Wireless Intelligent Network (WIN)
Tutorial
What is the Wireless Intelligent Network (WIN)?
• The extension of wireline Intelligent Network(IN) concepts to IS-41 based wireless network
• An architecture that separates the service logic and/or feature functionality from the wireless network switch and places that functionality in other platforms in the network
• The specific work of the Telecommunications Industry Association’s (TIA) WIN Task Group(TR- 45.2.2.4)
What is IS-41?
MSC MSC
HLR
MSC MSC
HLR
PSTN
Wireless Operator in U.S.
Wireless Operator in Latin America
IS-41 Intersystem Operations
MSC EIR
MSC PSTNBSMS
HLRAC VLR ISDN
MC MC VLRSME SME
IS-41 Intersystem Operations
• Network Elements– Mobile station(MS)
– Base station (BS)
– Mobile switching center (MSC)
– Home location register (HLR)
– Visitor location register (VLR)
– Authentication center (AC)
– Equipment identity register (EIR)
– Message center (MC)
– Short message entity (SME)
IS-41 Network Elements
• Mobile Station (MS)– The interface equipment used to terminate the radio
path at the user side. The MS provides the user the capabilities to access network services.
• Mobile Switching Center(MSC)– Automatic system which constitutes the interface for
user traffic between the wireless network and other public switched networks, or other MSCs in the same or other wireless networks
IS-41 Network Elements
• Home Location Register (HLR)– Location register to which a user’s identity is assigned for
record purposes such as:• Subscriber information• Mobile station information
– Provides service control and mobility management for subscribers
– HLR may or may not be located within, and be indistinguishable from, an MSC
– HLR may serve more than one MSC
IS-41 Network Elements
• Authentication Center (AC)– Element that manages the authentication
information related to the mobile station– The AC may or may not be located within, and be
indistinguishable from, an HLR
IS-41 Network Elements
• Visitor Location Register (VLR)– Location register used by an MSC to retrieve
information for handling calls to or from a visiting mobile station user
– Provides mobility management for subscribers in visited system
– VLR may or may not be located within, and be indistinguishable from, an MSC
– VLR may serve more than one MSC
IS-41 Network Elements
• Message Center (MC)– The message center stores and forwards short messages– It may also provide supplementary services for short
message services
• Short Message Entity (SME)– The short message entity composes and decomposes
short messages.– An SME may or may not be located within, and be
indistinguishable from, an HLR, MC, VLR, MS or MSC
Driving Forces for WIN
• Greater control of wireless network functionality
• Faster feature introduction• Flexibility to choose which features are
developed• Customized services for subscribers• Competitive solutions from multiple vendors
WIN Objectives
• Provide capabilities for rapid service introduction, service creation and service customization
• Service-independent WIN architecture• Compatible with existing wireless network
architecture
WIN Requirements
• Flexible distribution of service logic supporting functions– Wireless service provider can choose a WIN
architecture to match network topology
• New WIN-based services must coexist with existing wireless services– “Switch”-based services (e.g., call waiting)– Existing “HLR” based services (e.g., call forwarding)
WIN Requirements
• Transparent to subscriber– WIN-based services– “Switch”-based services– “HLR”-based services
• Seamless services– Home– Roaming
Intelligent Network Service
Dials 1-800-333-4444
12
3
4
56
7
313-456-6789 Rings
SSP SSP
STP
SCP
WIN Concepts
• Based on wireline IN concepts– During call processing, switch can detect events
(triggers) at various points where call processing can be interrupted to request IN processing (e.g., at origination or completion of dialing)
– The switch then queries IN service logic for further instructions
– Service logic can be programmed to provide new services
IN Architecture Elements
I P
SSP SCP
SSP
SN
Service
Subscriber
IN signaling
Voice Channel
IN Architecture Elements
• Service Switching Point (SSP)– Major function of the SSP is to detect events
during call processing, called triggers, that indicate an IN call event
– After triggering, the SSP suspends call processing and starts a series of transactions with the SCP to determine the handling of the call
IN Architecture Elements
• Service Control Point (SCP)– Real-time database and transaction processing
system that provides service control and service data functions
– Performs subscriber or application specific service logic in response to a query from SSP and then sends back instructions to perform specified functions and how to continue call processing
– Provides mechanisms for introducing new services and customizing services and features
IN Architecture Elements
• Intelligent Peripheral (IP)– Performs specialized resource functions such as:
• Playing announcements• Collecting digits• Speech recognition• Recording and storing voice messages• Facsimile services...
– Under the control of service logic
IN Architecture Elements
• Service Node (SN)– A programmable network node that allows the
service provider to create new circuit related services
– Provides both service logic processing and call terminations for specialized resource functions
– Combines capabilities of SCP and IP
IN Triggers
• Call termination triggers– Called party busy– No answer
• Call origination triggers– Calling party– Dialed number
• Trigger categories– Subscribed (individual subscriber-based)– Office/group
Services Supported by IS-41C
• Call delivery• Call forwarding - busy• Call forwarding - default• Call forwarding - no answer• Call forwarding - unconditional• Call transfer• Call waiting• Calling number ID presentation• Calling number ID restriction• Conference calling• Do not disturb• Flexible alerting
• Message waiting notification• Mobile access hunting• Password call acceptance• Preferred language• Priority access & channel
assignment• Remote feature control• Selective call acceptance• Subscriber PIN access & intercept• Three-way calling• Voice message retrieval• Voice privacy• Short message services
WIN Architecture of IS-41
• IS-41 architecture is a WIN architecture– Mobile switching center (MSC) is a service switching
point• Call origination/termination triggers• Queries to service logic for instructions• Specialized resource functions
– Home location register (HLR) provides service control, service data and mobility management functions
– Visitor location register (VLR) provides subscriber profile data and other mobility management functions
WIN Capabilities of IS-41C
• Profile (HLR to Serving System)– Profile follows the subscriber– Profile can be updated at any time
• Profile contains:– Service profile– Origination triggers– Termination triggers
WIN Capabilities of IS-41C
• Service profile (switch based services)– Origination indicator
• Type of call originations allowed
– Termination restrictions• Type of call terminations allowed
– Pre-subscribed long distance carrier– Preferred language indicator
WIN Capabilities of IS-41C
• Service profile (switch-based services)– Calling features
• Call waiting• Three-way calling• Calling number identification presentation• Calling number identification restriction• Call transfer
WIN Capabilities of IS-41C
• Call origination triggers (Serving MSC)– Triggers for specified call origination events
• All origination attempts• Local call attempts• Toll call attempts• International call attempts• Dialed numbers with specific number of digits• Dialed numbers beginning with *,**,#,## digits• e.g., dialed international call
WIN Capabilities of IS-41C
• Call termination triggers (Serving MSC)– Triggers for specified call termination events
• Busy• No page response• No answer• Not reachable• Routing failure
• Call termination triggers (originating MSC)– Incoming call to a mobile station– Call redirection
WIN Capabilities of IS-41CWIN Capabilities of IS-41C
IS-41 Queries to WIN Services
• Location request– Originating MSC to HLR– Triggered by calls to mobile stations
• Transfer-to-number request– Originating MSC/serving MSC to HLR– Triggered by an event corresponding to
termination Triggers received from HLR
IS-41 Queries to WIN Services
• Origination request– Serving MSC to HLR– Triggered by call origination event corresponding
to origination triggers received from the HLR
IS-41 User Interaction Control
• Remote user interaction directive– HLR to originating or serving MSC– Controls announcement played and collection of
digits• Subscribed
• Feature request– Serving MSC to HLR– Triggered by feature request made by user
Registration Notification
MSC
VLR HLR VLR
MSCMS
system access
REGNOT
REGNOT
regnot
regnotREGCANC
regcanc
Old Serving System New Serving System
Call Forwarding - Busy
MSC
HLR VLR
MSC
Originating Serving
call origination
LOCREQ[CALLED #]
ROUTREQ[MIN,ESN]
ROUTREQ
routreq[busy]
routreq[busy]
locreq[CF#]call setup
Selective Call Acceptance
MSC
HLR VLR
MSC
Originating Serving
call origination
LOCREQ[CALLING#,CALLED #]
locreq[CF#]
call forward
Subscriber PIN Intercept
MSC
HLR
Serving System
mobile call origination
ORIGREQ[DIGITS]
RUIDIR[ANNLIST, DIGITCC]
VLR
play announcement and collect digits
ruidir[DIGITS]
origreq[continue]
.
.
Feature Control Request
MSC
HLR
Serving System
feature access
FEATREQ[DIGITS]
featreq
VLR
tone or announcement
QUALDIR[PROFILE]
qualdir
.
.
.
Evolution to WIN
• IS-41 architecture and capabilities allow WIN-oriented services– Vendors have developed new and enhanced services
based on IS-41 intersystem operations• In a multi-vendor environment
– Wireless service providers have deployed SCPs in their networks• HLR functionality• Enhanced services• Customized services
Evolution to WIN
• Examples of WIN-based services– Call origination services based on:
• Calling party
• Location of caller
• Dialed number
– Call origination service examples:• Virtual network services
• Automatic retry on busy
Evolution to WIN
• Examples of WIN-based services– Call terminating services based on:
• Incoming call information (e.g. calling party)
• Mobile station location and status (e.g., busy)
• Mobile’s response to incoming call (e.g, no answer)
• Time of day
• ...
– Call terminating service examples:• Enhanced call screening
• Enhanced call forwarding
Evolution to WIN
• Examples of WIN-based services– Non-call-related services based on:
• Mobile station location• Mobile station status
– Non-call-related service example:• Location tracking
Current WIN Standards Work
• Add SCP, IP and SN elements to IS-41 network– Use existing IS-41 signaling network (SS7)– Use existing voice channel interconnections– Build on existing intersystem operations for
interactions with SCP and IP– IP supports broader range of resource functions than
currently specified for IS-41– MSCs can interact directly with SCP service logic
WIN Architecture
SCP
MSC PSTNBSMS
HLRAC VLR ISDN
MC MCVLR
SME SME
MSC IPSCP
SNHLRIP
EIR
Current WIN Standards Work
• WIN network element interactions– MSC to/from HLR/SCP/IP/SN– HLR to/from SCP/IP/SN– SCP to/from SCP/IP/SN
• Distribution of service control logic across multiple network elements (HLR, SCPs, SNs)
MSC Call Processing
• MSC call processing model – Basic call state models (BCSMs)
• Originating call model• Terminating call model
– Points in call (PICs)
– Detection points (DPs)
– PIC to DP transitions
– Based on ITU-T Q.1244 recommendations for CS-2
Originating BCSM
Route_Select_Failure DP
Collected_Information DP
invalid_information
Analyzed_Information DP
authorize_route_failure
O_Called_Party_Busy DP
O_Term_Seized DPO_Mid_Call DP
route_failure
Select_Route
Authorize_Call_Setup
Send_Call
Analyze_Information
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Terminating BCSM
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Termination_Attempt_Authorized DP
T_No_Answer DP
Facility_Selected_and_Available DP
presentation_failure
Call_Accepted DP
Termination_Attempt_DP
termination_denied
SS7_failure
T_Busy DP
Select_Facility
Authorize_Termination_Attempt
Present_Call
T_Alerting
call_rejected
.
.
.
Distributed Functional Plane
• WIN functional architecture– Functional entities
• Call control function (CCF)• Service switching function (SSF)• Service control function (SCF)• Service data function (SDF)• Specialized resource function (SRF)• Radio access control function (RACF)• Radio control function (RCF)
Distributed Functional Plane
SMAF SMF SCEF
SRFSCFSDF
LRF
SSF
CCF
RACF RCF
RTF
SCF
ACF
CCF
RACF
to any FE
ACF
LRF
Feature and Service Interaction Management
• Feature and service interaction management– Services for single subscriber can be distributed
across multiple network elements that provide service control
– Have to manage:• Feature precedence• Feature interaction• Feature data• Feature control
Feature and Service Interaction Management
FIM
BCM
SBSL iSBSL j
SSF/CCF
SCF
FSLP iFSLP j
FSLPk
SIM
SCF
FSLPxFSLPy
FSLPz
SIM
• Map existing IS-41C triggers to WIN DPs• Adding new call processing triggers and
trigger destinations for WIN
WIN IS-41 Operations
• New IS-41 operations– Seize resource
• HLR/SCP to IP (SCF to SRF)
– Connect resource • HLR/SCP/SN to MSC (SCF to SSF)
– Instruction requested• IP to HLR/SCP (SRF to SCF)
– Disconnect resource• HLR/SCP/SN to MSC (SCF to SSF)
WIN IS-41 Operations
• New IS-41 operations– Reset timer
• HLR/SCP/SN to MSC (SCF to SSF)
– Search• HLR/SCP/SN to HLR/SCP/SN (SCF to SDF)
– Modify• HLR/SCP/SN to HLR/SCP/SN (SCF to SDF)
– Service request• HLR/SCP/SN to HLR/SCP/SN (SCF to SCF)
WIN IS-41 Operations
• New IS-41 operations– Termination request
• MSC to HLR/SCP/SN (SSF to SCF)
• New IS-41 parameters• Network reference model• Stage 2 descriptions• Stage 3 descriptions
WIN IS-41 Operations
WIN Services
• New WIN-based features– Calling name identification presentation– Incoming call screening– Voice controlled services
• Voice-controlled feature activation and control• Voice-controlled dialing• Voice-based user authentication• Speech to text conversion (short message creation)
Calling Name Identification Presentation
• Displays the name of the calling party on the called party’s terminal. The calling party name information is derived from the calling number information (CNI) which is generally provided to the terminating network as part of basic call setup.
Calling Name Identification Presentation
MSC HLR VLR MSC MSSCP
LOCREQ[CNIDigits]
ROUTEREQ[MIN,CNIdigits]ROUTEREQ[MIN,CNIdigits]
routereq[TLDN]
routereq[TLDN]
locreq[TERMLIST]
call setup
TERMREQ
termreq[ACTCODE,DISTEXT]
alert(CNAP info)
call answer
Originating System Serving System
Incoming Call Screening - ICS
• ICS is an enhanced service which provides the capability of routing or blocking of incoming calls to a subscriber. The ICS service logic resides on the SCP which screens the call based on screening factors (e.g., CLID, serving MSC) and selects one of many possible terminating actions (e.g., forward call to message center).
Incoming Call Screening
MSC HLR SCP
LOCREQ[DGTSDIAL,CNIdigits]
SERVREQ[DGTSDIAL,SRVLIST,CNIdigits]
servreq[TERMACT,TERMLIST]
locreq[TERMLIST]
call setup to VMS
Originating System
call origination
• Allows the mobile subscriber to control features (e.g., CFU, CFB, MWI) by using voice commands. The subscriber dials a star code (e.g., *33) associated with an origination trigger for the service. The call is routed to an automatic speech recognition device that prompts the caller for feature control information and carries out the request.
Voice Controlled Feature Control
Voice Controlled Feature Control
Serving SystemMSC VLR SN HLR
call originationORREQ
CONNECTRESOURCE
prompt for feature control
collect feature control
call setup
clear call
FEATREQ
featreq
QUALDIRQUALDIR
qualdir qualdir
announce feature control success
orreq[ACTCODE]
Future WIN Standards Work
• International standards• Mobility and radio access triggers• Add wireline equivalent IN call processing
triggers• Wireless/wireline integration