SIST ES 201 873-4 V4.1.1:2009

• Abstract:

  Updated version of ES201 873-4 3.0.0 to reflect approved change requests related to the core language.

• Status: Published
• Publication Date: 16-Aug-2009
• ICS: 33.040.01 - Telecommunication systems in general
• Technical Committee: SPN - Services and Protocols for Networks
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 12-Jun-2009
• Due Date: 17-Aug-2009
• Completion Date: 17-Aug-2009
• Ref Project: ETSI ES 201 873-4 V4.1.1 (2009-06) - Methods for Testing and Specification (MTS); The Testing and Test Control Notation version 3; Part 4: TTCN-3 Operational Semantics

Overview

SIST ES 201 873-4 V4.1.1:2009 is the Slovene adoption of the ETSI standard focused on the operational semantics of TTCN-3. This standard is a key part of the “Methods for Testing and Specification (MTS)” series, specifically addressing The Testing and Test Control Notation version 3 (TTCN-3). It offers an updated approach to reflect approved changes in the TTCN-3 core language, making it essential for those developing, maintaining, or interpreting test specifications in telecommunication systems and software testing applications.

Key Topics

TTCN-3 Operational Semantics are at the heart of this standard, detailing how TTCN-3 test cases and modules are executed, ensuring consistent interpretation and interoperability across testing tools and environments. The document addresses:

• Replacement of short forms: Includes step-by-step procedures for handling global constants, module parameters, alt statements, interleave statements, and select-case statements.
• Flow graph semantics: Defines how TTCN-3 behaviour is mapped to flow graphs, covering representations for module control, test cases, functions, and more.
• State definitions and management: Covers module state, entity state, port state, timer state, and associated variable bindings.
• Messages and events: Explains the handling, matching, and retrieval of messages, procedure calls, replies, and exceptions during test execution.
• Evaluation procedures: Provides guidance on the TTCN-3 module lifecycle, including initialization, updating, selection, and execution phases.

Applications

The operational semantics specified in this standard have wide-reaching value for testing and quality assurance processes in modern communication systems. Practical applications include:

• Test Development and Automation: Enables precise implementation of TTCN-3-based automated tests for network and protocol validation.
• Interoperability Testing: Facilitates consistent behaviour among different TTCN-3 tools, platforms, and test environments, ensuring reliable results.
• Conformance Testing: Serves as the foundation for standardized test suites, reducing ambiguity in test case execution for telecommunication protocols and systems.
• Software Quality Assurance: Supports the development of robust and maintainable test infrastructures, crucial for complex system-level testing in telecommunications.
• Training and Education: Offers a consistent reference for professionals and students learning about TTCN-3 and the formal semantics of testing languages.

Related Standards

SIST ES 201 873-4 V4.1.1:2009 aligns closely with other standards and documents essential to TTCN-3 and test methodology, including:

• SIST ES 201 873-1: The core language specification for TTCN-3.
• Other parts of the ES 201 873 series: Covering additional aspects of TTCN-3, such as its use, core language, and test management.
• ETSI, ISO/IEC TTCN-3 standards: International equivalents and complementary documents offering harmonized approaches to test definition and execution.
• Telecommunication Systems Standards (ICS 33.040.01): Broader context for operational semantics in telecommunications.

Summary

SIST ES 201 873-4 V4.1.1:2009 enhances the reliability, interoperability, and clarity of TTCN-3 test specifications. By providing detailed operational semantics, it supports standardized implementation and interpretation of TTCN-3 in automated testing, conformance validation, and QA processes across the telecommunications industry. Organizations and professionals involved in network protocol testing, system validation, and test automation benefit from compliance with this standard, ensuring consistent and effective results in complex telecommunications environments.

Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
ETSI Standard
Methods for Testing and Specification (MTS);
The Testing and Test Control Notation version 3;
Part 4: TTCN-3 Operational Semantics

2 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)

Reference
RES/MTS-00107-4 T3 ed411 OS
Keywords
interoperability, methodology, MTS, testing,
TTCN
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

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
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the 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
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
http://portal.etsi.org/chaircor/ETSI_support.asp
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 2009.
All rights reserved.
TM TM TM TM
DECT , PLUGTESTS , UMTS , TIPHON , the TIPHON logo and the ETSI logo are Trade Marks of ETSI registered
for the benefit of its Members.
TM
3GPP is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners.
LTE™ is a Trade Mark of ETSI currently being registered
for the benefit of its Members and of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI
3 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
Contents
Intellectual Property Rights.7
Foreword.7
1 Scope.8
2 References.8
2.1 Normative references.8
2.2 Informative references.8
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations.9
4 Introduction .9
5 Structure of the present document.9
6 Restrictions.10
7 Replacement of short forms .10
7.1 Order of replacement steps.11
7.2 Replacement of global constants and module parameters .11
7.3 Embedding single receiving operations into alt statements.11
7.4 Embedding stand-alone altstep calls into alt statements.12
7.5 Replacement of interleave statements .12
7.6 Replacement of trigger operations.25
7.7 Replacement of select-case statements.25
7.8 Replacement of simple break statements.27
7.9 Replacement of continue statements .27
7.10 Adding default parameters to disconnect and unmap operations without parameters.28
7.11 Adding default values of parameters .28
8 Flow graph semantics of TTCN-3.28
8.1 Flow graphs.29
8.1.1 Flow graph frame.29
8.1.2 Flow graph nodes.29
8.1.2.1 Start nodes.29
8.1.2.2 End nodes.29
8.1.2.3 Basic nodes.29
8.1.2.4 Reference nodes.30
8.1.2.4.1 OR combination of reference nodes .30
8.1.2.4.2 Multiple occurrences of reference nodes.30
8.1.3 Flow lines.31
8.1.4 Flow graph segments.31
8.1.5 Comments.32
8.1.6 Handling of flow graph descriptions.33
8.2 Flow graph representation of TTCN-3 behaviour .33
8.2.1 Flow graph construction procedure .33
8.2.2 Flow graph representation of module control .34
8.2.3 Flow graph representation of test cases .35
8.2.4 Flow graph representation of functions .35
8.2.5 Flow graph representation of altsteps .36
8.2.6 Flow graph representation of component type definitions.37
8.2.7 Retrieval of start nodes of flow graphs .38
8.3 State definitions for TTCN-3 modules .38
8.3.1 Module state.38
8.3.1.1 Accessing the module state .39
8.3.2 Entity states.40
8.3.2.1 Accessing entity states .41
ETSI
4 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
8.3.2.2 Data state and variable binding .43
8.3.2.3 Accessing data states.43
8.3.2.4 Timer state and timer binding .44
8.3.2.5 Accessing timer states .45
8.3.2.6 Port references and port binding .46
8.3.2.7 Accessing port references .47
8.3.3 Port states.47
8.3.3.1 Handling of connections among ports.48
8.3.3.2 Handling of port states .48
8.3.4 General functions for the handling of module states .49
8.4 Messages, procedure calls, replies and exceptions.50
8.4.1 Messages.50
8.4.2 Procedure calls and replies .50
8.4.3 Exceptions.51
8.4.4 Construction of messages, procedure calls, replies and exceptions .51
8.4.5 Matching of messages, procedure calls, replies and exceptions .51
8.4.6 Retrieval of information from received items.52
8.5 Call records for functions, altsteps and test cases.52
8.5.1 Handling of call records.52
8.6 The evaluation procedure for a TTCN-3 module .53
8.6.1 Evaluation phases.53
8.6.1.1 Phase I: Initialization.53
8.6.1.2 Phase II: Update.54
8.6.1.3 Phase III: Selection .54
8.6.1.4 Phase IV: Execution.54
8.6.2 Global functions.54
9 Flow graph segments for TTCN-3 constructs .55
9.1 Action statement.55
9.2 Activate statement .56
9.2a Alive component operation .56
9.2a.1 Flow graph segment .58
9.2a.2 Flow graph segment .59
9.3 Alt statement.59
9.3.1 Flow graph segment .61
9.3.2 Flow graph segment .62
9.3.3 Flow graph segment .63
9.3.4 Flow graph segment .64
9.3.5 Flow graph segment .65
9.4 Altstep call.66
9.5 Assignment statement.66
9.5a Break statements in altsteps.66
9.6 Call operation.67
9.6.1 Flow graph segment .69
9.6.1a Flow graph segment .69
9.6.2 Flow graph segment .71
9.6.3 Flow graph segment .71
9.6.4 Flow graph segment .72
9.6.5 Flow graph segment .73
9.6.6 Flow graph segment .74
9.7 Catch operation.74
9.8 Check operation.75
9.8.1 Flow graph segment .76
9.8.2 Flow graph segment .77
9.9 Clear port operation.78
9.10 Connect operation.78
9.11 Constant definition.79
9.12 Create operation.80
9.13 Deactivate statement.81
9.13.1 Flow graph segment .82
9.13.2 Flow graph segment .82
9.14 Disconnect operation.83
ETSI
5 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
9.14.1 Flow graph segment .83
9.14.2 Flow graph segment .85
9.14.3 Flow graph segment .86
9.14.4 Flow graph segment .87
9.14.5 Flow graph segment .87
9.15 Do-while statement.88
9.16 Done component operation.89
9.17 Execute statement.91
9.17.1 Flow graph segment .92
9.17.2 Flow graph segment .93
9.17.3 Flow graph segment .94
9.18 Expression .94
9.18.1 Flow graph segment .95
9.18.2 Flow graph segment .95
9.18.3 Flow graph segment .96
9.18.4 Flow graph segment .96
9.19 Flow graph segment .97
9.20 Flow graph segment .97
9.20a Flow graph segment .98
9.20b Flow graph segment .98
9.21 Flow graph segment .99
9.22 Flow graph segment .99
9.23 For statement.100
9.24 Function call.101
9.24.1 Flow graph segment .103
9.24.2 Flow graph segment .103
9.24.3 Flow graph segment .104
9.24.3a Flow graph segment .104
9.24.4 Flow graph segment .105
9.24.5 Flow graph segment .106
9.25 Getcall operation.106
9.26 Getreply operation.106
9.27 Getverdict operation.107
9.28 Goto statement.107
9.28a Halt port operation.108
9.29 If-else statement.108
9.29a Kill component operation.109
9.29a.1 Flow graph segment .111
9.29a.2 Flow graph segment .112
9.29a.3 Flow graph segment .113
9.29b Kill execution statement.113
9.29b.1 Flow graph segment .114
9.29c Killed component operation .115
9.30 Label statement.116
9.31 Log statement.116
9.32 Map operation.117
9.33 Mtc operation.117
9.34 Port declaration.118
9.35 Raise operation.118
9.35.1 Flow graph segment .119
9.35.1a Flow graph segment .119
9.35.2 Flow graph segment .121
9.36 Read timer operation .122
9.37 Receive operation.123
9.37.1 Flow graph segment .124
9.37.2 Flow graph segment .125
9.37.3 Flow graph segment .126
9.38 Repeat statement.126
9.39 Reply operation.127
9.39.1 Flow graph segment .128
9.39.1a Flow graph segment .128
9.39.2 Flow graph segment .130
ETSI
6 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
9.40 Return statement.130
9.40.1 Flow graph segment .132
9.40.2 Flow graph segment .133
9.41 Running component operation .134
9.41.1 Flow graph segment .135
9.41.2 Flow graph segment .136
9.42 Running timer operation.137
9.43 Self operation.138
9.44 Send operation.138
9.44.1 Flow graph segment .139
9.44.1a Flow graph segment .139
9.44.2 Flow graph segment .141
9.45 Setverdict operation.141
9.46 Start component operation.142
9.47 Start port operation.144
9.48 Start timer operation.144
9.48.1 Flow graph segment .145
9.48.2 Flow graph segment .146
9.49 Stop component operation.146
9.49.1 Void.148
9.49.2 Flow graph segment .148
9.49.3 Flow graph segment .149
9.50 Stop execution statement.150
9.50.1 Void.151
9.51 Stop port operation.151
9.52 Stop timer operation .152
9.53 System operation.152
9.54 Timer declaration.153
9.54.1 Flow graph segment .153
9.54.2 Flow graph segment .154
9.55 Timeout timer operation.155
9.56 Unmap operation.156
9.56.1 Flow graph segment .158
9.56.2 Flow graph segment .159
9.56.3 Flow graph segment .160
9.57 Variable declaration.160
9.57.1 Flow graph segment .161
9.57.2 Flow graph segment .162
9.58 While statement.162
10 Lists of operational semantic components .163
10.1 Functions and states.163
10.2 Special keywords.164
10.3 Flow graphs of TTCN-3 behaviour descriptions .165
10.4 Flow graph segments.165
History .168

ETSI
7 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
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://webapp.etsi.org/IPR/home.asp).
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 ETSI Standard (ES) has been produced by ETSI Technical Committee Methods for Testing and Specification
(MTS), and is now submitted for the ETSI standards Membership Approval Procedure.
The present document is part 4 of a multi-part deliverable. Full details of the entire series can be found in part 1 [1].
ETSI
8 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
1 Scope
The present document defines the operational semantics of TTCN-3. The present document is based on the TTCN-3
core language defined in ES 201 873-1 [1].
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
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.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] ETSI ES 201 873-1: "Methods for Testing and Specification (MTS); The Testing and Test Control
Notation version 3; Part 1: TTCN-3 Core Language".
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
Not applicable.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in ES 201 873-1 [1] apply.
ETSI
9 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
BNF Backus-Nauer Form
MTC Master Test Component
SUT System Under Test
TTCN Testing and Test Control Notation
4 Introduction
This clause defines the meaning of TTCN-3 behaviour in an intuitive and unambiguous manner. The operational
semantics is not meant to be formal and therefore the ability to perform mathematical proofs based on this semantics is
very limited.
This operational semantics provides a state oriented view on the execution of a TTCN module. Different kinds of states
are introduced and the meaning of the different TTCN-3 constructs is described by:
1) using state information to define the preconditions for the execution of a construct; and
2) defining how the execution of a construct will change a state.
The operational semantics is restricted to the meaning of behaviour in TTCN-3, i.e. functions, altsteps, test cases,
module control and language constructs for defining test behaviour, e.g. send and receive operations, if-else-, or
while- statements. The meaning of some TTCN-3 constructs is explained by replacing them with other language
constructs. For example, interleave statements are short forms for series of nested alt statements and the meaning
of each interleave statement is explained by its replacement with a corresponding series of nested alt statements.
In most cases, the definition of the semantics of a language is based on an abstract syntax tree of the code that shall be
described. This semantics does not work on an abstract syntax tree but requires a graphical representation of TTCN-3
behaviour descriptions in form of flow graphs. A flow graph describes the flow of control in a function, alt step, test
case or the module control. The mapping of TTCN-3 behaviour descriptions onto flow graphs is straightforward.
NOTE: The mapping of TTCN-3 statements onto flow graphs is an informal step and is not defined by using the
BNF rules in ES 201 873-1 [1]. The reason for this is that the BNF rules are not optimal for an intuitive
mapping because several static semantic rules are coded into BNF rules in order to allow static semantic
checks during the syntax check.
5 Structure of the present document
The present document is structured into four parts:
1) The first part (see clause 6) describes restrictions of the operational semantics, i.e. issues related to the
semantics, which are not covered by the present document.
2) The second part (see clause 8) defines the meaning of TTCN-3 short cut and macro notations by their
replacement with other TTCN-3 language constructs. These replacements in a TTCN-3 module can be seen as
pre-processing step before the module can be interpreted according to the following operational semantics
description.
3) The third part (see clause 9) describes the operational semantics of TTCN-3 by means of flow graph
interpretation and state modification.
4) The fourth part (see clause 10) specifies the mapping of the different TTCN-3 statements onto flow graph
segments, which provide the building blocks for flow graphs representing functions, alt steps, test cases and
module control.
ETSI
10 Final draft ETSI ES 201 873-4 V4.1.1 (2009-03)
6 Restrictions
The operational semantics only covers behavioural aspects of TTCN-3, i.e. it describes the meaning of statements and
operations. It does not provide:
a) A semantics for the data aspects of TTCN-3. This includes aspects like encoding, decoding and the usage of
data imported from non-TTCN-3 specifications.
b) A semantics for the grouping mechanism. Grouping is related to the definitions part of a TTCN-3 module and
has no behavioural aspects.
c) A semantics for the import statement. The import of definitions has to be done in the definitions part of a
TTCN-3 module. The operational semantics handles imported definitions as if they are defined in the
importing module.
7 Replacement of short forms
Short forms have to be expanded by the corresponding complete definitions on a textual level before this operational
semantics can be used for the explanation of TTCN-3 behaviour.
TTCN-3 short forms are:
• lists of module parameter, constant and variable declarations of the same type and lists of timer declarations;
• stand-alone receiving operations;
• stand-alone altsteps calls;
• trigger operations;
• missing return and stop statements at the end of function and test case definitions;
• missing stop execution statements;
• interleave statements;
• select-case statements;
• break and continue statements;
• disconnect and unmap operations without parameters; and
• default values of missing actual parameters.
In addition to the handling of sh
...

ETSI Standard
Methods for Testing and Specification (MTS);
The Testing and Test Control Notation version 3;
Part 4: TTCN-3 Operational Semantics

2 ETSI ES 201 873-4 V4.1.1 (2009-06)

Reference
RES/MTS-00107-4 T3 ed411 OS
Keywords
interoperability, methodology, MTS, testing,
TTCN
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

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
Individual copies of the present document can be downloaded from:
http://www.etsi.org
The present document may be made available in more than one electronic version or in print. In any case of existing or
perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF).
In case of dispute, the reference shall be the printing on ETSI printers of the 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
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
http://portal.etsi.org/chaircor/ETSI_support.asp
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 2009.
All rights reserved.
TM TM TM TM
DECT , PLUGTESTS , UMTS , TIPHON , the TIPHON logo and the ETSI logo are Trade Marks of ETSI registered
for the benefit of its Members.
TM
3GPP is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners.
LTE™ is a Trade Mark of ETSI currently being registered
for the benefit of its Members and of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI
3 ETSI ES 201 873-4 V4.1.1 (2009-06)
Contents
Intellectual Property Rights.7
Foreword.7
1 Scope.8
2 References.8
2.1 Normative references.8
2.2 Informative references.8
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations.9
4 Introduction .9
5 Structure of the present document.9
6 Restrictions.10
7 Replacement of short forms .10
7.1 Order of replacement steps.11
7.2 Replacement of global constants and module parameters .11
7.3 Embedding single receiving operations into alt statements.11
7.4 Embedding stand-alone altstep calls into alt statements.12
7.5 Replacement of interleave statements .12
7.6 Replacement of trigger operations.25
7.7 Replacement of select-case statements.25
7.8 Replacement of simple break statements.27
7.9 Replacement of continue statements .27
7.10 Adding default parameters to disconnect and unmap operations without parameters.28
7.11 Adding default values of parameters .28
8 Flow graph semantics of TTCN-3.28
8.1 Flow graphs.29
8.1.1 Flow graph frame.29
8.1.2 Flow graph nodes.29
8.1.2.1 Start nodes.29
8.1.2.2 End nodes.29
8.1.2.3 Basic nodes.29
8.1.2.4 Reference nodes.30
8.1.2.4.1 OR combination of reference nodes .30
8.1.2.4.2 Multiple occurrences of reference nodes.30
8.1.3 Flow lines.31
8.1.4 Flow graph segments.31
8.1.5 Comments.32
8.1.6 Handling of flow graph descriptions.33
8.2 Flow graph representation of TTCN-3 behaviour .33
8.2.1 Flow graph construction procedure .33
8.2.2 Flow graph representation of module control .34
8.2.3 Flow graph representation of test cases .35
8.2.4 Flow graph representation of functions .35
8.2.5 Flow graph representation of altsteps .36
8.2.6 Flow graph representation of component type definitions.37
8.2.7 Retrieval of start nodes of flow graphs .38
8.3 State definitions for TTCN-3 modules .38
8.3.1 Module state.38
8.3.1.1 Accessing the module state .39
8.3.2 Entity states.40
8.3.2.1 Accessing entity states .41
ETSI
4 ETSI ES 201 873-4 V4.1.1 (2009-06)
8.3.2.2 Data state and variable binding .43
8.3.2.3 Accessing data states.43
8.3.2.4 Timer state and timer binding .44
8.3.2.5 Accessing timer states .45
8.3.2.6 Port references and port binding .46
8.3.2.7 Accessing port references .47
8.3.3 Port states.47
8.3.3.1 Handling of connections among ports.48
8.3.3.2 Handling of port states .48
8.3.4 General functions for the handling of module states .49
8.4 Messages, procedure calls, replies and exceptions.50
8.4.1 Messages.50
8.4.2 Procedure calls and replies .50
8.4.3 Exceptions.51
8.4.4 Construction of messages, procedure calls, replies and exceptions .51
8.4.5 Matching of messages, procedure calls, replies and exceptions .51
8.4.6 Retrieval of information from received items.52
8.5 Call records for functions, altsteps and test cases.52
8.5.1 Handling of call records.52
8.6 The evaluation procedure for a TTCN-3 module .53
8.6.1 Evaluation phases.53
8.6.1.1 Phase I: Initialization.53
8.6.1.2 Phase II: Update.54
8.6.1.3 Phase III: Selection .54
8.6.1.4 Phase IV: Execution.54
8.6.2 Global functions.54
9 Flow graph segments for TTCN-3 constructs .55
9.1 Action statement.55
9.2 Activate statement .56
9.2a Alive component operation .56
9.2a.1 Flow graph segment .58
9.2a.2 Flow graph segment .59
9.3 Alt statement.59
9.3.1 Flow graph segment .61
9.3.2 Flow graph segment .62
9.3.3 Flow graph segment .63
9.3.4 Flow graph segment .64
9.3.5 Flow graph segment .65
9.4 Altstep call.66
9.5 Assignment statement.66
9.5a Break statements in altsteps.66
9.6 Call operation.67
9.6.1 Flow graph segment .69
9.6.1a Flow graph segment .69
9.6.2 Flow graph segment .71
9.6.3 Flow graph segment .71
9.6.4 Flow graph segment .72
9.6.5 Flow graph segment .73
9.6.6 Flow graph segment .74
9.7 Catch operation.74
9.8 Check operation.75
9.8.1 Flow graph segment .76
9.8.2 Flow graph segment .77
9.9 Clear port operation.78
9.10 Connect operation.78
9.11 Constant definition.79
9.12 Create operation.80
9.13 Deactivate statement.81
9.13.1 Flow graph segment .82
9.13.2 Flow graph segment .82
9.14 Disconnect operation.83
ETSI
5 ETSI ES 201 873-4 V4.1.1 (2009-06)
9.14.1 Flow graph segment .83
9.14.2 Flow graph segment .85
9.14.3 Flow graph segment .86
9.14.4 Flow graph segment .87
9.14.5 Flow graph segment .87
9.15 Do-while statement.88
9.16 Done component operation.89
9.17 Execute statement.91
9.17.1 Flow graph segment .92
9.17.2 Flow graph segment .93
9.17.3 Flow graph segment .94
9.18 Expression .94
9.18.1 Flow graph segment .95
9.18.2 Flow graph segment .95
9.18.3 Flow graph segment .96
9.18.4 Flow graph segment .96
9.19 Flow graph segment .97
9.20 Flow graph segment .97
9.20a Flow graph segment .98
9.20b Flow graph segment .98
9.21 Flow graph segment .99
9.22 Flow graph segment .99
9.23 For statement.100
9.24 Function call.101
9.24.1 Flow graph segment .103
9.24.2 Flow graph segment .103
9.24.3 Flow graph segment .104
9.24.3a Flow graph segment .104
9.24.4 Flow graph segment .105
9.24.5 Flow graph segment .106
9.25 Getcall operation.106
9.26 Getreply operation.106
9.27 Getverdict operation.107
9.28 Goto statement.107
9.28a Halt port operation.108
9.29 If-else statement.108
9.29a Kill component operation.109
9.29a.1 Flow graph segment .111
9.29a.2 Flow graph segment .112
9.29a.3 Flow graph segment .113
9.29b Kill execution statement.113
9.29b.1 Flow graph segment .114
9.29c Killed component operation .115
9.30 Label statement.116
9.31 Log statement.116
9.32 Map operation.117
9.33 Mtc operation.117
9.34 Port declaration.118
9.35 Raise operation.118
9.35.1 Flow graph segment .119
9.35.1a Flow graph segment .119
9.35.2 Flow graph segment .121
9.36 Read timer operation .122
9.37 Receive operation.123
9.37.1 Flow graph segment .124
9.37.2 Flow graph segment .125
9.37.3 Flow graph segment .126
9.38 Repeat statement.126
9.39 Reply operation.127
9.39.1 Flow graph segment .128
9.39.1a Flow graph segment .128
9.39.2 Flow graph segment .130
ETSI
6 ETSI ES 201 873-4 V4.1.1 (2009-06)
9.40 Return statement.130
9.40.1 Flow graph segment .132
9.40.2 Flow graph segment .133
9.41 Running component operation .134
9.41.1 Flow graph segment .135
9.41.2 Flow graph segment .136
9.42 Running timer operation.137
9.43 Self operation.138
9.44 Send operation.138
9.44.1 Flow graph segment .139
9.44.1a Flow graph segment .139
9.44.2 Flow graph segment .141
9.45 Setverdict operation.141
9.46 Start component operation.142
9.47 Start port operation.144
9.48 Start timer operation.144
9.48.1 Flow graph segment .145
9.48.2 Flow graph segment .146
9.49 Stop component operation.146
9.49.1 Void.148
9.49.2 Flow graph segment .148
9.49.3 Flow graph segment .149
9.50 Stop execution statement.150
9.50.1 Void.151
9.51 Stop port operation.151
9.52 Stop timer operation .152
9.53 System operation.152
9.54 Timer declaration.153
9.54.1 Flow graph segment .153
9.54.2 Flow graph segment .154
9.55 Timeout timer operation.155
9.56 Unmap operation.156
9.56.1 Flow graph segment .158
9.56.2 Flow graph segment .159
9.56.3 Flow graph segment .160
9.57 Variable declaration.160
9.57.1 Flow graph segment .161
9.57.2 Flow graph segment .162
9.58 While statement.162
10 Lists of operational semantic components .163
10.1 Functions and states.163
10.2 Special keywords.164
10.3 Flow graphs of TTCN-3 behaviour descriptions .165
10.4 Flow graph segments.165
History .168

ETSI
7 ETSI ES 201 873-4 V4.1.1 (2009-06)
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://webapp.etsi.org/IPR/home.asp).
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 ETSI Standard (ES) has been produced by ETSI Technical Committee Methods for Testing and Specification
(MTS).
The present document is part 4 of a multi-part deliverable. Full details of the entire series can be found in part 1 [1].
ETSI
8 ETSI ES 201 873-4 V4.1.1 (2009-06)
1 Scope
The present document defines the operational semantics of TTCN-3. The present document is based on the TTCN-3
core language defined in ES 201 873-1 [1].
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
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.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] ETSI ES 201 873-1: "Methods for Testing and Specification (MTS); The Testing and Test Control
Notation version 3; Part 1: TTCN-3 Core Language".
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
Not applicable.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in ES 201 873-1 [1] apply.
ETSI
9 ETSI ES 201 873-4 V4.1.1 (2009-06)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
BNF Backus-Nauer Form
MTC Master Test Component
SUT System Under Test
TTCN Testing and Test Control Notation
4 Introduction
This clause defines the meaning of TTCN-3 behaviour in an intuitive and unambiguous manner. The operational
semantics is not meant to be formal and therefore the ability to perform mathematical proofs based on this semantics is
very limited.
This operational semantics provides a state oriented view on the execution of a TTCN module. Different kinds of states
are introduced and the meaning of the different TTCN-3 constructs is described by:
1) using state information to define the preconditions for the execution of a construct; and
2) defining how the execution of a construct will change a state.
The operational semantics is restricted to the meaning of behaviour in TTCN-3, i.e. functions, altsteps, test cases,
module control and language constructs for defining test behaviour, e.g. send and receive operations, if-else-, or
while- statements. The meaning of some TTCN-3 constructs is explained by replacing them with other language
constructs. For example, interleave statements are short forms for series of nested alt statements and the meaning
of each interleave statement is explained by its replacement with a corresponding series of nested alt statements.
In most cases, the definition of the semantics of a language is based on an abstract syntax tree of the code that shall be
described. This semantics does not work on an abstract syntax tree but requires a graphical representation of TTCN-3
behaviour descriptions in form of flow graphs. A flow graph describes the flow of control in a function, alt step, test
case or the module control. The mapping of TTCN-3 behaviour descriptions onto flow graphs is straightforward.
NOTE: The mapping of TTCN-3 statements onto flow graphs is an informal step and is not defined by using the
BNF rules in ES 201 873-1 [1]. The reason for this is that the BNF rules are not optimal for an intuitive
mapping because several static semantic rules are coded into BNF rules in order to allow static semantic
checks during the syntax check.
5 Structure of the present document
The present document is structured into four parts:
1) The first part (see clause 6) describes restrictions of the operational semantics, i.e. issues related to the
semantics, which are not covered by the present document.
2) The second part (see clause 8) defines the meaning of TTCN-3 short cut and macro notations by their
replacement with other TTCN-3 language constructs. These replacements in a TTCN-3 module can be seen as
pre-processing step before the module can be interpreted according to the following operational semantics
description.
3) The third part (see clause 9) describes the operational semantics of TTCN-3 by means of flow graph
interpretation and state modification.
4) The fourth part (see clause 10) specifies the mapping of the different TTCN-3 statements onto flow graph
segments, which provide the building blocks for flow graphs representing functions, alt steps, test cases and
module control.
ETSI
10 ETSI ES 201 873-4 V4.1.1 (2009-06)
6 Restrictions
The operational semantics only covers behavioural aspects of TTCN-3, i.e. it describes the meaning of statements and
operations. It does not provide:
a) A semantics for the data aspects of TTCN-3. This includes aspects like encoding, decoding and the usage of
data imported from non-TTCN-3 specifications.
b) A semantics for the grouping mechanism. Grouping is related to the definitions part of a TTCN-3 module and
has no behavioural aspects.
c) A semantics for the import statement. The import of definitions has to be done in the definitions part of a
TTCN-3 module. The operational semantics handles imported definitions as if they are defined in the
importing module.
7 Replacement of short forms
Short forms have to be expanded by the corresponding complete definitions on a textual level before this operational
semantics can be used for the explanation of TTCN-3 behaviour.
TTCN-3 short forms are:
• lists of module parameter, constant and variable declarations of the same type and lists of timer declarations;
• stand-alone receiving operations;
• stand-alone altsteps calls;
• trigger operations;
• missing return and stop statements at the end of function and test case definitions;
• missing stop execution statements;
• interleave statements;
• select-case statements;
• break and continue statements;
• disconnect and unmap operations without parameters; and
• default values of missing actual parameters.
In addition to the handling of short forms, the operational semantics requires a special handling for module parameters,
global constants, i.e. constants that are defined in the module definitions part, and pre-processing macro
...

SLOVENSKI STANDARD
01-september-2009
0HWRGH]DSUHVNXãDQMHLQVSHFLILFLUDQMH076UD]OLþLFD]DSLVDSUHVNXãDQMDLQ
NUPLOQLKSUHVNXVRYGHO2SHUDWLYQDVHPDQWLND77&1
Methods for Testing and Specification (MTS) - The Testing and Test Control Notation
version 3 - Part 4: TTCN-3 Operational Semantics
Ta slovenski standard je istoveten z: ES 201 873-4 Version 4.1.1
ICS:
33.040.01 Telekomunikacijski sistemi Telecommunication systems
na splošno in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ETSI Standard
Methods for Testing and Specification (MTS);
The Testing and Test Control Notation version 3;
Part 4: TTCN-3 Operational Semantics

2 ETSI ES 201 873-4 V4.1.1 (2009-06)

Reference
RES/MTS-00107-4 T3 ed411 OS
Keywords
interoperability, methodology, MTS, testing,
TTCN
ETSI
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The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2009.
All rights reserved.
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DECT , PLUGTESTS , UMTS , TIPHON , the TIPHON logo and the ETSI logo are Trade Marks of ETSI registered
for the benefit of its Members.
TM
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ETSI
3 ETSI ES 201 873-4 V4.1.1 (2009-06)
Contents
Intellectual Property Rights.7
Foreword.7
1 Scope.8
2 References.8
2.1 Normative references.8
2.2 Informative references.8
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations.9
4 Introduction .9
5 Structure of the present document.9
6 Restrictions.10
7 Replacement of short forms .10
7.1 Order of replacement steps.11
7.2 Replacement of global constants and module parameters .11
7.3 Embedding single receiving operations into alt statements.11
7.4 Embedding stand-alone altstep calls into alt statements.12
7.5 Replacement of interleave statements .12
7.6 Replacement of trigger operations.25
7.7 Replacement of select-case statements.25
7.8 Replacement of simple break statements.27
7.9 Replacement of continue statements .27
7.10 Adding default parameters to disconnect and unmap operations without parameters.28
7.11 Adding default values of parameters .28
8 Flow graph semantics of TTCN-3.28
8.1 Flow graphs.29
8.1.1 Flow graph frame.29
8.1.2 Flow graph nodes.29
8.1.2.1 Start nodes.29
8.1.2.2 End nodes.29
8.1.2.3 Basic nodes.29
8.1.2.4 Reference nodes.30
8.1.2.4.1 OR combination of reference nodes .30
8.1.2.4.2 Multiple occurrences of reference nodes.30
8.1.3 Flow lines.31
8.1.4 Flow graph segments.31
8.1.5 Comments.32
8.1.6 Handling of flow graph descriptions.33
8.2 Flow graph representation of TTCN-3 behaviour .33
8.2.1 Flow graph construction procedure .33
8.2.2 Flow graph representation of module control .34
8.2.3 Flow graph representation of test cases .35
8.2.4 Flow graph representation of functions .35
8.2.5 Flow graph representation of altsteps .36
8.2.6 Flow graph representation of component type definitions.37
8.2.7 Retrieval of start nodes of flow graphs .38
8.3 State definitions for TTCN-3 modules .38
8.3.1 Module state.38
8.3.1.1 Accessing the module state .39
8.3.2 Entity states.40
8.3.2.1 Accessing entity states .41
ETSI
4 ETSI ES 201 873-4 V4.1.1 (2009-06)
8.3.2.2 Data state and variable binding .43
8.3.2.3 Accessing data states.43
8.3.2.4 Timer state and timer binding .44
8.3.2.5 Accessing timer states .45
8.3.2.6 Port references and port binding .46
8.3.2.7 Accessing port references .47
8.3.3 Port states.47
8.3.3.1 Handling of connections among ports.48
8.3.3.2 Handling of port states .48
8.3.4 General functions for the handling of module states .49
8.4 Messages, procedure calls, replies and exceptions.50
8.4.1 Messages.50
8.4.2 Procedure calls and replies .50
8.4.3 Exceptions.51
8.4.4 Construction of messages, procedure calls, replies and exceptions .51
8.4.5 Matching of messages, procedure calls, replies and exceptions .51
8.4.6 Retrieval of information from received items.52
8.5 Call records for functions, altsteps and test cases.52
8.5.1 Handling of call records.52
8.6 The evaluation procedure for a TTCN-3 module .53
8.6.1 Evaluation phases.53
8.6.1.1 Phase I: Initialization.53
8.6.1.2 Phase II: Update.54
8.6.1.3 Phase III: Selection .54
8.6.1.4 Phase IV: Execution.54
8.6.2 Global functions.54
9 Flow graph segments for TTCN-3 constructs .55
9.1 Action statement.55
9.2 Activate statement .56
9.2a Alive component operation .56
9.2a.1 Flow graph segment .58
9.2a.2 Flow graph segment .59
9.3 Alt statement.59
9.3.1 Flow graph segment .61
9.3.2 Flow graph segment .62
9.3.3 Flow graph segment .63
9.3.4 Flow graph segment .64
9.3.5 Flow graph segment .65
9.4 Altstep call.66
9.5 Assignment statement.66
9.5a Break statements in altsteps.66
9.6 Call operation.67
9.6.1 Flow graph segment .69
9.6.1a Flow graph segment .69
9.6.2 Flow graph segment .71
9.6.3 Flow graph segment .71
9.6.4 Flow graph segment .72
9.6.5 Flow graph segment .73
9.6.6 Flow graph segment .74
9.7 Catch operation.74
9.8 Check operation.75
9.8.1 Flow graph segment .76
9.8.2 Flow graph segment .77
9.9 Clear port operation.78
9.10 Connect operation.78
9.11 Constant definition.79
9.12 Create operation.80
9.13 Deactivate statement.81
9.13.1 Flow graph segment .82
9.13.2 Flow graph segment .82
9.14 Disconnect operation.83
ETSI
5 ETSI ES 201 873-4 V4.1.1 (2009-06)
9.14.1 Flow graph segment .83
9.14.2 Flow graph segment .85
9.14.3 Flow graph segment .86
9.14.4 Flow graph segment .87
9.14.5 Flow graph segment .87
9.15 Do-while statement.88
9.16 Done component operation.89
9.17 Execute statement.91
9.17.1 Flow graph segment .92
9.17.2 Flow graph segment .93
9.17.3 Flow graph segment .94
9.18 Expression .94
9.18.1 Flow graph segment .95
9.18.2 Flow graph segment .95
9.18.3 Flow graph segment .96
9.18.4 Flow graph segment .96
9.19 Flow graph segment .97
9.20 Flow graph segment .97
9.20a Flow graph segment .98
9.20b Flow graph segment .98
9.21 Flow graph segment .99
9.22 Flow graph segment .99
9.23 For statement.100
9.24 Function call.101
9.24.1 Flow graph segment .103
9.24.2 Flow graph segment .103
9.24.3 Flow graph segment .104
9.24.3a Flow graph segment .104
9.24.4 Flow graph segment .105
9.24.5 Flow graph segment .106
9.25 Getcall operation.106
9.26 Getreply operation.106
9.27 Getverdict operation.107
9.28 Goto statement.107
9.28a Halt port operation.108
9.29 If-else statement.108
9.29a Kill component operation.109
9.29a.1 Flow graph segment .111
9.29a.2 Flow graph segment .112
9.29a.3 Flow graph segment .113
9.29b Kill execution statement.113
9.29b.1 Flow graph segment .114
9.29c Killed component operation .115
9.30 Label statement.116
9.31 Log statement.116
9.32 Map operation.117
9.33 Mtc operation.117
9.34 Port declaration.118
9.35 Raise operation.118
9.35.1 Flow graph segment .119
9.35.1a Flow graph segment .119
9.35.2 Flow graph segment .121
9.36 Read timer operation .122
9.37 Receive operation.123
9.37.1 Flow graph segment .124
9.37.2 Flow graph segment .125
9.37.3 Flow graph segment .126
9.38 Repeat statement.126
9.39 Reply operation.127
9.39.1 Flow graph segment .128
9.39.1a Flow graph segment .128
9.39.2 Flow graph segment .130
ETSI
6 ETSI ES 201 873-4 V4.1.1 (2009-06)
9.40 Return statement.130
9.40.1 Flow graph segment .132
9.40.2 Flow graph segment .133
9.41 Running component operation .134
9.41.1 Flow graph segment .135
9.41.2 Flow graph segment .136
9.42 Running timer operation.137
9.43 Self operation.138
9.44 Send operation.138
9.44.1 Flow graph segment .139
9.44.1a Flow graph segment .139
9.44.2 Flow graph segment .141
9.45 Setverdict operation.141
9.46 Start component operation.142
9.47 Start port operation.144
9.48 Start timer operation.144
9.48.1 Flow graph segment .145
9.48.2 Flow graph segment .146
9.49 Stop component operation.146
9.49.1 Void.148
9.49.2 Flow graph segment .148
9.49.3 Flow graph segment .149
9.50 Stop execution statement.150
9.50.1 Void.151
9.51 Stop port operation.151
9.52 Stop timer operation .152
9.53 System operation.152
9.54 Timer declaration.153
9.54.1 Flow graph segment .153
9.54.2 Flow graph segment .154
9.55 Timeout timer operation.155
9.56 Unmap operation.156
9.56.1 Flow graph segment .158
9.56.2 Flow graph segment .159
9.56.3 Flow graph segment .160
9.57 Variable declaration.160
9.57.1 Flow graph segment .161
9.57.2 Flow graph segment .162
9.58 While statement.162
10 Lists of operational semantic components .163
10.1 Functions and states.163
10.2 Special keywords.164
10.3 Flow graphs of TTCN-3 behaviour descriptions .165
10.4 Flow graph segments.165
History .168

ETSI
7 ETSI ES 201 873-4 V4.1.1 (2009-06)
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://webapp.etsi.org/IPR/home.asp).
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 ETSI Standard (ES) has been produced by ETSI Technical Committee Methods for Testing and Specification
(MTS).
The present document is part 4 of a multi-part deliverable. Full details of the entire series can be found in part 1 [1].
ETSI
8 ETSI ES 201 873-4 V4.1.1 (2009-06)
1 Scope
The present document defines the operational semantics of TTCN-3. The present document is based on the TTCN-3
core language defined in ES 201 873-1 [1].
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
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.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] ETSI ES 201 873-1: "Methods for Testing and Specification (MTS); The Testing and Test Control
Notation version 3; Part 1: TTCN-3 Core Language".
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
Not applicable.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in ES 201 873-1 [1] apply.
ETSI
9 ETSI ES 201 873-4 V4.1.1 (2009-06)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
BNF Backus-Nauer Form
MTC Master Test Component
SUT System Under Test
TTCN Testing and Test Control Notation
4 Introduction
This clause defines the meaning of TTCN-3 behaviour in an intuitive and unambiguous manner. The operational
semantics is not meant to be formal and therefore the ability to perform mathematical proofs based on this semantics is
very limited.
This operational semantics provides a state oriented view on the execution of a TTCN module. Different kinds of states
are introduced and the meaning of the different TTCN-3 constructs is described by:
1) using state information to define the preconditions for the execution of a construct; and
2) defining how the execution of a construct will change a state.
The operational semantics is restricted to the meaning of behaviour in TTCN-3, i.e. functions, altsteps, test cases,
module control and language constructs for defining test behaviour, e.g. send and receive operations, if-else-, or
while- statements. The meaning of some TTCN-3 constructs is explained by replacing them with other language
constructs. For example, interleave statements are short forms for series of nested alt statements and the meaning
of each interleave statement is explained by its replacement with a corresponding series of nested alt statements.
In most cases, the definition of the semantics of a language is based on an abstract syntax tree of the code that shall be
described. This semantics does not work on an abstract syntax tree but requires a graphical representation of TTCN-3
behaviour descriptions in form of flow graphs. A flow graph describes the flow of control in a function, alt step, test
case or the module control. The mapping of TTCN-3 behaviour descriptions onto flow graphs is straightforward.
NOTE: The mapping of TTCN-3 statements onto flow graphs is an informal step and is not defined by using the
BNF rules in ES 201 873-1 [1]. The reason for this is that the BNF rules are not optimal for an intuitive
mapping because several static semantic rules are coded into BNF rules in order to allow static semantic
checks during the syntax check.
5 Structure of the present document
The present document is structured into four parts:
1) The first part (see clause 6) describes restrictions of the operational semantics, i.e. issues related to the
semantics, which are not covered by the present document.
2) The second part (see clause 8) defines the meaning of TTCN-3 short cut and macro notations by their
replacement with other TTCN-3 language constructs. These replacements in a TTCN-3 module can be seen as
pre-processing step before the module can be interpreted according to the following operational semantics
description.
3) The third part (see clause 9) describes the operational semantics of TTCN-3 by means of flow graph
interpretation and state modification.
4) The fourth part (see clause 10) specifies the mapping of the different TTCN-3 statements onto flow graph
segments, which provide the building blocks for flow graphs representing functions, alt steps, test cases and
module control.
ETSI
10 ETSI ES 201 873-4 V4.1.1 (2009-06)
6 Restrictions
The operational semantics only covers behavioural aspects of TTCN-3, i.e. it describes the meaning of statements and
operations. It does not provide:
a) A semantics for the data aspects of TTCN-3. This includes aspects like encoding, decoding and the usage of
data imported from non-TTCN-3 specifications.
b) A semantics for the grouping mechanism. Grouping is related to the definitions part of a TTCN-3 module and
has no behavioural aspects.
c) A semantics for the import statement. The import of definitions has to be done in the defini
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