c307 Call Divert

7/31/2019 c307 Call Divert

1/16

Information

Supplementary Services

Automatic Routing of not completedCalls

A50016-D1108-C307-1-7629


2/16

2 A50016-D1108-C307-1-7629

Automatic Routing of not completed Calls InformationSupplementary Services

!Important Notice on Product SafetyElevated voltages are inevitably present at specific points in this electrical equipment. Some of theparts can also have elevated operating temperatures.

Non-observance of these conditions and the safety instructions can result in personal injury or in prop-erty damage.

Therefore only trained and qualified personnel may install and maintain the system.

The system complies with the standard EN 60950. All equipment connected has to comply with theapplicable safety standards.

Copyright (C) Siemens AG 1999.

Issued by the Information and Communication Networks Group

Hofmannstrae 51

D-81359 Mnchen

Technical modifications possible.

Technical specifications and features are binding only insofar as

they are specifically and expressly agreed upon in a written contract.


3/16

A50016-D1108-C307-1-7629 3

InformationSupplementary Services

Automatic Routing of not completed Calls

Reason for Update

Summary:

Announcement before forwarding calls to a voice mail system.

Details:

Chapter/Section Reason for Update

1/Definition enhanced with announcement

2/Mode of Operation management and call diversion are modified

3/Inputs at the CT administration of announcements is included

Issue HistoryIssue

Number

Date of issue Reason for Update

1 November 1999 Integration of the announcement into all chapters of

the description.


4/16

4 A50016-D1108-C307-1-7629



5/16

A50016-D1108-C307-1-7629 5



This document consists of a total of 16 pages. All pages are issue 1.

Contents

1 Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 Mode of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.1 Management of "Automatic Routing of not completed Calls" . . . . . . . . . . . . 9

2.2 Call Diversion to the Voice Mailbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.3 Voice Mail Retrieval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.4 Implementation of the Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3 Inputs at the Craft Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4 Inputs at the Mobile Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5 Call Charge Registration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6 Compatibility with other Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15


6/16

6 A50016-D1108-C307-1-7629



7/16

A50016-D1108-C307-1-7629 7



1 DefinitionThe D900/D1800/D1900 network allows a mobile subscriber who is temporarily unavail-

able, to divert incoming speech calls to a personal voice mailbox. This personal voice

mailbox is a computer box within a voice mail system (VMS) which acts as a kind of call

answering machine in the Public Land Mobile Network (PLMN). Instead of having a

speech dialog with the called party, the calling party can leave a speech message within

the called partys mailbox when the called party is unavailable at the moment. When the

speech message is recorded, the called party is notified by means of a short message

which indicates that voice mail is waiting for him in the mailbox. Later on, the subscriber

can retrieve the voice mail by dialing a special access code.

This feature is referred to as "automatic routing of not completed calls" and is a non-

GSM standardized supplementary service that is only relevant for a GSM network. This

service is very useful when a mobile subscriber is not able to answer an incoming

speech call due to one of the following:

when the subscriber is busy (e.g. the subscriber is already using a traffic channel on

the air interface)

when the subscriber does not reply within a specific time

when the subscriber is not reachable (e.g. the mobile station is switched off, radio

congestion).

Also, before the call is diverted the calling party will be informed that his call will be

routed to a mailbox, together with one of the following reasons why his call cannot be

completed.

the called party is busy

the called party does not reply

unsuccessful paging

radio congestion the subscribers station is inactive (IMSI detach)

"Automatic routing of not completed calls" can be controlled by the served mobile

subscriber himself. This means that he can activate and deactivate the service and

choose the voice mail system in which his voice mail should be stored. This subscriber

control is based on unstructured supplementary service data (USSD). The USSD

provides the subscriber with control procedures for non-GSM supplementary service

management.

This document describes how automatic routing is carried out when mobile terminating

calls (MTCs) cannot be completed and also explains some administration functions.


8/16

8 A50016-D1108-C307-1-7629


2 Mode of OperationWhen a called subscriber is provided with the "automatic routing of not completed calls"

supplementary service and when he is not able to receive a speech call, the calling

subscriber can leave a speech message in the called partys voice mailbox. This indi-

vidual subscriber mailbox is part of the voice mail system (VMS) which consists of a

number of subscriber mailboxes.

The MSC having access to the VMS knows whether a voice mail has to be deposited in

or retrieved from the VMS. The distinction is made according to the called number:

a VMS short code causes retrieval mode access;

a VMS directory number causes deposit mode access.

When a speech call arrives at the VMS, the latter informs the served mobile subscriber

by sending an appropriate short message. The short message is buffered in the short

message service center (SMS-SC) where it is kept until the message is successfully

received by the served mobile subscriber.The SMS-SC acts as a kind of intermediate store for short messages and provides facil-

ities for forwarding them. The SMS-SC is connected to the gateway/interworking MSC

(G/IWMSC) containing a gateway function capable of receiving short messages from

the SMS-SC and delivering it to the appropriate destination (Fig. 2.1). This document

does not concentrate on the short message delivery. If more information is required

regarding the short message subject, see feature document Short Message Service

Mobile Terminated.

Fig. 2.1 Network architecture for "automatic routing of not completed calls" service

SMS-SC

BSS

mobile station

G/IWMSC

SMS

voice mail system

voice mailboxes

. ..

HLR

MSC/VLR


9/16

A50016-D1108-C307-1-7629 9



2.1 Management of "Automatic Routing of not completed

Calls"

This supplementary service is added to a PLMN upon a project-specific basis depending

on whether the voice mail service can be supported or not. When it is implemented

within the PLMN, the service provider will offer the feature to specific mobile subscribers

as a result of a personal agreement.

For a proper management, administration procedures need to be carried out by both the

PLMN operator and the mobile subscriber provided with "automatic routing of not

completed calls".

Operator management

Operator controlled input (OCI) procedures are used by the PLMN operator for "auto-

matic routing of not completed calls" administration. To start these procedures, the

PLMN operator needs to enter the appropriate MML commands (listed in chapter 3) at

a craft terminal (CT).

MML commands are defined for the following purposes:

The PLMN operator defines the voice mail systems (VMSs) which can be used by

the mobile subscribers for their personal voice mailboxes. Therefore, a voice mail

table is created in the home location register (HLR) whereby each VMS is assigned

a voice mail short code and a voice mail directory number.

The short code is a 3 digit code used by the subscriber to retrieve his voice mail.

The directory number is a regular ISDN number complying with ITU-T Recom-

mendation E.164 used by the network to divert calls to.

Up to 32 VMSs can be supported by a PLMN which implies that a maximum of up

to 32 VMSs can be created within the voice mail table.

The mobile subscribers subscription to this supplementary service is accom-plished by the PLMN operator by entering the appropriate MML commands. For this

specific subscription, the operator can register to either one or all of the following:

the VMS short code with respect to the subscribers voice mailbox location;

the no reply condition timer to define when an incoming call has to be diverted to

the VMS if no reply is received from the served subscribers side. The value can

beset inbetween 5 and 30 seconds in steps of 5 seconds. If no valueis supplied,

the default value, as defined by the operator, will apply.

the respective announcements that must be available in the coordination

processor (CP) to properly inform the calling party.

This data is stored within the HLR subscriber database and inserted within the appro-

priate VLR database when the mobile subscriber roams into the VLR area. This supple-mentary service only applies within the home PLMN, so no affecting subscriber data is

sent to a foreign VLR. The registration of the subscription parameters as described

above automatically activates the "automatic routing of not completed calls".

Note that when a subscriber is provided with this service, he should also be provided

with the short message service, mobile terminated (SMS MT). Otherwise the served

subscriber will receive no notification when a voice mail is stored within the mailbox.

Subscriber management

The mobile subscriber provided with the "automatic routing of not completed calls"

service is able to control the feature himself. This means that the subscriber can:

activate/deactivate the service;


10/16

10 A50016-D1108-C307-1-7629


register service information (VMS short code, no reply condition timer);

obtain service data as stored in the HLR.

The control procedures are based on mobile initiated unstructured supplementary

service data (USSD) representing the control procedures between the mobile stationand the network for the PLMN specific supplementary services which do not comply with

the GSM specified functional signaling.

In general this implies the following (Fig. 2.2):

The mobile subscriber enters a predefined character string (given in chapter 4) to

activate/deactivate/register/interrogate this service at the mobile station (i.e. the

USSD request). This character string is recognized by the mobile station as a USSD

string and sent to the network.

When the USSD request is handled by the network, a USSD response (text indi-

cating the outcome of the request handling) is returned to the mobile station and

displayed. The USSD responses are administrable by the PLMN operator by means

of MML commands. Possible causes if the network cannot accept a mobilesubscribers request are the following:

telephony basic service not provisioned

VMS short code is invalid

"automatic routing of not completed calls" service not provisioned

insufficient information

conflicting situation with other supplementary services see chapter 5.

For more information about USSD, see feature document Support of Unstructured

Supplementary Service Data.

Fig. 2.2 USSD operations

2.2 Call Diversion to the Voice Mailbox

The network automatically invokes the "automatic routing of not completed calls" service

when:

it is active and operative, and

MSC/VLR

BTS/BSC

mobile

station

PLMN

HLR/AC

USSDoperation

"automatic routing of not

completed calls"

USSD

notification


11/16

A50016-D1108-C307-1-7629 11



an incoming speech call is addressed to the served mobile subscriber who is

unavailable at the moment.

The mobile subscriber is defined as unavailable if:

the subscriber is busy; the subscriber does not reply within a certain time as specified by the no reply condi-

tion timer;

the subscriber is unreachable because of the following:

no paging response received;

radio congestion;

roaming in forbidden area;

mobile subscriber detached;

no roaming number can be provided in the HLR for routing.

The unavailability of the mobile subscriber is either detected after HLR interrogation in

the gateway MSC, or after a VLR subscription check in the visited MSC. The MSC

detecting the unavailability invokes the service and diverts the incoming speech call tothe voice mailbox after informing the calling party of the reason why.

The call is diverted within the gateway MSC when the mobile subscriber is unreachable

due to the following:

roaming in forbidden area;

no roaming number available;

subscriber detached.

This state only will cause an announcement to the calling party.

The call is diverted within the visited MSC when:

the mobile subscriber is busy;

no reply or paging response is received;

there is radio congestion."Automatic routing provides for sending the incoming call to the mailbox anyhow, and

the related announcements will not have any impact on this call diversion.

Automatic routing of calls to an unavailable mobile station is triggered as follows

(Fig. 2.3).

1. An incoming speech call arrives at a(n) (gateway) MSC. The (gateway) MSC inter-

rogates the HLR for routing information. According to the information stored in the

HLR database, the HLR returns either:

an MSRN enabling the (gateway) MSC to route the call to the called party if the

latter is able to receive the call, or

a VMS directory number and the reason why the called subscriber is unable to

receive an incoming call. This applies only if the called party has subscription to

the "automatic routing of not completed calls" service and the called subscriber

cannot answer the call due to being detached, roaming in forbidden area or when

no roaming number is available.

2. If the latter case applies, the (gateway) MSC diverts the incoming call to the appro-

priate MSC which has access to the voice mail system (VMS). Therefore, the

(gateway) MSC consults its VMS table which is stored in every MSC of the PLMN

and provides for the appropriate routing data for call diversion.

The VMS directory number and the MSISDN of the called party are sent to the

appropriate MSC which establishes the call to the VMS for a voice mail deposit. The

called partys MSISDNallows the MSC to select the appropriate voice mailbox within

the VMS.


12/16

12 A50016-D1108-C307-1-7629


3. In the case that the (gateway) MSC receives an MSRN, the call is set up to the

visited MSC (VMSC) in whose area the called party is currently roaming.

4. The VMSC requests the called partys subscription parameters stored in the VLR.

The VLR indicates that the service is active; it also returns data on its no reply condi-

tion timer.

5. If so, the VMSC investigates whether or not the service conditions apply; i.e.

when the no reply condition timer is expired;

when the subscriber is busy;

when no paging response is received;

when there is radio congestion.

6. As soon as the "automatic routing of not completed calls" service becomes appli-

cable, the VMSC consults the VLR database again to retrieve the VMS directory

number.

7. The VMSC diverts the call to the VMS as outlined in point 2.

8. When a voice mail is stored within the voice mailbox, the VMS sends a short

message to the short message service center which delivers the short message tothe called subscriber the voice mail is intended for. This short message indicates to

the subscriber that a voice mail is waiting for him at the VMS. This notification is not

illustrated within the figure. The complete short message delivery is described in

document Short Message Service Mobile Terminated.

Fig. 2.3 Automatic routing of not completed calls

2.3 Voice Mail Retrieval

When the called subscriber knows that a voice mail is waiting in his mailbox, he canrequest this voice mail by dialing the VMS short code which results in a regular mobile

(gateway)

MSC

called party provided with

"automatic routing of not

completed calls"

D900/D1800/D1900 PLMN

HLR

.

.

.

.

calling party

(1)

(1)

VLR VMSC

(3)

(4) (6)

(7)

VMS

(7)(2)

(5)

BSS


13/16

A50016-D1108-C307-1-7629 13



originating call (MOC) being set up to the VMS. Note that dialing the VMS short code

causes voice mail retrieval whereas the VMS directory number is used for voice mail

deposit.

When the connection to the VMS is established, the voice mailbox offers some possibil-ities to the mobile subscriber e.g. by means of a voice menu. The subscriber can select

one possibility by pressing a specific key on the mobile station. Pressing the key gener-

ates a dual tone multifrequency (DTMF) signal. DTMF is an inband signaling system

built upon tones. The DTMF tone is sent to the mailbox which then takes the proper

action. For more information about DTMF, refer to document Support of DTMF.

2.4 Implementation of the Feature

The "automatic routing of not completed calls" supplementary service is implemented

in the D900/D1800/D1900 system as a software function. This software is located in the

software functional units of the line/trunk group (LTG), i.e. LTG call processing, and of

the coordination processor (CP), i.e. CP call processing.

The subscriber administration of the feature is carried out at the HLR. This function

handles the MML commands for operation and maintenance entered at a craft terminal

(CT).

The call sequences provided in the MSC and HLR redirect the incoming speech calls to

a voice mailbox where a voice mail can be deposited.

3 Inputs at the Craft TerminalThis section gives an overview of the tasks for operation and maintenance to be carried

out at the craft terminal (CT). The man-machine language (MML) commands are

described in detail in the Command Manual (CML).

The following commands are used to maintain the voice mail service table located in the

HLR. Each VMS is assigned a short code and a voice mail center directory number:

CR VMS

CAN VMS

MOD VMS

DISP VMS

Two specific MML commands are defined to handle the appropriate subscriber data.

ENTR CALLBACK

CAN CALLBACKThe PLMN operator can display a subscribers "automatic routing of not completed

calls" data by means of

DISP MSUB

The following commands allow the PLMN operator to administer the USSD responses:

MOD USSDTXT

DISP USSDTXT

The PLMN operator can administer the announcements to be provided to the calling

party when the call cannot be completed. Therefore, an appropriate identifier can be

entered for an announcement (see chapter 1 ) according to the called subscribers state.

CR INC


14/16

14 A50016-D1108-C307-1-7629


CAN INC

DISP INC

Automatic routing and call forwarding can restrict each other as described in chapter 6.

When administering announcements, the PLMN operator should be aware that, as faras (un)conditional call forwarding is concerned, notification suppression could have

been installed in the whole network. The calling subscriber will then only be informed of

rerouting if the service "automatic routing of not completed calls" is active.

The operator can remove this suppression:

DISP MSERVOPT

MOD MSERVOPT

4 Inputs at the Mobile StationMobile subscribers provided with the "automatic routing of not completed calls" service

can control it by entering character strings on their station.

Registration:

**SC*VMS short code*no reply condition timer#

Erasure:

##SC#

Activation:

*SC#

Deactivation:

#SC#

Interrogation:

*#SC#

After entering the input string, the mobile subscriber has to push the SEND key to

transmit the information to the network.

5 Call Charge RegistrationFour different charging records can be distinguished for the "automatic routing of not

completed calls" service.

Subscriber controlled input records

Charging records can be generated for each successful subscriber action perfomed at

the mobile station, i.e. registration, activation, deactivation, interrogation. This record is

generated at the VMSC.

whereby:

** start of registration

## start of erasure

* start of activation, and separator at digit input for registration

# start of deactivation

*# start of interrogation

SC assigned service code

# end of the input.


15/16

A50016-D1108-C307-1-7629 15



"Automatic routing of not completed calls" invocation records

Each time this service is invocated (forwarding the incoming call to the voice mailbox),

a separate call record can be generated. The record is generated at either the VMSC or

the (gateway) MSC diverting the call to the voice mailbox.

Voice mail notification records

Charging records can be generated for the short message retrieved by the served

mobile subscriber. This record is a regular short message mobile terminated record and

is generated at the VMSC.

Voice mail retrieval records

Charging records can be generated at the VMSC when the mobile subscriber wants to

retrieve his voice mail from the voice mailbox. This record consists of a regular MOC

record.

6 Compatibility with other Features

Interaction with roaming

The "automatic routing of not completed calls" supplementary service is available with

a reduced functionality for the subscribers roaming outside their home PLMN because

of its PLMN specific character. The following applies for subscribers roaming in a foreign

PLMN.

Subscriber service control is not affected by the condition that the PLMN supports

USSD.

Since no "automatic routing of not completed calls" data is sent to any VLR outsidethe home PLMN, call diversion is only invoked if detected in the HLR.

A call to the VMS cannot be set up by using the VMS short code. This applies since

the VMS routing table is only provided within the MSCs of the home PLMN. The

foreign MSC is not able to know the VMS short code.

Interaction with call forwarding unconditional

The activation of "automatic routing of not completed calls" is rejected if call forwarding

unconditional is active. The served mobile subscriber is informed of this incompatibility.

The activation of call forwarding unconditional is accepted if "automatic routing of not

completed calls" is active. However, the latter service is temporarily deactivated, i.e. the

service is no longer in effect once call forwarding unconditional is activated. After callforwarding unconditional has been deactivated, the service is activated again.

Interaction with the other call forwarding services

The call forwarding services (both the conditional forwardings as those by default) take

precedence over the "automatic routing of not completed calls" service. The speech call

meeting subscriber busy, not reachable, no reply or an unactive forwarding is diverted

to the subscribers voice mailbox only if the associated call forwarding service (CFB,

CFNRy, CFNRc or CFD) is not active for the telephony teleservice.

Note that an already forwarded call cannot be diverted to the VMS, no matter what the

number of forwardings (maximum 5) is.


16/16

16 A50016-D1108-C307-1-7629


Interaction with call waiting

Basically, the "automatic routing of not completed calls" service has a higher priority

than the supplementary service call waiting. I.e., while being active, the waiting call is

diverted to the voice mailbox if the served mobile subscriber does not react before theno reply condition timer expires. When the served mobile subscriber releases a waiting

call, the call is diverted to the mailbox or rejected (depends upon the release cause).

Interaction with closed user group (CUG)

CUG authorization is performed for the calling and the called party to guarantee the

integrity of a CUG. This means that authorization functions are performed to reject

CUG-related calls which are not authorized.

The served mobile subscriber needs outgoing access to be able to divert a call to a VMS

and to setup a call to the VMS.

Interaction with call barring

The activation of the "automatic routing of not completed calls" service is denied when

barring of all outgoing calls (BAOC) or barring of all incoming calls (BAIC) is active, and

vice versa. In both cases, the mobile subscriber is informed about the supplementary

service incompatibility.

No interaction exists with the following call barring services since the "automatic routing

of not completed calls" service is a national PLMN service which is only available while

roaming in the home PLMN:

barring of outgoing international calls (BOIC)

barring of outgoing international calls except those directed to the home PLMN

country (BOIC-exHC)

barring of incoming calls when roaming outside the home PLMN country (BIC-Roam).

Interaction with operator determined barring

The activation of the "automatic routing of not completed calls" service is denied when

the operator has activated a barring program for either all outgoing calls, or all incoming

calls.

If the service is active it will be deactivated when either of the two above mentioned

barring programs is activated.

Documents

c307 Call Divert