- TECHNICAL FIELD
This application is related to an application of Xiang Yang Li, Min Liu, John B. Reid, Guy H. Starner, Ashish Trivedi, Peng Wang, Yile Enoch Wang, Jun Zheng Yang, Lei Zhang, and Jay Z. Zhao entitled “New Call Authorization And Billing Message Routing Capability”, which application is assigned to the assignee of the present application and is being filed concurrently herewith.
- BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for charging and billing of Circuit Switch, Packet Switch, and IP Multimedia Subsystems.
This document describes a method and apparatus for enhancing the charge collection function, using third generation telecommunication systems as an example.
The introduction of the third Generation Partnership Project (3GPP) and the third Generation Partnership Project 2 (3GPP2) harmonization effort known as IP (Internet Protocol) Multimedia Sub-system (IMS) has introduced new convergence network elements based on IP based signaling protocols and bearer connections. The goal is to create a harmonized wireless and wireline IP based control network for telecommunications. The IMS network nodes include the Proxy-Call Session Control Function (P-CSCF), Interrogating-CSCF (I-CSCF), Serving-CSCF (S-CSCF), Media Gateway Control Function (MGCF), the Breakout Gateway Control Function (BGCF), the Media Resource Function Controller (MRFC), and Application Servers (AS). In order to perform charging functions in the converged IMS network, each of the network elements have a defined interface to a new node called the Charging Collection Function (CCF). CCF, defined in 3GPP and 3GPP2 standards documents, is an off-line charging network node in the IMS network. CCF collects session charging information from IMS nodes, and constructs and formats Call Detail Records (CDRs). It provides intermediate data storage buffering and provides a mechanism to transfer charging information to the operator's billing system (BS).
For IMS, the CCF provides the mechanism to transfer charging information from the IMS nodes to the operator's chosen Billing System(s). The CCF is responsible for the collection of session charging information from the IMS nodes. The CCF may also act as an intermediate data storage device and therefore needs to support storage of CDRs for a specified period of time given a usage profile. Further, the CCF in 3GPP standards must create ASN.1 (Abstract Syntax Notation.1) base Charging Detail Records. These CDRs are transferred to the BS/BMD (Billing Mediation Device) nominally using FTP (File Transfer Protocol), but other protocols and transport methods are possible. The CCF can receive data from the IMS nodes in a near real-time mode. It should have enough storage to enable it to transmit the collected charging data to the BS in file mode. The CCF may support several transmission protocols towards the BS. One of the purposes for the CCF is to reduce the number of different interfaces between the BS and the IMS nodes sending charging data.
In the IMS system, on-line charging is conducted by an Online Charging Server (OCS). IMS nodes query OCS with charging information. OCS rates calls with a built-in rating engine and provides charging cost and generates CDRs. OCS can support both prepaid and postpaid modes.
3GPP and 3GPP2 are generalizing the aforementioned IMS charging architecture to the entire 3G network, which includes Circuit Switch and Packet Switch networks.
- SUMMARY OF THE INVENTION
However, there are no standards (neither 3GPP nor 3GPP2) which support the charging and rating concept in CCF so that it cannot provide call cost in CDRs. All rating and billing information must be processed in a back office billing system. That limits the capability of IMS/CCF to postpaid and offline billing only.
Applicants have carefully analyzed the characteristics of prior art billing arrangements. In the most modern of these billing arrangements, designed for use with the third generation telecommunications systems, there are two distinct methods of billing calls, one method for use with deferred (off-line) billing (via CCF) and a second method for use with immediate billing (on-line) (via OCS). Calls with deferred billing build up a call data record (CDR) for each call, the call data record having data from which charging information can be derived (e.g., length of call or start and finish time of a call, calling and called customer identification); the call data records for these calls are then passed on to a billing system. The billing system includes a rating engine (i.e., software and data tables for calculating the charge for a call given the parameters of the call). The billing system then generates the customer's bills. Customer Care Systems can retrieve the CDRs from the billing system if the customers complain; the customer service representatives can modify charge records by crediting back an amount to the customer account if there is charge error.
For calls requiring immediate (on-line) billing, a call data record is built up and passed to an on-line charging system which includes a rating engine. This system can provide an output to whatever system needs the charging information (e.g., a hotel data link to provide charging information to a hotel or a prepaid account manager to adjust a prepaid balance). The on-line charging system then passes the call data record to the billing system which prepares bills (e.g., the bill to the hotel) for calls requiring both on-line and off-line charging.
BRIEF DESCRIPTION OF THE DRAWING(S)
Applicants have inventively discovered a method and apparatus for streamlining both the on-line and off-line billing process by utilizing a common charging system, which includes charging, rating, and subscriber balance management functions. The charging system is able to process online calls as an Online Charging System (OCS) as defined by 3GPP and 3GPP2, as well as a charging system for offline calls in real-time or non-real-time. If an offline call requires real-time charging, a call data record is built and a single rating engine built within the OCS is consulted immediately to determine charges on that call; for an offline call requiring only non-real-time billing, the call data record is built without immediately including the charge information and the single rating engine built within the OCS is consulted only when that rating engine is not busy calculating charges for an on-line billing call. As a result, advantageously, a common charging system can be used for both online and offline calls, thus achieving charging convergence, which reduces service provider investment, operation, and maintenance cost and enhances end user service experience. Advantageously, the billing information for calls requiring off-line billing can be derived outside the busy hour; advantageously, the billing system does not need to calculate bills but is required only to store a billing database in order to generate monthly invoices, statistical reports, etc. Advantageously, with this arrangement call data records with call cost can be stored in the billing database and be ready to be pulled by any back-office system, e.g., report generation, customer care, and invoice generation systems. Another benefit of this arrangement is that it can support charging for prepaid subscribers in case the subscriber is roaming in a foreign network that has no real time charging protocol support.
FIG. 1 is a block diagram illustrating the operation of a prior art system;
FIG. 2 is a block diagram illustrating the operation of Applicants' invention; and
FIG. 3 is a flow diagram illustrating the processing of rating data by the rating engine.
FIG. 1 is a block diagram illustrating the operation of a prior art system. The system is used in the third generation telecommunications systems and specifically in Internet Protocol (IP) Multimedia Subsystems for the third generation partnership project (3GPP). When a telecommunications call is processed using a call processing system 1 one of the outputs of this call processing system is a pair of outputs for billing purposes. Outputs for billing of calls billed by an off-line billing process are transmitted through an Rf interface 3. The Rf interface is defined, for example, by Section 5.1 of document 3GPP TS32.225, a standards document. The output for calls requiring on-line billing are transmitted through Ro interface 5 which is defined in Section 6.1 of the same document. The output of Rf interface 3 is transmitted to the charge collection function 7. The function of charge collection function 7 is to build a call data record which has the parameters for charging but contains no charging data (call cost) since the charging data will eventually be calculated by billing system 11, which includes a billing database 12 for storing billing records. The output of the charge collection function I in block 7 is transmitted to this billing system 11 which includes an off-line rating engine 13 for determining charges based on the call parameters of a call data record.
The back-office systems access and process the billing records in a batch mode. They do not wait for CDRs to come in for processing, but process whatever CDRs are available at a given time.
For calls requiring on-line billing processing, the connection from the call processing system 1 via Ro interface 5 is terminated on on-line charging system (OCS) 9. OCS 9 includes an on-line rating engine 10 for use in calculating charges for calls processed by OCS 9. Accordingly, OCS 9 builds a call data record including the call cost and transmits this call data record to billing system 11 for subsequent printing of bills and other back-office operations, and for access by the back-office systems.
FIG. 2 is a block diagram illustrating the operation of Applicants' invention. The treatment of calls requiring on-line processing is very similar to the treatment of such calls in the prior art system of FIG. 1. Data is sent from call processing via Ro interface 5 to on-line charging system 31. OCS 31 has been expanded from OCS 9 to illustrate that the block for building the call data record 33 is separate from the rating engine 35, in order to allow the rating engine 35 to be accessed by either the block for building a call data record 33 or the charge collection function (CCF) 21 to be described below. The data connection between blocks 33 and 35 requires immediate access because the calls must be billed on line. In contrast, the data connection between CCF 21 and rating engine 35 can accommodate deferred requests.
For calls requiring only off-line charge processing, the data is transmitted from call processing 1 via Rf interface 3 to CCF 21. Block 21 includes rating parameter forming rules software and tables (block 23), which populate call data records with corresponding rating parameters of interest, a charging information records manager 25, and a pre-biller unit 27 for interfacing with rating engine 35. The pre-biller unit 27 interfaces with rating engine 35 via R0 interface 5. Requests from the pre-biller to the rating engine can be deferred if the rating engine is fully occupied with rating on-line calls during the busy hour.
After charging information has been obtained for a particular call by the pre-biller 27, the charging information records manager 25 sends the call data record to a billing system 41, which includes a billing database 42 that can be accessed by the back-office systems. Note that the billing database 42 contains complete charging information for both on-line charged calls, the data being received from OCS 31, and for off-line charged calls, the data being received from CCF 21.
The system of FIG. 2 can also serve off-line billed calls received from other networks 51. Data for these calls passes through a CDR parser 53 to CCF 21.
FIG. 3 illustrates the processing of off-line, non-real-time charged calls. The call processing system 1 builds a call data record without charging data (action block 300). The pre-biller requests charging information (action block 301). The pre-biller sends a message over the Ro interface to the rating engine (action block 303). Test 305 determines whether the rating engine is available. If it is available, the rating engine processes the charging data (action block 306) and returns call cost data to the pre-biller via the Ro interface (action block 307).
If the rating engine is not available (negative result of test 305), the rating engine stores the charging data for subsequent processing (action block 311). The rating engine then queues the call charging data (action block 313) for processing when the rating engine becomes available. The rating engine (FIG. 2, block 35) contains a queue 36 for storing deferred processing call charging data. It may also be desirable to have a separate queue for charging data for real-time charged calls, to handle a flurry of requests. The latter queue (not shown) would be served before queue 36; queue 36 would only be served if this latter queue were empty. When the rating engine becomes available and has processed all previous queued calls, the rating engine processes the charging data for this call (action block 315). The rating engine then returns the call cost data to the pre-biller, via the R0 interface (action block 307, previously described).
The above description is of one preferred embodiment of Applicants' invention. Other embodiments, including embodiments for operation with other telecommunication systems, will be apparent to those of ordinary skills in the art without departing from the scope of the invention. The invention is limited only by the attached claims.