Abstract:
A method for charging control in a communications network comprises, at a policy manager, responsive to a request for policy regulations for a subscriber, a stimulus is provided to a control system to trigger pre-emptive retrieval of subscriber information. At the control system, responsive to the stimulus, subscriber information is retrieved, information is stored in a cache, and responsive to receiving a request from a party, the information in cache is consulted and a response is provided to the party based on the consultation.

Description:
RELATED REFERENCES 
     This application claims priority to Irish Patent Application No. 2008/0836 filed Oct. 13, 2008, entitled “A Method And System For Charging Control In Telecommunications Services, which is hereby incorporated by reference in its entirety as if fully set forth herein; and to European Patent Application No. 08017890.8, filed Oct. 13, 2008 (now EP Patent No. 2175588, granted Jul. 29, 2010), also entitled “A Method and System for Charging Control in Telecommunications Services. 
     FIELD 
     The field relates to a method and system for charging control in telecommunications services. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Illustrative embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  illustrates a policy and charging control system according to one embodiment; 
         FIG. 2  illustrates an access gateway initiated message flow according to one embodiment; and 
         FIG. 3  illustrates an application server initiated message flow according to one embodiment. 
     
    
    
     DESCRIPTION 
     Policy and charging control methods employed in various systems involve receiving connect requests for a subscriber from a gateway, querying a database to determine policy regulations associated with the subscriber, and provisioning the gateway with the policy regulations. Subsequently, upon receiving an authorisation request from the gateway to allow a subscriber to access an application, the method further involves querying a database to ascertain charging information associated with the subscriber, consulting the charging information to determine whether authorisation should be permitted or denied, and informing the gateway accordingly. 
     In many systems, a cache is provided for storing at least a portion of the charging information pertinent to the subscriber such that if a subsequent authorisation request is received on behalf of the subscriber, the cache may be queried as opposed to the database, thereby reducing the latency associated with the request. 
     For example, consider the case where the subscriber has a pre-paid credit account. On receipt of the policy regulations for the subscriber, the gateway requests authorisation for the subscriber to access an application. The system queries a database to determine charging information for the subscriber and determines that the subscriber has            5 credit. Based on the application the subscriber wishes to access, for example, a text messaging facility, the system predicts that the subscriber is unlikely to spend in excess of          0.50 and as such fills the cache with          0.50. Subsequent authorisation requests are processed by accessing the cache to determine the credit available and deducting the amount accordingly. Only if the subscriber uses in excess of          0.50 will the system need to query the database. In this way, the latency introduced by the authorisation requests is reduced.
     Referring to  FIG. 1 , there is illustrated a communications network comprising a policy and charging control system  100  according to one embodiment. The system  100  is arranged to allow users at a user terminal  104  to connect and access applications in accordance with subscriber policy and charging controls associated with the user or user terminal. 
     An access network  102  for example, 3GPP, 3GPP2, DOCSIS, or WiMAX is provided to connect a user at a terminal having IP enabled equipment  104 , for example, a mobile phone, a PDA, a PC, or a set top box, to the network via an access gateway  106  to access applications provided by applications server  108 . 
     As illustrated in  FIG. 1 , the system  100  comprises a policy manager  110  connected to a charging control system  112 . In one embodiment, the policy manager  110  and charging control system  112  are connected to a subscriber database  114 . However, in an alternative embodiment, instead of database  114  common to both the policy manager and the charging control system, the policy manager  110  is connected to a policy database and the charging control system  112  is connected to a charging database, the policy database being separate from the charging database. 
     The database  114  is an entity in an operator&#39;s charging domain and comprises subscriber related information required to personalise policy regulations. For example, the subscriber related information may comprise subscriber policy limitations such as roaming preferences, network preferences, content filtering, charging class, quality of service (QoS) attributes, permitted services and online charging control. 
     Where a subscriber&#39;s policy includes online charging control, the database  114  is further populated with information relating to the subscriber&#39;s charging limitations, for example, usage limitations for a given time period, spending limits for a given time period, prepaid credit balance, limitations of packages. However, in an alternative embodiment, information relating to the subscriber&#39;s charging limitations and requirements is stored in the charging control system  112  or in a charging database connected to the charging control system  112 . 
     The policy manager  110  provides policy provisioning to the access gateway for a session instigated by a subscriber at the terminal. The policy manager  110  comprises a rules database  110   a  for storing policy regulations and a policy interface  110   b  to enable communication between the policy manager  110  and the access gateway  106  for the IP access network  102 . The policy interface  110   b  may be implemented using Diameter, COPS, or RADIUS protocols. However, it will be appreciated that any suitable protocol may be employed. 
     In one embodiment, as illustrated in  FIG. 1 , a trigger interface  110   c  is provided to enable the policy manager  110  to trigger events to the charging control system  112 . 
     Similarly, the charging control system  112  comprises a trigger interface  112   a  for enabling the charging control system  112  to receive events triggered by the policy manager  110 , and for the charging control system  112  to acknowledge receipt of the triggered events. 
     In one embodiment, the trigger interface  112   a  and the trigger interface  110   c  are implemented using a Telco grade low latency protocol such as Diameter. 
     The charging control system  112  also comprises a charging interface  112   b  to enable communication between the charging system and the access gateway  106  for the IP access network  102 . The charging interface  112   b  is implemented in one embodiment using Diameter, COPS, or RADIUS protocols. However, it will be appreciated that any suitable protocol may be employed. 
     The charging control system  112  further comprises a rating device  112   d  and balance manager  112   e  for enabling transaction management, rating and account balance management of subscriber balances and a cache  112   c  for storing information retrieved from the database  114  or the balance manager  112   e.    
     In one embodiment, the triggered event supplied to the control system at trigger interface  112   a  comprises a subscriber identifier. However, it will be appreciated that the event may comprise any combination of the following data: a subscriber identifier, for example, IMSI, MSISDN, username; subscription ID; service information session information; billing information, online or offline; QoS profile information; and/or bearer information. 
     However, in one embodiment, on receipt of a triggered event at the trigger interface  112   a  from the policy manager  110 , the cache  112   c  is populated pre-emptively with subscriber information retrieved from the database  114 , or balance manager  112   e , utilising a subscriber identifier decoded from the triggered event, thereby enhancing system performance and user experience by reducing an average latency associated with real time credit control during service deliveries. It will however be appreciated that the cache  112   c  may be pre-emptively populated with information in response to stimuli from any external device. 
     In one embodiment, the cache is pre-emptively loaded with the subscriber&#39;s account balance information. However, it will be appreciated that the cache may be loaded with any combination of the following information: a balance or set of balances associated with the subscriber obtained from the balance manager  112   d  or the database  114 ; a set of costs for the subscriber&#39;s services obtained from the rating component  112   d ; a set of tariffs for the subscriber&#39;s services obtained from the rating component  112   d ; subscriber related data obtained from the database  114 . 
     Referring now to  FIG. 2 , there is illustrated an access gateway initiated message flow according to one embodiment. 
     A user at a terminal employs IP enabled user equipment (UE)  104  to connect to the network by sending  200  a connect request to the access gateway (AGW)  106 . In one embodiment, the connect request comprises information identifying the subscriber associated with the user terminal, and a destination network to which the user wished to connect. 
     The access gateway  106  processes the request and requests  202  policy regulations for the subscriber associated with the terminal from the policy manager (PM)  110 . 
     The policy manager  110  retrieves  204 , policy information from the subscriber database (SUB DB)  114 . In one embodiment, the policy information comprises an indication of whether an online charging control facility is applicable to the subscriber. 
     Based on the retrieved policy information, the policy manager  110  composes  206  policy regulations associated with the subscriber. 
     In one embodiment, if the policy information retrieved indicates that the online charging control facility is activated for the subscriber, an event is triggered  208  to the control system (OCS)  112 . In one embodiment, the event triggered to the control system  112  comprises subscriber information and in particular, subscriber identification. However, it will be appreciated that in an alternative embodiment, an event is triggered to the control system  112  independently of whether the policy information retrieved comprises any indication regarding online charging control. 
     The policy manager  110  provides  210  the access gateway with the policy regulations relating to the subscriber. 
     In response to the event triggered by the policy manager  110 , the control system  112  preemptively retrieves or pre-fetches charging information relating to the identified subscriber from the subscriber database  114  and stores  212  the charging information in cache  112   c.    
     The access gateway  106  sends  214  a connect response to the user at the user equipment  104  indicating whether the request was permitted or denied. 
     If the connect request was permitted, the subscriber subsequently attempts to access a telecommunications service by sending  216  a service request to the access gateway  106 . 
     In one embodiment, the access gateway  106  determines whether the online charging control facility is applicable to the subscriber and sends  218  an authorisation request to the charging system  112  to ascertain whether the service request is permitted. However, it will be appreciated that in an alternative embodiment, the access gateway  106  does not perform a determination in order to assess whether the subscriber is applicable for online charging control. 
     The control system  112  consults  220  the charging information relating to the subscriber stored in the cache  112   c  and processes the request. 
     The control system  112  then responds  222  to the access gateway  106  indicating that authorisation is permitted or denied. 
     The access gateway  106  then responds  224  accordingly to the user&#39;s service request. 
     Referring now to  FIG. 3 , there is illustrated an application server initiated message flow according to one embodiment. 
     The user at the terminal employs IP enabled user equipment  104  to send  300  an application start request to an application server (AS)  108  across the network in order to access an application. For example, the subscriber may wish to initiate a video conferencing session. 
     In response, the application server  108  triggers  302  a policy notification to the policy manager  112 . For example, the policy notification may comprise a notification that a higher QoS is required in order to enable the video conferencing session. 
     In one embodiment, the policy manager  110  retrieves  304  policy information from the subscriber database  114 , for example, to ascertain whether the subscriber is entitled to an improved QoS rating. However, it will be appreciated that this step is not essential to some embodiments. 
     The policy manager adapts  306  the policy regulations for the subscriber based on the policy notification received from the application server  108 . In the above example, the policy regulations are adapted to associate the subscriber with a higher quality of service. 
     The policy manager triggers  308  an event to the control system  112  identifying the subscriber at the terminal. 
     Optionally, the policy manager  110  provides  310  the access gateway with the updated policy regulations relating to the subscriber. 
     In response to receipt of the event from the policy manager, the control system  112  preemptively loads  312  the cache  112   c  with information relating to the identified subscriber. In one embodiment, the information is pre-fetched from the database  114 . 
     The policy manager acknowledges  314  the notification from the application server  108 . 
     The application server  108  determines that online charging control is applicable to the subscriber and sends  316  an authorisation request to the control system  112 . 
     The control system  112  processes  318  the request and sends  320  a response to the application server  108  indicating that authorisation is permitted or denied. 
     The access gateway  106  then responds  322  accordingly to the user&#39;s application start request. 
     The invention is not limited to the embodiment(s) described herein but can be amended or modified without departing from the scope of the present invention.