ETSI TR 102 022-2 V1.1.1 (2015-01)

ETSI TR 102 022-2 V1.1.1 (2015-01)






TECHNICAL REPORT
User Requirements Specification
Mission Critical Broadband Communications
Part 2: Critical Communications Application

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2 ETSI TR 102 022-2 V1.1.1 (2015-01)



Reference
DTR/TETRA-01203
Keywords
evolution, requirements, TETRA
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3 ETSI TR 102 022-2 V1.1.1 (2015-01)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 4
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.3 Abbreviations . 7
4 Critical Communications Application Requirements . 8
4.1 General . 8
4.1.1 Description of Interfaces in Figures 1 to 3 . 10
4.2 Group Addressed Services . 13
4.2.1 Emergency communication . 15
4.2.2 Dispatcher Override . 16
4.2.3 Local Fall Back . 17
4.3 Priority and Pre-Emption Services . 18
4.4 Off Network Services . 19
4.4.1 Public Safety Specific Requirements for Off Network Services . 19
4.4.2 Local network Extension . 20
4.5 Calling/Talking Party Identity Restriction . 20
4.6 Interoperability with Legacy Systems . 21
4.7 Support for White Boarding and other Multi-Media Operations. 21
4.8 Dispatching - a Video Case . 21
4.9 Video Briefing . 22
4.10 Net Preference . 22
4.11 Dual Watch . 22
5 Voice Requirements . 22
5.1 Intelligibility in Noisy Environments . 22
5.2 Call Set up Time . 22
6 Security. 22
7 Priorities for Functionality . 23
8 Summary of Baseline TETRA and Tetrapol Services and Exceptions to their Transfer to
Broadband Requirements (adopted from [i.13]) . 25
Annex A: Functionality Split Proposal for Group Addressed Calls from 3GPP (Preliminary
view) . 30
Annex B: Visualization of Relay Node Use . 32
Annex C: Possible Progression of Interoperability Requirement . 34
Annex D: Extract from 3GPP TS 22.278 V12.4.0 (2013-09) . 37
History . 40

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4 ETSI TR 102 022-2 V1.1.1 (2015-01)
Intellectual Property Rights
IPRs essential or potentially essential to the present document 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 (http://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.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee TETRA and Critical Communications
Evolution (TCCE).
The present document is part 2 of a multi-part deliverable covering the User Requirement Specification (URSs) Mission
Critical Broadband Communications, as identified below:
Part 1: " Mission Critical Broadband Communication Requirements";
Part 2: "Critical Communications Application".
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "may not", "need", "need not", "will",
(Verbal forms
"will not", "can" and "cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules
for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
The Terms of Reference for TC TCCE approved at ETSI Board meeting #42, 2013 is to produce ETSI deliverables (and
maintenance thereafter) in accordance with the following requirements:
a) To identify requirements for mission and business critical broadband services that will enable an evolution of
digital narrowband PMR services to mobile broadband.
b) To identify and fill standardization gaps such as:
1) Architectural design of critical communications services to be delivered over mobile broadband systems.
2) The development of standards for secure services and interfaces into private and commercial broadband
systems.
3) Interconnection of external PMR interfaces to critical communications systems.
c) The provision and development of proportionate security measures for TETRA and mission critical
communications services.
d) The selection and development of suitable CODECs for audio and video services.
e) The evolution and enhancement of TETRA and critical communications services as required by the market
with the provision of new services, facilities and functionality made possible by new technology innovations
and standards.
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5 ETSI TR 102 022-2 V1.1.1 (2015-01)
f) To identify requirements for the further development of the TETRA standard.
g) The maintenance of the TETRA standard.
Technical Objective:
• The present document provides the User Requirement Specifications for the Critical Communications
Application that facilitates digital PMR services over LTE™.
• The URS is required by TC TCCE to guide the design of the critical communications application to facilitate
broadband voice and data communications for critical communications users.
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6 ETSI TR 102 022-2 V1.1.1 (2015-01)
1 Scope
The present document provides the User Requirement Specifications for the Critical Communications Application
needed to support Broadband Mission Critical Communications over IP communications networks such as LTE.
The present document describes the functionalities which are most needed by users and the requirements they make on
the technology. The present document is applicable to the specification of broadband mission critical communications
equipment.
The user requirements contained in the present document are described in non-technical terms and are based on
discussions in TC TCCE WG1, TC TCCE WG4, LEWP RCEG and TCCA's CCBG SA and UR Groups.
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI TS 122 468 (V12.1.0): "LTE; Group Communication System Enablers for LTE (GCSE-
LTE) (3GPP TS 22.468 version 12.1.0 Release 12)".
[i.2] ETSI TS 122 278 (V12.5.0): "Universal Mobile Telecommunications System (UMTS); LTE;
Service requirements for the Evolved Packet System (EPS) (3GPP TS 22.278 version 12.5.0
Release 12)".
[i.3] ETSI TR 102 022-1: "User Requirement Specification; Mission Critical Broadband
Communication Requirements".
[i.4] NPSTC Recommendations for Push To Talk over Long Term Evolution Requirements, Public
Safety Broadband. A NPSTC Public Safety Communications Report.
[i.5] ETSI EN 300 392-9: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 9: General requirements for supplementary services".
[i.6] ETSI EN 300 392-12 (sub-parts 1, 3, 7, 8, 10, 16 and 22) : "Terrestrial Trunked Radio (TETRA);
Voice plus Data (V+D); Part 12: Supplementary services stage 3".
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7 ETSI TR 102 022-2 V1.1.1 (2015-01)
[i.7] 3GPP TS 22.278 (V12.4.0): "Service requirements for the Evolved Packet System (EPS)".
[i.8] Proximity-based Off Network Public Safety Use Case S1-113165 to 3GPP TSG-SA WG1 from
NIST et al.
[i.9] Requirements associated with Public Safety Off Network Use Case S1-113165 to 3GPP TSG-SA
WG1 from NIST.
[i.10] Tetrapol Specifications PAS 0001-1-2 (V3.0.1): "Part 1: "General Network Design: Part 2: Voice
and Data Services in Network and Direct Mode".
[i.11] WG4 WI DTR/TCCE-04186: "TCCE Critical Communications Architecture Reference Model".
[i.12] ETSI EN 300 392-1 (V1.4.1): "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 1: General network design".
[i.13] TETRA04(13)000074r2-Use-of-TETRA-services (Work in progress for ETSI TCCE04).
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Base Station (BS): set of equipment on a single site (which may be more than just a radio function)
mission critical broadband communications: work programme within ETSI Technical Committee TETRA and
Critical Communications Evolution to facilitate and enhance the services and facilities of digital PMR such as TETRA
operating over LTE in order to meet new user requirements for data and voice
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ASSI Alias Short Subscriber Identity
AVL Automatic Vehicle Location
BS Base Station
CCA Critical Communications Application
CCBG Critical Communications Broadband Group
CCS Critical Communication System
DGNA Dynamic Group Number Assignment
DISC Discovery (not in the ETSI list)
DMO Direct Mode of Operation
DTMF Dual Tone Multi Frequency
EPC Evolved Packet Core
ETSI European Telecommunications Standards Institute
E-UTRAN Evolved Universal Terrestrial Radio Access Network
GCSE Group Call Service Enablers
GSCE Group Communication System Enablers
IP Internet Protocol
ISI Inter System Interface
KPI Key Performance Indicator
LEWP Law Enforcement Working Party
LMR Land Mobile Radio
LS Liaison Statement
LTE 3GPP Long Term Evolution (4G)
MM Mobility Management
MS Mobile Station
MU Mobile Unit comprising UE plus CCA
NB Narrow Band
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NPSTC National Public Safety Telecommunications Council (not in the ETSI list)
OPS Operations
PABX Private Automatic Branch eXchange
PMR Private Mobile Radio
ProSe Proximity Services
PSTN Public Services Telephone Network
QoS Quality of Service
RCEG Radio Communications Experts Group, a working group of LEWP
RF Radio Frequency
SA System Architecture (Technical Specification Group of 3GPP)
SDS Short Data Service
SDS-TL SDS-Transport Layer
TA Tracking Area
TCCA TETRA + Critical Communications Association
TCCE TETRA and Critical Communications Evolution
TL Transport Layer
TPI Talking Party Identity
TR Technical Report
UE User equipment
UR User Requirements
URS User Requirement Specification
USIM Universal Subscriber Identity Module
4 Critical Communications Application Requirements
4.1 General
In order to ensure that IP communications networks such as LTE are able to meet the requirements of critical
communications some changes to the 3GPP™ standards are needed. The most critical have been proposed first and are
called Group Communication System Enablers (GCSE) [i.1] and Proximity Based Services (ProSE) [i.2]. These have
resulted in 3GPP Work Items for Release 12. There are likely to be further requirements. In order to benefit from the
market scale available for public LTE and the attendant benefits such as lower cost, open standards, supplier choice, fast
development of features and long term evolution of capability the changes proposed to date have been kept to a
minimum to improve the chances of them being implemented by manufacturers. This means that to deliver the full
mission critical/critical communications functionality there has to be a Critical Communications Application (CCA) that
sits above the LTE protocol. This application will need to provide the services required for critical communications
[i.3]. (One of these services is push or press to talk, and NPSTC have recommended requirements for Public Safety in
the US [i.4]. Outside of North America the PTT voice functionality of TETRA [i.5], [i.6], [i.12] and Tetrapol [i.10] is
taken as an assumed baseline on top of which further functionality appropriate to broadband is added. To avoid
describing all the many standards a summary of this functionality and the exceptions, that is baseline functionality not
needed in broadband are listed in clause 8). The application will need to have implementations in the infrastructure and
in terminals with a standardized interface between them so that different vendors can be used.
It is important that the standardization of the CCA should be rapid and co-ordinated to match planned releases of the
3GPP standard containing the appropriate enablers. A phased approach is considered but whilst most user groups want
to focus on data services there are some groups, for example in the UK working on their future mission critical
communications, who want to rapidly transition to voice services as well. This means that the first release of the CCA
has to support core voice and data requirements with extensions in functionality coming in later releases.
There are different needs for supporting migration away from legacy systems depending on the plans in the various user
groups for the rate of migration. Some users groups see little need to operate with legacy systems and others see a
sustained period of inter-working. The level of interoperability required also varies but there is clearly a need for the
first release of the CCA to support some interaction with legacy systems with fuller integration coming later for those
who wish to operate their legacy systems for voice and narrowband data for a longer period alongside broadband data or
voice and data systems. This is dealt with in more detail in clause 7.
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Some thoughts have been given to the partition between functionality to be supported in 3GPP and that by the CCA
(annex A). This led to a model of the architecture for Mission Critical Broadband Communications from TCCA CCBG
WG SA that defined the requirements of the CCA. This model is being developed in TCCE WG4 [i.11] and a version of
this is shown below purely to illustrate the scope of the requirements to be addressed. This diagram will not be updated
in this URS.

Figure 1: CCS Reference Model
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Figure 2: Proximity Services Reference Model

Figure 3:Terminal to Network Relay Reference Model
4.1.1 Description of Interfaces in Figures 1 to 3
Interface 1 LTE Core Network - UE
This interface is specified according to the network protocols of the underlying IP network. Where the underlying
network is LTE, it consists of the 3GPP specified standardized LTE UE to EPC interfaces.
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Interface 2 Infra CCA - LTE Core Network
This interface is specified according to the network protocols of the underlying IP network.
Where that underlying network is an LTE EPC, it consists of existing Rx and SGi interfaces, plus the GC2 interface
developed in the GCSE-LTE work item from 3GPP Release 12, to allow use and control of LTE broadcast bearers.
Interface 3 LTE UE to Mobile CCA
This interface relies on the services available from the IP network terminal.
In an LTE environment, it utilizes the interfaces provided by the UE to any application and may evolve to include
developments related to GCSE-LTE work item from 3GPP Release 12.
This interface itself is not fully standardized since it is dependent on the terminal implementation and operating system.
Interface 4 Infra CCA to Mobile CCA
The objective of this interface is to allow interoperability between a CCA infrastructure and terminals from different
manufacturers.
This interface provides similar functionality to existing digital PMR Layer 3 Air Interface messages, supporting, but not
limited to, user registration, setup and control of individual and group communications, media transfer and management
and short data transport.
Interface 5 Infra CCA to Application
The objective of this interface is to allow easy integration of Applications in a CCA environment, and portability of
those applications to CCAs from different manufacturers.
This interface is made of two main components:
• A Call interface, to provide control of sessions (C-Plane) and of media transport (U-Plane) within a
communication. This interface may be similar to a Dispatch interface in existing PMR systems, extended to
Multimedia.
NOTE 1: A single communication session can be an organized set of one or more communications used to transport
the same information to or from one or several mobiles. Independent sessions implies that there can be
several separate communications taking place between different sets of parties which can be accessed
through this interface.
• A Routed Transport interface to transport and route data messages (e.g. signalling, geo-location information,
text messages) and data files (e.g. picture, map) between mobiles and applications.
Interface 6 Mobile CCA to Mobile Application
The objective of this interface is to allow easy integration of Mobile Applications in a CCA environment, and
portability of those applications between terminals from different manufacturers.
Interface 7 Application to Mobile Application
Some components of this interface may be defined by standards, for specific applications that require generic formats to
ensure interoperability between mobile applications and control room application for instance: geo-location, video
format, vocoder, etc.
Interface 8 Inter CCA
The objective of this interface is to allow interoperability and interworking between CCS.
This interface supports interconnection of communications between users operating on different CCS.
This interface should support mobility of users between different CCS.
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Interface 8bis CCA to Legacy PMR
The objective of this interface is to allow interworking between a CCS and existing legacy PMR systems such as
TETRA, TETRAPOL and P25.
This interface is intended to support interconnection of communications between users operating on a CCS and on a
legacy PMR system.
Interface 9 Core Network to Core Network
This interface is determined by the underlying core IP network. Where the underlying network is an LTE EPC, it makes
use of 3GPP standard interfaces.
This interface provides support and control of mobility and roaming of terminals between different core networks.
NOTE 2: Where the underlying core networks use different technologies, a standardized interface may not be
available.
Interface 10 Terminal to Terminal
This interface is determined by the terminal technology.
Where the terminals are LTE Ues, this interface will be a standard 3GPP interface, defined under the Proximity
Services (ProSe) work item in 3GPP Release 12.
This interface supports direct communications between terminals and also the terminal to Network Relay configuration.
Interface 11 Mobile CCA to Mobile CCA
The objective of this interface is to provide control of direct CCA Services between two or more terminals without any
infrastructure path. Where the terminals are LTE Ues, it relies on underlying services defined by 3GPP ProSe.
Interface 12 Infra CCA to Relay CCA
The objective of this interface is to support the specific configuration of a Terminal to Network Relay. This interface
can be considered to be a subset of the interface 4 Infra CCA to Mobile CCA.
Interface 13 Mobile CCA to Relay CCA
The objective of this interface is to support the specific configuration of a Terminal to Network Relay. This interface
can be considered to be a subset of the interface 11 Mobile CCA to Mobile CCA.
CCA Features
User Management
– on top of device mobility
– Single Sign On
Group Management
Communication Control
– Handling the communication tree (connecting different transport sessions if needed)
– Individual and Group
– Floor Control (or exclusive transmitter within one session)
– Supplementary services
Session Control
– Set up, Release, priorities,… (C-Plane) of transport sessions
– Individual, Group (U-Plane)
Signaling Transport
– to transport and route signaling messages between mobile and applications
– similar to Short Data or to Control Channel messages
– e.g. geo-location information, Status,…

Figure 4: Critical Communications Application Features.
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The CCA then is broadly being asked to:
For Systems:
• Interface to legacy systems (TETRA, P25, Tetrapol) to allow a degree of interoperability. Is it assumed 3GPP
will manage the fallback from 4G to allow interoperability on a best efforts basis with 3G.
• Interface to other CCAs in the same or other networks. The intent is that initial CCA core functionality will be
standardized and that further functionality will be defined for subsequent releases that will in part depend and
be aligned with supporting feature releases from 3GPP.
• Interface to other LTE systems to allow roaming. There are two types of roaming to be supported; where 'LTE
roaming' is utilized (i.e. the user device is provided with an IP link back to their serving CCA via the roaming
networks), and application level roaming where the MU registers onto a visited CCA and communicates with
users there (interface 8 on the architecture reference model).
• The system (including the CCA) should support an Inter System Interface (ISI) for roaming of home
subscribers to other neighbour networks. It supports full dynamic subscriber migration.
• Group handling.
• C
...