Transcript Charging in 3GPP

Charging Management
in
3GPP SA5 SWGB
What the standards provide
Chair: Karl-Heinz Nenner (T-Mobile)
Vice Chair: Gerald Görmer (Siemens AG)
1
SA5 SWGB
Rapporteur Group Structure
General Charging Session
Karl-Heinz Nenner
(T-Mobile)
Bearer
Charging
Session
IMS
Charging
Session
Service
Charging
Session
Benni Alexander
(Nokia)
Göran Andersson
(Ericsson)
Gerald Görmer
(Siemens AG)
2
Table of contents
1. Motivation
2. Setting the scene for charging in 3GPP
2.1 Charging Levels
2.2 Charging Methods
3. Timeline
4. Release 6
4.1 Common Charging Architecture
4.2 Common Interfaces and Applications
5. Additional Functionality
5.1 The Online Charging System
5.2 Flow based Bearer Charging
3
Motivation
The business principles behind
The Vendor business paradigm:
–
–
to sell equipment to Operators,
purpose of equipment is to build telecom networks
The Operator business paradigm:
–
–
build and operate a (mobile) telecom network
purpose of network is to provide end user services
The Customer
–
uses – and will be billed for - the end user services
Charging is the central enabler for the end user billing
there will be no equipment sold, no network built and no service offered
unless the service can be billed
charging is at the core of the business for vendors and operators alike!
4
Motivation
The key terms in 3GPP
accounting: process of apportioning charges between the
Home Environment, Serving Network and Subscriber.
billing: function whereby CDRs generated by the charging
function(s) are transformed into bills requiring payment.
charging: a function within the telecommunications network
and the associated OCS/BD components whereby
information related to a chargeable event is collected,
formatted, transferred and evaluated in order to make it
possible to determine usage for which the charged party
may be billed.
OCS: Online Charging System
BD: Billing Domain
5
Setting the scene for charging in 3GPP
Charging Levels
• Bearer, Subsystem and Service charging
Charging Methods
• Online versus Offline charging
6
Setting the scene
Charging Levels
1. Bearer Charging, comprising
– Charging for the Circuit Switched Domain
– Charging for the Packet Switched Domain (GPRS)
– Charging for the I-WLAN
2. Subsystem Charging, i.e. IMS
3. Service Charging, comprising
–
–
–
–
MMS
LCS
More to come, e.g. MBMS, Push, Presence, Messaging
In future, OMA Services ?!
7
Setting the scene
Charging Methods
offline charging:
Charging mechanism where charging information does not
affect, in real-time, the service rendered. The final result of
this charging mechanism is the forwarding of CDR files to
the Billing Domain.
online charging:
Charging mechanism where charging information can
affect, in real-time, the service rendered and therefore a
direct interaction of the charging mechanism with
bearer/session/service control is required. The mechanism
comprises the execution of credit control and subscriber
account balance management on the Online Charging
System.
8
Setting the scene –
Bearer Charging : CS domain
CS domain charging involves:
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•
PSTN
CS Domain
Mc
MGW
gsm
SSF
Offline Charging:
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•
the GMSC
the MSC (server)
the HLR
the EIR
– TS 03.78/09.78 (GSM)
– TS 23.078 / 29.078 (3GPP)
CDR
C
CAP
CDR types for MOC, MTC,
IncGW, OutGW….
Online charging: CAMEL
GMSC
Server
CDR
HLR
D
CAP
VMSC
VMSC
Server
Server
McMc
gsm
SSF
gsm
SCF
SCF
SCF
CAP
CDR
Billing
Domain
System
CDR
MGW
MGW
A
IuCS
9
Setting the scene –
Bearer Charging : CS domain
Basic principles
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–
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„call records“ per call/duration
Multiple „partial records“ for long calls
Tariff Time Change captured within CDR
All service invocation information inside CDRs
Major CS charging parameters
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Origination / Destination of call
Invoked services (BS, TS, SS)
Radio resource usage for data
Special Cases
–
SMS (supported from the early days)
•
•
–
Mobile Originated SMS CDR
Mobile Terminated SMS CDR
LCS (supported as of Rel-4)
•
•
•
Mobile terminated location request CDR
Mobile originated location request CDR
Network induced location request CDR
10
Setting the scene –
Bearer Charging : PS domain
PS domain (GPRS) charging
involves the SGSN and the
GGSN
Offline Charging:
-
M-CDR records MM items when
user is GPRS attached
S-CDR and G-CDR capture PDP
context charging
Online charging:
•
CAMEL based
– TS 03.78/09.78 (GSM)
– TS 23.078 / 29.078 (3GPP)
•
Diameter based
– Built upon IETF DCC
11
Setting the scene –
Bearer Charging : PS domain
Basic principles
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–
–
–
–
–
–
There is no concept of „service invocation“, all traffic is plain IP
There is no concept of „mobile termination“, but „uplink“ and „downlink“ traffic
instead
CDRs are generated per user connection (“PDP context”)
CDRs are time and volume based
Each CDR contains one or more volume containers, characterised by QoS and
Tariff Time
Uplink and downlink volume counted separately
Non-volatile storage of CDRs on the CGF
Major GPRS charging parameters
–
–
–
User ID („origination“) as in CS
APN („destination“)
Time, data volume, QoS
Special Cases: SMS and LCS as in CS domain
12
Setting the scene –
Bearer Charging : WLAN
WLAN: an interworking architecture for non-3GPP WLAN (i.e. 802.11)
with the 3GPP core network
In Rel-6, there are two relevant interworking scenarios
– Scenario 2 is a SIM based authentication/authorisation, providing IP
connectivity via the WLAN
– Scenario 3 with Access to 3GPP services (IMS, SMS, MMS, …) on top
of the above
Charging functionality is currently being specified in SA5
– Will be similar to GPRS
– Will make use of IETF AAA technology (use of Diameter)
– Time and data volume to be counted
• in WLAN only in scenario 2  reported to VPLMN
• in WLAN, VPLMN AAA and HPLMN AAA in scenario 3, where user traffic
traverses VPLMN and HPLMN
13
Setting the scene –
Subsystem Charging
IP Multimedia Subsystem (IMS)
IP Multimedia Networks
Legacy mobile signalling Networks
PSTN
Mb
Mb
PSTN
BGCF
PSTN
CSCF
Mk
Mm
Mk
Mw
Mj
BGCF
C, D, Gc, Gr
Mi
Cx
IM-MGW
MGCF
Mc
Mr
Mb
MRFP
MRFC
PCF
Mb
Mb
P-CSCF
Gm
Go
SLF
Dx
Mw
Mp
Mb
HSS
CSCF
Mg
UE
IM Subsystem
14
Setting the scene –
Subsystem Charging
IMS Charging : Generals
Proxy Call Session Control Function („CSCF“)
–
–
–
Determines applicable I-CSCF
Routes SIP signalling between UE and S-CSCF
Resource control via embedded PCF
Serving CSCF
–
–
–
Responsible for session control
Interacts with service platforms
May behave as SIP proxy or user agent
•
•
accepts requests and services them internally or translates / forwards them on
may terminate and independently generate SIP transactions
Interrogation CSCF
–
–
Determines applicable S-CSCF
Routes SIP signalling to / from „foreign“ networks (Roaming)
Application Server
–
–
–
Provides any kind of „service“
Services are not standardised in the 3GPP specifications
Examples: movie / music clips, news flash, soccer goals, ….
15
Setting the scene –
Subsystem Charging
IMS Charging : Basic principles
 CDRs are generated per IMS session / duration
 Tariff Time Change is captured within CDR
 All media component invocation information is inside the CDRs
– Each CDR contains one or more media component descriptors
– AS information is captured, if AS(s) is / are involved
 many similarities with CS charging, BUT
– Completely different, distributed charging architecture
• ACR start / stop / interim are generated per SIP message
• CDRs are generated by CCF and then sent to BD
• ACRs and CDRs are asynchronous
– No transport network infomation (e.g. radio resources)
– If correlation with GPRS CDRs required, this is done by crosscorrelating GPRS and IMS „Charging IDs“
– Correlation between IMS CDRs is required (e.g. CSCF CDRs, AS CDRs)
– all CDRs contain the same IMS „Charging ID“
16
Setting the scene –
Subsystem Charging
IMS Charging : Aspects
Major IMS charging parameters
– Origination / Destination of session
– Invoked media components (audio, video, etc.)
– AS information, if applicable
Offline Charging with 7 CDR types: 1 each per IMS node type
– P-CSCF captures session related information
– S-CSCF captures similar information as the P-CSCF, but
• only S-CSCF CDR has AS related information
• only P-CSCF CDR has information on authorised QoS
– I-CSCF captures user registration events
– AS captures service invocation information
– Others (more details in „special cases“ below):
• interworking with CS services
• Conferencing
Online charging only in S-CSCF, AS and MRFC
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Setting the scene –
Subsystem Charging
IMS Charging : Special cases
SIP Events create ACR Events instead of start/interim/stop messages
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SIP NOTIFY
SIP MESSAGE
SIP REGISTER
SIP SUBSCRIBE
SIP Final Response indicating an unsuccessful SIP session set-up
SIP Final Response indicating an unsuccessful session-unrelated procedure
SIP CANCEL, indicating abortion of a SIP session set-up
I-CSCF completing a HSS Query that was issued for a SIP INVITE
AS service invocation events
CS interworking
–
–
Several nodes support CS interworking, i.e. MGCF, MGW, BGCF
MGCF and BGCF can generate call related CDRs
Conferencing
–
–
MRFC and MRFP provide conferencing capabilities (H.248)
MRFC can generate related CDRs
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Setting the scene –
Service Charging
Multimedia Messaging Service (MMS)
Online
Charging
System
MMS VAS
Applications
Postprocessing
System
MM9
MM7
MM8
MMS User
Databases
MM6
HLR
MMS User
Agent A
MM1
MMS Relay/Server
Relay
MM2
MM5
Server
MM4
MM3
“Foreign”
MMS
Relay/Server
MM1
External
Server #1
(e.g. E-Mail)
External
Server #2
(e.g. Fax)
External
Server #3
(e.g. UMS)
...
External
Server #N
MMS User
Agent B
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Setting the scene –
Service Charging
MMS Charging : Generals
 Multimedia Messaging Service (MMS) is based on a specific
service node called the MMS Relay / Server (MMS R/S)
 Originator MMS R/S serves the MM „originator“
 Recipient MMS R/S serves the MM „recipient“
 Inter-MMS R/S traffic uses SMTP (email)
 Differences to SMS:
– Only one MMS R/S involved for intra-PLMN MM transfer, e.g. T-D1 to TD1
– 2 MMS R/S involved if originator and recipient are subscribed to
different networks (e.g. T-D1 to Vodafone)
– In SMS, only one SMSC is involved
– In contrast to SMS, MMS charging is standardised in the service area
(i.e. the MMS R/S), not the bearer domain (MSC/SGSN)
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Setting the scene –
Service Charging
MMS Charging : Basic principles
 The MMS R/S collects charging information such as:
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–
–
–
destination / source addresses used by the “User Agent” (UA)
identification of the MMS R/S(s) involved in the MM transaction
the size of the MM and its components
storage duration, i.e. the time interval when a MM is saved on a nonvolatile memory media
– identification of the bearer resources used for the transport of the MM,
i.e. the identity of the network and the network nodes
 In scenarios involving a VASP, the charging information describes
the identification of the VASP and the amount of user data sent
and received between the MMS R/S and the VASP.
 The information listed above is captured for use cases in relation
to:
– MM submission, retrieval and forwarding
– transactions involving the MMbox
– transactions involving a VASP
21
Setting the scene –
Service Charging
MMS Charging : Aspects
Major charging parameters
– Originator and Recipient (user agent & network)
– MM volume (size)
Offline Charging
– MM1 CDR types to enable end user billing
• MM submission, retrieval and forwarding
• Read reply, delivery report, notification, deletion
• Upload, download, removal from / to MMBox
– MM4 CDR types intended for inter-network accounting
• MM exchange between MMS R/S in different networks
• Read-reply and delivery reports
– MM7 CDR types for VASP transactions
• Submission and cancellation
• Read-reply, delivery reports
Online Charging with Diameter Credit Control
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Setting the scene –
Service Charging
LoCation Service (LCS)
VPMLN
GERAN
A
Gb
Um
2GMSC
2GSGSN
UE
gsmSCF
Lg
PMD
Iu
VGMLC
UTRAN
Iu
3GSGSN
Lg
Iu
MSC
server
Lc
Le
HGMLC
RGMLC
Lr
Lr
Lg
Uu
Client
Lid
Lg
Iu
External LCS
OSA-LCS
Lpp
PPR
Lh
HSS/HLR
Lh
Lid
PMD
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Setting the scene –
Service Charging
LCS Charging : Generals
 Charging information in the Service domain (GMLC) is collected
for inter-operator accounting purposes; a network requesting
location info may be charged by the network providing the
location info
 The main charging parameters collected by the GMLCs are:
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–
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Identity of the mobile subscriber to be located
Identity of the entity requesting the location
Identity of the GMLC or PLMN serving the LCS client
the quality of the location requested by / delivered to the client
date / time the location procedure was requested by the client
Usage of continuous/periodic tracking
LBS information, describing the service specific parameters in
addition to the above location resource information
 The information listed above is captured for all BC use cases:
– Mobile Originated Location Request
– Mobile Terminated Location Request
– Network Induced Location Request
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Timeline of charging TS
• Bearer, Subsystem and Service charging
Releases
• Online & Offline charging
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Timeline of charging TS
CS and PS domains
 CS & PS Online
charging:
– TS 12.05 (GSM until Rel-98)
CAMEL
– TS 32.005 (3GPP Rel-99)
 CS Offline Charging
– TS 32.205 (3GPP Rel 4/5)
– TS 32.250 (3GPP Rel-6)
 PS Offline Charging
–
–
–
–
TS 12.15 (GSM Rel-97/98)
TS 32.015 (3GPP Rel-99)
TS 32.215 (3GPP Rel 4/5)
TS 32.251 (3GPP Rel-6)
– TS 03.78/09.78 (GSM)
– TS 23.078 / 29.078 (3GPP)
 PS Online Charging:
based on IETF DCC
– TS 32.251 (Rel-6)
26
Timeline of charging TS
IMS and Service Charging
IMS: Offline & Online Charging
• TS 32.225 (3GPP Rel-4/5) -> TS 32.260 (3GPP Rel-6)
• S-CSCF uses ISC interface for online charging
MMS: Offline Charging
• TS 32.235 (3GPP Rel-4/5) -> TS 32.270 (3GPP Rel-6)
Online Charging
• TS 32.270 (3GPP Rel-6)
LCS Offline & Online Charging
• TS 32.271 (3GPP Rel-6)
As a major change, Rel-6 sees the introduction of common
charging architecture, interfaces and applications for all
3GPP charging
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3GPP Release 6
• Common Charging Architecture
• Common Interfaces and Applications
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Charging Standards Rel-6
Getting more organised
 Every new technology came with its own charging solution
– Each domain was done independently
– Each domain has its own functional description and interfaces
 Result: Too many different architectures and solutions
However
 From an abstract viewpoint, it‘s always the same functionality,
regardless of system / technology
– Chargeable / billable items (events)
• Calls / Sessions
• Service Events
– The same basic tasks
• Collect charging relevant information (usually from signalling parameters)
• Create CDRs / perform online credit control
• Forward CDRs to billing domain
– Identical information flow from network to Billing Domain / OCS
according to the above basic tasks
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Charging Standards Rel-6
Charging Architecture
Billing Domain
CS - NE
Service
- NE
SIP AS
MRFC
MGCF
BGCF
CGF
CDF
P - CSCF
I - CSCF
S - CSCF
IMS
GWF
OCS
WLAN
SGSN
GGSN
TPF
OFFLINE
CHARGING
ONLINE
CHARGING
CRF
AF
30
Charging Standards Rel-6
Common offline charging architecture
3GPP network
CN
Domain
C
Service
nodes
T
F
C
Rf
D
F
C
Ga
G
Bx
Billing
Domain
F
Subsystem
31
Charging Standards Rel-6
Common offline charging architecture
Charging Trigger Function
– Collects „Metrics“ from the core system, based on system specific
triggers (e.g. signalling events)
– Formats these metrics into charging events
– forwards charging events to the CDF via Rf reference point
Charging Data Function
– Collects charging events and formats them into CDRs according to
system specific rules
– Forwards CDRs to CGF via Ga reference point
Charging Gateway Function
– Provides non-volatile CDR file store
– Uses Bx reference point for CDR file transfer to Billing Domain
Billing domain
– Receives CDR files from CGF
– No further standardisation
32
Charging Standards Rel-6
Common online charging architecture
3GPP network
OCS
CN
Domain
Rc
C
Service
element
T
F
Subsystem
ABMF
O
Ro
CAP
C
F
Re
RF
33
Charging Standards Rel-6
Common online charging architecture
Common approach for online charging
– Same Diameter based interface (IETF Diameter CCA)
– Same source collection (building on CTF)
CS and GPRS will retain CAMEL
GPRS will also see the addition of the Diameter
interface to GGSN; same as WLAN
All new Rel-6 services (MBMS, Push, Presence,
Messaging, …) will use same offline and online
charging functions
34
Charging Standards Rel-6
Structure of TS series
32.240
Charging Architecture
and Principles
32.250
32.251
32.252
32.260
CS-domain
Charging
PS-domain
Charging
WLAN
Charging
IM Subsystem
Charging
32.270
32.271
32.27x
MMS
Charging
LCS
Charging
x Service
Charging
32.295
32.297
32.299
Charging Data
Charging Data
Diameter
Record (CDR)
transfer
Record (CDR) file
Charging
Application
format and
transfer
32.296
Online Charging
System (OCS)
applications and
interfaces
32.298
Charging Data
Record (CDR)
parameter
description
35
Charging Standards Rel-6
Structure of TS series
 TS 32.240 Architecture and Principles
– Common online and offline charging architecture
– General principles of Charging
 One „Middle Tier“ TS per domain / subsystem / service
– Mapping of common architecture onto specific domain
– Domain / subsystem / service specific charging functionality,
especially type and content of CDRs and ACRs
 Common interfaces and applications between the entities of
the common architecture
–
–
–
–
Rf and Ro Diameter application (TS 32.299)
Bx interface to Billing Domain (TS 32.297)
Ga interface between CDF and CGF (TS 32.295)
CDR Parameter and ASN.1 Syntax Description (TS 32.298)
 Special case: Online Charging System (OCS) (TS 32.296)
36
Additional functionality
• The Online Charging System
• Flow based Bearer Charging
37
The Online Charging System
38
The Online Charging System
The following components of an „OCS“ have been identified
– „Charging functions“ for
• Session based charging
• Event based charging
– Account Balance Management Function (ABMF)
•
•
•
•
–
Holds subscriber account
Controls addition / deduction of monetary amounts from account
Performs credit reservation on the account
Management of counters applicable for the account
Rating Function (RF)
• unit determination: calculation of a number of non-monetary units
(“service units”, data volume, time and events);
• price determination: calculation of monetary units (price) for a
given number of non-monetary units;
• tariff determination: determination of tariff information based on
the subscribers contractual terms and service being requested;
• Management of counters applicable for rating
39
The Online Charging System
TS 32.296: OCS applications and interfaces
 Confined to Re (Rating) interface in Rel-6
 Two approaches are being standardised
1. Rating engine model (Class A)
• Charging function fetches data from the Account Balance
Management Function
• Charging function issues rating request towards the Rating
Function
• Charging function triggers counter / account update on the
Account Balance Management Function
• Design goal: allow common Rating Function for online & offline
charging
2. Extended rating engine model (Class B)
• Similar to the above, but the rating function also stores and
manages some of the counters needed for the rate calculation
• Requires additional scenario on Re to acknowledge service
delivery and counter update
40
Flow based Bearer Charging
Problem Statement
The problem:
• Charging for bearer resources does not take into account the
value of services accessed via these bearer resources
• Integrated service pricing: when the tariff model calls for
subscribers paying for the service (e.g. MMS), the charges for
bearer usage must be removed
• Due to different bearer charges in roaming and non-roaming
cases, the service price must depend on whether the customer is
on the HPLMN or roaming on a foreign network
The solution:
• Make bearer charging “service aware”
• Make service charging “access aware”
• Make bearer and service charging “roaming aware”
41
Flow based Bearer Charging
Functionality
• Differentiate between different service data flows for the
purpose of charging, e.g.
•
•
•
•
Web browsing
IP Video Telephony
MMS versus WAP traffic
…….
• Applicable to GPRS (GGSN – TS 32.251) and WLAN (PDG)
charging
• Charging rules for online / offline charging are predefined
or provided from a CRF (TS 29.210)
• Charging rules determine the CDR generation (offline
charging) and credit control procedure (online charging)
42
Backup
43
Service Based Local Policy
(SBLP) : Introduction
• SBLP was defined in Rel-5 to enable the IMS to
control the QoS provided by the GPRS bearer
service based on the requirements of the
negotiated application services.
• This is based on particular interest if the bearer
uses a high QoS and/or if an operator uses IMS
network entities to charge application services.
• In Rel-6 the concept was extended for non-IMS
application functions.
44
Service Based Local Policy
(SBLP) : Architecture
UE
GGSN
AF session
signalling
e. g SIP
GPRS bearers
PEP
Go
AF
(e.g P-CSCF)
Gq
PDF
User Plane
45
Service Based Local Policy
(SBLP) : Functions
• Policy Enforcement Point (PEP)
• Policy Decision Function (PDF)
• Application Function (AF)
46