|
TECHNICAL REPORT
Digital cellular telecommunications system (Phase 2+) (GSM);
Universal Mobile Telecommunications System (UMTS);
LTE;
Priority service feasibility study
(3GPP TR 22.950 version 15.0.0 Release 15)
---------------------- Page: 1 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 1 ETSI TR 122 950 V15.0.0 (2018-07)
Reference
RTR/TSGS-0122950vf00
Keywords
GSM,LTE,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 TR 22.950 version 15.0.0 Release 15 2 ETSI TR 122 950 V15.0.0 (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 Report (TR) 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 "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 TR 22.950 version 15.0.0 Release 15 3 ETSI TR 122 950 V15.0.0 (2018-07)
Contents
Intellectual Property Rights . 2
Foreword . 2
Modal verbs terminology . 2
Foreword . 4
Introduction . 4
1 Scope . 5
2 References . 5
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 7
4 High Level requirements . 7
4.1 Priority Call Origination . 7
4.2 Priority Call Termination . 7
4.3 Priority Call Progression . 7
4.4 Priority Radio Resource Queuing . 7
4.5 Priority Levels . 8
4.6 Invocation on Demand . 8
4.7 Applicability to Telecommunications Services . 8
4.8 Authorization . 8
4.9 Priority Service Service Code . 8
4.10 Roaming . 9
4.11 Handover . 9
4.12 Charging Data Record . 9
4.13 Priority Trunk Queuing . 9
4.14 Coexistence with eMLPP . 9
5 Additional Description of Priority Service . 9
5. 1 At call origination . 9
5. 2 During call progression . 10
5. 3 At call termination . 10
5.4 Exception Procedures or Unsuccessful Outcome . 10
5.5 Features Interactions. 11
6 Priority Service Gap Analysis . 12
6.1 Service Accessibility . 12
6.1.1 Summary of Service Accessibility Capabilities . 12
6.1.2 Support for Priority Service . 12
6.2 Enhanced Multi-Level Precedence and Pre-emption (eMLPP) . 16
6.2.1 Summary of eMLPP Capabilities . 16
6.2.2 Support for Priority Service . 18
6.3 Subscriber Identity Module (SIM) Specifications . 22
6.3.1 Summary of SIM-based Capabilities . 22
6.3.2 Support for Priority Service . 23
6.4 Assignment request Priority Information Element . 27
6.4.1 Summary and coding of Priority Information Element Capabilities . 27
6.4.2 Support for Priority Service . 28
7 Conclusions . 32
Annex A (Informative): Regional Priority Service Requirements . 34
Annex B (Informative): Change history . 37
History . 39
ETSI
---------------------- Page: 4 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 4 ETSI TR 122 950 V15.0.0 (2018-07)
Foreword
rd
This Technical Report 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.
Introduction
This Technical Report (TR) presents the results of the Feasibility Study on Priority Service. The intent of this
Feasibility Study is to assess the ability of 3GPP specifications to meet high-level requirements identified for Priority
Service. This Feasibility Study consisted of a multi-step process, namely:
1. Identify high-level requirements for Priority Service.
2. Determine existing relevant 3GPP specifications for Priority Service.
3. Perform a Gap Analysis to assess the ability of existing 3GPP specifications to meet the high-level Priority
Service requirements.
As defined in this document, Priority Service allows qualified and authorized users to obtain priority access to the next
available radio (voice or data traffic) channels on a priority basis before other PLMN users during situations when
PLMN congestion is blocking call attempts. In addition, Priority Service supports priority call progression and call
completion to support an “end-to-end” priority call.
Priority Service is intended to be used by qualified and authorized users, i.e., emergency service personnel, only during
times of emergency situations and network congestion. Access to Priority Service is limited to key personnel and those
with leadership responsibilities and is not intended for use by all emergency service personnel. This is to ensure that
non-emergency service personnel cannot “take over” the network and deny the other non-emergency service subscribers
a reasonably level of service.
Priority Service providers should adhere to uniform, nationwide operating access procedures. Priority Service can
provide significant benefits for public safety. There may be times during emergencies when non-Priority Service
subscribers will be unable to obtain access to their wireless services (because Priority Service personnel are using the
channels); nevertheless, the benefits of Priority Service outweigh any inconvenience to non-Priority Service subscribers.
Priority Service is to be available at all times in equipped markets in both the HPLMN and VPLMN within a country
where the PLMN provider is offering the service. The capability for pre-emption should be supported, with the option
to turn it on/off depending on regional requirements. Priority Service is applicable to both GERAN and UTRAN and is
activated on a per call basis using Priority Service dialing procedures.
Priority Service, supported by the 3GPP system set of services and features, is one element in ability to deliver calls of a
high priority nature from mobile to mobile networks, mobile to fixed networks, and fixed to mobile networks.
ETSI
---------------------- Page: 5 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 5 ETSI TR 122 950 V15.0.0 (2018-07)
1 Scope
This Technical Report (TR) presents the results of the Feasibility Study on Priority Service. The intent of this
Feasibility Study is to assess the ability of 3GPP specifications to meet high-level requirements identified for Priority
Service. This Feasibility Study consisted of a multi-step process, namely:
1. Identify high-level requirements for Priority Service.
2. Determine existing relevant 3GPP specifications for Priority Service.
3. Perform a Gap Analysis to assess the ability of existing 3GPP specifications to meet the high-level Priority
Service requirements.
Additional functionalities not documented in this TR are considered outside the scope of this TR. Such additional
functionality may be on a network-wide basis, nation-wide basis or particular to a group of users. Such additional
functionality shall not compromise conformance to the requirements of the Priority Service defined in this specification.
The Priority Service is intended to be utilised for both Voice and Data and therefore both elements are considered
within the scope of this document. While Priority Service is meant for both Voice and Data services, the initial set of
requirements address Circuit Switched Services (Voice as well as Data). Multimedia and non-circuit switched aspects
of Priority Service have not been addressed in this feasibility study and are for further study.
The Priority Service is intended to interwork with external networks to provide an end-to-end service. Therefore,
service interactions with external networks are considered within the scope of this document, although the specification
of these interactions may be in other standards. If this occurs, a reference to that specification shall be made.
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 41.001: "GSM Release specifications".
[2] TS 21.905: "Vocabulary for 3GPP Specifications"
[3] ETSI TS 100 921 version 7.0.1 (1999-07), Digital cellular telecommunications system (Phase 2+);
Service accessibility (GSM 02.11 version 7.0.1 Release 1998)
[4] 3GPP TS 22.011 version 3.5.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Services and System Aspects; Service accessibility (Release 1999)
[5] 3GPP TS 22.011 version 4.4.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Services and System Aspects; Service accessibility (Release 4)
[6] ETSI EN 300 924 version 7.0.1 (2005-01), Digital cellular telecommunications system (Phase 2+);
enhanced Multi-Level Precedence and Pre-emption (eMLPP) – Stage 1 (GSM 02.67 version 7.0.1
Release 1998)
[7] 3GPP TS 03.67 version 7.2.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Core Network; Digital cellular telecommunications system (Phase 2+);
enhanced Multi-Level Precedence and Pre-emption (eMLPP) – Stage 2 (Release 1998)
[8] ETSI EN 300 927 version 7.0.1 (2005-01), Digital cellular telecommunications system (Phase 2+);
enhanced Multi-Level Precedence and Pre-emption (eMLPP) – Stage 3 (GSM 04.67 version 7.0.1
Release 1998)
ETSI
---------------------- Page: 6 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 6 ETSI TR 122 950 V15.0.0 (2018-07)
[9] 3G TS 22.067 version 3.0.1 (1999-10), 3rd Generation Partnership Project; Technical
Specification Group Services and System Aspects; enhanced Multi-Level Precedence and Pre-
emption (eMLPP) – Stage 1 (Release 1999)
[10] 3GPP TS 23.067 version 3.3.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Core Network; enhanced Multi-Level Precedence and Pre-emption (eMLPP)
– Stage 2 (Release 1999)
[11] 3GPP TS 24.067 version 3.3.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Core Network; enhanced Multi-Level Precedence and Pre-emption (eMLPP)
– Stage 3 (Release 1999)
[12] 3G TS 22.067 version 4.0.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Services and System Aspects; enhanced Multi-Level Precedence and Pre-
emption (eMLPP) – Stage 1 (Release 4)
[13] 3GPP TS 23.067 version 4.1.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Core Network; enhanced Multi-Level Precedence and Pre-emption (eMLPP)
– Stage 2 (Release 4)
[14] 3GPP TS 24.067 version 4.1.0 (2005-01), 3rd Generation Partnership Project; Technical
Specification Group Core Network; enhanced Multi-Level Precedence and Pre-emption (eMLPP)
– Stage 3 (Release 4)
[15] GSM 11.11 v7.6.1, Specification of the Subscriber Identity Module - Mobile Equipment (SIM -
ME) interface; Release 1998
[16] GSM 04.08 v7.13.0, Mobile Radio Interface Layer 3 Specification; Release 1998
[17] 3GPP TS 11.11 v8.5.0, Specification of the Subscriber Identity Module - Mobile Equipment (SIM
- ME) interface; Release 1999
[18] 3GPP TS 51.011 v4.1.0, Specification of the Subscriber Identity Module - Mobile Equipment
(SIM - ME) interface; Release 4
[19] 3GPP TS 08.08 v. 7.7.0, Mobile-services Switching Centre- Base Station System (MSC - BSS)
interface Layer 3 specification; Release 1998
[20] 3GPP TS 08.08 v. 8.12.0, Mobile-services Switching Centre- Base Station System (MSC - BSS)
interface Layer 3 specification; Release 1999
[21] 3GPP TS 08.08 v. 9.0.0, Mobile-services Switching Centre- Base Station System (MSC - BSS)
interface Layer 3 specification; Release 4
[22] 3GPP TS 25.413 v. 3.9.0, UTRAN Iu interface RANAP signalling; Release 1999
[23] 3GPP TS 25.413 v. 4.2.0, UTRAN Iu interface RANAP signalling; Release 4
[24] 3GPP TS 24.008 v. 3.11.0, Mobile radio interface layer 3 specification; Core Network Protocols -
Stage 3; Release 1999
[25] 3GPP TS 24.008 v. 4.4.0, Mobile radio interface layer 3 specification; Core Network Protocols -
Stage 3; Release 4
[26] ITU Recommendation I.255.3, Multi-Level Precedence and Preemption Service (MLPP), 1990
[27] ITU Recommendation Q.85, Stage 2 Description for Community of Interest Supplementary
Services, Section 3 – Multi-Level Precedence and Preemption (MLPP) (rev. 1), 1992
[28] ITU Recommendation Q.735, Stage 3 Description for Community of Interest Supplementary
Services using SS No. 7, Section 3 – Multi-Level Precedence and Preemption (MLPP), 1993
[29] GSM 11.14, Specification of the SIM Application Toolkit for the Subscriber Identity Module -
Mobile Equipment (SIM - ME) interface
[30] 3GPP TS 31.102, Characteristics of the USIM Application
ETSI
---------------------- Page: 7 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 7 ETSI TR 122 950 V15.0.0 (2018-07)
[31] 3GPP TS 31.111, USIM Application Toolkit (USAT)
[32] 3GPP TS 25.321, Medium Access Control (MAC) protocol specification
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply.
Priority Service: A service that allows qualified and authorized users to obtain priority access to the next available
radio (voice or data traffic) channels during situations when PLMN congestion is blocking call attempts. In addition,
Priority Service supports priority call progression and call completion to support an “end-to-end” priority call.
Service User: A user subscribed to Priority Service.
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CDR Charging Data Record
eMLPP Enhanced Multi-Level Precedence and Pre-emption
ISDN Integrated Services Digital Network
MLPP Multi-Level Precedence and Pre-emption
PIN Personal Identification Number
PIE Priority Information Element
PSTN Public Switched Telephone Network
SC Service Code
UE User Equipment
4 High Level requirements
The following sections describe the high-level requirements to support Priority Service. These high-level requirements
are used as a basis for the gap analysis described in Section 6.
4.1 Priority Call Origination
A call shall receive priority treatment (priority access to voice or traffic channels) on the originating side, when the call
is setup by a Service User using the priority service dialling procedure described in section 4.9.
4.2 Priority Call Termination
A call shall receive priority treatment (priority access to voice or traffic channels) on the terminating side, when the call
is setup by a Service User using the priority service dialling procedure described in section 4.9.
4.3 Priority Call Progression
The Priority Service user shall receive priority call treatment/progression through the mobile network(s). A priority call
should be given higher priority over normal calls in the originating mobile network, to interconnected networks
(including the PSTN) and in the terminating network. Note: The ISDN MLPP feature may be used for signalling of
priority level in the core network.
4.4 Priority Radio Resource Queuing
Priority Service assumes a signalling channel is always available.
When a Priority Service call encounters a “no radio available” condition in the call path involving an access or egress
air-interface, or both, and,
ETSI
---------------------- Page: 8 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 8 ETSI TR 122 950 V15.0.0 (2018-07)
- at call origination, and upon recognition of the Priority Service dialing pattern, the Priority Service call is queued
in the cell serving the calling party and processed for the next available radio channel in that cell in accordance
with the caller’s priority level and call initiation time.
- at call termination upon recognition of a priority call indication in an incoming call, the Priority Service call is
queued in the cell serving the called party and processed for the next available radio channel in that cell in
accordance with the call’s priority level and arrival time.
4.5 Priority Levels
The Priority Service subscriber shall be assigned one of n priority levels. Priority levels are defined as 1, 2, 3,…,n , with
1 being the highest priority level and n being the lowest priority level. Refer to Annex A for Regional requirements for
priority levels.
4.6 Invocation on Demand
Priority Service is invoked only when requested and an idle voice or traffic channel required for an origination request
is not available.
If an idle voice or traffic channel is available when Priority Service is requested, the origination request is allowed to
proceed normally without delay.
Invocation of Priority Service at access (origination), during call progression (end-to-end), or egress (termination) is
considered complete when one of the following occurs:
- A radio (voice or traffic) channel is assigned to the call (at origination or termination),
- The loss of radio contact or roaming to another PLMN provider’s system (at origination only),
- The subscriber cancels the request by pressing the END key.
- Expiration of the maximum allowed time to hold for the next available radio (voice or traffic) channel (at
origination or termination), or
- Deletion of the Priority Service request due to arrival of a higher priority request coupled with lack of queue
capacity (at origination or termination).
4.7 Applicability to Telecommunications Services
Priority Service shall be applicable to voice and data telecommunications services that require a voice or traffic channel
assignment.
4.8 Authorization
A subscriber invoking Priority Service on call origination is authorized based on the caller’s subscription. It should also
be possible for an additional second level of authentication (e.g., by the use of PIN) to identify that the user is
authorized to make a priority call. In this case, authorization of the subscriber may be realized by the usage of a PIN.
The PIN solution is for further study and needs to be standardized. The user priority levels (1-n) and the associated PINs
are assigned by the appropriate national authority and are fixed, i.e., a subscriber may not be allowed to change the PIN
or the priority level. Note: There are some concerns related to security for “PIN Authorization”.
4.9 Priority Service Service Code
Priority Service is manually requested by adding on the Priority Service service code (SC) to the origination request, as
in:
ETSI
---------------------- Page: 9 ----------------------
3GPP TR 22.950 version 15.0.0 Release 15 9 ETSI TR 122 950 V15.0.0 (2018-07)
Figure 1: Priority Service manual request
4.10 Roaming
Priority Service shall be able to be supported during roaming when the roaming network supports Priority Service.
4.11 Handover
Priority Service shall be able to be supported during handover.
4.12 Charging Data Record
The system should record the following Priority Service charging data record (CDR) information, in addition to non-
Priority Service CDR information:
a Priority Service invocation attempts.
b Call legs (origination and/or termination) on which Priority Service was used to gain access to the radio channel.
c Recording of appropriate Priority Service information (e.g., Priority Level,
...