intelligent network
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IN Introduction:.................................................................................................................. 3 History of the telephone service......................................................................................... 4 2.1 Manual switching ....................................................................................................... 4 2.2 Automatic switching: ................................................................................................. 5 2.3 Electronic switching:.................................................................................................. 6 2.4 Digital switching ........................................................................................................ 6 2.5 Network architecture:................................................................................................. 7 IN goals: ............................................................................................................................. 8 Overview of Typical IN Services..................................................................................... 10 User Hierarchy: ................................................................................................................ 11 5.1 Network Operator, IN Operator: .............................................................................. 11 5.2 Service Provider ....................................................................................................... 11 5.3 Service Customer / Service Subscriber .................................................................... 11 5.4 Service User ............................................................................................................. 12 Examples of an IN call setup: .......................................................................................... 12 Intelligent network architecture: ...................................................................................... 12 Common channel signalling SS7: .................................................................................... 14 8.1 SS7 Protocol stack.................................................................................................... 16 INAP Protocol .................................................................................................................. 17 9.1 Trigger points an events ........................................................................................... 17 9.2 Call Control Function & Basic Call State Model..................................................... 18 9.3 List of INAP Operation ............................................................................................ 25 9.4 Usage of the INAP operation and there parameters................................................. 27 9.4.1 Activate Service Filtering ASF ........................................................................ 27 9.4.2 Activity Test AT............................................................................................... 27 9.4.3 Activity Test Response ATR............................................................................ 27 9.4.4 Apply Charging AC ......................................................................................... 28 9.4.5 Apply Charging Report ACR........................................................................... 28 9.4.6 Assist Request Instruction ARI ....................................................................... 28 9.4.7 Call Gap CG ..................................................................................................... 29 9.4.8 Call Information Report CIR............................................................................ 29 9.4.9 Call Information Request CIQ ......................................................................... 30 9.4.10 Cancel Call Information Request CA............................................................... 30 9.4.11 Collect Information CI ..................................................................................... 30 9.4.12 Connect CON .................................................................................................. 30 9.4.13 Connect to Resource CTR................................................................................ 31 9.4.14 Continue CUE .................................................................................................. 31 9.4.15 Continue With Argument CWA....................................................................... 31 9.4.16 Disconnect Forward Connection DFC ............................................................. 31
9.4.17 Disconnect Forward Connection with Argument DFCWA ............................. 32 9.4.18 Entity Released ER........................................................................................... 32 9.4.19 Establish Temporary Connection ETC ............................................................ 32 9.4.20 Event Notification Charging ENC ................................................................... 33 9.4.21 Event Report BCSM ERB................................................................................ 33 9.4.22 Furnish Charging Information FCI .................................................................. 33 9.4.23 Initial DP IDP................................................................................................... 34 9.4.24 Initiate Call Attempt ICA................................................................................. 34 9.4.25 Move Leg ML .................................................................................................. 34 9.4.26 Play Announcement PA ................................................................................... 34 9.4.27 Prompt and Collect User Information PAC ................................................. 35 9.4.28 Release Call RC ............................................................................................... 35 9.4.29 Release Leg RL ................................................................................................ 35 9.4.30 Request Notification Charging Event RNCE.................................................. 36 9.4.31 Request Report BCSM Event RRB.................................................................. 36 9.4.32 Reset Timer RT ................................................................................................ 36 9.4.33 Send Charging Information SCI....................................................................... 37 9.4.34 Service Filtering Response SFR....................................................................... 37 9.4.35 Specialized Resource Report SRR ................................................................... 37 9.4.36 Split Leg SL ..................................................................................................... 38 10 Example of IN dialogue ............................................................................................... 39 10.1 Call set up without monitoring................................................................................. 39 10.2 Call set up with monitoring, busy detected .............................................................. 39 10.3 Call set up after playing announcement with charge information ........................... 40 10.4 Credit Limit Supervision.......................................................................................... 41 11 Distributed functional plane model Q1204 .................................................................. 42 12 Service creation ............................................................................................................ 43 12.1 Definition of the SIB ................................................................................................ 43 12.2 SIB chains for the service creation........................................................................... 44 12.3 The standard SIB:..................................................................................................... 44 12.4 Example of a service creation .................................................................................. 45
1 IN Introduction:
In the late 80 Years, different American operator tries to solve some problems related to the realisation of different services with the modification of the switch programs. And so the realisation of each service needs a new implementation and upgrade of all switches. In fact this leads to an expansion of the costs related to the SW of the mentioned switches, as the provider were in a strong position to set the prices without any control. In fact the cost of every service implementation will be multiplied with the number of the switch provider. This in addition to time needed for the development and implementation of the service which exceeds in the majority of cases 4 years. This in addition to the fact that for some services a central database is needed. The implementation of the service in all switches needs a multiple effort as the same database has to be copied over all. This will lead additionally, to a huge expansion of the costs related to the administrative and operational work for the operator.
2 History of the telephone service
2.1 Manual switching
In 1876, Dr. Alexander Graham Bell, a Boston Professor of Speech, and his partner, Thomas A. Watson, had been working for several months to develop a harmonic telegraph. The harmonic telegraph would allow several telegraph messages to be transmitted on a single wire by tuning the transmitted signals into different frequencies. As their work progressed, Bell and Watson thought that if they could transmit basic frequencies, they could also build a device that could transmit actual speech. Bell knew that others were making progress toward the same invention using similar techniques. Bell, early on February 14, 1876, filed for a patent on the device that he and Watson felt would be capable of transmitting the spoken word. Only hours later, Elisha Gray filed for a patent on a very similar device. The used receiver and transmitter are realised according to the figure 1 and 2.
Fig 1 Transmitter
Fig. 2 Receiver
To interconnect the different new telephone subscribers and also different localities a manual switchboard was used as firstp Fig 3. During this area the operator was the master of the telephony, so that the intelligence and the flexibility were at a very high level.
Fig. 3. Manual switch
2.2 Automatic switching:
Within 5 years of the first telephone conversation, nearly 150,000 subscribers were using the new local telephone service. Rates were high, even by today’s standards: $100 a year for residential service and $150 a year for business service. Lines were strung between the local offices, or Telephone Exchanges, and it was soon possible to call from one city to another using two or more operators in the different exchanges through which the call passed. This huge explosion of the subscriber numbers leads to the situation of blockage as it was very expensive to covers all demands only by operators. So the next step was introduced with the automatic switches. This area is characterized by two switch types the step by step and the crossbar. The step by step switch uses the dialled information digit by digit and selects the route accordingly. This method does not allow alternate routes and so the call will be rejected even if other possibility exists to continuing it. Contrarily the crossbar stores the dialled information in a central unit and so it will be possible to use this common control unit to find a second route and send the information to the neighbour switches.
2.3 Electronic switching:
During the 1950s, Bell Laboratories began working on a new type of switching system to meet the growing demand for telephone services more economically. These electronic switching systems were made possible by the invention of the transistor in 1947. By employing computer techniques, the functions of the common controls can be achieved using a Central Processing Unit (CPU) programmed with appropriate software to perform all the functions desired in processing telephone calls. This method of control is called Stored Program Control (SPC). Fig 4.
Fig 4 SPC Stored Program control
2.4 Digital switching
In the 1950s, AT&T’s Bell Laboratories and Western Electric Manufacturing introduced a new carrier system to be used in the trunking and long distance networks. This new carrier system, called a T-carrier, uses digital transmission instead of analogue transmission. Because of the many advances to solid-state electronics and integrated circuits that handle digital signals, telephone system designs are changing toward an all digital network. The newer systems convert voice and signalling information to digital signals for transmission. There are three techniques used in the transmission of a digital signal: Pulse Amplitude Modulation (PAM), Pulse Code Modulation (PCM), and Time Division Multiplexing (TDM). A person’s voice can be displayed on an oscilloscope as a sine wave. A sample of this sine wave or signal, taken in an instant of time, can closely represent the signal on either side of the sample point for that same instant of time.
If the signal is sampled at twice the rate of the highest frequency component in the signal, the samples will contain all of the information contained in the original signal. In the case of telephone signals, since the voice channel bandwidth has been set at 4,000 Hz, the sample rate of 8,000 samples per second would be sufficient to reproduce the signal. In case that the sampling will use one byte for the amplitude per sample, than a 64 Kbit/s channel per call direction will be generated. Fig. 5.
Fig. 5 Digital Carrier Systems
2.5 Network architecture:
Core networks are as a rule composed of several network layers. In this way, for instance, a difference is made between the local level (local network) and the long-distance level (transit network for the connection of the local networks). The number of network layers and to what degree the network has a star-shaped, intermeshed, or a mixed structure differs from network operator to network operator. Figure 5 shows an example of a possible network configuration by an operator.
Local Local Local Gateway
Transi t
Transi t
Local
Transi t
Transi t
Local netwo
Local
Local Local
Chanel associated Or Common channel Signalling
Local netwo Local Local Local netwo
Network architecture
3 IN goals:
Intelligent Networks are used to make public switched telecommunication networks more flexible. IN can serve fixed networks (PSTN/ISDN) as well as mobile networks (GSM). Additional flexibility is enabled according to different aspects: Flexible Service creation centralized service management and adaptation. No changes are needed in the switching networks for the introduction of new IN-based services.
Flexible routing selects the destination of a telephone call according to criteria like time, origin, user input and so on. It also includes features like percentage distribution or “the nth call” and “every nth call“. Flexible routing answers the question: “Where to put the call?” Flexible screening checks whether it is allowed to connect a certain call according to criteria like time, origin, destination, user input and so on. Black or white lists can be used as check patterns. Flexible Billing allows flexible online or offline charging methods. Criteria like time or distance can be evaluated. Flexible User Interactive Dialogue (UID) enables the service to request additional input from the calling user such as PIN or to select a choice from a menu. Statistics data can be achieved according to counters, call information, etc.
4 Overview of Typical IN Services
Freephone Universal Access Number (alias Universal Number, UN) Premium-Rate (alias Tele-Info Service) are also termed Number Translation Services (NTS), according to their principal function: they translate the IN number into a public phone number (public directory number) by executing the service logic. Technically they just differ in their charging modality. Televoting is a service especially designed for voting by a phone call, especially for Mass Calling. The Virtual Private Network service can be seen as the simulation of a Private Branch Exchange (PBX) on a public network. It meets the increasing demands of companies and institutions for flexible, customizable private networks eliminating restrictions found in the basic public network. Service variants for fixed and mobile networks are available as well as fixed/mobile integrating ones. Virtual Card Calling and Universal Personal Telecommunication offer flexibility in charging and mobility also within fixed networks. Prepaid Service Card or Prepaid Card Service is a service for online charging of the subscriber. Therefore an account is continuously decremented according to the implemented charging algorithm. Personal Number Service offers a set of possible destinations, a Service Customer may own. The Service tries one destination phone after the other until the incoming call is answered at one of it. Additional screening functions both for incoming and outgoing calls are available.
5 User Hierarchy:
We distinguish: Network Operator, IN Operator Service Provider Service Customer / Service Subscriber Service User
5.1 Network Operator, IN Operator:
Manages Network Establish connection to other networks (interworking) Sets up contracts with service providers
5.2 Service Provider
Uses one or more IN-networks Is customer of one or more network operator Create services, customizes, markets and manage them Sets up contract with service customers
5.3 Service Customer / Service Subscriber
Subscribes to one or more IN services Is assigned to corresponding IN numbers Is customer of one or more service providers Parameterizes the services
5.4 Service User
Diales an IN number Uses the services offered to him Is supported by service subscriber May parameterize the IN service via DTMF
6 Examples of an IN call setup:
7 Intelligent network architecture:
An Intelligent Network separates the control of calls from the call itself. Logic programs residing at Service Control Points (SCP) implement services. The switch only implements basic call processing so that if any services are requested by the call, a query is sent to the SCP which instructs the switch on the call control required for the service requested. Bellow figure 7 is the general intelligent network architecture.
SMF Service Managemen SCF Service INAP/SS7 INAP/SS7
SCF Service Creation, SDF Service
SS
INAP/SS
FORE SYSTEMS
SRF Intelligent Peripheral, e.g.IVR
Voice
Voice
SSF Service
Fig. 7 IN architecture
8 Common channel signalling SS7:
With CCS, the signalling paths and voice paths are carried on separate facilities. The voice channels are dedicated for voice and information type signals only (tones, announcements). The signalling channels carry the control, address, and supervisory signals for the calls. In networks that employ common-channel signalling, there are actually two separate networks working in conjunction with each other: · Message Network - This consists of the trunks that transport the voice or data between locations. · Signalling Network - This consists of “common” high speed data links that transport supervision and control signals for trunks, as well as data messages associated with other enhanced network services. Common-channel signalling improves the efficiency of the conventional network by providing a faster, more flexible means for the exchange of call set-up information and by providing the capability for enhanced services through its ability to exchange information packets with other users of the network. The network of the future is expected to be an intelligent, high speed, digital network using common channelling signalling. TERM: COMMON CHANNEL SIGNALING -- A system for exchanging trunk signalling information between processor equipped signalling systems over a network of signalling links. Fig 8 shows the functionality of the SS7 and fig. 9 a SS7 network.
Fig 8 SS7
Fig. 9 SS7 networks
8.1 SS7 Protocol stack
The mostly used signalling in telephony networks is the SS7 with the protocol stack shown in the fig 10.
SS7 user
ISUP
INAP BSSAP
CAMEL
MAP
TCAP
SCCP
MTP
Fig. 10 SS7 Protocol stack
9 INAP Protocol
9.1 Trigger points an events
Trigger Detection Points
if call processing is detecting an inquiry of the SCP a call becomes an IN-call there are defined points within call processing to interrupt it these points are called Trigger Detection Points TDP TDP's are permanent created at the switches there are 2 types of TDP's: TDP-R (request) suspend call processing and activate a dialogue to the SCP TDP-N (notification) causes a message transfer to the SCP without suspension of call processing
9.2 Call Control Function & Basic Call State Model
SCP
• Call Control Function
realizes call processing
• Basic Call State Model
defines the IN-related call states
• BCSM distinguishes SSP SSF CCF
between: - Detection Points - states to input or output call processing -Points in Call - noninterruptible phases of call processing
SCP
Ex A
Ex B
O BCSM
T BCSM
O BCSM
T BCSM
Originating Basic Call State Model
PIC 1: Null & Auth. Orig. Attempt DP 10
PIC 6: Exception
o Abandon
DP 1
Orig Attempt Authorized
PIC 2: Collect Info
DP 2
Collected Info
PIC 3: Analyze Info
DP 3 PIC 4: Routing & Alerting
Analyzed Info
DP 4
DP 5 DP 7 DP 9
Answer
DP 6
PIC 5: Active
o Disconnect
DP 8
DP - Detection Point
o mid call PIC - Point in call
Detection Points of O BCSM
DP 1 Origination Attempt Authorized
a call request is detected and accepted ( dial tone is played )
DP 2 Collected Information
a complete digit string has been received
DP 3 Analyzed Information
at this point a complete routing address is available and the type of party is known
DP 4 Route Select Failure
routing to a destination was not successful,e.g. due to a congested route. The causes for DP 4 should be defined.
DP 5 O Called Party Busy
The B-Sub is busy
DP 6 O No Answer
B-party does not answer in a defined time period
DP 7 O Answer
B-party has accepted the call . Begin of crossconnection and charging.
DP 8 O Mid Call
A service feature request is received ,e.g. hook-flash
DP 9 O Disconnect
One of the two parties has hooked on
DP 10 O Abandon
The calling party abandons the call as a normal behavior
Terminating Basic Call State
PIC 7: T Null & Auth. Term. Attempt DP 18
PIC 11: T Exception
T Abandon
Term Attempt Authorized
DP 12
T Called Party Busy
DP 13
PIC 8: Select Facility & Present Call
T No Answer
PIC 9: T Alerting DP 14
T Answer
DP 17
DP 15
PIC 10: T Active
T Disconnect
DP 16
T mid call
DP - Detection Point PIC - Point in call
Detection Points of T
•
DP 12 Termination Attempt
Detection of an incoming call and authorization to route the call to the destination.
• •
DP 13 T Called Party
Terminating party is busy
DP 14 T No Answer
Terminating party does not answer in a specified time
• •
DP 15 T Answer
Call is accepted and answered by the B-party
DP 16 T Mid Call
A service feature request is received,e.g. hook-flash
• •
DP 17 T Disconnect
One of the two parties has hooked on
DP 18 T Abandon
Calling party has abandoned the call
9.3 List of INAP Operation
Operation (CS1) activate service filtering activity test apply charging apply charging report assist request instruction call gap call information report call information request cancel collect information connect connect to resource continue disconnect forward connection establish temporary connection event notification charging event report BCSM furnish charging information initialDP initiate call attempt play announcement prompt and collect information release call request notification charging event request report BCSM event reset timer send charging information service filtering response specialized resource report
abbreviation ASF AT AC ACR ARI CG CIR CIQ CA CI CON CTR CUE DFC ETC ENC ERB FCI IDP ICA PA PAC RC RNCE RRB RT SCI SFR SRR
Operation (CS2) disconnect fwd conn with arguments continue with argument disconnect leg entity released move leg split leg
abbreviation DFCWA CWA DL ER ML SL
9.4 Usage of the INAP operation and there parameters
9.4.1 Activate Service Filtering ASF
The SCP uses this operation to instruct the SSP to deal with requests for a specific service and to count each specific call. The count of filtered calls will be returned to the SCP after a specified interval. Parameters filtered call treatment filtering characteristics filtering time out filtering criteria start time
9.4.2 Activity Test AT
The SCP checks for the continued existence of a relationship between SCP and SSP. If the relationship still exists, then the SSP will respond with activity test response. In case that no reply is received, the SCP will assume that the SSP has failed and will take the appropriate action. Parameters None
9.4.3 Activity Test Response ATR
ATR is the response to the activity test of the SCP.
Parameters None
9.4.4 Apply Charging AC
The operation is used by the SCP for interacting with the SSP on-line mechanisms that are used in calculating the current call charge. This operation may be invoked several times during a call. Used for e.g. credit limit supervision and SMP/SCP based charging. Parameters Billing Charging characteristics (network operator specific) Send calculation to SCP indicator Party to charge
9.4.5 Apply Charging Report ACR
This operation is used by the SSP to report to the SCP the occurrence of a specific charging event as requested by the SCP using the ApplyCharging operation. Parameters Call result as requested by the AC.
9.4.6 Assist Request Instruction ARI
ARI is sent to SCP by the SSP, which is acting as the assisting SSP in an assist procedure. It is generated when the assisting SSP receives a call from an initiating SSP containing information indicating an assist procedure. Parameters Correlation Id IP available IP SSP capabilities
9.4.7 Call Gap CG
This Operation is used to request the SSP to reduce the rate at which specific service requests are sent to the SCF. Parameters Gap criteria : - called party number - calling party number - service key Gap indicators : - duration - gap interval Gap treatment
9.4.8 Call Information Report CIR
CIR is used to send call information for a single call to the SCP in a previous call information request. It is sent at the end of the call.
Parameters Requested information Call attempt elapse time Call stop time Call connected time Called address Release cause
9.4.9 Call Information Request CIQ
It is used to request the SSP to save information about a call and report it to the SCP at the end of the call. Parameters Requested information Call attempt elapse time Call stop time Call connected time Called address Release cause
9.4.10
Cancel Call Information Request CA
CA is used to cancel a previous call information request. Parameters Invoke id
9.4.11
Collect Information CI
It requests the SSP to perform basic call processing actions to prompt calling party for destination information (more digits of B-party). Parameters Numbering plan
9.4.12
Connect CON
CON is used to set up a call to a defined destination. Parameters Destination routing address Nat Service Interaction Indicator
9.4.13
Connect to Resource CTR
CTR is used to create a connection between the SSP and the IP. After this the SSP works as a relay station for all operations and reports exchanged between SCP and IP. Parameters IP routing address Service interaction indicator
9.4.14
Continue CUE
CUE requests the SSP to proceed with call processing at the DP at which it previously suspended call processing to await SCP instructions. SSP completes DP processing and continues basic call processing. Parameters None
9.4.15
Continue With Argument CWA
CWA requests the SSP to proceed with call processing at the DP at which it previously suspended call processing to await SCP instructions (i.e., proceed to the next point in call in the BCSM). It is also used to provide additional service related information to a User (Called party or Calling party) whilst the call processing proceeds. Parameters Leg Id
9.4.16
Disconnect Forward Connection DFC
DFC is used to disconnect the calling party from the IP Parameters None
9.4.17
Disconnect Forward Connection with Argument DFCWA
This operation is used to disconnect one party from the IP. Parameters Call Segment Id
9.4.18
Entity Released ER
This operation is used to inform the SCP of an error or exception. Parameters Call Segment Id Reason Cause
9.4.19
Establish Temporary Connection ETC
ETC is used to set up a connection between an initiating SSP and an assisting SSP to get finally a connection to the IP. Parameters Assisting SSP routing address Correlation id Party to Connect
9.4.20
Event Notification Charging ENC
ENC is used to report the occurrence of a specific charging event as requested by the SCP using the request notification charging event operation
Parameters Event type charging Event specific information charging Leg Id
9.4.21
Event Report BCSM ERB
ERB is used to notify the SCP of a call-related event (e.g. busy or no answer) previously requested by the SCP in a request report BCSM event. Parameters Event type BCSM Leg Id Event specific information BCSM
9.4.22
Furnish Charging Information FCI
FCI gives some charging information to the SSP, to enable it to generate a billing record for the service subscriber (B-party). FCI may be invoked several times during a call. Parameters Billing charging characteristics
9.4.23
Initial DP IDP
IDP is generated by the SSP when a trigger is detected at any DP in the BCSM, to request instructions from the SCP. Parameters
Service key Called party number Calling party number Calling party category
9.4.24
Initiate Call Attempt ICA
SCP requests the SSP to set up a call using address information provided Parameters Destination routing address Alerting pattern Calling party number
9.4.25
Move Leg ML
This operation is used to move a leg from one Call Segment to another with which it is associated . Parameters Leg Id to Move Target Call Segment
9.4.26
Play Announcement PA
It is used after establishment of a connection to IP to play an announcement or a tone. Parameters • Information to send • Disconnection from IP forbidden • Request Announcement completed indication
9.4.27
Prompt and Collect User Information
PAC
It is used after establishment of a connection to the IP to play an announcement or a tone and to collect information from the caller. Parameters Information to send Disconnection from IP forbidden Collected information
9.4.28
Release Call RC
RC is used by the SCP to cancel an existing call at any phase of the call for all parties of a call. Parameters Initial Call Segment Associated Call Segment Release Cause
9.4.29
Release Leg RL
This operation is used to release a certain leg with a required cause or alternatively to initiate a delayed release of the whole IN call (after playing of a warning tone to one or both parties involved in the call) Parameters • Cause • Leg Id • Warning before Release
9.4.30
Request Notification Charging Event
RNCE
RNCE is used to request the SSP to monitor for a charging related event, then send a notification back to the SCP when the event is detected. Parameters Event type charging Monitor mode Leg id
9.4.31
Request Report BCSM Event RRB
RRB is used to request the SSP to monitor for a call-related event (e.g. busy or no answer), then send a notification back to the SCP when the event is detected. Parameters BCSM event list: - event type - monitor mode - leg id - specific criteria
9.4.32
Reset Timer RT
RT is used to request the SSP to refresh an application timer in the SSP set by a previous operation RRB. Parameters Timer id Timer value
9.4.33
Send Charging Information SCI
This operation is used to instruct the SSP on the charging information to be sent by the SSP to the calling side. The sending of the charging information can either be by charge pulses or signaling or internal if SSP is local exchange. The SCI can be sent several times during a call, e.g. before setup, but also during the connections.
Parameters Billing charging characteristics (network operator specific) Leg id (for two party calls)
9.4.34
Service Filtering Response SFR
This operation is used to send back to the SCP the values of counters specified in a previous ASF operation. Parameters Counters value Filtering criteria
9.4.35
Specialized Resource Report SRR
SRR is the response to a play announcement operation when the request announcement completed indication is set or to indicate the start of an announcement caused by operation PA or PAC. Parameters Announcement completed Announcement started
9.4.36
Split Leg SL
This operation is issued by the SCP to separate one joined leg from a multi-way connection or to interrupt the bearer connection between the involved legs of a single 2 party CS Parameters Leg to be split New Call Segment
10 Example of IN dialogue
10.1 Call set up without monitoring
10.2 Call set up with monitoring, busy detected
10.3 Call set up after playing announcement with charge information
10.4 Credit Limit Supervision
11 Distributed functional plane model Q1204
12 Service creation
New services are designed with standard SW elements named SIB.
12.1 Definition of the SIB
SIBs are service independent building blocks which are used to build a new service. The SIBs are independent from any physical architecture consideration. Each SIB has an interface with one or more inputs and one or more outputs. SIBs are reusable modular building blocks, describing a single complete activity and used by the service designer to create services.
Service support data
Start point
SIB
Call instance data
Call instance data
12.2 SIB chains for the service creation
SIB1
SIB1
SIB1
SIB1
SIB1
SIB1
Point of input
Point of return 1
Point of return 2
12.3 The standard SIB:
Algorithm: execute a mathematical operation like plus, minus and so on.. Authenticate: verification of the user Screen: compare the identification with a data in a stored table Charge: used to adapt a specific charging method Service Data Management: To manipulate the data of a specific service. Compare: Compare two parameters and gives the result Status Notification: To identify the status of a call Distribution: Distribute calls to different outputs. Translate: Translate an input parameter to a output parameter according to a stored table. Limit: Limit the maximum amount of calls User Interaction: Used to activate a dialogue with the user. Log Call: Store the call information. Verify: Verification of the received information Queue: Used for queuing the calls.
12.4 Example of a service creation
3 4 5
6 7 8 9
IN Introduction:.................................................................................................................. 3 History of the telephone service......................................................................................... 4 2.1 Manual switching ....................................................................................................... 4 2.2 Automatic switching: ................................................................................................. 5 2.3 Electronic switching:.................................................................................................. 6 2.4 Digital switching ........................................................................................................ 6 2.5 Network architecture:................................................................................................. 7 IN goals: ............................................................................................................................. 8 Overview of Typical IN Services..................................................................................... 10 User Hierarchy: ................................................................................................................ 11 5.1 Network Operator, IN Operator: .............................................................................. 11 5.2 Service Provider ....................................................................................................... 11 5.3 Service Customer / Service Subscriber .................................................................... 11 5.4 Service User ............................................................................................................. 12 Examples of an IN call setup: .......................................................................................... 12 Intelligent network architecture: ...................................................................................... 12 Common channel signalling SS7: .................................................................................... 14 8.1 SS7 Protocol stack.................................................................................................... 16 INAP Protocol .................................................................................................................. 17 9.1 Trigger points an events ........................................................................................... 17 9.2 Call Control Function & Basic Call State Model..................................................... 18 9.3 List of INAP Operation ............................................................................................ 25 9.4 Usage of the INAP operation and there parameters................................................. 27 9.4.1 Activate Service Filtering ASF ........................................................................ 27 9.4.2 Activity Test AT............................................................................................... 27 9.4.3 Activity Test Response ATR............................................................................ 27 9.4.4 Apply Charging AC ......................................................................................... 28 9.4.5 Apply Charging Report ACR........................................................................... 28 9.4.6 Assist Request Instruction ARI ....................................................................... 28 9.4.7 Call Gap CG ..................................................................................................... 29 9.4.8 Call Information Report CIR............................................................................ 29 9.4.9 Call Information Request CIQ ......................................................................... 30 9.4.10 Cancel Call Information Request CA............................................................... 30 9.4.11 Collect Information CI ..................................................................................... 30 9.4.12 Connect CON .................................................................................................. 30 9.4.13 Connect to Resource CTR................................................................................ 31 9.4.14 Continue CUE .................................................................................................. 31 9.4.15 Continue With Argument CWA....................................................................... 31 9.4.16 Disconnect Forward Connection DFC ............................................................. 31
9.4.17 Disconnect Forward Connection with Argument DFCWA ............................. 32 9.4.18 Entity Released ER........................................................................................... 32 9.4.19 Establish Temporary Connection ETC ............................................................ 32 9.4.20 Event Notification Charging ENC ................................................................... 33 9.4.21 Event Report BCSM ERB................................................................................ 33 9.4.22 Furnish Charging Information FCI .................................................................. 33 9.4.23 Initial DP IDP................................................................................................... 34 9.4.24 Initiate Call Attempt ICA................................................................................. 34 9.4.25 Move Leg ML .................................................................................................. 34 9.4.26 Play Announcement PA ................................................................................... 34 9.4.27 Prompt and Collect User Information PAC ................................................. 35 9.4.28 Release Call RC ............................................................................................... 35 9.4.29 Release Leg RL ................................................................................................ 35 9.4.30 Request Notification Charging Event RNCE.................................................. 36 9.4.31 Request Report BCSM Event RRB.................................................................. 36 9.4.32 Reset Timer RT ................................................................................................ 36 9.4.33 Send Charging Information SCI....................................................................... 37 9.4.34 Service Filtering Response SFR....................................................................... 37 9.4.35 Specialized Resource Report SRR ................................................................... 37 9.4.36 Split Leg SL ..................................................................................................... 38 10 Example of IN dialogue ............................................................................................... 39 10.1 Call set up without monitoring................................................................................. 39 10.2 Call set up with monitoring, busy detected .............................................................. 39 10.3 Call set up after playing announcement with charge information ........................... 40 10.4 Credit Limit Supervision.......................................................................................... 41 11 Distributed functional plane model Q1204 .................................................................. 42 12 Service creation ............................................................................................................ 43 12.1 Definition of the SIB ................................................................................................ 43 12.2 SIB chains for the service creation........................................................................... 44 12.3 The standard SIB:..................................................................................................... 44 12.4 Example of a service creation .................................................................................. 45
1 IN Introduction:
In the late 80 Years, different American operator tries to solve some problems related to the realisation of different services with the modification of the switch programs. And so the realisation of each service needs a new implementation and upgrade of all switches. In fact this leads to an expansion of the costs related to the SW of the mentioned switches, as the provider were in a strong position to set the prices without any control. In fact the cost of every service implementation will be multiplied with the number of the switch provider. This in addition to time needed for the development and implementation of the service which exceeds in the majority of cases 4 years. This in addition to the fact that for some services a central database is needed. The implementation of the service in all switches needs a multiple effort as the same database has to be copied over all. This will lead additionally, to a huge expansion of the costs related to the administrative and operational work for the operator.
2 History of the telephone service
2.1 Manual switching
In 1876, Dr. Alexander Graham Bell, a Boston Professor of Speech, and his partner, Thomas A. Watson, had been working for several months to develop a harmonic telegraph. The harmonic telegraph would allow several telegraph messages to be transmitted on a single wire by tuning the transmitted signals into different frequencies. As their work progressed, Bell and Watson thought that if they could transmit basic frequencies, they could also build a device that could transmit actual speech. Bell knew that others were making progress toward the same invention using similar techniques. Bell, early on February 14, 1876, filed for a patent on the device that he and Watson felt would be capable of transmitting the spoken word. Only hours later, Elisha Gray filed for a patent on a very similar device. The used receiver and transmitter are realised according to the figure 1 and 2.
Fig 1 Transmitter
Fig. 2 Receiver
To interconnect the different new telephone subscribers and also different localities a manual switchboard was used as firstp Fig 3. During this area the operator was the master of the telephony, so that the intelligence and the flexibility were at a very high level.
Fig. 3. Manual switch
2.2 Automatic switching:
Within 5 years of the first telephone conversation, nearly 150,000 subscribers were using the new local telephone service. Rates were high, even by today’s standards: $100 a year for residential service and $150 a year for business service. Lines were strung between the local offices, or Telephone Exchanges, and it was soon possible to call from one city to another using two or more operators in the different exchanges through which the call passed. This huge explosion of the subscriber numbers leads to the situation of blockage as it was very expensive to covers all demands only by operators. So the next step was introduced with the automatic switches. This area is characterized by two switch types the step by step and the crossbar. The step by step switch uses the dialled information digit by digit and selects the route accordingly. This method does not allow alternate routes and so the call will be rejected even if other possibility exists to continuing it. Contrarily the crossbar stores the dialled information in a central unit and so it will be possible to use this common control unit to find a second route and send the information to the neighbour switches.
2.3 Electronic switching:
During the 1950s, Bell Laboratories began working on a new type of switching system to meet the growing demand for telephone services more economically. These electronic switching systems were made possible by the invention of the transistor in 1947. By employing computer techniques, the functions of the common controls can be achieved using a Central Processing Unit (CPU) programmed with appropriate software to perform all the functions desired in processing telephone calls. This method of control is called Stored Program Control (SPC). Fig 4.
Fig 4 SPC Stored Program control
2.4 Digital switching
In the 1950s, AT&T’s Bell Laboratories and Western Electric Manufacturing introduced a new carrier system to be used in the trunking and long distance networks. This new carrier system, called a T-carrier, uses digital transmission instead of analogue transmission. Because of the many advances to solid-state electronics and integrated circuits that handle digital signals, telephone system designs are changing toward an all digital network. The newer systems convert voice and signalling information to digital signals for transmission. There are three techniques used in the transmission of a digital signal: Pulse Amplitude Modulation (PAM), Pulse Code Modulation (PCM), and Time Division Multiplexing (TDM). A person’s voice can be displayed on an oscilloscope as a sine wave. A sample of this sine wave or signal, taken in an instant of time, can closely represent the signal on either side of the sample point for that same instant of time.
If the signal is sampled at twice the rate of the highest frequency component in the signal, the samples will contain all of the information contained in the original signal. In the case of telephone signals, since the voice channel bandwidth has been set at 4,000 Hz, the sample rate of 8,000 samples per second would be sufficient to reproduce the signal. In case that the sampling will use one byte for the amplitude per sample, than a 64 Kbit/s channel per call direction will be generated. Fig. 5.
Fig. 5 Digital Carrier Systems
2.5 Network architecture:
Core networks are as a rule composed of several network layers. In this way, for instance, a difference is made between the local level (local network) and the long-distance level (transit network for the connection of the local networks). The number of network layers and to what degree the network has a star-shaped, intermeshed, or a mixed structure differs from network operator to network operator. Figure 5 shows an example of a possible network configuration by an operator.
Local Local Local Gateway
Transi t
Transi t
Local
Transi t
Transi t
Local netwo
Local
Local Local
Chanel associated Or Common channel Signalling
Local netwo Local Local Local netwo
Network architecture
3 IN goals:
Intelligent Networks are used to make public switched telecommunication networks more flexible. IN can serve fixed networks (PSTN/ISDN) as well as mobile networks (GSM). Additional flexibility is enabled according to different aspects: Flexible Service creation centralized service management and adaptation. No changes are needed in the switching networks for the introduction of new IN-based services.
Flexible routing selects the destination of a telephone call according to criteria like time, origin, user input and so on. It also includes features like percentage distribution or “the nth call” and “every nth call“. Flexible routing answers the question: “Where to put the call?” Flexible screening checks whether it is allowed to connect a certain call according to criteria like time, origin, destination, user input and so on. Black or white lists can be used as check patterns. Flexible Billing allows flexible online or offline charging methods. Criteria like time or distance can be evaluated. Flexible User Interactive Dialogue (UID) enables the service to request additional input from the calling user such as PIN or to select a choice from a menu. Statistics data can be achieved according to counters, call information, etc.
4 Overview of Typical IN Services
Freephone Universal Access Number (alias Universal Number, UN) Premium-Rate (alias Tele-Info Service) are also termed Number Translation Services (NTS), according to their principal function: they translate the IN number into a public phone number (public directory number) by executing the service logic. Technically they just differ in their charging modality. Televoting is a service especially designed for voting by a phone call, especially for Mass Calling. The Virtual Private Network service can be seen as the simulation of a Private Branch Exchange (PBX) on a public network. It meets the increasing demands of companies and institutions for flexible, customizable private networks eliminating restrictions found in the basic public network. Service variants for fixed and mobile networks are available as well as fixed/mobile integrating ones. Virtual Card Calling and Universal Personal Telecommunication offer flexibility in charging and mobility also within fixed networks. Prepaid Service Card or Prepaid Card Service is a service for online charging of the subscriber. Therefore an account is continuously decremented according to the implemented charging algorithm. Personal Number Service offers a set of possible destinations, a Service Customer may own. The Service tries one destination phone after the other until the incoming call is answered at one of it. Additional screening functions both for incoming and outgoing calls are available.
5 User Hierarchy:
We distinguish: Network Operator, IN Operator Service Provider Service Customer / Service Subscriber Service User
5.1 Network Operator, IN Operator:
Manages Network Establish connection to other networks (interworking) Sets up contracts with service providers
5.2 Service Provider
Uses one or more IN-networks Is customer of one or more network operator Create services, customizes, markets and manage them Sets up contract with service customers
5.3 Service Customer / Service Subscriber
Subscribes to one or more IN services Is assigned to corresponding IN numbers Is customer of one or more service providers Parameterizes the services
5.4 Service User
Diales an IN number Uses the services offered to him Is supported by service subscriber May parameterize the IN service via DTMF
6 Examples of an IN call setup:
7 Intelligent network architecture:
An Intelligent Network separates the control of calls from the call itself. Logic programs residing at Service Control Points (SCP) implement services. The switch only implements basic call processing so that if any services are requested by the call, a query is sent to the SCP which instructs the switch on the call control required for the service requested. Bellow figure 7 is the general intelligent network architecture.
SMF Service Managemen SCF Service INAP/SS7 INAP/SS7
SCF Service Creation, SDF Service
SS
INAP/SS
FORE SYSTEMS
SRF Intelligent Peripheral, e.g.IVR
Voice
Voice
SSF Service
Fig. 7 IN architecture
8 Common channel signalling SS7:
With CCS, the signalling paths and voice paths are carried on separate facilities. The voice channels are dedicated for voice and information type signals only (tones, announcements). The signalling channels carry the control, address, and supervisory signals for the calls. In networks that employ common-channel signalling, there are actually two separate networks working in conjunction with each other: · Message Network - This consists of the trunks that transport the voice or data between locations. · Signalling Network - This consists of “common” high speed data links that transport supervision and control signals for trunks, as well as data messages associated with other enhanced network services. Common-channel signalling improves the efficiency of the conventional network by providing a faster, more flexible means for the exchange of call set-up information and by providing the capability for enhanced services through its ability to exchange information packets with other users of the network. The network of the future is expected to be an intelligent, high speed, digital network using common channelling signalling. TERM: COMMON CHANNEL SIGNALING -- A system for exchanging trunk signalling information between processor equipped signalling systems over a network of signalling links. Fig 8 shows the functionality of the SS7 and fig. 9 a SS7 network.
Fig 8 SS7
Fig. 9 SS7 networks
8.1 SS7 Protocol stack
The mostly used signalling in telephony networks is the SS7 with the protocol stack shown in the fig 10.
SS7 user
ISUP
INAP BSSAP
CAMEL
MAP
TCAP
SCCP
MTP
Fig. 10 SS7 Protocol stack
9 INAP Protocol
9.1 Trigger points an events
Trigger Detection Points
if call processing is detecting an inquiry of the SCP a call becomes an IN-call there are defined points within call processing to interrupt it these points are called Trigger Detection Points TDP TDP's are permanent created at the switches there are 2 types of TDP's: TDP-R (request) suspend call processing and activate a dialogue to the SCP TDP-N (notification) causes a message transfer to the SCP without suspension of call processing
9.2 Call Control Function & Basic Call State Model
SCP
• Call Control Function
realizes call processing
• Basic Call State Model
defines the IN-related call states
• BCSM distinguishes SSP SSF CCF
between: - Detection Points - states to input or output call processing -Points in Call - noninterruptible phases of call processing
SCP
Ex A
Ex B
O BCSM
T BCSM
O BCSM
T BCSM
Originating Basic Call State Model
PIC 1: Null & Auth. Orig. Attempt DP 10
PIC 6: Exception
o Abandon
DP 1
Orig Attempt Authorized
PIC 2: Collect Info
DP 2
Collected Info
PIC 3: Analyze Info
DP 3 PIC 4: Routing & Alerting
Analyzed Info
DP 4
DP 5 DP 7 DP 9
Answer
DP 6
PIC 5: Active
o Disconnect
DP 8
DP - Detection Point
o mid call PIC - Point in call
Detection Points of O BCSM
DP 1 Origination Attempt Authorized
a call request is detected and accepted ( dial tone is played )
DP 2 Collected Information
a complete digit string has been received
DP 3 Analyzed Information
at this point a complete routing address is available and the type of party is known
DP 4 Route Select Failure
routing to a destination was not successful,e.g. due to a congested route. The causes for DP 4 should be defined.
DP 5 O Called Party Busy
The B-Sub is busy
DP 6 O No Answer
B-party does not answer in a defined time period
DP 7 O Answer
B-party has accepted the call . Begin of crossconnection and charging.
DP 8 O Mid Call
A service feature request is received ,e.g. hook-flash
DP 9 O Disconnect
One of the two parties has hooked on
DP 10 O Abandon
The calling party abandons the call as a normal behavior
Terminating Basic Call State
PIC 7: T Null & Auth. Term. Attempt DP 18
PIC 11: T Exception
T Abandon
Term Attempt Authorized
DP 12
T Called Party Busy
DP 13
PIC 8: Select Facility & Present Call
T No Answer
PIC 9: T Alerting DP 14
T Answer
DP 17
DP 15
PIC 10: T Active
T Disconnect
DP 16
T mid call
DP - Detection Point PIC - Point in call
Detection Points of T
•
DP 12 Termination Attempt
Detection of an incoming call and authorization to route the call to the destination.
• •
DP 13 T Called Party
Terminating party is busy
DP 14 T No Answer
Terminating party does not answer in a specified time
• •
DP 15 T Answer
Call is accepted and answered by the B-party
DP 16 T Mid Call
A service feature request is received,e.g. hook-flash
• •
DP 17 T Disconnect
One of the two parties has hooked on
DP 18 T Abandon
Calling party has abandoned the call
9.3 List of INAP Operation
Operation (CS1) activate service filtering activity test apply charging apply charging report assist request instruction call gap call information report call information request cancel collect information connect connect to resource continue disconnect forward connection establish temporary connection event notification charging event report BCSM furnish charging information initialDP initiate call attempt play announcement prompt and collect information release call request notification charging event request report BCSM event reset timer send charging information service filtering response specialized resource report
abbreviation ASF AT AC ACR ARI CG CIR CIQ CA CI CON CTR CUE DFC ETC ENC ERB FCI IDP ICA PA PAC RC RNCE RRB RT SCI SFR SRR
Operation (CS2) disconnect fwd conn with arguments continue with argument disconnect leg entity released move leg split leg
abbreviation DFCWA CWA DL ER ML SL
9.4 Usage of the INAP operation and there parameters
9.4.1 Activate Service Filtering ASF
The SCP uses this operation to instruct the SSP to deal with requests for a specific service and to count each specific call. The count of filtered calls will be returned to the SCP after a specified interval. Parameters filtered call treatment filtering characteristics filtering time out filtering criteria start time
9.4.2 Activity Test AT
The SCP checks for the continued existence of a relationship between SCP and SSP. If the relationship still exists, then the SSP will respond with activity test response. In case that no reply is received, the SCP will assume that the SSP has failed and will take the appropriate action. Parameters None
9.4.3 Activity Test Response ATR
ATR is the response to the activity test of the SCP.
Parameters None
9.4.4 Apply Charging AC
The operation is used by the SCP for interacting with the SSP on-line mechanisms that are used in calculating the current call charge. This operation may be invoked several times during a call. Used for e.g. credit limit supervision and SMP/SCP based charging. Parameters Billing Charging characteristics (network operator specific) Send calculation to SCP indicator Party to charge
9.4.5 Apply Charging Report ACR
This operation is used by the SSP to report to the SCP the occurrence of a specific charging event as requested by the SCP using the ApplyCharging operation. Parameters Call result as requested by the AC.
9.4.6 Assist Request Instruction ARI
ARI is sent to SCP by the SSP, which is acting as the assisting SSP in an assist procedure. It is generated when the assisting SSP receives a call from an initiating SSP containing information indicating an assist procedure. Parameters Correlation Id IP available IP SSP capabilities
9.4.7 Call Gap CG
This Operation is used to request the SSP to reduce the rate at which specific service requests are sent to the SCF. Parameters Gap criteria : - called party number - calling party number - service key Gap indicators : - duration - gap interval Gap treatment
9.4.8 Call Information Report CIR
CIR is used to send call information for a single call to the SCP in a previous call information request. It is sent at the end of the call.
Parameters Requested information Call attempt elapse time Call stop time Call connected time Called address Release cause
9.4.9 Call Information Request CIQ
It is used to request the SSP to save information about a call and report it to the SCP at the end of the call. Parameters Requested information Call attempt elapse time Call stop time Call connected time Called address Release cause
9.4.10
Cancel Call Information Request CA
CA is used to cancel a previous call information request. Parameters Invoke id
9.4.11
Collect Information CI
It requests the SSP to perform basic call processing actions to prompt calling party for destination information (more digits of B-party). Parameters Numbering plan
9.4.12
Connect CON
CON is used to set up a call to a defined destination. Parameters Destination routing address Nat Service Interaction Indicator
9.4.13
Connect to Resource CTR
CTR is used to create a connection between the SSP and the IP. After this the SSP works as a relay station for all operations and reports exchanged between SCP and IP. Parameters IP routing address Service interaction indicator
9.4.14
Continue CUE
CUE requests the SSP to proceed with call processing at the DP at which it previously suspended call processing to await SCP instructions. SSP completes DP processing and continues basic call processing. Parameters None
9.4.15
Continue With Argument CWA
CWA requests the SSP to proceed with call processing at the DP at which it previously suspended call processing to await SCP instructions (i.e., proceed to the next point in call in the BCSM). It is also used to provide additional service related information to a User (Called party or Calling party) whilst the call processing proceeds. Parameters Leg Id
9.4.16
Disconnect Forward Connection DFC
DFC is used to disconnect the calling party from the IP Parameters None
9.4.17
Disconnect Forward Connection with Argument DFCWA
This operation is used to disconnect one party from the IP. Parameters Call Segment Id
9.4.18
Entity Released ER
This operation is used to inform the SCP of an error or exception. Parameters Call Segment Id Reason Cause
9.4.19
Establish Temporary Connection ETC
ETC is used to set up a connection between an initiating SSP and an assisting SSP to get finally a connection to the IP. Parameters Assisting SSP routing address Correlation id Party to Connect
9.4.20
Event Notification Charging ENC
ENC is used to report the occurrence of a specific charging event as requested by the SCP using the request notification charging event operation
Parameters Event type charging Event specific information charging Leg Id
9.4.21
Event Report BCSM ERB
ERB is used to notify the SCP of a call-related event (e.g. busy or no answer) previously requested by the SCP in a request report BCSM event. Parameters Event type BCSM Leg Id Event specific information BCSM
9.4.22
Furnish Charging Information FCI
FCI gives some charging information to the SSP, to enable it to generate a billing record for the service subscriber (B-party). FCI may be invoked several times during a call. Parameters Billing charging characteristics
9.4.23
Initial DP IDP
IDP is generated by the SSP when a trigger is detected at any DP in the BCSM, to request instructions from the SCP. Parameters
Service key Called party number Calling party number Calling party category
9.4.24
Initiate Call Attempt ICA
SCP requests the SSP to set up a call using address information provided Parameters Destination routing address Alerting pattern Calling party number
9.4.25
Move Leg ML
This operation is used to move a leg from one Call Segment to another with which it is associated . Parameters Leg Id to Move Target Call Segment
9.4.26
Play Announcement PA
It is used after establishment of a connection to IP to play an announcement or a tone. Parameters • Information to send • Disconnection from IP forbidden • Request Announcement completed indication
9.4.27
Prompt and Collect User Information
PAC
It is used after establishment of a connection to the IP to play an announcement or a tone and to collect information from the caller. Parameters Information to send Disconnection from IP forbidden Collected information
9.4.28
Release Call RC
RC is used by the SCP to cancel an existing call at any phase of the call for all parties of a call. Parameters Initial Call Segment Associated Call Segment Release Cause
9.4.29
Release Leg RL
This operation is used to release a certain leg with a required cause or alternatively to initiate a delayed release of the whole IN call (after playing of a warning tone to one or both parties involved in the call) Parameters • Cause • Leg Id • Warning before Release
9.4.30
Request Notification Charging Event
RNCE
RNCE is used to request the SSP to monitor for a charging related event, then send a notification back to the SCP when the event is detected. Parameters Event type charging Monitor mode Leg id
9.4.31
Request Report BCSM Event RRB
RRB is used to request the SSP to monitor for a call-related event (e.g. busy or no answer), then send a notification back to the SCP when the event is detected. Parameters BCSM event list: - event type - monitor mode - leg id - specific criteria
9.4.32
Reset Timer RT
RT is used to request the SSP to refresh an application timer in the SSP set by a previous operation RRB. Parameters Timer id Timer value
9.4.33
Send Charging Information SCI
This operation is used to instruct the SSP on the charging information to be sent by the SSP to the calling side. The sending of the charging information can either be by charge pulses or signaling or internal if SSP is local exchange. The SCI can be sent several times during a call, e.g. before setup, but also during the connections.
Parameters Billing charging characteristics (network operator specific) Leg id (for two party calls)
9.4.34
Service Filtering Response SFR
This operation is used to send back to the SCP the values of counters specified in a previous ASF operation. Parameters Counters value Filtering criteria
9.4.35
Specialized Resource Report SRR
SRR is the response to a play announcement operation when the request announcement completed indication is set or to indicate the start of an announcement caused by operation PA or PAC. Parameters Announcement completed Announcement started
9.4.36
Split Leg SL
This operation is issued by the SCP to separate one joined leg from a multi-way connection or to interrupt the bearer connection between the involved legs of a single 2 party CS Parameters Leg to be split New Call Segment
10 Example of IN dialogue
10.1 Call set up without monitoring
10.2 Call set up with monitoring, busy detected
10.3 Call set up after playing announcement with charge information
10.4 Credit Limit Supervision
11 Distributed functional plane model Q1204
12 Service creation
New services are designed with standard SW elements named SIB.
12.1 Definition of the SIB
SIBs are service independent building blocks which are used to build a new service. The SIBs are independent from any physical architecture consideration. Each SIB has an interface with one or more inputs and one or more outputs. SIBs are reusable modular building blocks, describing a single complete activity and used by the service designer to create services.
Service support data
Start point
SIB
Call instance data
Call instance data
12.2 SIB chains for the service creation
SIB1
SIB1
SIB1
SIB1
SIB1
SIB1
Point of input
Point of return 1
Point of return 2
12.3 The standard SIB:
Algorithm: execute a mathematical operation like plus, minus and so on.. Authenticate: verification of the user Screen: compare the identification with a data in a stored table Charge: used to adapt a specific charging method Service Data Management: To manipulate the data of a specific service. Compare: Compare two parameters and gives the result Status Notification: To identify the status of a call Distribution: Distribute calls to different outputs. Translate: Translate an input parameter to a output parameter according to a stored table. Limit: Limit the maximum amount of calls User Interaction: Used to activate a dialogue with the user. Log Call: Store the call information. Verify: Verification of the received information Queue: Used for queuing the calls.
12.4 Example of a service creation
