- Task objectives
- Organization and timing
- Project management
This description outlines the overall objectives, background, task
objectives, organization and timing and project management of a special project
to coordinate the development, adoption and use of formalized languages, both
within ITU-T and as recommended by ITU-T.
Study Group 17, in its role as Lead Study Group on languages and
description techniques, leads this project.
The overall objectives are to:
- improve the product engineering process by providing a framework and a set
of languages that are smoothly integrated;
- allow easy integration with relevant languages developed and maintained
- improve Recommendations, in the sense that they can be more easily
implemented as products and that products can be more rigorously tested for
This project addresses an additional market by branding the set of ITU-T
languages and using several languages together to address domains where a single
language may not suffice. At the same time, some languages address a specific
target market on their own in addition to their usefulness within a language
set. Both markets - those for individual languages and those for a language set
- are addressed in order to broaden the overall base for the languages.
Thus, in addition to the language coordination project, individual projects can prove beneficial and will be encouraged if judged to be so, as in
the case of the ASN.1 project.
ITU-T is already recommending a long series of formalized languages, such as
SDL, MSC, ASN.1, TTCN, ODL, GDMO and CHILL.
Furthermore, it is developing new languages to handle currently unaddressed
domains, such as URN, and adopting additional
languages, such as IDL, XML, and some UML notations. Other notations are for
observation. This effort focused on adopting non-ITU-T languages
where they fit into the ITU-T language framework and the further development and
maintenance of those that are either already in the core competence of ITU-T or which are not
available from outside ITU-T.
As telecommunication becomes increasingly IT-oriented, formalized languages
will be used more in the writing of Recommendations and will also be recommended for
application in the industry by the language and techniques Recommendations (in
particular by SG 17).
There is a need to present the ITU-T languages in a coordinated framework to
- users to understand where they can be used;
- standardization bodies to coordinate and set priorities;
so that everyone can see what is covered or not covered by the ITU-T languages.
The project addresses the need:
- to present all the languages/notations in a common framework as a coordinated language family;
- to have a common approach to presenting the languages;
- to coordinate methods for use of the languages; and
- to have a common approach to promotion.
3. Task objectives
The task objectives are:
- Invite, write and collect proposals and integrate them into a project work
- Coordinate decisions on prioritization of activities within each Question.
- Follow-up and record work progress.
- Provide a named (hence easily identifiable and promoted) branding of the ITU-T language family.
- Provide a framework for languages to be used in software and standards development.
- Identify a set of languages within the framework, of which a subset is identified for
development and maintenance within ITU-T.
- Identify a list of customers of the framework and of individual languages.
- Initiate and follow-up development of methodology guidelines for
applications, which recommend language use at the various steps and results.
- Initiate and follow-up development of architecture guidelines (ODP, three-tier, etc.)
for applications that recommend language use for the various components and interfaces.
- Coordinate methodology and architecture frameworks with other SGs.
- Develop and carry-out a marketing/promotion plan for the integrated ITU-T language family.
- Integrate the results of the project and provide a procedure or process to maintain
and further develop those results after termination of the project.
4. Organization and timing
The project will provide to the closing plenary of each Study Group 17
status report on plans, work in progress and results. In addition, SG 17 will
keep TSAG informed.
Some of the task objectives, such as framework development, require new
contributions, while others require coordination across various groups.
Therefore, the project is expected to last throughout the current Study Period
The initial activities planned up to and including the first meeting of SG 17 (27 February - 8 March 2002) were:
At the SG 17 meeting and workshop on 2 March 2002 it was proposed to refer to:
- Collect coordination issues from all SG 17 Questions, ref. Task Objective 1.
- Propose and decide on a brand name for the ITU-T language family, ref. Task Objective 4.
- Organize a workshop on language frameworks (Geneva, Saturday 2 March 2002)
with contributions from both inside and outside ITU-T.
- Develop and agree on a work plan for the language coordination project.
SG 17 agreed that study of appropriate names would
continue until the SG meeting in November 2002 taking
into consideration expertise from marketing consultants.
- the set of languages as the Unified Language Family (ULF)
- the framework environment for the use of the set of ITU-T languages as
The ITU-T Language Environment (TILE)
umbrella of the language project, a new Question on
"Grammars for Recommendations defining
notations" was approved at the February/March 2002 SG 17 meeting. The results of the
Question are expected to be one or more Recommendations
that define the meta-grammars used in language Recommendations (for example, a common BNF meta-syntax).
The plan for work upto November 2002 is to:
- Consolidate and refine the contributions from SG
17 Question studies on particular languages (in
particular ASN.1, MSC, SDL, TTCN and ODL);
- Initiate study of key concepts crucial for the
real-time and telecommunications area (such as
signal consumption, time) identify mapping
between languages at the semantic level that
concentrate on the most important issues, and
enabling key terminology to be harmonised to avoid
confusion and related behaviour semantics, to
determine whether mappings between the languages are realistic.
- Initiate a feasibility study on defining a common
mathematical data model for the data languages of
ASN.1, SDL and TTCN. If it is decided that this
can be done cost effectively, then further work
would be done (in the project or as a Question
study) to define the model. Such a model would
allow unified data notation that can be used with
all three languages. A decision would have to be
made whether defining yet another data notation
might not create more divergence than
There may be a need for new Recommendations to be developed under this
Question. When and if such Recommendations are identified, this will be reported
in the plans and reports to SG 17.
5. Project management
The Chairman of Working Party 3/17 "Languages and notations", Mr
Rick Reed (TSE Limited, United Kingdom), is appointed as Project Leader. The SG
17 Language Advisory Board (LAB) will act as a reference group for this project.
Generally speaking, each of the notations had previously been developed largely in isolation
from other notations used in the engineering process, with the result that
integration between the notations was not as good as it could be. The consequence
is that where languages overlap, engineers sometimes have to learn two different
ways of doing the same thing and choose between them. There are other
consequences, such as the same term being used for different constructs in
different languages, and different terms being used for the same (or essentially
the same) concept in different languages.
To some extent, these problems can be overcome in two ways:
- by using tools that integrate the notations;
- by relating the languages by means of common semantic models.
These two approaches have much in common. It is difficult to integrate
notations in tools without implicit or explicit common semantics.
Those who are familiar with the UML notation as standardized by OMG will
recognize the above approach. UML originated from a number of separate notations
covering different aspects of software engineering. What UML tries to achieve is
to unify these notations, thereby making it easier to use them together in a number of engineering activities. UML still has a number of different notations
used for different engineering purposes, but these are related to one another
through a common model. In terms of general awareness, UML has certainly been a
success, in the same way as the Ada programming language became well known.
There are many books on UML and several tools that support various
interpretations of UML.
Although UML notations have many desirable features, when a comparison is
made with the individual notations recommended by ITU-T, such as ASN.1, SDL and
TTCN, the current ITU-T Recommendations are either superior for telecommunication
applications, or UML (at least currently) offers no alternative. However, it
will not be productive to view the situation in terms of competition between UML
notations and ITU-T notations: it would be better to have common models between
the notations so that they can be used together. For example, there is already
Recommendation Z.109, relating SDL and UML, and MSC has much in common with UML
sequence diagrams. A common basis between the OMG and ITU-T languages will enable
members of both organizations to benefit from tools that support the common
model. Some member organizations already recognize the common interest and are
participating in both OMG and SG 17.
A further issue that has to be considered by ITU-T is legacy investment.
There are many Recommendations and telecommunication products that use existing
versions of ITU-T notations. Moreover, engineers in the industry have established
expertise in the use of these notations.