1

Customized Applications for Mobile Network Enhanced

Logic(CAMEL)

Zhaohui DengYinyan Zhou

2

What Is CAMEL CAMEL is the wireless intelligent network

standard for GSM networks CAMEL is not a separate service but a new

feature ( It is a tool to help the network operator to provide the subscribers with OSS even when roaming outside the HPLMN)

In North America the corresponding standard is WIN

WIN and CAMEL use almost the same Intelligent Network Conceptual Model

OSS: Operator Specific Services HPLMN: Home Public Land Mobile Network

3

Evolution of Wireless Intelligent Network

Switchboard: Operator manually intervene with an intelligent routing decision

Automatic Switching: hard-wired service logic, dependent on switching vendor for all aspects of service logic necessary to deploy new features, equipment from different vendors made it hard for ubiquitous service deployment

4

Evolution of Wireless Intelligent Network (Cnt)

Stored Program Control: programmable service logic, but not modular. New service introduction is hard due to dependency between service and service specific logic associated with that service. Service logic used for one service could not be used for another

Common Channel Signaling: mid-1970s. Out-band signaling vs. in-band signaling path

5

Evolution of Wireless Intelligent Network (Cnt)

Advanced Intelligent Network: provide service-independent service logic and service management, facilitate independent service development capability

WIN and CAMEL: standardized capabilities in conjunction with SS7 signaling, provide network intelligence efficiently and seamlessly in wireless networks

6

Driver for CAMEL Emerging

Prior to CAMEL, GSM has INAP as protocol injecting intelligence into GSM network. INAP designed for wireline networks, no mobility management.

CAMEL: standard to provide wireless intelligent network capabilities for development, deployment and operation of enhanced mobile communications service and roaming across different vendor switches

7

WIN BCSM DP Example

Originating BCSM detection Points: Origination_attempt_Authorized DP – A point in

the call ( such as an authorized customers initiates a call) when an external element is queried prior to the calling party dialing digits. Can be used for service such as voice activated dialing.

Analyzed_Information DP: for Incoming call screening at customer’s home MSC????

Collected_information DP: used for providing service to calling party such as Call forwarding

BCSM: basic call state model

8

WIN BCSM DP Example

Terminating BCSM Detection Points:

Facility_Selected-and_Available DP: calling name service to customer

T_Busy and T_No_Answer DP: for routing call to a voice message system or special announcements/tones

9

Service Drivers for WIN Phase I

Calling Name Presentation (CNAP) Voice Controlled Service (VCS)

Such as basic voice controlled dialing VCS with voice authentication, speech –to-text

conversion,etc Incoming Call Screening (ICS)

Answer, don’t answer, redirect

10

Service Drivers for WIN Phase II

Prepaid Charging(PPC) Should be invoked before any other service to verify the

balance Preferred Language Support Free Phone

Launch AnalyzedInformation message to SCP, seize IP to set up ConnectionResource message to MSC to connect to IP and IP play announcement to direct how to make the call, completely toll free and mobile airtime free

Billing Service Capabilities Advice of charging; inform cost of impending call

Call management service Rejection of undesired annoying call

11

Example of WIN phase IIFree Phone

IP SCP MSC

Serving System

MS originationANLYZD[TRIGTYPE, DGTSDIAL, TRANSCAP, WINCAP]

SEIZED[SRFCapability, PLIND]

Seizes[TLDN]CONNRES[DSTDGT,CARDGTS,ROUTDGTS]

TLDNAT call setup

INSTREQ[ ]

SRFDIR[ANNLIST

PLAY ANNOUNCEMENT

srfdir[]

anlyzd[TERMLIST, DMH_SVCIDLIST, BILLDGTS]

Release messageinstreq[ ]

Call setup

MSC upon recognizing a FreePhone call attempt, launched a Analyzed Information(ANLYZD) message to SCP. The SCP getting the request, seizes the IP resource and IP send Connect Resource(CONNRES) message to the MSC, directing it to set up a connection to IP. IP plays an announcement to the caller(relative to the FreePhone number called)Upon listening to the announcement, a a series of release messages are played prior to the MSC setting the call up to the appropriate telephone number associated with FreePhone number.

12

Service Drivers for WIN Phase III

Location-Based Service

13

Phased Development of Standards – CAMEL Phase I

Introduce basic INAP capabilities such as support of initial DP message

Basic call set-up reporting capabilities: inform CSE of mobile origination and termination status, call-related CSE interactions

Suppress announcement tones at the serving system during call termination, allowing the home system to play announcements in native language of the home system

Offer Any Time Interrogation (ATI) message, a GSM MAP message: interrogate HLR to derive info about specific customer’s location and status

CSE: CAMEL Service EnvironmentMAP: Mobile Application Part, protocol that interconnects wireless telephone system

14

Example of CAMEL phase IMS Originating CAMEL call

MSC/VLR +gmsSSF

gsmSCF PSTN

A B

C

A: MSC gets CAEML service info from VLR during the call setup of a MS, gmsSSF in the visiting network send the InitialDP message to gsmSCF and suspend the call processing. The InitialDP message contains service key, called and calling party number, calling party’sCategory, location number, bearer capability, event type BCSM, location and IMSI. After the service logic processing, B gsmSCF can for example do number translation, a CAMEL-specific Service logic is initiated from gsmSCF C MSC uses the information received to set up a call

MS

CAP-initialDP

CAP-Connect

ISUP-IAM

15

Phased Development of Standards – CAMEL Phase II

Most significant enhancement over phase I is to support SRF, would allow user interaction with a VRU within CSE

Provide additional GSM MAP related improvements including support of USSD, another user interaction capability enhancement, this call-unrelated CSE interaction capability allows the subscriber to invoke CAMEL-based service via USSD commands.

Online charge indication via the Advice of Charge( AoC) feature for mobile originated calls. AoC is call-related CSE interaction that can be very useful when deployed in conjunction with services such as a Free Phone, prepaid and premium calling services.

SRF: Specialized Resource FunctionVRU: Voice Response Unit USSD: Unstructured Supplementary Service Data

16

CAMEL Phase I Architecture

HLR gsmSCF

GMSC

gsmSSF

VMSC

gsmSSFVLR

MAP

MAPMAP

CAP

CAP

Roaming leg

Home Network

Interrogating NetworkVisiting Network

Dotted lines for signaling connection, continuous line present a voice connectionMAP: Mobile Application Part GMSC: gateway MSCCAP: CAMEL Application Protocol VMSC: visiting MSC

17

CAMEL Phase I Architecture

Home Network present home PLMN (public land mobile

network) of CAMEL subscriber Home Location Register (HLR) and GSM

Service Control Function are the network elements involved in CAMEL

HLR stores for subscriber requiring CAMEL support information regarding O-CSI, T-CSI, TIF-CSI, U-CSI and SS-CSI

O-CSI, SS-CSI are sent to VLR in case of location update or O-CSI, SS-CSI update

U-CSI: USSD-CSI SS-CSI: Supplementary Service_CSI

18

CAMEL Phase I Architecture

Home Network O/T-CSI is sent to GMSC when HLR responds to a

request for routing information

TIF-CSI, U-CSI and UG-CSI are stored in HLR only.

HLR may provide an interface towards gsmSCF for Any Time Interrogation

SS-CSI: Supplementary Service – CSITIF-CSI: translation information flag – CSI, subscriber data

indicate that when subscriber register a forward-to number, that HLR shall not attempt to perform any translation, number format check, (Forward To Number) FTN check, call barring check

19

CAMEL Phase I Architecture Interrogating Network

Perform the interrogation of the home network for information on treatment of terminating CAMEL calls

Calling party of the terminating CAMEL call resides in the interrogating network and the called party resides in the visiting network.

Gateway MSC (GMSC) and gsmSSF are the entities handling of terminating CAMEL calls

When processing the calls for subscriber requiring CAMEL support, GMSC receive O/T-CSI from HLR. If T-CSI exists, indicating GMSC to request instructions from gsmSSF for further execution

20

CAMEL Phase I Architecture Visiting Network

It is PLMN where the CAMEL subscriber is roaming. Involve handling of originating and forwarded

CAMEL calls May request for location information and status of

the subscriber Set up calls from and towards the visiting

subscriber, while handling the originating calls, VMSC detects if O-CSI exists, if does, then initial contact to gsmSCF take place

When roaming to a visiting network which doesn’t support CAMEL, home network handle the roaming

21

Relationship

HLR-VLR interface: send CAMEL related subscriber data to VPLMN and provision of Mobile Station Roaming Number (MRSN), retrieve subscriber status and location, or to suppression of announcement for CAMEL service

GMSC-HLR interface: used at terminating calls to exchange routing information, subscriber status and location, suppression of announcement

GMSC-gsmSSF interface: internal interface, make it easy for handling DPs

22

Relationship

gsmSSF-gsmSCF interface: used for gsmSCF to send instruction to gsmSSF to play tones.announcements to the users.

gsmSCF-HLR interface: used by gsmSCF to request information from HLR

23

CAMEL Phase I: Originating Basic Call State Model

DP9

O-Null&Authorize_Origination_Attempt_Collect-Info

O_Exception

DP2

DP7

Analyze, Routing & Alerting

Collect_Info

O_Answer

O_Active

O-Disconnect

24

Description of O-BCSM DPs in the MSC

CAMEL Detection

DP Type Description:

DP2 Collected_Info TDP-R Indication that the O-CSI is analysed.

DP 4 Route_Select_Failure

EDP-N, EDP-R Indication that the call establishment failed

DP 5 O_Busy EDP-N, EDP-R Indication that:a busy indication is received from the terminating party, a not reachable event is determined upon a cause IE in the ISUP release message

DP6 O_No_Answer EDP-N, EDP-R Indication that an application timer associated with the O_No_Answer DP expires

DP7 O_Answer EDP-N, EDP-R Indication that the call is accepted and answered by the terminating party.

DP9 O_Disconnect EDP-N, EDP-R A disconnect indication is received from the originating party or from the terminating party.

DP 10 O_Abandon EDP-N Indication that a disconnect indication is received from the originating party during the call establishment procedure

Note:BLUEfor phase IBLACK is addedIn phase II

25

Originating Call Example, Phase I

gsmSCF MSC

DP2 encountered (InitialDP)

Monitor DP7 (N)(REquesrReportBCSMEvent)

Monitor DP9 (R)(REquesrReportBCSMEvent)

Continue call processing (Continue)

Check connection (ActivityTest)

Answer to connection check(activityTest Response)

DP7 encountered (EventReportBCSM)

DP9 encountered (EventReportBCSM)

Continue call processing (Continue)

N: NotificationR: request

26

DP17

T-Null T_Exception

DP12

DP15

Terminating Call Handling

Terminating_Attempt_Authorized

T_Answer

T_Active

T-Disconnect

CAMEL Phase I: Terminating Basic Call State Model

27

Description of T-BCSM DPs in the GMSC

CAMEL Detection Point:

DP Type Description:

DP12 Terminating_Attempt_Authorised

TDP-R Indication that the T-CSI is analysed.

DP 13 T_Busy EDP-N, EDP-R

Indication that:a busy indication is received from the destination exchange, Not reachable or call establishment failure event is determined from the HLR response or upon a cause IE in the ISUP release message.

DP 14 T_No_Answer

EDP-N, EDP-R

Indication that an application timer associated with the T_No_Answer DP expires

DP15 T_Answer EDP-N, EDP-R

Call is accepted and answered by terminating party

DP17 T_Disconnect

EDP-N, EDP-R

A disconnect indication is received from the terminating party or from the originating party.

DP 18 T_Abandon

EDP-N A disconnect indication is received from the originating party during the call establishment procedure

28

CAMEL Phase II Architecture

HLR

GMSC

gsmSCF

MSC

Forwarded leg

MS Incoming line

Visiting Network Interrogating Network

Home Network

gsmSSF VLR

Roaming leg

CAP CAP

MAP

MAP MAP

gsmSSF

gsmSRF Home/Interrogating/Visiting Network

CAP

MO call - Outgoing leg (or Forwarding leg)

MAP

29

CAMEL Phase II Architecture and Relationship

Phase II is based on phase I architecture. The basic new component is the gsmSRF. It provides a pool of resources for access by other network entities

gsmSCF –gsmSRF interface: used by gsmSCF to instruct the gsmSRF to play tones/announcement to the users

30

CAMEL Phase II: Originating Basic Call State Model

O_Null & Authorise_Origination_Attempt_Collect_Info

DP2

O_Exception

DP9

DP7

Collected_Info

O_Answer

Basic Call transition

Transition beyond Basic Call

DP4

DP5

DP6

O_Disconnect

O_Active

Route_Select_Failure

O_Busy

O_No_Answer

DP10

O_Abandon

& Alerting

Analyse, Routing

A

A

DP explanationPlease refer to former slide

31

CAMEL Phase II: Terminating Basic Call State Model

T_Null

Terminating Call Handling

DP12

T_Exception

DP17 T_Active

DP15

Terminating_Attempt_Authorised

T_Answer

Basic Call transition

Transition beyond Basic Call

DP13

DP14

T_Busy

T_No_Answer

DP18

T_Abandon

T_Disconnect

A

A

DP explanationPlease refer to former slide

32

gsmSCFMSC

DP12 encountered (InitialDP)

Monitor DP15 (N)(REquesrReportBCSMEvent)

Monitor DP17 (R)(REquesrReportBCSMEvent)

Continue call processing (Continue)

Check connection (ActivityTest)

Answer to connection check(activityTest Response)

DP15 encountered (EventReportBCSM)

DP17 encountered (EventReportBCSM)

Terminating Call Example, Phase II

Continue call processing (Continue)

33

An example of Virtual Private Network in a visited network using CAMEL

34

An example of VPN in a visited network using CAMEL(Cnt)

1. A subscriber who has a VPN service in his home network is "roaming" in a network abroad. To call a colleague at the home office, all he has to do is dialing

the colleague's four-digit extension number “4772”. The exchange (SSP/MSC) in the visited network classifies the

call as a "CSE event“. DP2 is encountered, this InitialDP message contains from VMSC to gsmSCF contains service key and other subscription information. The set-up

process is temporarily interrupted.

VPN: Virtual private networks

35

An example of VPN in a visited network using CAMEL(Cnt)

2. gsmSCF in the home network ask VMSC to monitor the DP7 and DP9, then it translates the extension number into a B-number for international routing and transfers the information to the MSC in the visited network, which resumes the set-up process.

36

Reference

3GPP TS 03.78: Customised Application for Mobile Network Enhanced Logic phase 2

3GPP TS 02.78: Service Definition Igor Faynberg, L. R. Gabuzda, T Jacobson, H.L Lu: The

development of the Wireless Intelligent Network and its Relation to the international Intelligent Network Standards

E. Geulen, J Hartmann: Open Service Provisioning in GSM – What do we gain with CAMEL

J Hartmann: The Alignment of IN and GSM Gerry Christensen etc. Wireless Intelligent Network