Abstract:
A method for enhancing charging rules in packet data service includes: allocating an identifier for identifying a charging rule and the identifier provided by a CRF is stored by a TPF. The identifier is used to identify the charging rule or a service data flow filter. Therefore, when the CRF provides action indication and identifier for the TPF, the TPF performs a corresponding operation on the charging rule or on the service data flow filter according to the identifier. A method for performing modifying operation or installing operation on the charging rule is also disclosed, which avoids redundant information between the CRF and the TPF and reduces greatly the message flow load between the CRF and the TPF. In addition, a mechanism for the TPF to return operation response to the CRF is also disclosed, so that the CRF can get the status of operations performed by the TPF.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation application of International Application No. PCT/CN2005/000425, filed Mar. 21, 2005, which claims priority in Chinese Application No. 2004-10033720.4, filed Apr. 9, 2004, both of which are entitled “Enhanced Charging Rule for Packet Data Service and Operation Method Therefor”. The full disclosure of these applications are hereby incorporated by reference. 
     
    
     FIELD OF THE TECHNOLOGY  
       [0002]     The present invention relates to charging technology, and more specifically to a method for enhancing charging rules for packet data service and for operation of the charging rules.  
       BACKGROUND OF THE INVENTION  
       [0003]     With the wide application of packet data service, how to charge packet data service accurately and reasonably has become a common concern of operators.  
         [0004]      FIG. 1  is a flowchart illustrating an activation, data transmission and de-activation of a Packet Data Protocol Context (PDP Context). As shown in  FIG. 1 , in General Packet Radio Service (GPRS), an implementing procedure of activation, data transmission and de-activation of a PDP Context includes the following steps:  
         [0005]     Step  101 : A User Equipment (UE) sends an Activate PDP Context Request to a Serving GPRS Support Node (SGSN), and this Activate PDP Context Request carries information of a Network Layer Service Access Point Identifier (NSAPI), PDP type, an Access Point Name (APN), a number of Quality of Service (QoS) parameters, a Transaction Identifier (TI) and so on. The NSAPI is used as a component of a Tunnel Identifier (TEID) between the SGSN and a Gateway GPRS Support Node (GGSN) to identify the PDP Context. The PDP Type includes the Peer-Peer Protocol (PPP) type, Internet Protocol (IP) type, etc. The APN can be provided for the SGSN by the UE, by which the SGSN addresses a corresponding GGSN and the GGSN determines the external network to be accessed by the UE, or the UE can choose not to provide the APN for the SGSN, in that case, the SGSN selects the default APN according to the subscriber information of the UE. The QoS parameters represent the quality required by the packet data service specified by the UE. The TI is used for the UE to identify a PDP context.  
         [0006]     Step  102 : After receiving the Activate PDP Context Request, the SGSN performs a security check and encryption with the UE, and this step is optional.  
         [0007]     Step  103 : The SGSN analyses GGSN address information according to the APN, and creates the TEID for the PDP Context if the SGSN successfully figure out the GGSN address information according to the APN. The TEID can be a combination of an International Mobile Subscriber Identity (IMSI) and the NSAPI to uniquely identify a PDP Context between the SGSN and the GGSN. Then the SGSN sends a Create PDP Context Request to the GGSN, which carries the PDP type, the PDP address, the APN, a number of QoS parameters, the TEID, and a select mode therein. The PDP address is an IP address of the UE, which is an optional parameter. When a Create PDP Context Request doesn&#39;t carry a PDP address therein, the IP address of the UE may be allocated by the GGSN in the subsequent process, or by a Packet Data Network (PDN) that is finally connected with the UE. The select mode refers to an APN-selecting mode, namely whether the APN is selected by the UE or by the SGSN. If the GGSN address information is not accessed for the SGSN according to the APN, the SGSN will reject the Activate PDP Context Request from the UE.  
         [0008]     Step  104 : After receiving the Create PDP Context Request, the GGSN determines an external PDN according to the APN, then allocates a Charging ID, starts charging, and confers on QoS. The GGSN sends a Create PDP Context Response back to the SGSN, when the service quality requirement is met. The Create PDP Context Response carries the information of the TEID, the PDP address, a Backbone Bearer protocol, the number of QoS parameters, and the Charging ID. When the GGSN does not meet the service quality requirement of the QoS parameters, the GGSN rejects the Create PDP Context Request from the SGSN, and the SGSN rejects the Activate PDP Context Request from the UE.  
         [0009]     Step  105 : After receiving the Create PDP Context Response, the SGSN adds the NSAPI and the GGSN address information into the PDP Context in order to identify this PDP Context, selects wireless precedence according to QoS parameters, and then returns an Activate PDP Context Accept to the UE. The Activate PDP Context Accept carries the information of the PDP type, the PDP address, the TI, the number of QoS parameters, the wireless precedence, and a number of PDP configuration options. Moreover, the SGSN starts charging. The UE receives the Activate PDP Context Accept and establishes a route with the GGSN. By this time the transmission channel between the UE and the PDN is established and data transmission is able to start.  
         [0010]     Step  106 : The UE transmits data with the PDN through the SGSN and the GGSN.  
         [0011]     Step  107 : On finishing the data transmission, the UE sends a Deactivate PDP Context Request to the SGSN carrying the TI therein.  
         [0012]     Step  108 : After receiving the Deactivate PDP Context Request, the SGSN performs Security check and encryption with the UE, and this step is optional.  
         [0013]     Step  109 ˜Step  111 : The SGSN sends a Delete PDP Context Request carrying the TEID to the GGSN. After receiving the Delete PDP Context Request, the GGSN ends the charging of the UE, deletes the PDP Context corresponding to the TEID, and then sends a Delete PDP Context Response to the SGSN. The Delete PDP Context Response carries the TEID. After receiving the Delete PDP Context Response, the SGSN ends the charging of the UE, deletes the PDP Context corresponding to the TEID, and sends a Deactivate PDP Context Response carrying the TI to the UE. After receiving the Deactivate PDP Context Response, the UE deletes the PDP Context corresponding to TI.  
         [0014]     As shown in  FIG. 1 , in the present GRPS charging system, the charging starts when the PDP context is activated and comes to its end when the PDP context is de-activated, which means the present charging system can only charges according to a transmitted data flow or an activate time duration of the PDP context. In practice, however, after establishing a transmission channel with the PDN, the UE can perform a plurality of services based on one activated PDP Context, i.e., if the PDN can provide a plurality of services, such as Send/Receive Email services, Wireless Application Protocol (WAP) based browse services, File Transfer Protocol (FTP) based file transfer services and so on, an activated PDP Context can bear various services provided by the PDN after the UE establishes a transmission channel with this PDN. Meanwhile operators or service providers may adopt different charging approaches for different charging modes of various services, for instance, Send/Receive Email service can be charged on times of Sending and Receiving events, WAP browse service can be charged according to flow, file transfer service can also be charged according to flow, and yet, a charging rate of WAP browse service is different from that of file transfer service. Thus, it is totally impossible to perform separate charging with the existing GPRS charging system for different services the same PDP Context bears.  
         [0015]     In view of the above, it is being discussed in the 3rd Generation Partnership Project (3GPP) as to how to implement IP Flow Based Charging (FBC). As far as a packet data service is concerned, all the transmitted and received IP Flows or IP Packets when a UE user uses the service may be called Service Data Flow, i.e. the Service Data Flow is a set of a plurality of IP Flows, therefore the IP Flow Based Charging can truly reflect the resource occupation of a certain service. The IP Flow Based Charging can be described like this: IP Flows of different services that the same PDP Context bears are separately screened out through some filters similar to sieves, then IP Flows screened out by different filters are respectively charged so as to respectively charge different Service Data Flows. In this way, a charging granularity based on IP Flows is far less than that based on a PDP Context. The charging granularity may be regarded as the size of a hole of a sieve, therefore the charging granularity based on PDP Context will be like a sieve hole determined by one PDP Context while the charging granularity based on IP Flow will be like a sieve hole determined by one IP Flow, that is, there will be more than one sieve holes contained in one PDP Context. Therefore, compared with the charging based on PDP Context, charging based on IP Flow can provide more charging approaches for operators or service providers.  
         [0016]     In 3GPP, aspects of FBC like system architectures, function requirements and flow of interactive messages are described. The FBC system architecture supporting online charging is shown in  FIG. 2A , in which Online Charging System (OCS)  206  is composed of a Service Control Point (SCP)  201  of Customized Application for Mobile Network Enhanced Logic (CAMEL) and a service data flow based Credit Control Function (CCF)  202 . The CCF  202  is connected with service data flow based Charging Rule Function (CRF)  203  via an interface Ry. The CRF  203  is connected with an Application Function (AF)  204  via an interface Rx and with a Traffic Plane Function (TPF)  205  via an interface Gx. The CCF  202  is connected with the TPF  205  via an interface Gy.  
         [0017]     The FBC system architecture supporting offline charging is shown in  FIG. 2B , in which the CRF  203  is connected with the AF  204  via an interface Rx and with the TPF  205  via an interface Gx, and the TPF  205  is connected with a Charging Gateway Function (CGF)  207  and a Charging Collection Function (CCF)  208  respectively via an interface Gz.  
         [0018]     According to the 3GPP provision for functions implementing the FBC, the TPF  205  bears IP Flows. During the establishment of the IP Flow bearer, the TPF  205  sends a Charging Rule Request to the CRF  203  via the Gx interface. The Charging Rule Request carries relevant information of subscriber and the UE, bearer characteristics, network information, and so on. The relevant information of subscriber and the UE may be a Mobile Station ISDN (MSISDN), an International Mobile Subscriber Identity (IMSI) and the relevant information of network may be MNC, MCC, etc. In addition, the bearer may be modified during the IP Flow transmission. For example, when QoS parameters of the same service are different, charging rules may be different accordingly. For instance, the charging rate may be decrease as QoS parameters decrease. Therefore it is necessary to re-confer on QoS parameters. In this case, during the modification of the bearer, the TPF  205  resends a Charging Rule Request to the CRF  203  to request for new charging rules. The CRF  203  selects a proper charging rule according to the input information provided by the TPF  205  and then returns the selected charging rule to the TPF  205 . The charging rule includes information of charging mechanism, charging type, charging key, Service Data Flow Filter, and charging rule precedence. The charging mechanism may be online charging or offline charging. The charging type may be a type of time span based charging or a type of data flow based charging. The charging key is a parameter related with the charging rate, and the CRF  203  may provide only parameters related with charging rate for the TPF  205 , rather than directly provide charging rate for the TPF  205 . The Service Data Flow Filter is used to indicate the TPF  205  which IP Flows are to be filtered, and then the TPF  205  charges these filtered IP Flows according to the charging rules. Service Data Flow Filter may include an IP quintuple having such information as Source/Destination IP Address, Source/Destination Port Number, and Protocol ID. For instance, the CRF  203  indicates the TPF  205  to filter the IP Flow with the Source IP Address  10 . 0 . 0 . 1 , Destination IP Address  10 . 0 . 0 . 2 , Source/Destination Port Number  20  and the protocol type Transmission Control Protocol (TCP), and then charges the filtered IP Flow according to the charging rule. Finally, during the deletion of the bearer, the TPF  205  may as well send a Charging Rule Request to the CRF  203  to request a new charging rule from the CRF. At this time, the CRF  203  may request the TPF  205  to delete the previously installed charging rule.  
         [0019]     In addition, the CRF  203  may determine the charging rule according to the input information of the AF  204  or the OCS  20  besides the input information of the TPF  205 . For example, the AF  204  may notify the CRF  203  of the current service type used by the user, and the CRF  203  may select the corresponding charging rule according to this service type.  
         [0020]     For a GPRS network, the TPF  205  is the GGSN, the AF is a service gateway or a service server in the PDN and the CRF  203  is an added logical entity. The TPF  205  is the executing point of charging rules and the CRF  203  is the control point of charging rules.  
         [0021]      FIG. 3A  is the flow chart of issuing the charging rule when a bearer is established. As shown in  FIG. 3A , the implementing procedure of issuing the charging rule when a bearer is established includes the following steps:  
         [0022]     Step  301 A: The UE sends an establish bearer service request to the TPF while in a GPRS network the corresponding process is that the GGSN receives a Create PDP Context Request.  
         [0023]     Step  302 A: After having received the establish bearer service request, the TPF sends a Charging Rule Request to the CRF, and the Charging Rule Request carries input information for the CRF to determine the charging rule.  
         [0024]     Steps  303 A- 304 A: After having received the Charging Rule Request, the CRF selects a charging rule according to the input information carried by the Charging Rule Request, and then returns Provision Charging Rules. The Provision Charging Rules may carry the selected charging rule.  
         [0025]     Steps  305 A- 306 A: After having received Provision Charging Rules, the TPF installs a new charging rule according to the charging rule selected by the CRF, or deletes the original charging rule, or installs a new charging rule while deleting the original one. Then the TPF returns an Establish Bearer Service Accept to the UE, accepts the establish bearer service request initiated by the UE and continues with the subsequent steps of the Establish Bearer process.  
         [0026]      FIG. 3B  is the flow chart of issuing the charging rule when a bearer is modified. As shown in  FIG. 3B , the implementing procedure of issuing the charging rule when a bearer is modified includes the following steps:  
         [0027]     Step  301 B: The UE sends a modify bearer service request to the TPF while in a GPRS network the corresponding process is that the GGSN receives an Update PDP Context Request.  
         [0028]     Step  302 B: After having received the modify bearer service request, the TPF sends a Charging Rule Request to the CRF, and the Charging Rule Request carries the input information for the CRF to determine the charging rule.  
         [0029]     Steps  303 B- 304 B: After having received the Charging Rule Request, the CRF selects a charging rule according to the input information carried by this Charging Rule Request, and then returns Provision Charging Rules carrying the selected charging rule.  
         [0030]     Steps  305 B- 306 B: After having received Provision Charging Rules, the TPF installs a new charging rule according to the charging rule selected by the CRF, or deletes the original charging rule, or installs a new charging rule while deleting the original one. Then the TPF returns a Modify Bearer Service Accept to the UE, accepts the modify bearer service request initiated by the UE and continues with the subsequent steps of the Modify Bearer process.  
         [0031]      FIG. 3C  is the flow chart of issuing the charging rule when a bearer is deleted. As shown in  FIG. 3B , the implementing procedure of issuing the charging rule when a bearer is deleted includes the following steps:  
         [0032]     Step  301 C: The UE sends a remove bearer service request to the TPF while in a GPRS network the corresponding process is that the GGSN receives a Delete PDP Context Request.  
         [0033]     Step  302 C: After having received the remove bearer service request, the TPF sends a Charging Rule Request to the CRF, and the Charging Rule Request carries the input information for the CRF to determine the charging rule.  
         [0034]     Steps  303 B- 304 B: After having received the Charging Rule Request, the CRF selects a charging rule according to the input information carried by this Charging Rule Request, and then returns Provision Charging Rules carrying the selected charging rule.  
         [0035]     Steps  305 B- 306 B: After having received Provision Charging Rules, the TPF installs a new charging rule according to the charging rule selected by the CRF, or deletes the original charging rule, or installs a new charging rule while deleting the original one. Then the TPF returns a Remove Bearer Service Accept to the UE, accepts the remove bearer service request initiated by the UE and continues with the subsequent steps of the Remove Bearer process.  
         [0036]     Besides, the CRF may also voluntarily send a charging rule to the TPF. For instance, in the data transmission process between the UE and the AF, after having received the input information relating to charging of the AF, the CRF selects a proper charging rule according to the input information provided by the AF, and then voluntarily issues the selected charging rule to the TPF. The specific implementing procedure of the AF providing the input information of charging for the CRF is shown in  FIG. 4 :  
         [0037]     Step  401 : The AF sends Application/Service Data Flow Charging Information to the CRF.  
         [0038]     Step  402 : After having received the Application/Service Data Flow Charging Information, the CRF returns an Acknowledgement (Ack) to the AF to notify the AF of already receiving the Application/Service Data Flow Charging Information sent by the AF.  
         [0039]      FIG. 5  is the flow chart of the CRF voluntarily issuing the charging rule to the TPF. As shown in  FIG. 5 , the implementing procedure of the CRF voluntarily issuing the charging rule to the TPF includes the following steps:  
         [0040]     Step  501 : The CRF receives a certain Internal or External Trigger Event and relevant information about this event, such as the event of the AF sending the input information of charging rule selection to the CRF.  
         [0041]     Step  502 : The CRF selects the corresponding charging rule according to the acquired information. The acquired information may be the charging-relevant input information provided by the AF. For instance, the user is using a certain service of the AF, and the service has special charging requirements, e.g., the charging rate is different from that of other services, therefore, the AF provides relevant charging information of this service for the CRF. The acquired information may also be the charging-relevant input information provided by the TPF.  
         [0042]     Step  503 : The CRF sends the Provision Charging Rules to the TPF when needed, and the Provision Charging Rules may carry the selected charging rule.  
         [0043]     Step  504 : After having received Provision Charging Rules, the TPF installs a new charging rule according to the charging rule selected by the CRF, or deletes the original charging rule, or installs a new charging rule while deleting the original one.  
         [0044]     A charging rule defined in the 3GPP Specification may include the following information: online charging or offline charging for the service data flow; data-flow-based offline charging or time-span-based offline charging; charging keys; filters of the service data flow; the precedence of the charging rule.  
         [0045]     It is defined in the present 3GPP Specification that, the TPF may remove original charging rules when the TPF receives a new charging rule from the CRF. However, as the charging rules cannot be differentiated from each other, even if the new charging rule that the CRF sends to the TPF contains an action instruction of removing an original charging rule, the TPF cannot determine which charging rule is to be removed. As a result, after the TPF receives a new charging rule, it is not possible for the TPF to perform a correct operation on the original charging rules and remove the corresponding charging rule as required by the CRF, leading to repeated charging of the user.  
         [0046]     In addition, one charging rule may include more than one Service Data Flow Filter. In some cases, a certain Service Data Flow Filter under the charging rule needs to be removed. However, as the Service Data Flow Filters cannot be differentiated either, it is not possible for the TPF to determine the Service Data Flow Filter to be removed.  
         [0047]     Besides, as defined in the present 3GPP Specification, when the CRF is issuing a charging rule to the TPF, the CRF may indicate the TPF to remove an original charging rule, or install a new charging rule, or leave the original charging rule as it is. However, in some cases, a new charging rule may require modification of only a few parameters of the original charging rule or just add some parameter information, for instance, only the charging keys of the original charging rule is to be modified or a new Service Data Flow Filter to be added while other parameters remain the same. According to the current 3GPP Specification, the CRF needs to send an instruction of removing a charging rule first, then sends an instruction of installing a new charging rule. In this way, to modify the same charging rule, the CRF needs to provide two instructions, thereby leading to a great deal of redundant information transmitted between the CRF and the TPF, consequently increasing the load of message flow between the CRF and the TPF and making the TPF operation more complicated.  
         [0048]     Moreover, in the current 3GPP Specification, there is no feedback mechanism from the TPF to the CRF after the TPF executes a charging rule action as instructed by the CRF. As a result, the CRF cannot learn exactly the operations performed by the TPF and cannot adjust correctly the subsequent operation instructions to be issued.  
       SUMMARY OF THE INVENTION  
       [0049]     In view of the above, the present invention provides a method to enhance charging rules of packet data service so as to make the charging of packet data service more reasonable.  
         [0050]     The present invention provides another method to operate charging rules of packet data service so as to avoid redundant information transmission between the CRF and the TPF and greatly reduce the message flow load between the CRF and the TPF.  
         [0051]     In addition, a method for responding to operations in packet data service is provided in the present invention so that the CRF can find the operation result performed by TPF.  
         [0052]     The method for enhancing charging rules in packet data service includes the following steps: an identifier is allocated to identify a charging rule and provided to a Traffic Plane Function (TPF).  
         [0053]     Preferably, the action indication includes a remove operation indication, or a modify operation indication, or an install operation indication, or an activate operation indication, or a combination of the above indications. The parameter information is sent to the TPF together with said indications and the TPF performs the indicated operation on the parameter information in the charging rule according to the action indication. The action indication, or the identifier, or the parameter information, or a combination of the mentioned above, is sent to the TPF together with the charging rule.  
         [0054]     Preferably, the identifier includes identifier to identify charging rule, or the identifier to identify service data flow filter.  
         [0055]     Preferably, the identifier is allocated by a CRF, the TPF, or a network operator, or defined by specification, or determined by a combination of the mentioned above.  
         [0056]     A method for performing operations on charging rules in packet data service is also disclosed in the present invention, which includes that a modify indication is provided to the TPF and the TPF modifies the charging rule according to the action indication. The method further includes that while the modify indication is sent to the TPF, a charging rule is sent to the TPF, and the TPF installs a new modified charging rule after removing the original charging rule according to the Modify indication.  
         [0057]     Another method for performing operations on charging rules in packet data service includes that an install indication is provided to the TPF. The method further includes that after providing an install indication to the TPF, the TPF performs the install operation on charging rule according to the action indication. Furthermore, the method further includes that while sending the install indication to the TPF, the identifier and the parameter information are sent to the TPF and the TPF performs the install operation on the parameters of the charging rule corresponding to the identifier according to the install indication.  
         [0058]     Preferably, while sending the install indication to the TPF, the identifier and the parameter information are sent to the TPF and the TPF performs the install operation on the parameters of the charging rule corresponding to the identifier according to the install indication.  
         [0059]     A method for responding to operations on charging rules in packet data service is also disclosed in the present invention, which includes that an action indication is provided to the TPF, and the TPF performs the indicated operation on charging rule and the TPF returning an operation response. The operation response may include an Operation Success Response or an Operation Failure Response.  
         [0060]     Preferably, the Operation Failure Response carries error cause information.  
         [0061]     In the preferred embodiments of the present invention, the CRF further provides an identifier while providing a charging rule. The identifier may be used to identify charging rule, or service data flow filter, or service data flow filter in the charging rule. After the CRF has provided action indications and the identifier for the TPF, the TPF can perform correct operations on the charging rule(s) or service data flow filter(s) according to the identifier so as to make the charging of packet data service more reasonable.  
         [0062]     In addition, the present invention also provides a method for performing a Modify or establish operation on the charging rule(s) in packet data service, which allows the CRF to provide the TPF with only the parameter information required to be modified or installed instead of other charging rule information that is the same, thereby avoiding redundant information transmission between the CRF and the TPF and reducing greatly the message flow load between the CRF and the TPF. In addition, the present invention also provides a method for responding the operations in packet data service so that the CRF can learn the operations result performed by the TPF. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0063]      FIG. 1  is a flowchart illustrating an activation, data transmission and de-activation of a PDP Context;  
         [0064]      FIG. 2A  is a schematic diagram illustrating a structure of an online charging FBC system;  
         [0065]      FIG. 2B  is a schematic diagram illustrating a structure of an offline charging FBC system;  
         [0066]      FIG. 3A  is a flowchart illustrating a charging rule when a bearer is established;  
         [0067]      FIG. 3B  is a flowchart illustrating a charging rule when a bearer is modified;  
         [0068]      FIG. 3C  is a flowchart illustrating a charging rule when a bearer is deleted;  
         [0069]      FIG. 4  is a flowchart illustrating an AF providing charging input information for a CRF;  
         [0070]      FIG. 5  is a flowchart illustrating a CRF voluntarily issuing a charging rule to a TPF;  
         [0071]      FIG. 6  is a schematic diagram illustrating an embodiment of the present invention; and  
         [0072]      FIG. 7  is a schematic diagram illustrating another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0073]     The preferred embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings.  
         [0074]     In a preferred embodiment of the present invention, a plurality of identifiers is respectively allocated for the plurality of charging rules and all provided to the TPF by the CRF. The identifiers are used to identify the charging rules, the Service Data Flow Filters, or the Service Data Flow Filters in the charging rules, so that the TPF can perform corresponding operations on the charging rules or the Service Data Flow Filters according to the identifiers. The identifier may be allocated by the CRF or the TPF, or by the operators, or may be defined in some specifications. For example, the identifier of the charging rules pre-configured in the TPF is probably allocated by the operators; and the CR 1 ˜CR 5  identifiers pre-configured and directly issued by the CRF to identify some charging rules is defined in the specification, with which the TPF is able to find a suitable charging rule to adopt.  
         [0075]     When the CRF provides a charging rule for the TPF, a charging rule identifier is allocated for uniquely identifying this charging rule and this charging rule is then provided to the TPF. The charging rule identifier may be a combination of certain symbols and serial numbers, like CR 1  and CR 2 , where CR is the abbreviation of Charging Rule; or a single serial number or in other patterns.  
         [0076]     In addition, while providing charging rules with charging rule identifiers to the TPF, the CRF also provides a plurality of action indications with charging rule identifiers, requiring the TPF to perform indicated operations on the charging rule corresponding to the charging rule identifier. The action indication may be an Install charging rule, a Remove charging rule, or a Modify charging rule. When the action indication is substantially the Install charging rule, the CRF needs to provide the information of the to-be-Install charging rule for the TPF. When the action indication is substantially the Remove charging rule, the CRF needs to provide the identifier of the to-be-removed charging rule for the TPF. When the action indication is substantially the Modify charging rule, the CRF needs to provide the identifier of the to-be-modified charging rule as well as the to-be-modified part of the charging rule for the TPF. The to-be-modified part may be some parameters contained in the charging rule. For instance, the CRF provides a Remove indication and an identifier CR 2  for the TPF, which means the CRF requires the TPF to remove the charging rule with identifier of CR 2 ; or the CRF provides a Modify indication, an identifier CR 3  and a precedence parameter  3 , which means the CRF requires the TPF to modify the precedence class of the charging rule with identifier of CR 3  to Precedence  3 .  
         [0077]     When the TPF executes a Modify action indication provided by the CRF, the specific implementing procedure may include: while deleting the original one, installing a new charging rule which is substantially the modified charging rule, In addition, in order to make the management convenient and the system design less complicated, some charging rule parameters, such as the charging rule identifier and charging method (e.g. online charging, offline charging or non-charging, may be set as unmodifiable for a Modify operation.  
         [0078]     When providing a Service Data Flow Filter for the TPF, the CRF allocates a filter identifier to uniquely identify this Service Data Flow Filter and provides the filter identifier for the TPF. The filter identifier may be a combination of certain symbols and serial numbers, e.g. Filter 1  and Filter 2 , a combination of a charging rule identifier, certain symbols and serial numbers so as to indicate the charging rule to which the Service Data Flow Filter belongs, e.g. CR 1 Filter 1 , CR 1 Filter 2 , and CR 3 Filter 2 , or a single serial number independent of a charging rule or in other forms.  
         [0079]     In addition, while providing a Service Data Flow Filter together with a filter identifier for the TPF, the CRF may also provide an action indication with a filter identifier, requiring the TPF to perform the indicated operation on the Service Data Flow Filter corresponding to the filter identifier. The action indication may be an indication of Installing Service Data Flow Filter, Removing Service Data Flow Filter, Modifying Service Data Flow Filter, and Activating Service Data Flow Filter. When the action indication is the Install Service Data Flow Filter indication, the CRF needs to provide information of the to-be-installed Service Data Flow Filter for the TPF. When the action indication is the Remove Service Data Flow Filter indication, the CRF needs to provide the identifier of the to-be-removed Service Data Flow Filter for the TPF. When the action indication is the Modify Service Data Flow Filter indication, the CRF needs to provide the identifier of the to-be-modified Service Data Flow Filter as well as the to-be-modified part of the charging rule for the TPF. When the action indication is the Activate Service Data Flow Filter indication, the CRF needs to provide the identifier of the to-be-activated Service Data Flow Filter; furthermore, the CRF may provide contents of the to-be-activated Service Data Flow Filter as well as the corresponding charging rule identifier for the TPF. For instance, if the CRF provides the Remove operation indication and Filter 1  for the TPF, which means the CRF requires the TPF to remove the Service Data Flow Filter with the identifier Filter 1 . If the CRF provides the Modify operation indication, CR 2 Filter 1 , and the protocol identifier Hyper Text Transfer Protocol (HTTP) for the TPF, which means the CRF requires the TPF to modify the protocol identifier of Service Data Flow Filter with identifier CR 2 Filter 1  to HTTP. For another instance, if the CRF provides the Activate operation indication for the TPF, charging rule CR 0 , and Filter 0 , where Filter 0  is the Service Data Flow Filter predefined in the TPF, the TPF will add the predefined Filter 0  to the charging rule CR 0 .  
         [0080]     After performing the operation according to the action indication from the CRF, the TPF may return an Operation Success Response or an Operation Failure Response to the CRF according to the operation result. While the TPF returns an Operation Failure Response to the CRF, the TPF may further provide corresponding error cause information to the CRF.  
         [0081]     According to a preferred embodiment of the present invention, a charging rule may, include the information not only the charging method for the service data flow such as online charging or offline charging, volume-based or time-based if the charging method is offline charging, charging keys, Service Data Flow Filters, Precedence of the charging rule, and the identifiers that can be the charging rules identifier, a filter identifier, or the filter identifiers of each Service Data Flow Filter in the charging rule, but also the information like the action indications that can be the Remove operation indications, the Modify operation indications, the Activate operation indications, the install operation indications, or any combination of the above-mentioned operation indications.  
         [0082]      FIG. 6  is a schematic diagram illustrating an embodiment of the present invention. As shown in  FIG. 6 , the user activates a PDP Context, through which a service information interaction is performed. For instance, the user access an “online game”service on a WAP game website through the UE, which is charged by the charging rule with the identifier of CR 1 . This charging rule includes the charging method of online charging , a charging key  12345 , the charging rule Precedence  1 , and the filter setting of the source IP address  10 . 129 . 10 . 1 , the destination IP address  10 . 129 . 10 . 2 , the source port number wildcard, the destination port number  80 , the protocol ID WAP 2 . 0 , and the charging rule identifier of CR 1 .  
         [0083]     When the WAP game website finds that the user is updated to a super player, according to the preferential policy of this WAP game website, super player has a 50% discount with the “online game”service charging. In this case, the WAP game website sends a charging-relevant input information, such as service information and event information, to the CRF of this UE, requiring the CRF to send a new charging rule to the TPF so that the TPF can charge this user of the “online game”service according to the new charging rule.  
         [0084]     According to the charging-relevant input information of the WAP game website, the CRF installs a new charging rule with the identifier of CR 2 , and then sends the charging rule with identifier of CR 2  to the TPF. The charging rule includes: the charging method of offline charging, the charging key  67890 , the charging rule Precedence  1 , and the filter setting of the source IP address  10 . 129 . 10 . 1 , the destination IP address  10 . 129 . 10 . 2 , the source port number wildcard, the destination port number  80 , the protocol ID WAP 2 . 0 , and the charging rule identifier of CR 2 . Besides, the CRF may carry an install operation indication, requiring the TPF to install a charging rule with identifier of CR 2 ; furthermore, the CRF may provide a Remove operation indication and the CR 1 , requiring the TPF to remove the original charging rule with the identifier CR 1 .  
         [0085]     After receiving the charging rule with identifier of CR 2  and the corresponding install operation indication, charging rule with identifier of CR 1  and the corresponding Remove operation indication, the TPF searches for the charging rule with identifier of CR 1 , ends the collection of a Charging Data Record (CDR) of the charging rule CR 1 , and removes the charging rule CR 1 . Then the TPF installs the new charging rule CR 2 , and collects statistics of the charging information of the online game service of the user according to charging rule CR 2 .  
         [0086]     There&#39;s also another approach of the above process. The CRF determines the modification needed to be carried out on the current charging rule according to the charging-relevant input information of the WAP game website, and then sends the Modify operation indication, the to-be-modified parameters and the to-be-modified charging rule identifier to the TPF, e.g. the charging key  67890  and the charging rule identifier CR 1 . After receiving the Modify operation indication, the to-be-modified parameter charging key  67890  and the to-be-modified charging rule identifier CR 1 , the TPF searches for the charging rule with identifier CR 1 , ends the collection of the CDR of charging rule CR 1 , and then modifies the corresponding parameters in the charging rule, e.g. modifies the charging key of the charging rule with identifier of CR 1  to  67890 , and collects CDR of the “online game”service accessed by the user according to the current charging rule.  
         [0087]      FIG. 7  is a schematic diagram illustrating another embodiment of the present invention. As shown in  FIG. 7 , the default charging rule set in the TPF is the rule with identifier CR 0 . The charging rule includes the following information: the charging method of offline charging, the charging key  11111 , precedence of the charging rule  3 , the source IP address of the filter wildcard, the destination IP address wildcard, source port number wildcard, the destination port number wildcard, and the protocol ID WAP 2 . 0 , and the charging rule identifier CR 0 . In default condition, the TPF charges the user for all common WAP services by adopting the charging rule with the identifier CR 0 . The user may activate a PDP Context and perform information interaction of a plurality of services through this PDP Context. For instance, the user may browse news and stock market information on a certain WAP website through the UE. The news information browse service and stock market information browse service of this WAP website are charged with the same charging rule, but have a higher charging rate than that of common WAP service. In this case, according to the charging-relevant input information provided by the WAP website, the CRF sends the charging rule with identifier of CR 1  to the TPF. The charging rule includes the following information: the charging method of offline charging, the charging key  24561 , the precedence of the charging rule  1 , and the filter CR 1 Filter 1  setting of the source IP address  10 . 129 . 10 . 5 , destination IP address  10 . 129 . 10 . 6 , source port number wildcard, destination port number  80 , the protocol ID WAP 2 . 0 , and the Universe Resource Location (URL) of stock information browse (wap.sina.com/gushi), and the filter CR 1 Filter 2  setting of the source IP address of  10 . 129 . 10 . 5 , destination IP address  10 . 129 . 10 . 6 , source port number wildcard, destination port number  80 , the protocol ID WAP 2 . 0 , the Universe Resource Location (URL) of stock information browse (wap.sina.com/gushi), and the charging rule identifier CR 1 . The TPF charges the user for the news information browse service and stock market information browse service according to the charging rule with identifier CR 1 .  
         [0088]     According to the preferential policy of this WAP game website, charging rate from 8:00 pm of the day to 8:00 am of the next day for the news information browse service is the same as that of the common WAP service. When it is 8:00 pm, WAP website sends to the CRF the above event and the charging-relevant input information, such as the corresponding Service Data Flow Filter information, requiring the CRF to send a new charging rule to the TPF, so that the TPF can charge according to the new charging rule, thereby charging the user with the same rate as the common WAP charging rule for the news information browse service.  
         [0089]     The CRF determines that the news information browse service should be charged according to charging rule CR 0  of common WAP services while the stock market information browse service is still charged according to charging rule CR 1  according to the charging-relevant input information provided by WAP game website. Then the CRF sends a Provision Charging Rule message to the TPF. The Provision Charging Rule includes the action indication of removing Service Data Flow Filter as well as the identifier of the to-be-removed Service Data Flow Filter, CR 1 Filter 2 . After receiving the Provision Charging Rule message from the CRF, according to the Remove operation indication and CR 1 Filter 2 , the TPF searches for the original charging rule with identifier CR 1  and ends CDR collection of this charging rule. The TPF may also end the collection of the CDR of charging rule CR 0  to synchronize with the subsequent CDR statistics. The TPF then removes the Service Data Flow Filter with identifier CR 1 Filter 2 . After the Service Data Flow Filter with identifier CR 1 Filter 2  is removed, the charging rule CR 1  includes the following information: the charging method of offline charging, the charging key  24561 , Precedence of the charging rule  1 , and the filter CR 1 Filter 1  setting of the source IP address  10 . 129 . 10 . 5 , destination IP address  10 . 129 . 10 . 6 , source port wildcard, destination port number  80 , the protocol ID WAP 2 . 0 , and the URL of stock market information browse (wap.sina.com/gushi), and the charging rule identifier CR 1 . In this way, the TPF collects CDR of the stock market information browse service accessed by the user according to charging rule CR 1  and the news information browse service and other WAP services accessed by the user according to charging rule CR 0 .  
         [0090]     According to the charging setting of the WAP game website, the charging rate of news information browse service should be reset when it is 8:00 am. At this time, therefore, the WAP website sends the charging-relevant input information to the CRF, requiring the CRF to send a new charging rule to the TPF, so that the TPF can charge according to the new charging rule, thereby charging the user in terms of the same charging rule as that of stock market information browse service for the news information browse service.  
         [0091]     The CRF determines that the news information browse service should be charged according to the same charging rule CR 1  as that of the stock market information browse service, according to the charging-relevant input information provided by the WAP game website. The CRF sends a Provision Charging Rule message to the TPF. The Provision Charging Rule includes the action indication of modifying a Service Data Flow Filter, the corresponding charging rule identifier CR 1  and the identifier of the to-be-added Service Data Flow Filter CR 1 Filter 2  with the source IP address  10 . 129 . 10 . 5 , destination IP address  10 . 129 . 10 . 6 , source port number wildcard, destination port number  80 , protocol ID WAP 2 . 0 , and URL of the news information browse (wap.sina.com/xinwen). After receiving the Provision Charging Rule message from the CRF, the TPF searches according to the modify operation indication and corresponding charging rule CR 1  for the original charging rule with identifier of CR 1 , ends CDR collection based on the charging rule CR 1 , and adds the Service Data Flow Filter CR 1 Filter 2  to the charging rule CR 1 . After the Service Data Flow Filter with identifier CR 1 Filter 2  is added, the charging rule CR 1  includes the following information: the charging method of offline charging, the charging key  24561 , precedence of the charging rule  1 , and the filter CR 1 Filter 1  setting of the source IP address  10 . 129 . 10 . 5 , destination IP address  10 . 129 . 10 . 6 , source port number wildcard, destination port number  80 , protocol ID WAP 2 . 0 , URL of the stock market information browse (wap.sina.com/gushi), and the filter CR 1 Filter 2  setting of the source IP address of  10 . 129 . 10 . 5 , destination IP address  10 . 129 . 10 . 6 , source port number wildcard, destination port number  80 , protocol ID WAP 2 . 0 , URL of the news information browse (wap.sina.com/xinwen), and the charging rule identifier CR 1 . In this way, the TPF collects CDR for stock market information browse service and news information browse service accessed by the user according to charging rule CR 1 , and for other WAP services accessed by the user according to charging rule CR 0 .  
         [0092]     In short, the above description is just preferred embodiments of this invention and not to be construed as limits to the protection scope thereof.