1、 TIA DOCUMENT All-IP Core Network Multimedia Domain IP Multimedia Subsystem Charging Architecture TIA-873.007 DECEMBER 2003 TELECOMMUNICATIONS INDUSTRY ASSOCIATION The Telecommunications Industry Association represents the communications sector of Copyright Telecommunications Industry Association Pr
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7、ision should be directed to: Standards CWTS China Wireless Telecommunications Standards group, 4 China; ETSI European Telecommunications Standards Institute; ATIS, USA; TTA - Telecommunications 5 Technology Association, Korea; and TTC Telecommunication Technology Committee, Japan), which 6 have gran
8、ted license for reproduction and for use by 3GPP2 and its Organizational Partners. 7 8 9 Revision History 10 11 Revision Changes Date 0 Initial Publication December 2003 12 13 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or net
9、working permitted without license from IHS-,-,-TIA-873-007 1 1 Scope 1 The present document describes the architecture for charging and billing for IMS services. 2 For the purpose of the present document, the charging data is considered to be generated and collected by 3 charging functions in the ne
10、twork elements. 4 The objectives of the present document are: 5 - to describe principles of charging in an IMS network; 6 - to provide a description of the charging architecture; and 7 - to provide the descriptions of events and triggers for the generation of charging data. 8 2 References 9 The foll
11、owing documents contain provisions which, through reference in this text, constitute provisions of 10 the present document. 11 References are either specific (identified by date of publication, edition number, version number, 12 etc.) or non-specific. 13 For a specific reference, subsequent revision
12、s do not apply. 14 For a non-specific reference, the latest version applies 15 1 3GPP2 X.S0013-008: “IP Multimedia Subsystem; Accounting Information Flows and Protocol” 16 TIA-873-008: “IP Multimedia Subsystem; Accounting Information Flows and Protocol” 17 2 3GPP2 X.S0013-000: “All-IP Core Network M
13、ultimedia Domain; Overview” 18 TIA-873-000: “All-IP Core Network Multimedia Domain; Overview” 19 3 Definitions, abbreviations and symbols 20 3.1 Definitions 21 For the purposes of the present document, the following apply: 22 accounting: process of apportioning charges between the Home Environment,
14、Serving Network and User. 23 accounting information record: record generated by a network element for the purpose of passing 24 relevant data or information to a centralized accounting function. 25 advice of charge: real-time display of the network utilization charges incurred by the Mobile Station
15、26 The charges are displayed in the form of charging units. If a unit price is stored by the MS then the display 27 may also include the equivalent charge in the home currency. 28 billing: function whereby records generated by the charging function are transformed into bills requiring 29 payment. 30
16、 chargeable event: activity utilizing telecommunications network infrastructure and related services for 31 user to user communication (e.g. a single call, a data communication session or a short message), or for 32 user to network communication (e.g. service profile administration), or for inter-ne
17、twork communication 33 (e.g. transferring calls, signalling, or short messages), or for mobility (e.g. roaming or inter-system 34 handover), which the network operator wants to charge for. 35 charged party: user involved in a chargeable event who has to pay parts or the whole charges of the 36 charg
18、eable event, or a third party paying the charges caused by one or all users involved in the chargeable 37 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA-873-007 2 event, or
19、 a network operator. 1 charging: function whereby information related to a chargeable event is formatted and transferred in order 2 to make it possible to determine usage for which the charged party may be billed. 3 charging data: data generated by a network element for the purpose of billing a subs
20、criber for the provided 4 service. It includes data identifying the user, the session and the network elements as well as information 5 on the network resources and services used to support a subscriber session. 6 near real time: near real time charging and billing information is to be generated, pr
21、ocessed, and 7 transported to a desired conclusion in less than 1 minute. 8 rating: The act of determining the cost of the service event. 9 real time: real time charging and billing information is to be generated, processed, and transported to a 10 desired conclusion in less than 1 second. 11 settle
22、ment: payment of amounts resulting from the accounting process. 12 3.2 Abbreviations 13 For the purposes of the present document, the following abbreviations apply: 14 3G 3rdGeneration 15 AAA Authentication, Authorization, and Accounting 16 AS Application Server 17 BCF Bearer Charging Function 18 BG
23、CF Breakout Gateway Control Function 19 BS Billing System 20 CPCF Content Provider Charging Function 21 CSCF Call Session Control Function 22 ECF Event Charging Function 23 ICID IMS Charging ID 24 ICN IP Connectivity Network 25 I-CSCF Interrogating CSCF 26 IMS IP Multimedia Subsystem 27 IP Internet
24、Protocol 28 MGCF Media Gateway Control Function 29 MRFC Media Resource Function Controller 30 MS Mobile Station 31 OCS Online Charging System 32 P-CSCF Proxy CSCF 33 PDF Policy Decision Function 34 PDSN Packet Data Serving Node 35 PLMN Public Land Mobile Network 36 SCCF Subscriber Content Charging F
25、unction 37 SCF Session Charging Function 38 S-CSCF Serving CSCF 39 SDP Session Description Protocol 40 SGW Signaling Gateway41 SIP Session Initiation Protocol 42 TCID Transport Charging ID 43 UE User Equipment 44 3.3 Symbols 45 For the purposes of the present document the following symbols apply: 46
26、 Rb Online Charging Reference Point between Session Charging Function and Correlation 47 Function 48 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA-873-007 3 Rc Online Char
27、ging Reference Point between ECF and Correlation Function 1 Re Online Charging Reference Point towards a Rating Server 2 Rf Offline Charging Reference Point between an IMS Network Entity or an AS and AAA 3 Ro Online Charging Reference Point between an AS or MRFC and the ECF 4 4 Architecture 5 4.1 Ch
28、arging Mechanisms 6 The charging functionality is based on the IMS network nodes reporting accounting information upon 7 reception of various SIP methods or ISUP messages, as most of the accounting relevant information is 8 contained in these messages. This reporting is achieved by sending Diameter
29、Accounting Requests (ACR) 9 Start, Interim, Stop and Event from the IMS nodes to the AAA and/or ECF. 10 4.1.1 Off-line Charging 11 For off-line charging the accounting information is gathered from various IMS network nodes where it may 12 be held for later forwarding to the Billing System. See Secti
30、on 4.3.2 for further information. 13 4.1.2 On-line Charging 14 On-line charging interacts in real time or near real time with the service being provided by the system. The 15 subscribers account is decremented in some units based on current usage of the system. Charging may be 16 based on events, ti
31、me, or resource usage. 17 4.2 Logical Network and Charging Architecture 18 4.2.1 IMS Architecture 19 The overall IMS architecture is described in 2. 20 21 Figure 4.1: Null 22 4.2.1.1 Architecture reference model for off-line charging 23 Figure 4.2 presents the off-line IMS charging architecture for
32、non-roaming scenario. 24 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA-873-007 4 Home(B) = Visited(B) Vi i d(B)ASASMRFCMRFCS-CSCFS-CSCFI-CSCFI-CSCFP-CSCFP-CSCFBGCFBGCFBSRf
33、 Home(A) = Visited(A) AS AS AAA MRFCMRFC S - CSCFS - CSCFI - CSCFI - CSCFP - CSCFP - CSCFBGCFBGCF BS Rf AAA BGCF PDSN PDSN 1 2 Figure 4.2: Off-line IMS Charging architecture for non-roaming scenario 3 NOTE: The topological merging of some of the lines representing the Rf reference points for 4 conne
34、cting with the AAA are performed for figure layout purposes only, and do not imply 5 any other logical or physical association. 6 The interfaces between the PDSN and AAA and between AAA of User As Home System and User Bs 7 Home System are outside the scope of this specification. 8 Figure 4.3 present
35、s the off-line IMS charging architecture for roaming scenario. 9 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA-873-007 5 Visited(A) Visited(B) Home(B) ASASMRFCMRFCS-CSCFS-
36、CSCFI-CSCFI-CSCFP-CSCFP-CSCFBGCFBGCFBS Rf Home(A) AS AS AAA MRFCMRFCS - CSCFS - CSCFI - CSCFI - CSCFP - CSCFP - CSCFBGCFBGCFBS Rf AAA AAA BSP-CSCFP-CSCFRfBS P - CSCFP - CSCFAAA Rf PDSN PDSN1 2 Figure 4.3: Off-line IMS Charging architecture for roaming scenario 3 NOTE 1: The topological merging of so
37、me of the lines representing the Rf reference points for 4 connecting with the AAA are performed for figure layout purposes only, and do not imply 5 any other logical or physical association. 6 In the off-line charging model operators have traditionally exchanged charging information between billing
38、 7 systems as shown in the figure. Operators may desire to exchange charging information in near real time 8 utilizing the AAA infrastructure. In this case, the AAA in the visited network may pass information to the 9 AAA in the home network. The interface between the PDSN and AAA, those between bil
39、ling systems and 10 the interfaces between AAA of User As Home System and User Bs Home System are outside the scope 11 of this specification. 12 4.2.1.2 Architecture reference model for on-line charging 13 Figure 4.4 below presents the on-line IMS charging architecture. 14 Copyright Telecommunicatio
40、ns Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA-873-007 6 Charging information flowISCITSITSOnline Charging SystemHome(A) + Visited(A)ReRbRoRoReRcMRFCFAS(s)AS(s)ISCITSITSOnline Charging SystemHome(B)
41、 + Visited(B)ReRbRoRoReRcAccountCorrelation FunctionBearer Charging FunctionAccountCorrelation Function Bearer Charging FunctionRatingFunctionRatingFunctionS-CSCFS-CSCFS-CSCFS-CSCFAS(s)AS(s)MRFCF SCCFCPCFSCCFCPCFSessionCharging FunctionSessionCharging FunctionEventCharging FunctionEventCharging Func
42、tion1 2 Figure 4.4: On-line IMS Charging architecture 3 Access Charging is performed using the appropriate IP Transport Subsystem charging interface to the 4 Bearer Charging Function. This may involve the use of AAA infrastructure to transfer information from the 5 visited network to the home networ
43、k. 6 Session Charging is performed using the ISC interface between the IMS Session Charging Function and the 7 S-CSCF. Routing to the Session Charging Function is performed as per regular ISC procedures. 8 Event-based charging between an AS or MRFC and the Event Charging Function (ECF) is performed
44、using 9 the Ro reference point. The Ro reference point is described in subclause 4.5.1. ECF address information is 10 distributed using SIP signalling such that Application Servers or MRFCs can use it to find the ECF. 11 Note: It is for further study as to whether the AAA can serve as the Event Char
45、ging Function. 12 The Re reference point allows the interaction with a Rating server. 13 The Rc reference point performs the following functions: 14 The Event Charging Function can reach the Session Charging Function or the Bearer Charging 15 Function via the Correlation Function. 16 Correlation 17
46、Access to the Account of the subscriber. 18 The Rb reference point performs the following functions: 19 . The Session Charging Function can reach the Event Charging Function or the Bearer Charging 20 Function via the Correlation Function. 21 Copyright Telecommunications Industry Association Provided
47、 by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TIA-873-007 7 Correlation 1 Access to the Account of the subscriber. 2 The SCCF and the CPCF, which are described in sub-clauses 4.3.4.1 and 4.3.4.2, constitute the ECF. 3 4.3 Charging Fu
48、nctions 4 4.3.1 AAA 5 The AAA main functionalities for IMS are that it provides the mechanism to transfer charging information 6 from the IMS nodes to the network operators chosen Billing Systems(s). The main functions of the AAA 7 are: 8 - the collection of Session charging information from the IMS
49、 nodes; 9 - intermediate data storage buffering; 10 - the transfer of the charging data to the billing systems. 11 The AAA acts as storage buffer for near real-time charging data collection. It provides the charging data to 12 the billing system. This specification identifies the external interfaces of the AAA for accounting purposes, 13 but does not specify the internal functionality.
