|
TECHNICAL SPECIFICATION
Digital cellular telecommunications system (Phase 2+) (GSM);
Universal Mobile Telecommunications System (UMTS);
Follow-Me (FM);
Stage 2
(3GPP TS 23.094 version 15.0.1 Release 15)
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
---------------------- Page: 1 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 1 ETSI TS 123 094 V15.0.1 (2018-07)
Reference
RTS/TSGC-0423094vf01
Keywords
GSM,UMTS
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
If you find errors in the present document, please send your comment to one of the following services:
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2018.
All rights reserved.
TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.
TM TM
3GPP and LTE are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M logo is protected for the benefit of its Members.
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI
---------------------- Page: 2 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 2 ETSI TS 123 094 V15.0.1 (2018-07)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or
GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables.
The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under
.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI
---------------------- Page: 3 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 3 ETSI TS 123 094 V15.0.1 (2018-07)
Contents
Intellectual Property Rights . 2
Foreword . 2
Modal verbs terminology . 2
Foreword . 4
1 Scope . 5
2 References . 5
3 Definitions and abbreviations . 5
3.1 Definitions . 5
3.2 Abbreviations . 6
4 Handling of Follow Me . 6
4.1 General . 6
4.1.1 Provision . 7
4.1.2 Registration . 7
4.1.3 Erasure . 7
4.1.4 Interrogation . 7
4.2 Information Flows . 7
4.2.1 Information Flow for the handling of FM by the initiating subscriber . 7
4.2.2 Information Flow for the handling of FM by the remote party . 10
4.3 Handling of FM control in HLRa and FFNb . 10
4.3.1 Handling of FM control in HLRa . 10
4.3.2 Handling of FM control in FFNb . 13
4.4 USSD interworking and Cross-phase compatibility . 22
5 Information stored in the network entities. 22
5.1 Information stored in HLRa and FFNb . 22
5.2 State transition model . 23
5.3 Information stored in the VLR . 24
5.4 Transfer of information from HLR to VLR . 24
Annex A (informative): Checking matrix for FM-CFU interaction in FFNb . 25
Annex B (normative): FM control Messages and their contents . 27
B.1 General principles . 27
B.2 Information Elements used in the messages . 27
B.3 Messages Contents of the FM Request . 27
B.4 Messages Contents of the HLR-FM-Request . 28
B.5 Contents and Format of the USSD String of the USSD-Notify . 31
B.6 Inter-process Message Init-Notify . 32
Annex C (informative): Change history . 33
History . 34
ETSI
---------------------- Page: 4 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 4 ETSI TS 123 094 V15.0.1 (2018-07)
Foreword
rd
This Technical Specification (TS) has been produced by the 3 Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
ETSI
---------------------- Page: 5 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 5 ETSI TS 123 094 V15.0.1 (2018-07)
1 Scope
The present document specifies the stage 2 description for the Follow Me feature.
The Follow Me feature enables a mobile subscriber A to manipulate the Follow Me data of a remote party B in such a
way that subsequent calls directed to remote party B will be forwarded to subscriber A.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] 3GPP TR 21.905: "3G Vocabulary".
[2] 3GPP TS 22.004: "General on Supplementary Services".
[3] 3GPP TS 22.030: "Man-Machine Interface (MMI) of the Mobile Station (MS)".
[4] 3GPP TS 22.082: "Call Forwarding (CF) supplementary services - Stage 1".
[5] 3GPP TS 22.094: "Follow Me (FM) feature - Stage 1".
[6] 3GPP TS 23.011: "Technical realisation of Supplementary Services - General Aspects".
[7] 3GPP TS 23.015: "Technical realisation of Operator Determined Barring (ODB)".
[8] 3GPP TS 23.090: "Unstructured Supplementary Services Data (USSD)- Stage 2".
[9] 3GPP TS 23.082: "Call Forwarding (CF) supplementary services - Stage 2".
[10] 3GPP TS 22.090: "Unstructured Supplementary Services Data (USSD)- Stage 1".
[11] 3GPP TS 24.090: "Unstructured Supplementary Services Data (USSD)- Stage 3".
[12] 3GPP TS 29.002: "Mobile Application Part (MAP)".
3 Definitions and abbreviations
3.1 Definitions
initiating subscriber: mobile subscriber who modifies the Follow Me data of the remote party.
initiating number: number (the MSISDN of the initiating subscriber) to which incoming calls, originally destined for
the remote party, shall be forwarded. It is subsequently also referred to as MSISDNA.
remote party: is characterised by the remote number which is defined in the numbering plan of a PLMN operator. The
Follow Me feature enables the initiating subscriber to modify the Follow Me data of the remote party. In particular
cases the remote party is a GSM subscriber of the PLMN and the remote number denotes her basic MSISDN.
Previously registered subscriber: Is the initiating service subscriber who has registered Follow Me with respect to a
remote party. Her Registration can be erased by herself or by an FM service supervisor via forced erasure procedure.
ETSI
---------------------- Page: 6 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 6 ETSI TS 123 094 V15.0.1 (2018-07)
FM service supervisor: is an initiating subscriber who is allowed to modify the Follow Me data of a remote party who
has been registered to a previously registered subscriber for the Follow Me application. The FM service supervisor shall
be authorised by her network operator.
remote number: is a number in E.164 format which identifies a remote party. In general this number is not assigned to
a subscriber and can be regarded as a "dummy MSISDN". In particular cases the remote party is a GSM subscriber of
the PLMN and the remote number denotes her basic MSISDN. The remote number is entered by the initiating
subscriber for registration, interrogation, forced erasure and erasure of the Follow Me feature with respect to the remote
party.
Follow Me function node: is a network node in the PLMN operator of the remote party. The FM data of the remote
party are stored in this node. This node can be implemented in:
- an HLR;
- any other operator specific network node e.g.:
- a gsmSCF;
- an SCP.
3.2 Abbreviations
FFN Follow Me function node
FM Follow Me
SCP Service Control Part
Other abbreviations used in this ETS are listed in 3GPP TR 21.905.
4 Handling of Follow Me
4.1 General
Follow Me enables an initiating mobile subscriber A to have control over the Follow Me data of a remote party B. The
remote party B is characterised by the remote number which is defined in the numbering plan of a PLMN operator.
Initiating Subscriber A shall be able to manipulate the Follow Me data of remote party B such that subsequent calls
destined for remote party B are forwarded to initiating subscriber A. In the case of Forced Erasure by an FM service
supervisor, the initiating subscriber is allowed to erase the Follow Me data of a remote party who has been registered to
a different initiating subscriber for the Follow Me application.
Follow Me is a PLMN specific feature and the control operations of FM are based on USSD. All messages between the
MS and the mobile network and internal to the mobile network are USSD messages.
The present document deals with the control operations of FM in HLRa and FFN. If the FFN is an HLR, the control of
the requests for both FM and CFU services is specified (see subclause 4.3.2).
The functionality of forwarding calls for remote party B to initiating subscriber A (after successful registration of FM)
is out of the scope of the present document. This functionality is the same as the functionality of the Call Forwarding
Unconditional Supplementary Service applied to all telecommunication services of remote party B for which CFU is
applicable.
NOTE 1: the "served mobile subscriber" in 3GPP TS 22.094 [5] corresponds to the "remote party" in the present
document and the "forwarded-to subscriber" in 3GPP TS 22.094 [5] corresponds to the "initiating
subscriber" in the present document.
NOTE 2: The forwarding of calls for remote party B to initiating subscriber A can be achieved by invoking the Call
Forwarding Unconditional Supplementary Service or by making use of an equivalent operator specific
service (e.g. via CAMEL).
The functionality of the control of Follow Me (registration, erasure, forced erasure and interrogation) is split between
the HLR of the initiating subscriber A (HLRa) and the FFN of the remote party B (FFNb).
ETSI
---------------------- Page: 7 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 7 ETSI TS 123 094 V15.0.1 (2018-07)
4.1.1 Provision
FM can be registered / erased / interrogated by an initiating subscriber A with respect to a remote party B if both parties
are provisioned with FM.
To enable forced erasure by an FM service supervisor, the FM service shall be provisioned to the FM service
supervisor. Additionally, she needs the subscription entitlement to perform the forced erasure.
NOTE: In general remote party B does not correspond to a GSM subscriber. In this case provisioning of FM for
remote party B is operator specific.
If remote party B is a GSM subscriber and if the forwarding of calls for remote party B to initiating subscriber A is
achieved by invoking the Call Forwarding Unconditional Supplementary Service, provision of CFU for remote party B
is required.
4.1.2 Registration
The initiating subscriber registers the FM feature with respect to a particular remote party.
If an initiating subscriber A successfully registers FM with respect to a remote party B then FM becomes registered,
active and operative for remote party B.
As a result of the registration subsequent calls directed to remote party B are forwarded to initiating subscriber A.
NOTE: The remote party cannot register FM with respect to herself.
4.1.3 Erasure
If an initiating subscriber A or the FM service supervisor successfully erases FM with respect to a remote party B then
FM becomes not registered and not active for remote party B.
For forced erasure by the FM service supervisor the previously registered subscriber shall be informed of the successful
forced erasure via a network initiated USSD Notify message with appropriate contents. This message is sent by the
FFN.
If remote party B is a GSM subscriber and successfully erases FM then FM becomes not registered and not active for
remote party B.
4.1.4 Interrogation
If an initiating subscriber A or the FM service supervisor successfully interrogates FM with respect to a remote party B
then this procedure interrogates the FM data of subscriber B.
If remote party B is a GSM subscriber and successfully interrogates FM then this procedure interrogates her own FM
data.
4.2 Information Flows
4.2.1 Information Flow for the handling of FM by the initiating subscriber
Figure 4.1 shows the Information Flow for the control of FM (registration, erasure, forced erasure and interrogation) by
the initiating subscriber.
For any control operation on FM, the initiating subscriber (MSa) enters a Follow Me Request (FM-Request). This is a
USSD string containing the requested FM operation and the remote number. The Follow Me Request is routed via the
MSC/VLR to the HLR of the initiating subscriber (HLRa).
The HLRa performs a series of checks as described in the SDLs (subclause 4.3). If these checks fail, the MSa receives a
response (FM-Response) indicating the error.
If the checks pass, the HLRa forwards the operation request (HLR-FM-Request) to the FFN of the remote party (FFNb).
FFNb carries out the appropriate control operation and checks as described in the SDLs (subclause 4.3) for the remote
party.
ETSI
---------------------- Page: 8 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 8 ETSI TS 123 094 V15.0.1 (2018-07)
The result of this operation (success or error) is reported back in a USSD Response to the initiating subscriber.
For successful forced erasure by a service supervisor, the FFN shall send a Network Initiated USSD notify message
with the corresponding USSD string to the HLR of the previously registered subscriber who had registered the Follow
Me data. The HLR shall forward the USSD notify to VLR which will relay the USSD Notify towards the MS.
Upon receipt of the USSD Notify, the MS shall respond by sending a FACILITY message with empty return result
component.
An error response with corresponding reason can be returned from any entity, when error happens at the entity 3GPP
TS 23.090 [8].
ETSI
---------------------- Page: 9 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 9 ETSI TS 123 094 V15.0.1 (2018-07)
MSa
MSC
VLR HLRa FFNb
FM-Request
(OC,SC,RN, FM-Request
[(SI,PIM,)] [AI])
FM-Request
(OC,SC,RN,
(OC,SC,RN,
[(SI,PIM,)] [AI])
[(SI,PIM,)] [AI])
OR1:
N
FM-Response
(Error)
FM-Response
(Error)
FM-Response
OR1:
(Error)
Y
HLR-FM-Request
(OC,SC,RN,
[(SI,PIM,)] [AI,]
MSISDN-A)
HLR-FM-Response
FM-Response
(Result)
FM-Response
(Result)
(Result)
FM-Response
In case of successful
(Result)
forced erasure by a
service supervisor,
an USSD Notify with
corresponding USSD
string is sent to the
MSp
previously registered
MSC VLR HLRp
subscriber.
USSD-Notify
(OCSC,FN,SI,
MSISDN-A,AI)
USSD-Response
USSD-Notify
(error)
(OCSC,FN,SI,
MSISDN-A,AI)
USSD-Response
USSD-Response
USSD-Notify
(error)
(error)
(OCSC,FN,SI,
MSISDN-A,AI)
USSD-Response
USSD-Response
USSD-Response
USSD-Notify (error)
(error)
(error)
(OC,SC,FN,SI,
MSISDN-A,AI)
USSD-Response
USSD-Response
USSD-Response
(error)
(error)
USSD-Response
(error)
USSD-Response
(error)
USSD-Response
(result)
USSD-Response
(result)
USSD-Response
(result)
(result)
Figure 4.1: Information flow for the control of FM by the initiating subscriber or service supervisor
ETSI
---------------------- Page: 10 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 10 ETSI TS 123 094 V15.0.1 (2018-07)
NOTE 1: OR1:N: The case where the checks in the HLR result in a negative outcome, e.g. FM is not
provisioned for the initiating subscriber or the initiating subscriber is not allowed to
operate FM for the remote party.
OR1:Y: The case where all the checks in the HLR are successful, e.g. FM is provisioned for the
initiating subscriber and the initiating subscriber is allowed to operate FM for the remote
party.
NOTE 2: [.] Optional parameter.
(.)] Conditional parameter.
OC Operation Code (Register, Erase or Interrogate).
SC Service Code for FM.
RN Remote Number.
SI Supervisor Indicator. This parameter is conditional and only used for forced erasure by a
FM service supervisor.
PIM MSISDN of previously registered subscriber who has registered the FM to remote
number. This parameter is conditional and only used for forced erasure by a FM service
supervisor.
AI Supplementary Information containing additional information.
MSISDN-A initiating number in international format. It is not a part of the USSD string, but is sent
from HLRa to the FFNb together with the HLR-FM-Request within the MAP operation.
For forced erasure, the MSISDN-A corresponds to the supervisor's MSISDN and will be
part of the USSD-notify.
MSp MS of previously registered service subscriber.
HLRp HLR of the previously registered service subscriber.
4.2.2 Information Flow for the handling of FM by the remote party
Control of FM by the remote party is possible if the remote party is a GSM subscriber.
The information flow for control of FM by the remote party (erasure and interrogation of her own FM data) is the same
as the information flow for control of FM by the initiating subscriber.
If a remote party tries to register FM to herself the registration is rejected and an error is reported.
4.3 Handling of FM control in HLRa and FFNb
HLRa and FFNb can both receive FM control messages, based on USSD. The USSD handler in each entity analyses the
Service Code contained in the USSD string and, recognising the Service Code for FM, invokes the FM USSD
application.
The FM control messages and their contents are given in Annex B (normative).
4.3.1 Handling of FM control in HLRa
The FM USSD application in HLRa is the process FM_initiating_subscriber_handling_in_HLR (figure 4.2). It
receives the FM-Request from the initiating subscriber. This FM-Request is an USSD-string containing:
- the operation code (register, erase, interrogate);
- the remote number;
- an additional operator specific information field.
The HLR checks:
ETSI
---------------------- Page: 11 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 11 ETSI TS 123 094 V15.0.1 (2018-07)
- the provisioning of FM to the initiating subscriber;
- whether the FFN can be deduced from the remote number;
- whether any operator specific restrictions to engage in FM activity with the remote party apply;
- if the initiating subscriber requires forced erasure, the HLR checks Whether the initiating subscriber is entitled to
do it, i.e. Whether the initiating subscriber is a FM service supervisor.
The basic MSISDN of the initiating subscriber is sent together with the original USSD string to the FFN of the remote
party.
The HLR forwards the response from the FFN to the initiating subscriber.
For successful forced erasure by a service supervisor, the HLR of the previously registered subscriber (HLRp) shall
relay the USSD Notify to the VLR when the USSD Notify from the FFN is received. The VLR will then forward the
USSD Notify towards the MS of the previously registered service subscriber.
On receipt of an USSD response from the MS of the previously registered subscriber, the HLRp shall relay it to the
FFN.
ETSI
---------------------- Page: 12 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 12 ETSI TS 123 094 V15.0.1 (2018-07)
Process FM_Initiating_Subscriber_Handling_in_HLR 1(1)
A process in the HLR to handle
an FM-Request from an initiating
Idle
subscriber.
FM-Request
Signals to/from the left HLR receives USSD
(Operation,
are to/ftom the VLR of the string from initiating
Remote_Number,
initiating subscriber; subscriber
Additional_Info)
Signals to/from the right
are to/from the FFN
check if initiating
no
FM
subscriber is FM
provisioned?
provisioned
Error :=
yes
FM not subscribed
check if address of FFN
no
Remote_Number
can be deduced from
known? Remote_Number
Error :=
yes
unknown Remote
Party
no
Supervisor
Indicator
present?
yes
Check iif the forced erasure
is allowed to the initiating
no Forced subscriber.
Erasure
allowed?
yes
check operator specific
restrictions on initiating
no subscriber to engage
FM allowed with
Remote Party in FM activity
remote_number?
yes
Error :=
unauthorised
Basic MSISDN of initiating
HLR-FM-Request :=
request
subscriber is sent to the FFNb
FM-Request
together with the FM-Request
+ initial MSISDN
within the MAP operation.
HLR-FM-Request
FM-Response
(Operation,
(Error)
Remote_Number,
Additional_Info,
Initial_MSISDN)
Idle
wai_ for_answer_
from_FFN
HLR-FM-Response
(Result)
FM-Response
(Result)
Idle
Figure 4.2: Process: FM_Initiating_Subscriber_Handling_in_HLR
ETSI
---------------------- Page: 13 ----------------------
3GPP TS 23.094 version 15.0.1 Release 15 13 ETSI TS 123 094 V15.0.1 (2018-07)
Process Notification_for_previously_registered_subscriber_in_HLRp 1(1)
Process in HLRp to handle
the forced erasure notification
sent from the FFN
Signals to/from the left Idle
are to/ftom the VLR of the
initiating subscriber;
Signals to/From the right from the FFN
process FF N_Forced
are to/from the FFN
USSD-Notify Erasure_Notify
(OC,SC,FN,SI,
MSISDN-A,AI)
Errors can orrucr
in HLRp when
yes handling
any error
USSD-Notify
occurred?
no
USSD-Notify
send to VLR
(OC,SC,FN,SI,
MSISDN-A,AI)
wait for USSD-
Notify-
Response
Response
from VLR
USSD-Notify-
Response()/
(error)
send to the FFN
process FF N_
Forced_Erasure_
USSD-Notify- USSD-Notify-
Notify
Response(error) Response()/(error)
Idle
Figure 4.2a: Process Notification_for_previously_registered_subscriber_in_HLRp
4.3.2 Handling of FM control in FFNb
If the FFN is an HLR, the FFN is responsible for handling the interactions between FM and CFU. Two kinds of request
may be received in an FFN which deals with forwarding services:
- CFU requests sent by the VLR for CFU operations (only if the FFN is a HLR);
- FM-
...