1 Customized Applications for Mobile Network Enhanced Logic (CAMEL) Zhaohui Deng Yinyan 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 II Free Phone IPSCP MSC Serving System MS origination ANLYZD[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 message instreq[ ] 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 Environment MAP: Mobile Application Part, protocol that interconnects wireless telephone system

14 Example of CAMEL phase I MS Originating CAMEL call MSC/VLR + gmsSSF gsmSCFPSTN 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’s Category, 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 Function VRU: Voice Response UnitUSSD: Unstructured Supplementary Service Data

16 CAMEL Phase I Architecture HLRgsmSCF GMSC gsmSSF VMSC gsmSSF VLR MAP CAP Roaming leg Home Network Interrogating Network Visiting Network Dotted lines for signaling connection, continuous line present a voice connection MAP: Mobile Application Part GMSC: gateway MSC CAP: CAMEL Application ProtocolVMSC: 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-CSISS-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 – CSI TIF-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 Note: BLUE for phase I BLACK is added In 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: Notification R: 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

28 CAMEL Phase II Architecture

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 DP explanation Please refer to former slide

31 CAMEL Phase II: Terminating Basic Call State Model DP explanation Please refer to former slide

32 gsmSCF MSC 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