ISO/IEC 15431:1999

INTERNATIONAL ISO/IEC
STANDARD 15431
First edition
1999-09-15
Information technology —
Telecommunications and information
exchange between systems — Private
Integrated Services Network —
Inter-exchange signalling protocol —
Wireless terminal call handling additional
network features
Technologies de l'information — Télécommunications et échange
d'information entre systèmes — Réseau privé à intégration de services —
Protocole de signalement d'interéchange — Caractéristiques de réseau
additionnelles pour le traitement d'appel de terminal sans fil
Reference number
Contents
Foreword.iv
Introduction .v
1 Scope .1
2 Conformance.1
3 Normative references .1
4 Terms and definitions.3
4.1 External definitions.3
4.2 Other definitions .4
5 Symbols and abbreviated terms.4
6 Signalling protocol for the support of ANF-WTMI.5
6.1 ANF-WTMI description .5
6.2 ANF-WTMI operational requirements .6
6.3 ANF-WTMI coding requirements .6
6.4 ANF-WTMI state definitions .9
6.5 ANF-WTMI signalling procedures for invocation and operation .10
6.6 ANF-WTMI impact of interworking with public ISDNs .13
6.7 ANF-WTMI impact of interworking with non-ISDNs .14
6.8 Protocol interactions between ANF-WTMI and other supplementary services and ANFs .14
6.9 ANF-WTMI parameter values (timers).17
7 Signalling protocol for the support of ANF-WTMO .18
7.1 ANF-WTMO description.18
7.2 ANF-WTMO operational requirements.18
7.3 ANF-WTMO coding requirements .18
© ISO/IEC 1999
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Printed in Switzerland
ii
© ISO/IEC
7.4 ANF-WTMO State definitions.19
7.5 ANF-WTMO signalling procedures .19
7.6 ANF-WTMO impact of interworking with public ISDNs.20
7.7 ANF-WTMO impact of interworking with non-ISDNs .20
7.8 Protocol interactions between ANF-WTMO and other supplementary services and ANFs.20
7.9 Parameter values (timers).23
Annex A (normative) Protocol Implementation Conformance Statement (PICS) proforma.24
Annex B (informative) Imported ASN.1 Definitions .34
Annex C (informative) Examples of Message Sequences.35
Annex D (informative) Specification and Description Language (SDL) representation of procedures .40
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© ISO/IEC
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission)
form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC
participate in the development of International Standards through technical committees established by the
respective organization to deal with particular fields of technical activity. ISO and IEC technical committees
collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in
liaison with ISO and IEC, also take part in the work.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote.
International Standard ISO/IEC 15431 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information
technology,SubcommitteeSC6, Telecommunications and information exchange between systems.
Annex A forms a normative part of this International Standard. Annexes B to D are for information only.
iv
© ISO/IEC
Introduction
This International Standard is one of a series of International Standards defining services and signalling protocols
applicable to Private Integrated Services Networks (PISNs). The series uses ISDN concepts as developed by
ITU-T and conforms to the framework of International Standards for Open Systems Interconnection as defined by
ISO/IEC.
This particular International Standard is one of a series of signalling protocol standards that together specify Private
Signalling System Number 1 (PSS1) (informally known as QSIG) for use at the Q reference point between Private
Integrated Services Network Exchanges (PINXs). This International Standard supports the Wireless Terminal Call
Handling additional network features.
v
INTERNATIONAL STANDARD © ISO/IEC ISO/IEC 15431:1999(E)
Information technology — Telecommunications and information
exchange between systems — Private Integrated Services
Network — Inter-exchange signalling protocol — Wireless terminal
call handling additional network features
1 Scope
This International Standard specifies the signalling protocol for the support of the Wireless terminal call handling
additional network features (ANF-WTMI and ANF-WTMO) at the Q reference point between Private Integrated
Services Network Exchanges (PINX) connected together within a Private Integrated Services Network (PISN).
ANF-WTMI is a feature that directs incoming calls to a WTMI user within the PISN regardless of the WTMI user’s
geographical location within the PISN, provided that the WTMI user’s location is known. Roaming outside the PISN
is outside the scope of this edition of this International Standard.
ANF-WTMO permits the PISN to process call requests from a WTMO user at the home location, if required.
The Q reference point is defined in ISO/IEC 11579-1.
Service specifications are produced in three stages and according to the method specified in CCITT
Recommendation I.130. This International Standard contains the stage 3 specification for the Q reference point and
satisfies the requirements identified by the stage 1 and stage 2 specifications in ISO/IEC 15430.
The signalling protocol for ANF-WTMI and ANF-WTMO operates on top of the signalling protocol for basic circuit
switched call control, as specified in ISO/IEC 11572, and uses certain aspects of the generic procedures for the
control of supplementary services specified in ISO/IEC 11582.
This International Standard also specifies additional signalling protocol requirements for the support of interactions
at the Q reference point between ANF-WTMI / ANF-WTMO and other supplementary services and ANFs.
This International Standard is applicable to PINXs which can interconnect to form a PISN.
2 Conformance
In order to conform to this International Standard, a PINX shall satisfy the requirements identified in the Protocol
Implementation Conformance Statement (PICS) proforma in annex A.
3 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO/IEC 11571:1994, Information technology - Telecommunications and information exchange between systems -
Numbering and sub-addressing in private integrated services networks.
© ISO/IEC
ISO/IEC 11572, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Circuit mode bearer services - Inter-exchange signalling procedures and
protocol.
ISO/IEC 11574:1994, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network – Circuit-mode 64k bit/s bearer services - Service description, functional
capabilities and information flows.
ISO/IEC 11579-1:1994, Information technology - Telecommunications and information exchange between systems -
Private integrated services network - Part 1: Reference configuration for PISN Exchanges (PINX).
ISO/IEC 11582:1995, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Generic functional protocol for the support of supplementary services - Inter-
exchange signalling procedures and protocol.
ISO/IEC 13241:1997, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Route Restriction Class additional
network feature.
ISO/IEC 13868:1995, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Name identification supplementary
services.
ISO/IEC 13873:1995, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Call diversion supplementary services.
ISO/IEC 13874:1995, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Path replacement additional network
feature.
ISO/IEC 14843:1996, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Call offer supplementary service.
ISO/IEC 14844:1996, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Do not disturb and do not disturb
override supplementary services.
ISO/IEC 14846:1996, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Call intrusion supplementary service.
ISO/IEC 15050:1997, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Advice of charge supplementary
services.
ISO/IEC 15054:1997, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Call Interception additional network
feature.
ISO/IEC 15056:1997, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Transit counter additional network
feature.
ISO/IEC 15430:1999, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Specification, functional model and information flows - Wireless terminal call
handling additional network features.
ISO/IEC 15506:1997, Information technology - Telecommunications and information exchange between systems -
Private Integrated Services Network - Inter-exchange signalling protocol - Message waiting indication
supplementary service.
© ISO/IEC
ITU-T Rec. I.112:1993, Vocabulary of terms for ISDNs.
CCITT Rec. I.130:1988, Method for the characterization of telecommunication services supported by an ISDN and
network capabilities of an ISDN (Blue Book).
ITU-T Rec. I.210:1993, Principles of telecommunication services supported by an ISDN and the means to describe
them.
ITU-T Rec. Q.850:1993, Usage of cause and location in the digital subscriber signalling system No. 1 and the
signalling system No. 7 ISDN user part.
ITU-T Rec. Q.950:1993, Digital Subscriber Signalling System No. 1 (DSS1) - Supplementary services protocols,
structure and general principles.
ITU-T Rec. Z.100:1993, Specification and Description Language.
4 Terms and definitions
For the purposes of this International Standard, the following definitions apply.
4.1 External definitions
This International Standard uses the following terms defined in other documents:
— Additional Network Feature (ANF) (ISO/IEC 11582)
— Application Protocol Data Unit (APDU) (ISO/IEC 11582)
— Basic service (ITU-T Rec. I.210)
— Call, Basic call (ISO/IEC 11582)
— Call independent (ISO/IEC 11582)
— Call independent signalling connection (ISO/IEC 11582)
— Call related (ISO/IEC 11582)
— Complete number (ISO/IEC 11571)
— Co-ordination function (ISO/IEC 11582)
— End PINX (ISO/IEC 11582)
— Incoming Gateway PINX (ISO/IEC 11572)
— Incoming WTM call (ISO/IEC 15430)
— Interpretation APDU (ISO/IEC 11582)
— Network Facility Extension (NFE) (ISO/IEC 11582)
— Originating PINX (ISO/IEC 11572)
— Private Integrated Services Network (PISN) (ISO/IEC 11579-1)
— Private Integrated Services Network Exchange (PINX) (ISO/IEC 11579-1)
— PISN number (ISO/IEC 11571)
© ISO/IEC
— Signalling (ITU-T Rec. I.112)
— Supplementary service (ITU-T Rec. I.210)
— Supplementary Service Control Entity (ISO/IEC 11582)
— Subsequent PINX (ISO/IEC 11572)
— Terminating PINX (ISO/IEC 11572)
— Transit PINX (ISO/IEC 11572)
— User (ISO/IEC 11574)
— WTMI user (ISO/IEC 15430)
— WTMO user (ISO/IEC 15430)
4.2 Other definitions
4.2.1
Alternative identifier: An identifier, other than the PISN number, which identifies the WTMI user uniquely.
4.2.2
Home data base (HDB): The data base in which the current location and all associated parameters of a wireless
terminal are stored.
4.2.3
Home PINX: The PINX which has direct access to the HDB entry for a particular WTMI or WTMO user.
4.2.4
Rerouteing PINX: The PINX which executes the rerouteing of the incoming WTM call to the current Visitor PINX.
NOTE In case of rerouteing, the Rerouteing PINX is either the Originating PINX or the Incoming Gateway PINX. In case of
forward switching, the Rerouteing PINX is the WTMI-detect PINX.
4.2.5
Visitor data base (VDB): The data base in which all relevant parameters concerning a wireless terminal are stored
for as long as it is located in an area controlled by this data base.
4.2.6
Visitor PINX: The PINX which has direct access to the VDB entry for a particular WTMI or WTMO user.
4.2.7
WTMI-detect PINX: The PINX which detects that an incoming call is to a WTMI user.
NOTE The WTMI-detect PINX is either the Home PINX, a Transit PINX, the Incoming Gateway PINX or the Originating
PINX.
5 Symbols and abbreviated terms
ANF Additional Network Feature
ANF-CINT Call Interception additional network feature
ANF-PR Path Replacement additional network feature
ANF-RRC Route Restriction Class additional network feature
ANF-TC Transit counter additional network feature
© ISO/IEC
(ANF-)WTMI Wireless Terminal Incoming Call (additional network feature)
(ANF-)WTMO Wireless Terminal Outgoing Call (additional network feature)
APDU Application Protocol Data Unit
ASN.1 Abstract Syntax Notation no. 1
HDB Home Data Base
ISDN Integrated Services Digital Network
NFE Network Facility Extension
PICS Protocol Implementation Conformance Statement
PINX Private Integrated Services Network Exchange
PISN Private Integrated Services Network
SDL Specification and Description Language
SS-AOC Advice Of Charge supplementary services
SS-CD Call Deflection supplementary service
SS-CFB Call Forwarding Busy supplementary service
SS-CFNR Call Forwarding No Reply supplementary service
SS-CFU Call Forwarding Unconditional supplementary service
SS-CI Call Intrusion supplementary service
SS-CNIP Calling Name Identification Presentation supplementary service
SS-CO Call Offer supplementary service
SS-DNDO Do Not Disturb Override supplementary service
SS-MWI Message Waiting Indication supplementary service
VDB Visitor Data Base
WTM Wireless Terminal Mobility
6 Signalling protocol for the support of ANF-WTMI
6.1 ANF-WTMI description
ANF-WTMI enables calls to be directed to a WTMI user within the PISN. As there is no predetermined PINX for the
connection of a WTMI user to the PISN, the directing of such calls requires that information regarding the location
of the user is available.
© ISO/IEC
6.2 ANF-WTMI operational requirements
6.2.1 Requirements on the Rerouteing PINX
ISO/IEC 11572 protocol control procedures for call establishment at the outgoing side of an inter-PINX link shall
apply to the establishment of the connection to the Visitor PINX. ISO/IEC 11572 protocol control procedures for call
clearing shall apply to the release of the connection to the WTMI-detect PINX.
Generic procedures for the call related control of supplementary services, as specified in ISO/IEC 11582 for an End
PINX, shall apply.
6.2.2 Requirements on the WTMI-detect PINX
ISO/IEC 11572 protocol control procedures for call establishment at the incoming side of an inter-PINX link shall
apply to the establishment of the connection from the Originating or Incoming Gateway PINX. ISO/IEC 11572
protocol control procedures for call clearing shall apply to the release of the connection to the Rerouteing PINX.
Generic procedures for the call related control of supplementary services, as specified in ISO/IEC 11582 for an End
PINX, shall apply.
Generic procedures for the call independent control (connection oriented) of supplementary services, as specified
in ISO/IEC 11582 for an Originating PINX, shall apply.
6.2.3 Requirements on the Home PINX
Generic procedures for the call independent control (connection oriented) of supplementary services, as specified
in ISO/IEC 11582 for a Terminating PINX, shall apply.
6.2.4 Requirements on the Visitor PINX
ISO/IEC 11572 protocol control procedures for call establishment at the incoming side of an inter-PINX link shall
apply to the establishment of the connection from the Rerouteing PINX.
Generic procedures for the call related control of supplementary services, as specified in ISO/IEC 11582 for an End
PINX, shall apply.
6.2.5 Requirements on a Transit PINX
Basic call procedures for call establishment and call clearing at a Transit PINX, as specified in ISO/IEC 11572,
shall apply.
Generic procedures for the call related control and call independent control (connection oriented) of supplementary
services, as specified in ISO/IEC 11582 for a Transit PINX, shall apply.
6.3 ANF-WTMI coding requirements
6.3.1 Operations
The operations wtmiEnquiry, wtmiDivert and wtmiInform defined in Abstract Syntax Notation number 1 (ASN.1) in
Table 1 shall apply.
Table 1 - Operations in support of call handling additional network features
Wireless-Terminal -Call-Handling-Operations
{ iso (1) standard (0) pss1-wtm-call-handling (15431) operations (0)}
DEFINITIONS EXPLICIT TAGS ::=
© ISO/IEC
BEGIN
IMPORTS OPERATION, ERROR FROM Remote-Operation-Notation
{ joint-iso-ccitt (2) remote-operations (4) notation (0) }
Extension FROM Manufacturer-specific-service-extension-definition
{ iso (1) standard (0)
pss1-generic-procedures (11582) msi-definition (0) }
PSS1InformationElement FROM Generic-parameters-definition
{ iso (1) standard (0)
pss1-generic-procedures (11582) pss1-generic-parameters (6) }
Name FROM Name-Operations
{ iso (1) standard (0)
pss1-name (13868) name-operations (0) }
basicServiceNotProvided, invalidServedUserNumber, notAvailable FROM
General-Error-List
{ ccitt (0) recommendation (0) q (17) 950 general-error-list (1) }
Address, PartyNumber, PartySubaddress, PresentedNumberScreened FROM
Addressing-Data-Elements
{ iso (1) standard (0) pss1-generic-procedures (11582)
addressing-data-elements (9) };
-- Operations for ANF-WTMI: --
WtmiEnquiry ::= OPERATION
-- Sent from the WTMI-detect PINX to the Home PINX.
ARGUMENT EnquiryArg
RESULT EnquiryRes
ERRORS { invalidServedUserNumber, locationNotKnown,
notAvailable, basicServiceNotProvided, unspecified }
WtmiDivert ::= OPERATION
-- Sent from the WTMI-detect PINX to the Rerouteing PINX.
ARGUMENT DivertArg
RESULT DummyRes
ERRORS { notAvailable, unspecified }
WtmiInform ::= OPERATION
-- Sent from the Rerouteing PINX to the Visitor PINX.
ARGUMENT InformArg
EnquiryArg ::= SEQUENCE { pisnNumber PartyNumber,
-- The PISN number of the WTMI user
qSIGInfoElement PSS1InformationElement,
-- The basic call information elements Bearer capability, High layer compatibility,
-- Low layer compatibility can be embedded in the qSIGInfoElement
-- in accordance with clause 6.5.2.1.
argExtension WtmiExtension OPTIONAL }
DivertArg ::= SEQUENCE { visitPINX PartyNumber,
-- The PISN number of the Visitor PINX,
-- always a Complete Number.
callingNumber PresentedNumberScreened,
wtmIdentity WtmIdentity,
-- The PISN number (always a Complete Number)
-- and/or an alternative identifier of the WTMI user.
qSIGInfoElement PSS1InformationElement,
-- The basic call information elements Bearer capability, High layer compatibility,
-- Low layer compatibility, and Progress indicator
-- can be embedded in the qSIGInfoElement in accordance with clause 6.5.2.1.
callingUserSub [ 1 ] PartySubaddress OPTIONAL,
callingName [ 2 ] Name OPTIONAL,
© ISO/IEC
wtmUserSub [ 3 ] PartySubaddress OPTIONAL,
argExtension WtmiExtension OPTIONAL }
InformArg ::= SEQUENCE { wtmIdentity WtmIdentity,
-- The PISN number (always a Complete Number)
-- and/or an alternative identifier of the WTMI user.
argExtension WtmiExtension OPTIONAL }
EnquiryRes ::= CHOICE { currLocation [ 1 ] IMPLICIT CurrLocation,
cfuActivated [ 2 ] IMPLICIT CfuActivated }
CurrLocation ::= SEQUENCE { visitPINX PartyNumber,
-- The PISN number of the Visitor PINX,
-- always a Complete Number.
wtmIdentity WtmIdentity,
-- The PISN number (always a Complete Number)
-- and/or an alternative identifier of the WTMI user
argExtension WtmiExtension OPTIONAL }
CfuActivated ::= SEQUENCE { divToAddress Address,
divOptions SubscriptionOption,
wtmName [ 1 ] Name OPTIONAL,
argExtension WtmiExtension OPTIONAL }
SubscriptionOption ::= ENUMERATED { noNotification (0),
notificationWithoutDivertedToNr (1),
notificationWithDivertedToNr (2) }
DummyRes ::= CHOICE { null NULL,
extension [ 1 ] IMPLICIT Extension,
sequOfExtn [ 2 ] IMPLICIT SEQUENCE OF Extension }
WtmiExtension ::= CHOICE { extension [ 4 ] IMPLICIT Extension,
sequOfExtn [ 5 ] IMPLICIT SEQUENCE OF Extension }
WtmIdentity ::= CHOICE { pisnNumber PartyNumber,
alternativeId [ 10 ] IMPLICIT AlternativeId,
both [ 11 ] IMPLICIT SEQUENCE
{ pisnNumber PartyNumber,
alternativeId AlternativeId } }
AlternativeId ::= OCTET STRING(SIZE(1.20))
-- Operation for ANF-WTMO --
WtmoCall ::= OPERATION
ARGUMENT WtmoArg
WtmoArg ::= SEQUENCE { destinationNumber [0] PartyNumber OPTIONAL,
sendingComplete [1] IMPLICIT NULL OPTIONAL,
extension CHOICE
{single [2] IMPLICIT Extension,
multiple [3] IMPLICIT SEQUENCE OF Extension
}OPTIONAL}
wtmiEnquiry WtmiEnquiry ::= localValue 54
wtmiDivert WtmiDivert ::= localValue 55
wtmiInform WtmiInform ::= localValue 56
wtmoCall WtmoCall ::= localValue 71
locationNotKnown ERROR ::= localValue 1015
unspecified Unspecified ::= localValue 1008
Unspecified ::= ERROR PARAMETER Extension
END -- of Wireless-Terminal-Call-Handling-Operations
© ISO/IEC
6.3.2 Information elements
6.3.2.1 Facility information element
The operations defined in 6.3.1 shall be coded in the Facility information element in accordance with ISO/IEC
11582.
When conveying the invoke APDU of operations defined in 6.3.1 the destinationEntity data element of the NFE
shall contain value endPINX.
When conveying the invoke APDU of operations defined in 6.3.1, the Interpretation APDU shall either be omitted or
be included with value rejectAnyUnrecognisedInvokePdu.
6.3.2.2 Other information elements
Any other information elements (e.g. Calling party number, Called party number) shall be coded in accordance with
the rules of ISO/IEC 11572 and ISO/IEC 11582.
6.3.3 Messages
The Facility information element shall be conveyed in the messages as specified in clause 10 of ISO/IEC 11582.
Messages used for call establishment shall be as specified in ISO/IEC 11572.
6.4 ANF-WTMI state definitions
6.4.1 States at the Rerouteing PINX
The procedures for the Rerouteing PINX are written in terms of the following conceptual states existing within the
ANF-WTMI Supplementary Service Control entity in that PINX in association with a particular call.
6.4.1.1 State ExecIdle
Ready for receipt of a wtmiDivert APDU.
6.4.2 States at the WTMI-detect PINX
The procedures for the WTMI-detect PINX are written in terms of the following conceptual states existing within the
ANF-WTMI Supplementary Service Control entity in that PINX in association with a particular call.
6.4.2.1 State WTMI-Idle
ANF-WTMI is not operating.
6.4.2.2 State WTMI-Detected
A call to a WTMI user has been detected and a wtmiEnquiry invoke APDU requesting the current location of the
WTMI user has been sent to the Home PINX.
6.4.2.3 State WTMI-Divert
The current location of the WTMI user is known and a wtmiDivert invoke APDU has been sent to the Rerouteing
PINX.
6.4.3 States at the Home PINX
The procedures for the Home PINX are written in terms of the following conceptual states existing within the ANF-
WTMI Supplementary Service Control entity.
6.4.3.1 State HomeIdle
Ready for receipt of a wtmiEnquiry APDU.
© ISO/IEC
6.4.4 States at the Visitor PINX
The procedures for the Visitor PINX are written in terms of the following conceptual states existing within the ANF-
WTMI Supplementary Service Control entity in that PINX in association with a particular call.
6.4.4.1 State VisitIdle
Ready for receipt of a wtmiInform APDU.
6.5 ANF-WTMI signalling procedures for invocation and operation
Examples of message sequences are shown in annex C.
6.5.1 Actions at the Rerouteing PINX
The SDL representation of procedures at the Rerouteing PINX is shown in D.1 of annex D.
6.5.1.1 Normal procedures
On receipt of a wtmiDivert invoke APDU in a FACILITY message during basic call protocol control state Outgoing
Call Proceeding, the Rerouteing PINX shall determine whether it can proceed with ANF-WTMI. If so, it shall initiate
a new call establishment to the Visitor PINX and release the leg towards the WTMI-detect PINX by sending a
DISCONNECT message containing a wtmiDivert return result APDU.
The SETUP message for the new call establishment shall include a wtmiInform invoke APDU.
The following specific basic call information elements shall be included in the SETUP message:
� Called party number, containing the number received in the visitPINX data element within the
wtmiDivert invoke APDU;
� Called party subaddress, containing the subaddress received in the wtmUserSub data element
within the wtmiDivert invoke APDU (optional);
� Calling party number, containing the number received in the callingNumber data element within
the wtmiDivert invoke APDU;
� Calling party subaddress, containing the subaddress received in the callingUserSub data
element within the wtmiDivert invoke APDU (optional);
� Bearer capability information element as received in embedded form within the wtmiDivert
invoke APDU, and any of the following information elements which were also received in
embedded form in this APDU: High layer compatibility, Low layer compatibility and Progress
indicator information elements.
The wtmiInform invoke APDU shall contain the data element wtmIdentity with the same contents as the
corresponding data element in the argument of the received wtmiDivert invoke APDU.
6.5.1.2 Exceptional procedures
If the Rerouteing PINX can not proceed with ANF-WTMI, it shall answer the wtmiDivert invoke APDU with a return
error APDU containing the error notAvailable.
6.5.2 Actions at the WTMI-detect PINX
The SDL representation of procedures at the WTMI-detect PINX is shown in D.2 of annex D.
When a WTMI-detect PINX also provides Rerouteing PINX functionality, in support of ANF-WTMI by forward
switching, the joint requirements of 6.5.1 (for a Rerouteing PINX) and 6.5.2 (for a WTMI-detect PINX) shall apply,
with the exception that any communication between the WTMI-detect PINX functionality and the Rerouteing PINX
functionality will be an intra-PINX matter. The messages specified for sending from the WTMI-detect PINX towards
the Rerouteing PINX or vice versa will not appear on any inter-PINX link.
© ISO/IEC
6.5.2.1 Normal procedures
On determining that ANF-WTMI is to be invoked following the arrival of an incoming call, the WTMI-detect PINX
shall send a wtmiEnquiry invoke APDU to the Home PINX of the called WTMI user, using the call reference of a
call independent signalling connection. The call independent signalling connection shall be established (or used, if
an appropriate connection is already available) in accordance with the procedures specified in 7.3 of ISO/IEC
11582. The WTMI-detect PINX shall enter state WTMI-Detected and start timer T1.
NOTE The number to be used in the Called party number information element when establishing the call independent
signalling connection to the Home PINX is outside the scope of this International Standard. It can, for example, be the Called
party number information element received in the incoming SETUP message.
The following data elements shall be included in the argument of the wtmiEnquiry invoke APDU:
� element pisnNumber as received in the incoming SETUP message in the Called party number
information element;
� element qSIGInfoElement containing an embedded Bearer capability information element, as
received in the incoming SETUP message, and any of the following information elements which
were received in the incoming SETUP message: High layer compatibility and Low layer
compatibility.
On receipt of the wtmiEnquiry return result APDU containing choice currLocation, the WTMI-detect PINX shall stop
timer T1, send a wtmiDivert invoke APDU in a FACILITY message to the Rerouteing PINX using the call reference
of the incoming call, start timer T2 and enter state WTMI-Divert.
The following data elements shall be included in the argument of the wtmiDivert invoke APDU:
� element visitPINX as received in the wtmiEnquiry return result APDU;
� element callingNumber as received in the incoming SETUP message in the Calling party number
information element;
� element wtmIdentity as received in the wtmiEnquiry return result APDU;
� element qSIGInfoElement containing an embedded Bearer capability information element, as
received in the incoming SETUP message, and any of the following information elements which
were received in the incoming SETUP message: High layer compatibility, Low layer compatibility
and Progress indicator;
� element callingUserSub, if a Calling party subaddress information element was received in the
incoming SETUP message;
� element wtmUserSub, if a Called party subaddress information element was received in the
incoming SETUP message.
On receipt of a wtmiEnquiry return result APDU containing choice cfuActivated, if the WTMI-detect PINX does not
support the procedures of 6.8.6.1 the actions taken shall be an implementation matter, e.g. route the incoming call
onwards to the Home PINX or release the incoming call.
The WTMI-detect PINX is responsible for clearing the call independent signalling connection towards the Home
PINX. This may occur on receipt of a return result APDU. Alternatively, the signalling connection may be retained
for other applications, if appropriate.
On receipt of the wtmiDivert return result APDU, the WTMI-detect PINX shall stop timer T2 and enter state WTMI-
Idle.
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6.5.2.2 Exceptional procedures
On receipt of a wtmiEnquiry return error APDU from the Home PINX indicating ‘invalidServedUserNumber’, the
WTMI-detect PINX shall stop timer T1, stimulate the sending of a DISCONNECT message with cause value #1
‘Unallocated (unassigned) number’ for release of the basic call, and enter state WTMI-Idle.
On receipt of a wtmiEnquiry return error APDU from the Home PINX indicating ‘locationNotKnown’, the WTMI-
detect PINX shall stop timer T1, stimulate the sending of a DISCONNECT message with cause value #3 ‘No route
to destination’ for release of the basic call, and enter state WTMI-Idle.
On receipt of a wtmiEnquiry return error APDU from the Home PINX indicating ‘notAvailable’, the WTMI-detect
PINX shall stop timer T1, stimulate the sending of a DISCONNECT message with cause value #20 ‘Subscriber
absent’ for release of the basic call, and enter state WTMI-Idle
On receipt of a wtmiEnquiry return error APDU from the Home PINX indicating ‘basicServiceNotProvided’, the
WTMI-detect PINX shall stop timer T1, stimulate the sending of a DISCONNECT message with cause value #88
‘Incompatible destination’ for release of the basic call, and enter state WTMI-Idle.
On receipt of a wtmiEnquiry reject APDU from the Home PINX, the WTMI-detect PINX shall stop timer T1, enter
state WTMI-Idle, and continue with normal basic call procedures.
If timer T1 expires (i.e. the wtmiEnquiry invoke APDU is not answered by the Home PINX), the WTMI-detect PINX
shall enter state WTMI-Idle and either stimulate the sending of a DISCONNECT message with cause value #41
‘Temporary failure’ for release of the basic call, or continue with normal basic call procedures.
On call clearing during state WTMI-Detected, the WTMI-detect PINX shall stop timer T1 and enter state WTMI-Idle.
On receipt of a wtmiDivert return error or reject APDU from the Rerouteing PINX, the WTMI-detect PINX shall stop
timer T2, enter state WTMI-Idle, and either stimulate the sending of a DISCONNECT message for release of the
basic call, or provide Rerouteing PINX functionality locally by initiating a new call establishment to the Visitor PINX
in accordance with 6.5.1.1.
If timer T2 expires (i.e. the wtmiDivert invoke APDU is not answered by the Rerouteing PINX), the WTMI-detect
PINX shall enter state WTMI-Idle and either stimulate the sending of a DISCONNECT message for release of the
basic call, or provide Rerouteing PINX functionality locally by initiating a new call establishment to the Visitor PINX
in accordance with 6.5.1.1.
On call clearing during state WTMI-Divert, the WTMI-detect PINX shall stop timer T2 and enter state WTMI-Idle.
The WTMI-detect PINX is responsible for clearing the call independent signalling connection towards the Home
PINX. This may occur on receipt of a return error or reject APDU, on expiry of timer T1 or on call clearing during
state WTMI-Detect. Alternatively, the signalling connection may be retained for other applications, if appropriate.
6.5.3 Actions at the Home PINX
The SDL representation of procedures at the Home PINX is shown in D.3 of annex D.
When a Home PINX also provides WTMI-detect PINX functionality, in support of ANF-WTMI, the joint requirements
of 6.5.2 (for a WTMI-detect PINX) and 6.5.3 (for a Home PINX) shall apply, with the exception that any
communication between the Home PINX functionality and the WTMI-detect PINX functionality will be an intra-PINX
matter. The messages specified for sending from the Home PINX towards the WTMI-detect PINX or vice versa will
not appear on any inter-PINX link.
6.5.3.1 Normal procedures
On receipt of a wtmiEnquiry invoke APDU using the call reference of a call independent signalling connection (as
specified in 7.3 of ISO/IEC 11582), the Home PINX shall check that the WTMI user, as identified by the PISN
number in element pisnNumber, is defined in the HDB and that the basic service indicated by the basic call
information elements embedded in element qSIGInfoElement is provided to that user.
© ISO/IEC
If the WTMI user is defined in the HDB, and the current location of the WTMI user is known for the basic service
concerned, then the Home PINX shall answer the wtmiEnquiry invoke APDU with a return result APDU containing
choice currLocation. Element visitPINX shall contain the PISN number of the Visitor PINX and element wtmIdentity
shall contain the PISN number and/or an alternative identifier of the WTMI user. The PISN number, if included,
shall be in the form of a complete number even if the PISN number received in the invoke APDU was not a
complete number.
6.5.3.2 Exceptional procedures
If the WTMI user is not found in the HDB, the Home PINX shall answer the wtmiEnquiry invoke APDU with a return
error APDU containing the error invalidServedUserNumber.
If the WTMI user has deregistered, the Home PINX shall answer the wtmiEnquiry invoke APDU with a return error
APDU containing the error notAvailable.
If the current location of the WTMI user is unknown, the Home PINX shall answer the wtmiEnquiry invoke APDU
with a return error APDU containing the error locationNotKnown.
If the requested basic service is not provided, the Home PINX shall answer the wtmiEnquiry invoke APDU with a
return error APDU containing the error basicServiceNotProvided.
6.5.3.3 Additional procedures for Call Forwarding Unconditional
On receipt of a wtmiEnquiry invoke APDU, if the WTMI user is defined in the HDB and SS-CFU is active, the Home
PINX shall answer the wtmiEnquiry invoke APDU with a return result APDU containing choice cfuActivated.
6.5.4 Actions at the Visitor PINX
The SDL representation of procedures at the Visitor PINX is shown in D.4 of annex D.
6.5.4.1 Normal procedures
On receipt of a wtmiInform invoke APDU in a SETUP message, the Visitor PINX shall check that there is an entry
in the VDB for the WTMI user, as indicated by the PISN number or alternative identifier in element wtmIdentity, for
the basic service indicated by basic call information elements, and that the WTMI user is accessible. If so, the
Visitor PINX shall attempt to establish the call to the PISN access indicated by the VDB entry.
NOTE On receipt of an incoming call authentication of the WTMI user can be performed.
6.5.4.2 Exceptional procedures
If the WTMI user is not found in the VDB, the Visitor PINX shall initiate call clearing according to the procedures in
ISO/IEC 11572 with cause value #41 ‘Temporary failure’.
If the WTMI user is not accessible, the Visitor PINX shall initiate call clearing according to the procedures in
ISO/IEC 11572 with cause value #18 ‘No user responding’.
6.5.5 Actions at a Transit PINX
There are no special actions required in support of ANF-WTMI.
6.5.6 Actions at an Originating PINX
An Originating PINX shall act as the Rerouteing PINX in accordance with 6.5.1, except where Rerouteing PINX
functionality is provided at a separate WTMI-detect PINX.
6.6 ANF-WTMI impact of interworking with public ISDNs
When interworking with a public ISDN which does not support an equivalent feature, the Incoming Gateway PINX
shall act as the Rerouteing PINX in accordance with 6.5.1 in order to perform ANF-WTMI within the PISN, except
where Rerouteing PINX functionality is provided at a separate WTMI-detect PINX.
© ISO/IEC
6.7 ANF-WTMI impact of interworking with non-ISDNs
When interworking with a non-ISDN which does not support an equivalent feature, the Incoming Gateway PINX
shall act as the Rerouteing PINX in accordance with 6.5.1 in order to perform ANF-WTMI within the PISN, except
where Rerouteing PINX functionality is provided at a separate WTMI-detect PINX.
6.8 Protocol interactions between ANF-WTMI and other supplementary services and ANFs
This clause specifies protocol interactions with other supplementary services and ANFs for which stage 3
standards had been published at the time of publication of this International Standard. For interactions with
supplementary services and ANFs for which stage 3 standards are published subsequent to the publication of this
International Standard, see those other stage 3 standards.
NOTE 1 Additional interactions that have no impact on the signalling protocol at the Q reference point can be found in the
relevant stage 1 specifications.
NOTE 2 Simultaneous conveyance of APDUs for ANF-WTMI and other supplementary services or ANFs in the same
message, each in accordance with the requirements of its respective stage 3 standard, does not, on its own, constitute a
protocol interaction.
6.8.1 Interaction with Calling Name Identification Presentation (SS-CNIP)
The following interaction shall apply if SS-CNIP is supported in accordance with ISO/IEC 13868.
6.8.1.1 Actions at the Rerouteing PINX
When executing ANF-WTMI, the Rerouteing PINX shall include a calling
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