Customized Applications for Mobile Network Enhanced Logic (CAMEL)

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Customized Applications for Mobile Network
Enhanced Logic(CAMEL)

• Zhaohui Deng
• Yinyan Zhou

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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

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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

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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

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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

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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 customers home MSC????
• Collected_information DP used for providing
  service to calling party such as Call forwarding
• BCSM basic call state model

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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

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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, dont answer, redirect

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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

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Example of WIN phase IIFree Phone
Serving System
IP
SCP
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.
MSC
MS origination
ANLYZDTRIGTYPE, DGTSDIAL, TRANSCAP, WINCAP
SEIZEDSRFCapability, PLIND
SeizesTLDN
CONNRESDSTDGT,CARDGTS,ROUTDGTS
TLDNAT
call setup
INSTREQ
SRFDIRANNLIST
PLAY ANNOUNCEMENT
srfdir
anlyzdTERMLIST, DMH_SVCIDLIST, BILLDGTS
Release message
instreq
Call setup
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Service Drivers for WIN Phase III

• Location-Based Service

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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 customers location and status
• CSE CAMEL Service Environment
• MAP Mobile Application Part, protocol that
  interconnects wireless telephone system

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Example of CAMEL phase IMS Originating CAMEL call
MS
MSC/VLR gmsSSF
gsmSCF
PSTN
CAP-initialDP
A
B
CAP-Connect
C
ISUP-IAM
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 partys 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
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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 Unit USSD Unstructured
  Supplementary Service Data

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CAMEL Phase I Architecture
Home Network
HLR
gsmSCF
MAP
MAP
CAP
MAP
CAP
gsmSSF
gsmSSF
VLR
GMSC
VMSC
Roaming leg
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 Protocol VMSC visiting MSC
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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
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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

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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

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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 doesnt
  support CAMEL, home network handle the roaming

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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

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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

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CAMEL Phase I Originating Basic Call State
Model
O-NullAuthorize_Origination _Attempt_Collect-Info
O_Exception
Collect_Info
DP2
Analyze, Routing Alerting
DP7
O_Answer
O_Active
DP9
O-Disconnect
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Description of O-BCSM DPs in the MSC
Note BLUE for phase I BLACK is added In phase II
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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)
N Notification R request
DP7 encountered (EventReportBCSM)
DP9 encountered (EventReportBCSM)
Continue call processing (Continue)
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CAMEL Phase I Terminating Basic Call State Model
T_Exception
T-Null
Terminating_Attempt_Authorized
DP12
Terminating Call Handling
DP15
T_Answer
T_Active
DP17
T-Disconnect
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Description of T-BCSM DPs in the GMSC
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CAMEL Phase II Architecture
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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

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CAMEL Phase II Originating Basic Call State
Model
DP explanation Please refer to former slide
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CAMEL Phase II Terminating Basic Call State
Model
DP explanation Please refer to former slide
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Terminating Call Example, Phase II
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)
Continue call processing (Continue)
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An example of Virtual Private Network in a
visited network using CAMEL

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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

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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.

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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