used. During the processing of the session associated with the assigned user, information about the user is passed to the OSC by requesting credit control for initialization, update and connection setup, respectively, which can be achieved due to AS or S-SCCF interaction in the IMS network with OCS.

[0035] As described above, when the VCC service is provided by static anchoring and a centralized IMS solution of domain transfer control, when the VCC user calls or sets up the initial CS connection, because the connection must be routed to the IMS home network user for CCCF anchoring, the connection can be established by both CS domain and IMS before domain transfer, while for communication with the opposite user, the user can initiate connection setup with CCCF alternatively in IMS and IMS and CS domain during the domain transfer procedure. Therefore, the simultaneous or separate use of the above method of providing a CS domain prepayment service and the method of providing an online toll collection service in the state of the art in IMS will result in either recurring charging or incomplete charging. Meanwhile, because there are differences in charging depending on whether the user is making or receiving a call, the newly set up voice call is always set up by the user of the VCC service in the initial mode, and consequently because there is a difference between charging for one long-lasting call or a set of short connections with the same total time, the assigned fee may not be correctly collected by the simple separate or simultaneous use of existing technologies to provide the CS domain prepayment service and / or the IMS online toll service, which require accurate real-time determination of the amount of fees. In addition, although it is possible to apply existing CS / IMS mechanisms separately and guarantee the completeness and correctness of the fees charged by making sure that

- 9 correlation of fees charged in CS / IMS parts and execution of assigned charging processes in accordance with information about two correlated parts, such a system of correlated charging in IMS and CS domain will be very difficult to achieve in real time with very high requirements. In addition, it is difficult to prevent the request to update the VMSC or GMSC in an existing network due to the requested correlation information and corresponding events for gsmSCF, so that the provision of the roaming user service may be disrupted or all MSCs in the existing network must be updated so to support the roaming user, resulting in extremely high workloads, and therefore no implementation in practice.

[0036] Although the above descriptions relate to a specific service simultaneously involving the CS domain and the IMS subsystem, in other words to the VCC service, it can easily be understood that in other services simultaneously involving the CS domain and the IMS subsystem, because two network domains are simultaneously involved in providing the service to the user, similar problems may arise with the separate or cumulative use of existing technologies for providing the CS domain prepayment service and / or the IMS online toll service that require accurate real-time toll determination. Services that simultaneously apply to the CS domain and the IMS subsystem include the integrated CS and IMS transfer service and the central control service for the use of IMS to provide centralized service control for providing user access to the network through the CS domain and / or IMS.

Document "Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); Telecommunication management; Charging management; Charging principles (3GPP TS 32.200 version 5.9.0 Release 5); ETSI TS 132 200 "ETSI STANDARDS, LIS, SOPHIA ANTIPOLIS CEDEX, FRANCE, volume 3-SA5, No. V5.9.0, September 1, 2005 (2005-09-01), XP014032791 ISSN: 0000-0001" discloses management related technical information telecommunications connections, toll management and toll rules.

Document "MILADINOVIC I ET AL:" Intelligent network services in the time of network migration "TELECOMMUNICATIONS NETWORK STRATEGY AND PLANNING SYMPOSIUM. NETWORKS 2 004, 11TH INTERNATIONAL VIENNA, AUSTRIA JUNE 13-16, 2004, PISCATAWAY, NJ, USA, IEEE, June 13, 2004 (2004-06-13), pages 33-38, XP010732348 ISBN: 978-3-8007-2840 -4 "reveals information about intelligent network services during network migration.

Document "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Voice Call Continuity between CS and IMS Study (Release 7) "INTERNET CITATION, July 2005 (2005-07), XP002486356" discloses information about the application server and connection continuity control function to control the service for both the CS domain and the IMS subsystem.

Summary of the Invention [0037] The present invention provides a method, apparatus and system for performing online tolling to solve the problem when existing online tolling solutions can

- 10 do not correctly process the relevant fee when providing the service for both the CS domain and the IMS subsystem, and also to avoid the need for correlation of online CS / IMS toll collection in order to solve the problem of incorrect roaming support or incorrect implementation in practice due to the enormity work caused by the correlation of charging CS / IMS fees.

[0038] The present invention provides the following solutions.

[0039] A method of performing online toll collection, comprising:

[0040] in the CS domain, no online tolling for the user who subscribes to the service of both the CS domain and IMS simultaneously and requires online tolling when the user calls or sets up the connection in the CS domain and when the connection, called or set up by the user in the CS domain, is processed in IMS, where at least one of the service indication concerning the CS domain and IMS simultaneously towards the current connection and domain of the network in which the user is currently involved in communication, is placed in the credit control request provided by the network element in IMS that implements credit control in the online toll system (OCS) in IMS.

[0042] In the method [0043] the non-invocation of online charging for a user in the CS domain is accomplished by canceling the user's subscription CAMEL data for carrying out the online charging in the CS domain or by modifying the service data by the intelligent service platform.

[0044] Modifying service data by a smart service platform that includes: modifying data or settings associated with the service logic determination unit in the GSM service control function, gsmSCF, and / or service data point, SDP; and when the user's connection to gsmSCF is triggered, if gsmSCF determines in accordance with the post-connection information that the service applies to both the CS domain and IMS, it is to implement non-invoking online charging logic for the user service in the CS domain.

[0045] The network element in IMS that performs credit control is an AS application server that controls the service of both the CS domain and the IMS domain simultaneously.

The method further includes performing credit control by interaction of the AS with a prepay system in the CS domain. The method further includes that: when the user subscribes to the online toll collection service simultaneously in the CS and IMS domain CS and IMS, execution by the AS controlling the service involving the CS and IMS domain simultaneously, controlling the CS and IMS domain credit by interacting with OCS in IMS directly via the standard Ro interface and interaction with the prepayment system in the CS domain by OCS in IMS according to the user's subscription data or execution, by AS controlling the service for both the CS domain and IMS, credit control in the CS and IMS domain by interacting with OCS in IMS directly

- 11 through the standard Ro interface and interaction with the prepay system in the CS domain via the CAP interface according to the user subscription data.

[0047] The network element in the IMS that performs credit control is the S-CSCF unit assigned to the user.

[0048] When the user subscribes to the online toll collection service simultaneously in the CS domain and IMS CS and IMS, the user's credit control is performed in the CS and IMS domain respectively by the S-CSCF unit assigned to the user by interacting with OCS in IMS and interacting with the prepayment system in the CS domain by OCS in IMS or control of the user's credit is performed in the CS and IMS domain by the unit

S-CSCF assigned to the user by interacting with OCS in IMS and interacting with the prepay system in the CS domain according to the user's subscription data.

The method further includes performing credit control by interacting with the S-CSCF with the CS domain prepay system.

[0049] In this method, [0050] triggering by the S-CSCF entity of interaction with the OCS in the IMS to implement credit control includes:

[0051] forwarding, by S-CSCF, a user correlated service request to the IMS gateway function according to the user subscription data and [0052] performing, by the IMS gateway function, credit control by interacting with the OCS in the IMS via a standard Ro interface.

[0053] Interaction with a prepay based fee collection system in the CS domain for implementing credit control includes:

[0054] forwarding, by S-CSCF, a user-correlated service request to IMSSF in accordance with the user subscription data and [0055] performing, by IM-SSF, credit control by interacting with the prepay system in the CS domain via a CAP interface.

[0056] If subscribers of services with fees charged online simultaneously operate in the CS and IMS domain, credit control includes: when the user is currently involved in communication in the CS domain, execution, by the prepay system in the CS domain, credit control in the CS domain for a given user or when the user is currently involved in communication in IMS, execution, by OCS in IMS, credit control in IMS for a given user or performing credit control for a user who is simultaneously in IMS and the CS domain in a certain proportion by OCS in IMS and the prepay system in the CS domain respectively.

[0057] The credit control comprises the implementation, by the network element in the IMS domain performing the credit control, of the assigned control for current user communication after detecting that the user entity in the CS domain and / or the IMS domain has been exhausted, which includes: compilation, by the network element in IMS implementing

- 12 credit control, ongoing user communication; instructing - when the user's unit is exhausted in one of the CS and IMS domains, while in another unit is not exhausted - the user to switch the network domain for communication to the one with the remaining unit and forbidding - when the user's unit remains in the network domain, in whose user is currently involved in communication while it expires in the second domain - moving the user's current communication to the network domain with the exhausted unit.

[0058] The service involving both the CS domain and the IMS is a VCC service; and the method includes: not triggering online charging for a user in a CS domain when the initial CS connection or user-established connection is routed to the assigned CCCF for anchoring and performing credit control for the user in the IMS after anchoring the user's conversation in the CCCF.

[0059] The credit control device comprises:

[0060] a triggering module configured to trigger interactions for online credit control in the IP multimedia subsystem (IMS) for a connection called or set up in the CS domain by a user subscribed to the service simultaneously involving the CS domain and IMS when the user connection is processed in IMS and [0061 ] the first credit control module configured to interact with OCS in IMS to implement credit control after triggering interaction for online credit control, wherein at least one of the service indication simultaneously in the CS and IMS domain, the direction of the current connection and the network domain in which the user is currently involved in communication is included in the credit control request provided by the first credit control module.

[0062] The credit control device further comprises:

[0063] a selection module configured to select the implementation of credit control in the IMS or CS domain after triggering interaction for online credit control and [0064] a second credit control module configured to interact with the prepay system in the CS domain for implementing credit control after triggering interaction control online loan.

[0065] The communication system includes:

[0066] A CS domain control device configured to not trigger online charging in the CS domain when a user who subscribes to both the CS domain and IMS and the online charging service simultaneously calls or sets up the connection in the CS domain;

[0067] IMS control device configured to trigger interaction for online credit control in IMS to perform credit control when a call made or set up by a user in the CS domain is processed in the user's home IMS and sending a credit control request to the online charging system (OCS) ) in IMS, which request contains at least one of the service indication

- 13 concerning both the CS and IMS domain, the direction of the current connection and the domain of the network in which the user is currently involved in communication;

[0068] The OCS in the IMS configured to perform the credit control for the user in accordance with the credit control request, sent from the IMS control device.

[0069] In the case of centralized credit control implemented in IMS, the present invention provides a method for performing accurate and complete real-time charging / online charging while providing a service involving a CS and IMS domain simultaneously. In addition, the present invention further refines the existing static anchoring and IMS centralized control solution for domain transfer in the VCC service. Thanks to the present invention, it is possible to provide a prepayment service that uses the real-time / online charging mode and has been widely used in a complicated control scenario and thus avoids the problem that when downloading CS / IMS online charges, a correlation is needed to correct the corresponding charge , what causes, that the solution was not suitable for roaming support or could not be implemented in practice due to the enormous amount of work involved. In addition, inventive solutions increase the ability to control the online charging service in the sense that CS / IMS belong to different networks and there are differences in the tariff for different network domains, so it is further improved the integrated application in CS, WLAN and IMS networks, and meeting differentiated operational needs.

Brief Description of the Drawings [0070] Figure 1 is a diagram showing that the VCC user domain transfer is performed by the user's home IMS control (CCCF) according to the prior art;

[0071] Figure 2A is a flowchart of a procedure for setting up a signaling connection and a transfer connection in an initial CS connection before performing a transfer of the VCC domain from the CS domain to IMS according to the prior art;

[0072] Figure 2B is a block diagram showing that a user initiates the transfer of a VCC domain from a CS domain to IMS according to the prior art;

[0073] Figure 2C shows a flowchart of a procedure for setting up a signaling connection and a transfer connection in a subsequent domain transfer from IMS back to the CS domain according to the prior art;

[0074] Figure 3 is an OCS diagram in IMS according to the prior art;

[0075] Figure 4 is a block diagram of the implementation of online CS / IMS credit control in IMS during all voice communication, where the initial CS connection is anchored to the IMS, the online toll charging interaction is triggered in the IMS and the user is transferred to IMS in an embodiment of the present invention;

[0076] Figure 5A is a diagram of the real-time interaction between an entity that triggers the online charging interaction in IMS and the prepay system in the CS domain by OCS in IMS in the embodiment of the present invention;

[0077] Figure 5B is a user-assigned CCCF scheme that is configured to trigger online user charging collection interaction in OCS in IMS and prepay system in CS domain respectively in the embodiment of the present invention;

[0078] Figure 5C illustrates a S-CSCF interaction scheme, assigned to a user, which is configured to trigger online user charging interactions in OCS in IMS and a prepay system in a CS domain respectively in the embodiment of the present invention and [0079] Figure 6 shows a diagram CCCF units according to an embodiment of the invention.

Detailed Description of the Embodiments [0080] To describe the inventive methods and systems in a more transparent manner, the inventive solutions will be described in detail in the example that credit control for online charging (also called real-time charging) in the CS and / or IMS domain is implemented during the implementation of a specific service involving both the CS and IMS domain, e.g. the VCC service. However, the use of inventive solutions can not only be limited to the VCC service and the inventive principles and methods can also be used to control credit for online charging services in the CS and / or IMS domain in the case of the implementation of other services simultaneously involving the CS domain and IMS. In an embodiment of the present invention, the collection of online fees can also be described by means of an example of a CS and IMS prepay service.

[0081] Given the problem that simultaneous or separate applications of methods for providing online toll collection services in the CS and IMS domains may not perform correct toll collection when the VCC service is provided by static anchoring and a centralized IMS control method for domain transfer, and the problem that the correlation of CS / IMS charging in real time necessary for the correct processing of the relevant fee may be a solution unable to support roaming or a solution that cannot be implemented in practice due to the enormous amount of work involved. According to the present invention, during the routing procedure of the initial CS domain of a connection called or set up by a user who subscribes to the VCC service and online toll collection service, to the CCCF for anchoring unit, the online toll collection service (e.g. prepayment service) is not called in the CS domain; and after anchoring the caller of the user who subscribes to the VVC service to the user CCCF, the interaction for online charging is triggered in IMS for centralized credit control for the user subscribed to the VCC service.

[0082] In order not to invoke the online charging / prepay service in the CS domain for a call called or set up by the user in the CS domain, the following method may be used.

[0083] (1) The online charging service / prepayment service in the CS domain for a call made or set up by the user in the CS domain cannot be called by deleting the CAMEL subscription data including the subscription data

- 15 CAMEL on the calling party and / or CAMEL subscription data on the party setting up the connection for the user, which is used to trigger interactions for the online toll service / prepayment service in CS by the user who subscribes to the VCC service and the online toll service / prepayment service (thus after the user cancels the VCC service, you still need to restore your CAMEL subscription data to trigger interactions for the online toll / prepay service.)

[0084] (2) The online charging service / prepayment service in the CS domain for a call called or set up by the user in the CS domain cannot be called by modifying the service data of the smart service platform, and in other words, by deleting data related to the calling service logic online toll collection / CS prepayment service, which the user subscribes to on his assigned gsmSCF and / or SDP. Hence, even if the assigned gsmSCF is triggered due to a user subscription with another smart service, the control of the online charging / prepayment service will not be called and implemented.

[0085] Also, alternatively, if the call logic of the control of the online toll service / prepayment service is avoided by modifying the data of the smart service platform service, it is possible not to call the online toll service / prepayment service in the CS domain by modifying the data or settings related to the service logic called for the prepayment service CS, which the user subscribes to on the assigned gsmSCF and / or SDP. Hence, according to the information related to the connection, gsmSCF may conclude whether to anchor the VCC-related connection and then conclude whether to call the original logic of controlling the online charging / prepay service in the processing of the current service. Connection-related information includes, but is not limited to: transfer performance and / or current user connection and / or called number, etc.

[0086] The method of triggering interactions for online charging in IMS to enable centralized credit control includes the following components.

[0087] (1) Inducing interactions for online charging in IMS can be implemented by triggering OCS in IMS by a user-assigned CCCF.

[0088] According to the user subscription data, the CCCF entity calls the online credit control for OCS in the IMS directly via the standard Ro interface.

[0089] (2) Triggering interactions for online charging in IMS can also be implemented by triggering OCS in IMS via the IMS gateway function by the user assigned SCSCF. In particular, the S-CSCF forwards the user-related service request to the IMS gateway function according to the user subscription data, and the IMS gateway function triggers interaction with OCS in the IMS directly via the standard Ro interface for OCS.

[0090] In the credit control request provided by the CCCF or unit

S-CSCF to OSC in IMS, the following information may be included next to the information originally required by the IMS online toll service: indication of the VCC service

- and / or the direction of the current connection (i.e., whether the processed connection is being called by a served user or is being called by a second user and delivered to a served user) and / or the domain of the network in which the user is currently involved in communication.

[0091] The CCCF entity or S-CSCF entity may determine information about the domain of the network in which the user is currently involved in communication based on the content of the p-access-network-Info header field in the session setup message or based on the next routing direction , specified by the network domain selection (NeDS) function.

[0092] The CCCF entity or S-CSCF entity may determine the direction information of the current connection according to the information of the calling user and the user selected in the connection setup message.

[0093] In addition, after a domain transfer occurs during user communication subscribed to the VCC service, OCS in IMS is instructed to perform a credit control update, for example to enter a revised tariff to correctly charge fees, which can be described as follows.

[0094] When a user requests a domain transfer in a VCC service, the network element that triggers the interaction for collecting online fees in IMS informs about the request to perform a credit control update to OCS in IMS. In addition to the information originally requested by the IMS online charging service, the request includes: a domain of the network in which the user is involved in pre-domain communication and / or a domain of the network in which the user will be involved in communication after the domain transfer. In particular, the network element in IMS that triggers the interaction for charging online fees can be a user-assigned CCCF unit or a user-assigned S-CSCF unit; and an element of the network in IMS that triggers interaction for charging online fees can, based on the local record, determine the domain of the network in which the user was involved in communication before the domain transfer and specify the domain of the network in which the user will be involved in communication after the domain transfer based on contents of the p-access-network-Info header field of the domain transfer request message.

[0095] As described above for correct charging, the network element in IMS that triggers the interaction for online charging, adds information related to the VCC service to the delivered message, and OCS in IMS can integrate information originally required by the online charging service in IMS and related information added to calculate the fee due. Information related to VCC includes, but is not limited to, the indication of the VCC service and / or the direction of the current connection and / or the domain of the network in which the user was involved in communication before the transfer of the domain and / or the domain of the network in which the user will be involved in communication after domain transfer.

[0096] When a user subscribes to an online toll collection service at the same time in a domain

CS and IMS, there may be different accounting systems in the CS and IMS domain to store different user prepaid data in the CS and IMS domain. For example, when the CS domain and IMS belong to different operators, for centralized implementation

- 17 IMS credit control, a network element in IMS that triggers interaction for charging online fees, can implement indirect real-time interaction with the CS domain prepayment system by OCS in IMS to implement simultaneous CS and IMS domain credit control. Alternatively, the network element in IMS that triggers the interaction for charging online fees can communicate with OCS in IMS and the prepay system in the CS domain, respectively, to realize simultaneous credit control in the CS and IMS domain. Regardless of which method is used to implement online credit control in the CS and / or IMS domain, the methods of implementing credit control may include the following.

[0097] (1) A suitable network domain may be determined to perform credit control according to which network domain the user is currently involved in communication. In other words, if the user is currently involved in communication in the CS domain, credit control in the CS domain, including deduction of units in real time and monitoring, is carried out by interacting with the prepayment system in the CS domain, and if the user is currently involved in communication in IMS, IMS credit control, including real-time deduction of units and monitoring, is done by interacting with OCS in IMS.

[0098] (2) Regardless of which network domain the user is currently involved in communication, credit control in the CS I IMS domain, including real-time deduction of units and monitoring, is carried out simultaneously by the proportion in interaction with OCS respectively IMS and prepayment system in the CS domain.

[0099] When the user subscribes to the online charging service only in the CS or IMS domain, the interaction for online charging in IMS is still triggered to implement online credit control. At this point, by OCS in IMS and / or a prepay system in the CS domain, with respect to the user's subscription or indication of a network element triggering interaction for charging online fees in IMS, credit control, including real-time deduction of units and monitoring, is not implemented for domain in which the user does not subscribe to the online toll service.

[0100] When the prepay system in the CS and / or OCS domain in IMS and / or the network element triggering the interaction for online charging in IMS detects that the user has exhausted the overpaid unit in the CS and / or IMS domain, the network element triggering the interaction ê for charging online fees in IMS may specify to provide other control for ongoing user communication in accordance with a service strategy, including:

[0101] (1) Where different accounting systems exist in the CS and IMS domain, the appropriate network domain is selected for performing credit control based on which network domain the user is currently involved in communication.

[0102] A) If the entity in the CS domain has been exhausted and the user is currently involved in communication in the CS domain, or the entity in IMS has been exhausted and the user is currently involved in communication in IMS, a network element triggering interaction for charging online fees in IMS disconnects current user communication or

- 18 instructs the user to transfer the domain to another domain with the remaining unit to continue ongoing communication.

[0103] The interaction triggering network element for charging online in IMS may instruct the user to perform a domain transfer to another domain with the remaining entity or to continue ongoing communication by USSD message in CS domain or SIP notification or INFO message in IMS, respectively, depending on in which domain of the network the user is currently involved in communication.

[0104] B) If the entity in the domain has been exhausted and the user is currently involved in communication in IMS or the entity in IMS has been exhausted and the user is currently involved in communication in the CS domain, the network element that triggers the interaction for charging online fees in IMS prohibits ongoing communication transfer user to the domain of the network in which the unit was exhausted.

[0105] The interaction triggering network element for charging online in IMS may reject a request to set up a new user session for a domain transfer request with a specific reason value by the CCCF or inform the user of the reason for prohibiting domain transfer by USSD in the CS domain or SIP notification or INFO message in IMS.

[0106] (2) Where the same accounting system is used in the CS and IMS domain, or there is no need to distinguish in which domain the user is currently involved in communication, and the credit control in the CS and IMS domain is performed in proportion to the domain in which the user is currently involved in communication, the network element that triggers the interaction for charging online fees in IMS disconnects the user's current communications after that, how the user unit in CS and / or IMS will be exhausted.

[0107] Because no online charging / prepayment service is called in the CS domain, a detailed connection record (CDR) will be generated in the CS domain after the CS connection is established based on the state of the art. To avoid error when charging, when controlling the routing for routing a CS connection called or set up by the user with the assigned CCCF unit for anchoring, it is possible to use a specific identifier in the generated CDR in the CS domain. This identifier may be a specific CCCF unit number; alternatively, the identifier may be a specific prefix before the connection number, which is inserted by the GSM service switching function (gsmSSF) in the form of a gsmSCF instruction implemented by an existing CAP CONNECT operation or a free of charge information format sent by gsmSCF to gsmSCF by an existing CAP FCI operation (information about the delivery fee); and the CS domain fee processing device performs free of charge processing on the CDR generated in the CS based on the specific identifier.

[0108] Detailed descriptions will be provided with reference to specific embodiments and in combination with the drawings.

[0109] Embodiment 1 [0110] For example, a user calls a connection in a CS domain and then requests a domain transfer to IMS after anchoring the connection to CCCF, and the CCCF triggers the interaction for charging online fees in IMS, which specific implementation is depicted in Figure 4 (in which steps 1 to 5 refer to the "CS call connection being called" section, steps 6 to 8 refer to the "domain transfer" section, step 9 refers to the "disconnect session" portion and step 10 refers to the "unit exhausted" portion in Figure 4).

[0111] As mentioned above, it should be noted that the prior art provides various solutions with different details for implementing the called CS connection and domain transfer between the CS and IMS domain, but these solutions are not related to the implementation of the inventive solution. Hence, in the current embodiment, as an example, only the anchoring scheme of the induced CS connection to CCCF and the domain transfer from CS to IMS shown in Figure 2 are taken into account, and other implementation procedures in accordance with the state of the art that are not related to the implementation of inventive solutions will not be repeated . However, inventive solutions also apply to other implementation procedures.

[0112] 1. A VCC user calls a VMSC exchange in the CS domain in which the user is registered.

[0113] 2. The VMSC triggers the intelligent service on the calling side in accordance with the user subscription data and sends the initial detection point (IDP) message to the gsmSCF responsible for controlling the routing on the calling side. At this time, since the calling user's anchoring to CCCF is implemented by gsmSCF responsible for controlling the routing on the calling party, it is possible to modify the data or set the intelligent service platform related to the determination of the service logic to avoid calling the online charging / prepayment service in CS domain so that even when the assigned gsmSCF is triggered due to enrollment of the user to the VCC service, the logic of controlling the online toll service / prepayment service will not be called. In addition, gsmSCF may determine the need to provide the VCC service according to the connection information and thus specify that the logic of controlling the online toll / prepay service that the user subscribes to in the CS domain will not be called.

[0114] If the caller's anchoring to CCCF in the VCC service is implemented by means of a solution other than CAMEL and the user does not subscribe to any other intelligent service, it is possible to cancel the assigned CAMEL subscription data of the user in the CS domain before making the connection, in other words avoid direct triggering CAMEL service to avoid calling the online toll service / prepayment service provided as a CAMEL service in the CS domain.

[0115] 3. gsmSCF responsible for controlling routing on the calling side returns a virtual roaming number, i.e. IP multimedia routing number (IMRN),

Pointing to the CCCF of the user's home IMS via a CONNECT message, and on this basis the VMSC routes the CS-IMS communication session to the CCCF unit assigned to the user through other network elements in the CS domain, through the CS / IMS MGCF communication gateway and IMS related network elements (interrogation connection session controller (ICSCF) function as shown in the figure).

[0116] 4. The CCCF unit triggers the interaction to control the online charging in IMS according to the user subscription data, e.g. the online charging service subscription, and sends the initial CCR to the OCS in the IMS. In addition to the information originally required by the IMS online charging service, the initial CCR may also include: an indication of the VCC service and / or the direction of the current connection (i.e. whether the processed connection is being called by a supported user or is being called by a second user and delivered to a supported user) and / or the domain of the network in which the user is currently involved in communication.

[0117] 5. The OCS in the IMS performs payment control according to the information provided and returns a credit control response (CCA) containing the allocated unit for use or service information, and on this basis the CCCF unit initiates credit control. Then the CCCF unit as the last called element sets up the received session, communicates with HSS to obtain functions - CSCF assigned to the user, and then, according to the information contained in the received session set up request, re-initiates the next segment of the session to the original opposite user on behalf of the service user VCC via S-CSCF and as a result controls the set of two session segments in the 3PCC method. Finally, a CS-IMS communication session is established between the VCC user and the CCCF entity of the home domain of the IMS user of the VCC service through the CS domain and the CSIMS MGCF communication gateway, and a session from the CCCF entity to the opposite user, and as a result, the CCCF unit controls two session segments to set up the transfer connection including the CS transfer segment and the IP transfer segment separated by the IM-MGW (until now the first stage of anchoring the calling call CS has been completed).

[0118] 6. When the user completes the IMS registration and decides to perform the domain transfer to the IMS, the user initiates a request to set up an IMS calling session to CCCF with information about the initial session and the public service identifier (PSI) of the CCCF entity contained therein in the form of a transfer indication domains that require the CCCF to transfer the domain from the CS domain to IMS for the currently established CS domain connection. The CSCF-enabled (S-CSCF) assigned to the user via the network routes the session setup request to the CCCF based on the initial filtering (iFC) criterion in the user subscription data.

[0119] 7. The CCCF entity performing the credit monitoring sends the CCR update to

OCS in IMS for the implementation of credit control updates. In addition to the information originally required by the IMS online charging service, the CCR update may also include: the domain of the network in which the user was involved in communication before

- 21 domain transfer and / or domain of the network in which the user will be involved in communication after the domain transfer.

[0120] 8. The OSC in the IMS performs the credit control update based on the information provided and returns the CCA with the assigned entity or service information and, on this basis, the CCCF unit performs the updated credit control. Then the CCCF performs the SIP session transfer procedure to replace the CS access stage of the VCC user with the IMS access stage and redirects media stream interaction by means of an UPDATE or re-INVITE message through the session segment with the opposite side. After successful SIP session transfer, the signaling connection and transfer connection corresponding to the CS access stage of the VCC user are released (until now the second domain transfer stage will be completed and subsequent domain transfer procedures will be similar to that described and will not be repeated).

[0121] 9. When the user decides to terminate the current communication (for example, a supported user subscribing to the VCC service initiates disconnection of the connection), the user sends a session release request to the CCCF unit, and the SCSCF unit assigned to the user via the network routes the session release request to the CCCF unit . The credit monitoring CCCF unit communicates with users on both sides to complete the release of two session segments, interrupts credit monitoring and sends CCR terminations to OCS in IMS. Based on the information provided, OCS in IMS interrupts charging control and returns CCA to terminate the online charging procedure. In this document, for the convenience of processing unusual situations in communication with OCS in IMF, the CCCF unit may also terminate local credit monitoring after receiving CCA from OCS in IMS (by now the third stage of disconnection of the session will be completed).

[0122] 10. If the CCCF unit that performs credit monitoring detects the exhausted user unit before the user releases the session itself (if only the monetary unit assigned to use is exhausted, the CCCF unit will simply report the need for a new grant by sending the CCR update, and here, for example, the user unit has been completely exhausted), it is the CCCF that will initiate the release message itself and will communicate with users on both sides to complete the release of the two session segments, then complete the credit monitoring and send the termination CCR to OCS in IMS. Based on the information provided, OCS in IMS interrupts charging control and returns CCA to terminate the online charging procedure. Similarly, for the convenience of processing unusual situations in communication with OCS in IMF, the CCCF unit may also terminate local credit monitoring after receiving CCA from OCS in IMS (until now processing of the exhausted unit will be completed).

[0123] For the first embodiment, descriptions are provided for analyzing the case in which, as an example, a VCC user calls a domain connection

CS. If the user sets up a connection in a CS domain, how to avoid calling

- 22 prepay services in the CS domain and the centralized IMS credit control procedure are virtually identical except for the anchoring procedure.

[0124] If the initial connection is a call made or set up by the user in UMS, the control procedure in the CS domain routing to the home IMS is absent compared to the above scheme. Hence, there will be no problem avoiding calling the online charging / prepay service in the CS domain during initial connection setup (however, the same problem may still arise if the connection setup request is initiated by the user while the connection setup request points to the CCCF and requests execution domain transfer from IMS to the CS domain, and the problem can also be solved as above). In addition, the centralized credit control in the IMS is identical to the first embodiment.

[0125] In the first embodiment, the CCCF unit triggers interactions for centralized credit control and based on existing online charging technologies in IMS, the user-assigned S-CSCF unit can also trigger for centralized credit control via the IMS gateway function, although the CCCF unit, as a VCC service control point, it can learn more relevant information.

[0126] In addition, to focus on the credit control procedure in the VCC service, the descriptions in the current implementation are devoted to the credit control interaction between the network element in IMS that triggers interaction for online charging, and OCS in IMS. When different user accounting systems are present in the CS and IMS domains to properly store user prepayment data in the CS and IMS domains, interactions with the prepay system in the CS and / or OCS domain in the IMS will be implemented for online credit control in accordance with the second embodiment.

[0127] Embodiment 2 [0128] When different user accounting systems are present in the CS and IMS domain to properly store user prepayment data in the CS and IMS domain, the network element in the IMS triggering interactions for online charging, can communicate with OCS in IMS and communicate indirectly in real time with the prepay system in the CS domain through OCS in IMS. Alternatively, the IMS network element that triggers the interaction for online tolling can communicate directly with OCS in IMS and the prepay system in the CS domain to properly deduct the unit in the CS and IMS domain, as detailed below.

[0129] The first method is indirect real-time interaction with the CS domain prepay system via OCS in IMS as shown in Figure 5A.

[0130] After receiving the CCR sent by the network element in IMS triggering interaction for charging online, OCS in IMS requests directly from the prepayment system of the CS domain including the accounting system CS the implementation of credit control as needed and returns CCA to the network element in the IMS triggering interaction for charging online fees

- 23 based on results returned from the CS domain prepayment system including the CS domain accounting system. OCS in IMS and the CS domain prepayment system, including the CS domain accounting system, communicate using the CAMEL (CAP) application protocol or other proprietary protocol.

[0131] The second method uses the direct interaction of the user-assigned CCCF entity in OCS in IMS and in the prepay system in the CS domain as shown in Figure 5B.

[0132] In addition to interacting with OCS in the IMS via the standard Ro interface, the network element in the IMS triggers the interaction for online charging, i.e. the CCCF unit also provides the service as IMSSF, which triggers interaction for the prepayment service in the CS prepayment system including the CS accounting system using the CAP interface and requests credit control in a manner consistent with the original interactions of the CAP interface of the prepayment service, and also implements CS domain credit control including real-time unit deductions and monitoring. Until now, the CCCF will also decide to implement credit control, including deduction of the unit and monitoring, in the CS and / or IMS domain based on the domain of the network in which the user is currently involved in communication and / or ongoing strategy (when e.g. communication separated according to a certain ratio between CS / IMS) as described above. In addition, because the CAP interface is not suitable for informing about a change of indicator during a connection, it is required that the control relationship between the CCCF unit and the prepay system in the CS domain is managed during the entire communication period and you can charge for communication or in the form of a fixed value for the entire communication; or so that the CCCF entity calls control of the CS prepay system service several times based on the need to offset the unit and monitor in the CS domain.

[0133] The third method is to use the interaction by the SCSF entity assigned to the user in OCS and IMS, respectively, and the prepay system in the CS domain, as shown in Figure 5C.

[0134] A network element in IMS that triggers the interaction for online charging, i.e. a unit

S-CSCF, respectively, triggers IM-SSF and IMS gateway function simultaneously according to the user's subscription data. The IM-SSF triggers interaction for the prepayment service in the CS domain prepay system including the accounting system using the CAP interface, requests credit control in a manner consistent with the original interactions of the CS prepay service CAP interface, and also implements the CS domain credit control including real-time unit deductions and monitoring. The IMS gateway function communicates with OCS in IMS via a standard Ro interface to implement IMS credit control. Until now, the S-CCCF entity will also decide to implement credit control, including entity deduction and monitoring, in the CS and / or IMS domain based on the domain of the network in which the user is currently involved in communication and / or current strategy (when e.g. communication fee distributed according to a certain ratio between CS / IMS) as described above. In addition, because the CAP interface is not suitable for providing indicator change during connection, it is required to control dependency

- 24 between the IMSSF unit and the prepayment system in the CS domain was managed during the entire duration of communication and fees may be charged for communication or as a fixed value for all communication; or so that the IM-SSF unit calls control of the CS prepay system service several times based on the need to offset the unit and monitor in the CS domain.

[0135] Although the above embodiments are described with the VCC service as an example of those services that simultaneously apply to the CS domain as well as the IMS, those skilled in the art will appreciate that the method of centralized credit control in the CS and / or IMS domain that is implemented by avoiding calling the online toll service / prepay service in the CS domain and by triggering interactions for online toll collection in IMS, can also solve problems in other services involving both the CS domain and IMS simultaneously, although there may usually be differences in the specific processing of events or in information related to services. Other services involving both CS and IMS domains include combined CS transfer and IMS (CSI) CS transfer linking and IMS service, as well as IMS centralized service control (ICS) for implementing IMS centralized service control to a user accessing the domain through the domain CS and / or IMS, and problems include that the separate or combined use of existing online toll / prepay services in the CS and IMS domain can lead to failure in correct and full toll collection or failure to provide repetitive toll collection in the CS and IMS domain. The difference in specific processing includes event processing and related information for the VCC domain transfer as considered in the above embodiments and processing for AS that processes the service involved in communication simultaneously in the CS and IMS domain.

[0136] Accordingly, the communication system of the invention comprises the following components:

[0137] A CS domain control device configured not to invoke an online charging service / prepay service in the CS domain when a user subscribing to the service of both the CS domain and IMS and the prepay service simultaneously calls or sets up a connection in the CS domain. The CS domain control device includes, for example: user's home HLR, configured to cancel the user's CAMEL subscription data, used by the user to activate the online toll collection / prepay service in the CS domain in the user's subscription data, provided to the VMSC and the user's GMSC during the anchoring of the CS call being called or set up by the user to the user's home IMS in the VCC service and thus avoiding calling the online toll / prepay service for the user in the CS domain; gsm-SCF unit configured to not call the logic of the online charging / prepayment service, which the user subscribes to in the CS domain after determining the need to provide the service simultaneously in the CS and IMS domain CS and IMS after receiving the connection release message correlated with the user and the like.

[0138] An IMS control device configured to trigger interaction for charging online in IMS for centralized credit control when a user-correlated connection is processed in IMS. The IMS control device includes, for example, an S-CSCF or AS unit in IMS, in particular an S-CSCF unit or CCCF unit in the VCC service configured to trigger an interaction for charging online fees after anchoring a correlated connection with the user controlling the VCC service, i.e. CCCF.

[0139] As shown in Figure 5A, the IMS control device can communicate with OCS in the IMS and directly communicates with the prepay system in the CS domain through real-time interactions between OCS in the IMS and the prepay system in the CS domain to implement centralized credit control. Alternatively, as shown in Figures 5B and 5C, the IMS control device may also directly communicate with the OCS in the IMS and the prepay system in the CS domain, respectively, to implement centralized credit control.

[0140] OCS in the IMS and / or prepay system in the CS domain configured to perform credit control for the user based on CCR sent from the IMS control device.

[0141] In the VCC service, if the user subscribing to the online toll collection service / prepayment service in the CS domain, the CS domain also includes a CS domain charging system configured to implement free of charge CDR processing generated in the CS domain for based on specific information such as such as CCCF unit number or specific prefix inserted before the connection number or a fee-free format for charging information sent by gsmSCF to gsmSSF.

[0142] Accordingly, Figure 6 shows an AS structure with a credit control function, including a trigger module 600, a first credit control module 601, a second credit control module 602 and a selection module 603. Trigger module 600 triggers interaction for online charging after receiving a session request, the first credit module 601 communicates with OCS in IMS after triggering interaction for online charging to perform credit control, the second credit module 602 communicates with the prepay system in the CS domain after triggering the interaction to complete online charging to implement credit control, and the 603 selection module decides whether to implement credit control for the IMS or for the CS domain.

[0143] Regarding the various ways of interacting with the CS domain prepay system, as shown in Figures 5A and 5B, it can be seen that the second credit control module and the selection module are optional elements. In other words, when only the triggering module and the first credit control module are included, the triggering module in the AS triggers the interaction for online charging according to the user subscription data, uses the first credit control module to communicate with the OCS in the IMS directly via the standard Ro interface and communicates with the prepayment system in the CS domain by OCS in IMS, as shown in Figure 5A, and thus implements

- 26 credit control in the CS and IMS domain for the user. When the second credit control module and the selection module are further included, as shown in Figure 5B, the triggering module in the AS triggers the interaction for charging online according to the user subscription data, accordingly uses the first credit control module to communicate with OCS in the IMS via a standard interface Ro and uses the second credit control module to communicate with the prepay system in the CS domain through the CAP interface, and also uses a selection module to make a selection based on the domain of the network in which the user is currently involved in communication or a pre-set charging strategy and thus implements credit control in the CS and IMS domain for the user.

[0144] Of course, based on the foregoing, in the case of triggering interaction for the IMS online charging service for the implementation of centralized credit control, the present invention provides a method for accurate and complete control of online charging / charging in real time while providing the service simultaneously in the CS domain and IMS CS and IMS, to provide a way for online charging / prepayment services using real-time / online charging. In addition, the present invention further improves the existing static anchoring and IMS centralized control solution for domain transfer in the VCC service. Thanks to the inventive solutions, it is possible to provide a commonly used online toll collection service / prepayment service, and thus you can avoid problems such as the correlation requirement for real-time CS / IMS toll collection for the correct processing of the relevant fee, which makes roaming not possible or not possible to implement in practice due to the huge amount of workload. In addition, inventive solutions extend the ability to control the online toll service, taking into account that the CS and IMS domain belong to different operators and there are differences in the tariff in different network domains. The integrated application in the CS domain, WLAN and IMS networks can be further facilitated by the present invention.

It is obvious that those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Accordingly, the present invention includes modifications and variations, assuming that they fall within the scope of the claims of this invention or their equivalents.

Prepared and verified

Grażyna Palka Patent Attorney