SIST ETS 300 925 E1:2003

• Abstract:

  This European Telecommunication Standard (ETS) specifies the stage one description of the Voice Group Call Service (VGCS) which allows speec h conversation of a predefined group of service subscribers in half du plex mode on the radio link taking into account multiple mobile servic e subscribers involved in the VGCS call per cell. The VGCS is applicable to all mobile stations in a certain network and area which have the technical capability and the corresponding subscr iption, respectively, to participate in a VGCS call. NOTE: It is not considered as requirement that normal GSM phase 2 mobi le stations will be able to be used for this service. The service is described from the service subscriber s and user s poin t of view; in particular: - the procedure for normal operation with successful outcome; - the action to be taken in exceptional circumstances; - the interaction with other GSM services and features. This ETS does not deal with the Man-Machine Interface (MMI) requiremen ts, but makes reference to the appropriate Global System for Mobile Co mmunications (GSM) specifications. This ETS defines a teleservice of the digital cellular telecommunicati ons system GSM. Any interaction with other services and/or networks no t dealt with in clauses 8 or 9 are outside the scope of this ETS.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Mandate: UIC
• Ref Project: ETSI ETS 300 925 ed.1 (1997-05) - Digital cellular telecommunications system (Phase 2+) (GSM); Voice Group Call Service (VGCS); Stage 1 (GSM 02.68 version 5.1.1)

Overview

SIST ETS 300 925 E1:2003 defines the Stage 1 requirements for the Voice Group Call Service (VGCS) within the digital cellular telecommunications system, specifically in the context of GSM Phase 2+ networks. The standard, developed by the Slovenian Institute for Standardization (SIST) through ETSI, outlines the procedures, features, and operational scenarios for delivering speech conversations to predefined groups of subscribers using half-duplex radio links. This group communication service is designed to meet the needs of multiple users in the same network and area, provided their devices and subscriptions support VGCS functionality.

VGCS primarily enables efficient, spectrum-conscious group voice calls, where one user or dispatcher can communicate with several participants within defined geographic areas, such as coverage cells or service clusters. The focus is on subscriber experience, network interactions, and the integration of VGCS with other GSM services.

Key Topics

• Group Call Functionality: VGCS enables a calling subscriber or dispatcher to establish a speech call with a group of mobile users defined by group and area IDs, operating in half-duplex mode to optimize radio resources.
• Service Eligibility: Only subscribers and dispatchers with appropriate technical capability and valid VGCS subscription can participate. Regular GSM Phase 2 terminals are not required to support VGCS.
• Operational Procedures:
  • Steps for normal VGCS establishment, including notification, call set-up, and release.
  • Handling of exceptional circumstances (e.g., subscription or entitlement failure).
  • Call release can be managed by the calling subscriber, a dispatcher, or the network, with automatic timeout options in case of inactivity.
• Dispatcher Integration: Special users identified as dispatchers have added privileges, such as initiating group calls from outside the service area and simultaneous voice participation.
• Interoperability and Supplementary Services: Interaction with existing GSM services such as Call Forwarding, Call Waiting, CLIP/CLIR, and SMS is specified, detailing how they coexist or are restricted during VGCS sessions.
• Subscription and Configuration: Assignment of group IDs to subscribers and dispatchers, as well as service area definitions, are managed administratively at the network level.

Applications

VGCS, as described in SIST ETS 300 925 E1:2003, is critical for organizations and operations requiring instant group voice communication, including:

• Public Safety and Emergency Services: Police, fire, and ambulance services for coordinated responses.
• Railways and Transportation: Supporting operational communications among train crews, dispatchers, and control centers, with emergency call features and priority handling.
• Utilities and Field Operations: Utility companies, maintenance teams, and large-scale event organizers benefit from rapid, simultaneous communication with distributed teams.
• Roaming Scenarios: The standard supports cross-network group calls for roaming users with appropriate subscriptions and defined supra-PLMN group IDs.

The practical value of VGCS comes from its integration with GSM, allowing organizations to use existing digital cellular infrastructure for robust, low-latency voice group calls.

Related Standards

For comprehensive deployment and interoperability of VGCS, the following related GSM specifications should be considered:

• GSM 01.04 (ETR 350) – Abbreviations and acronyms for GSM standards
• GSM 02.40 – Procedures for call progress indications
• GSM 02.67 / ETS 300 924 – Enhanced Multi-Level Precedence and Pre-emption Service (eMLPP), addressing call priority and pre-emption aspects
• Additional GSM supplementary services, as referenced within the document

SIST ETS 300 925 E1:2003 provides a foundational framework for implementing efficient group call services in GSM Phase 2+ networks, ensuring reliable communication for mission-critical and commercial applications across Europe.

SLOVENSKI STANDARD
01-december-2003
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VNXSLQVNHJDNOLFD9*&6±6WRSQMD*60UD]OLþLFD
Digital cellular telecommunications system (Phase 2+) (GSM); Voice Group Call Service
(VGCS); Stage 1 (GSM 02.68 version 5.1.1)
Ta slovenski standard je istoveten z: ETS 300 925 Edition 1
ICS:
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 925
TELECOMMUNICATION May 1997
STANDARD
Source: ETSI TC-SMG Reference: DE/SMG-010268QR
ICS: 33.020
Key words: Digital cellular telecommunications system, Global System for Mobile communications (GSM)
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system (Phase 2+);
Voice Group Call Service (VGCS) - Stage 1
(GSM 02.68 version 5.1.1)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright
and the foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1997. All rights reserved.

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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .7
3.1 Definitions .7
3.2 Abbreviations .8
4 Description .9
5 Normal operation with successful outcome.12
5.1 Provision .12
5.2 Withdrawal .12
5.3 Network related service configuration.12
5.4 Normal operation for group call establishment .12
5.5 Charging requirements .12
6 Exceptional procedures or unsuccessful outcome.13
7 Interaction with other GSM services.13
7.1 Calling Line Identification Presentation (CLIP) .13
7.2 Calling Line Identification Restriction (CLIR) .13
7.3 Connected Line Identification Presentation (COLP) .13
7.4 Connected Line Identification Restriction (COLR) .13
7.5 Call Forwarding Unconditional (CFU) .13
7.6 Call Forwarding on mobile subscriber Busy (CFB).13
7.7 Call Forwarding on No Reply (CFNRy).13
7.8 Call Forwarding on mobile subscriber Not Reachable (CFNRc) .14
7.9 Call Waiting (CW).14
7.10 Call Hold (HOLD).14
7.11 Multi-party Service (MPTY).14
7.12 Closed User Group (CUG).14
7.13 Advice of Charge (AoC).14
7.14 Barring of All Outgoing Calls (BAOC) .14
7.15 Barring of Outgoing International Calls (BOIC).14
7.16 Barring of Outgoing International Calls except those to the Home PLMN country
(BOIC-exHC) .14
7.17 Barring of All Incoming Calls (BAIC).15
7.18 Barring of Incoming Calls when Roaming outside the home PLMN country (BIC-Roam).15
7.19 Call Transfer (ECT).15
7.20 Completion of Calls to Busy Subscriber (CCBS) .15
[7.21 Enhanced Multi-Level Precedence and Pre-emption service (eMLPP).15
7.22 Short Message Service (SMS).15
8 Interworking considerations.15
Annex A (informative): Status of Technical Specification GSM 02.68 .16
History.17

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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee (TC) of the European Telecommunications Standards Institute (ETSI).
This ETS specifies the stage one description of the Voice Group Call Service (VGCS) within the digital
cellular telecommunications system.
The contents of this ETS is subject to continuing work within TC-SMG and may change following formal
TC-SMG approval. Should TC-SMG modify the contents of this ETS, it will be resubmitted for OAP by
ETSI with an identifying change of release date and an increase in version number as follows:
Version 5.x.y
where:
y the third digit is incremented when editorial only changes have been incorporated in the
specification;
x the second digit is incremented for all other types of changes, i.e. technical enhancements,
corrections, updates, etc.
Transposition dates
Date of adoption: 18 April 1997
Date of latest announcement of this ETS (doa): 31 August 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 28 February 1998
Date of withdrawal of any conflicting National Standard (dow): 28 February 1998

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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
1 Scope
This European Telecommunication Standard (ETS) specifies the stage one description of the Voice Group
Call Service (VGCS) which allows speech conversation of a predefined group of service subscribers in
half duplex mode on the radio link taking into account multiple mobile service subscribers involved in the
VGCS call per cell.
The VGCS is applicable to all mobile stations in a certain network and area which have the technical
capability and the corresponding subscription, respectively, to participate in a VGCS call.
NOTE: It is not considered as requirement that normal GSM phase 2 mobile stations will be
able to be used for this service.
The service is described from the service subscriber's and user's point of view; in particular:
- the procedure for normal operation with successful outcome;
- the action to be taken in exceptional circumstances;
- the interaction with other GSM services and features.
This ETS does not deal with the Man-Machine Interface (MMI) requirements, but makes reference to the
appropriate Global System for Mobile Communications (GSM) specifications.
This ETS defines a teleservice of the digital cellular telecommunications system GSM. Any interaction with
other services and/or networks not dealt with in clauses 8 or 9 are outside the scope of this ETS.
2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by the amendment or revision. For undated references, the
latest edition of the publication referred to applies.
[1] GSM 01.04 (ETR 350): "Digital cellular telecommunications system (Phase 2+);
Abbreviations and acronyms".
[2] GSM 02.40: "Digital cellular telecommunications system; Procedures for call
progress indications".
[3] GSM 02.67 (ETS 300 924): "Digital cellular telecommunications system
(Phase 2+); enhanced Multi-Level Precedence and Pre-emption service
(eMLPP) - Stage 1".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this ETS, the following definitions apply:
network operator: Entity which provides the network operating elements and resources for the execution
of the VGCS.
service provider: Entity which offers the VGCS for subscription. The network operator may be the
service provider.
group call: An instance of the VGCS initiated by a subscriber. This term is used synonymously with the
term "VGCS call".
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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
service subscriber: Mobile subscriber which subscribes to the VGCS.
group identification (group ID): A numerical classification. There can be up to [tbd] (note) different
group IDs in one PLMN. Service subscriber shall be provided with one or up to [tbd] group IDs.
dispatcher: Particular fixed line or mobile users are identified within the network as dispatchers.
Dispatchers shall receive all group calls to a certain group ID in a service area (this shall be done
automatically by the network). In addition they can initiate group calls to a group ID in a service area.
Dispatchers shall be connected to a group call by means of standard links via radio or via an ISDN.
They shall be called by their ISDN or MSISDN number, respectively. When dispatchers initiate
group calls, they shall call a particular MSISDN number which is related to a group ID and service
area. Dispatchers using the GSM network can be located outside of this service area.
The identities of the dispatchers are exclusively predefined in the network by the service provider.
There will be none or up to five dispatchers involved in a particular group call.
destination subscriber: Service subscriber or dispatcher to which the VGCS call is directed.
calling subscriber: Service subscriber or dispatcher which originates the VGCS call.
service area: Predefined area composed of one or a cluster of cells to which a particular VGCS call is
distributed. Up to [tbd] (note) different service areas can be defined in one PLMN. The composition of a
service area is predefined in the network by the service provider. Changing of cell allocation in the network
due to operational reasons will need an adaptation of the service area definition. The service area may
include more than one MSC area and cells of more than one PLMN.
[Remark: this requirement is under study and may affect performance and implementation issues.]
group call member: Any service subscriber or dispatcher participating in an on going group call.
NOTE: The maximum number of group IDs which can be defined in one PLMN depends on
the maximum number of service areas defined in this PLMN. The maximum number of
group IDs and service areas shall be [108-1, tbc].
3.2 Abbreviations
Abbreviations used in this ETS are listed in GSM 01.04.

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ETS 300 925 (GSM 02.68 version 5.1.1): May 1997
4 Description
The VGCS is defined in the following. Figure 1 gives an explanation of the logical concept of the VGCS.
a) The VGCS enables a calling subscriber to establish a group speech call to destination subscribers
belonging to a predefined service area and group ID.
[Remark: the service may be provided by use of half duplex transmission mode.]
Applications for group call services typically involve multiple group members in a small service area,
for which the VGCS should provide spectrum efficient solutions.
b) The calling subscriber as well as the destination subscribers may be any service subscriber which
has subscribed to the related group ID or any dispatcher who is entitled to it by his identity which
shall be registered in the network.
c) Destination subscribers are all service subscribers or a group of service subscribers identified by
the called group ID which have their present location in the service area, and pre-registered
dispatchers. Destination service subscribers shall be notified with the group ID, not by paging the
subscriber individually. Dispatchers shall be called individually with their identity.
Service subscribers may become late destination subscribers when entering the service area within
500 ms after reception of the first notification message related to the VGCS call. Service
subscribers which leave the corresponding service area during an on going VGCS call of which they
are member cease to be destination subscribers.
d) The group call shall be established in a service area which is comprised of one or a cluster of cells.
Service areas shall be predefined in the network by the service provider, co-ordina
...