SDL '99 (eBook)

The Next Millennium

G.V. Bochmann, R. Dssouli, Y. Lahav (Herausgeber)

eBook Download: PDF

1999 | 1. Auflage
489 Seiten
Elsevier Science (Verlag)
978-0-08-054080-1 (ISBN)

Infos

This book represents the proceedings of the 9th SDL Forum which was held in Montreal, Quebec, Canada, during the week of June 21-25, 1999. The 9th SDL Forum presents papers on the past and future development of the MSC and SDL languages.The volume presents information on experience with the use of these languages in industrial development projects, on tools and techniques for using these languages in the software and hardware development process, and other aspects of these languages.

Inhalt

Front Cover 1
SDL '99: The Next Millennium 4
Copyright Page 5
Table of Contents 8
Introduction 6
Section I: Applications I 14
Chapter 1. IN Service prototyping using SDL models and animation 16
Chapter 2. SDL framework for prototyping and validation of IN services 32
Chapter 3. Evaluating an SDL framework for AXE development 46
Session II: Deriving SDL 62
Chapter 4. New results on deriving SDL specifications from MSCs 64
Chapter 5. From timed scenarios to SDL: specification, implementation and testing of real-time systems 80
Session III: Language Extension 94
Chapter 6. SDL enhancements and application for the design of distributed services 96
Chapter 7. Modelling interfaces in SDL with gate types 108
Chapter 8. MSC and data: dynamic variables 118
Session IV: Testing I 134
Chapter 9. SDL-based specification and testing strategy for communication network protocols 136
Chapter 10. Automated test generation from SDL specifications 148
Chapter 11. Methods and methodology for an incremental test generation from SDL specifications 166
Session V: SDL and MSC for the Next Millennium 182
Chapter 12. Towards a new formal SDL semantics - outline of an abstract state machines 184
Session VI: UML in Collaboration with MSC and SDL 204
Chapter 13. Towards a harmonization of UML-sequence diagrams and MSC 206
Chapter 14. Three scenarios for combining UML and SDL'96 222
Chapter 15. Automatic synthesis of SDL models in use case methodology 238
Chapter 16. Integrating schedulability analysis and SDL in an object-oriented methodology for embedded real-time systems 254
Session VII: Code Generation 270
Chapter 17. COCOS - A configurable SDL compiler for generating efficient protocol implementations 272
Chapter 18. Using declarative mappings for automatic code generation from SDL and ASN.1 288
Session VIII: Metric 304
Chapter 19. Using design metrics to identify error-prone components of SDL designs 306
Chapter 20. Application of SDL metric suite through development phases 320
Session IX: Applications II 336
Chapter 21. Dynamic scenario-based approach to re-engineering of legacy telecommunication software 338
Chapter 22. Specification, validation and implementation of ATM UNI signaling protocols in SDL 354
Chapter 23. Using metapatterns with SDL 368
Chapter 24. External communication with SDL systems 386
Session X: Testing II 400
Chapter 25. SDL and MSC based test generation for distributed test architectures 402
Chapter 26. A test case generation tool for conformance testing of SDL systems 418
Session XI: Time, Performance and Simulation 434
Chapter 27. IF: An intermediate representation for SDL and its applications 436
Chapter 28. PerfSDL: Interface to protocol performance analysis by means of simulation 454
Chapter 29. Early performance prediction of SDL/MSC specified systems by automated synthetic code generation 470
Chapter 30. A simulation model for message sequence charts 486
Author Index 502

Textauszug

IN Service Prototyping using SDL Models and Animation

Miguel Alabau [e-mail]; Pierre Combes [e-mail]; Béatrice Renard [e-mail]    France Telecom - BD Cnet DAC/PRI, 38, rue du Général Leclerc, 92794 ISSY-LES-MOULINEAUX Cédex 9, FRANCE

ABSTRACT

This paper describes a environment for service prototyping based on the graphical animation of the service logic. It is based on SDL models of services and network. It aims at simulating and animating the service behaviour from different actors points of view, mainly from the user and subscriber points of view. Applied at different steps of service creation, from the elaboration of the first idea of a new service to the validation of the service logic design, taking into account architectural constraints, this simulation and animation environment helps to guarantee the validation of service requirements between service provider, service developer, subscriber and users. The environment presented here allows the validation of different service domains: call processing but also management scripts.

Keywords

Intelligent Network

Service Prototyping

Service Validation

Simulation

Animation

SDL

MSC

1 Service Validation and Service Animation

Service creation involves numerous actors (service and network provider, service developer, service subscriber, users) and follows a specific process divided into different activities (requirements gathering and analysis, specification and rapid prototyping, service design, coding and final testing).

The will for introducing quickly and customising new services necessitates to insist on careful service validation tasks to ensure that the service satisfies the needs of the different actors [3]. It should be performed at different steps during the creation of the service. In particular, user and subscriber needs have to be validated as soon as possible to fix very early service functionalities and some ergonomic aspects. The validation of the requirements has also to be performed during the design activity where the service logic is refined depending on architectural or platform constraints (including existing building blocks).

This paper presents how the integration of service simulation and animation in a Service Creation Environment will allow:

• to easily play with the service specification in order to elaborate and quickly modify the service requirements, specially the ergonomic aspects,

• to validate with service subscribers and users the service specification, using a comprehensive graphical view of the service behaviour,

• to validate that the service design is still conform to the subscriber and user requirements,

• to obtain a basis for the contracts between different actors (e.g., service developer and provider, service provider and subscriber) with animation scenarios and MSC [10] that are derived from the specification.

The proposed environment is based on formal SDL model, which ensures that the animation is obtained from a specification semantically clear. It also guarantees the consistency between the different refined models.

The methodology presented here focuses not only on real time aspects; it allows to validate in a same environment service data, real time service logic and management scripts.

The paper is structured as follows:

• Section 2 describes the animation tool, its main graphical features, its dependencies with an SDL model and how it communicates with the simulator,

• Section 3 presents how the environment helps to validate service management scripts based on SDL specifications; in particular, the modelling of a French Videotexservice is presented,

• Section 4 describes the complexity of the Intelligent Network and how it should be modelled in order to analyse and validate the behaviour of a service logic distributed on the different network entities,

• Section 5 describes the benefits provided by the use of SDL96 for the construction of such a model,

• Section 6 is dedicated to the application of simulation and animation to the service interaction problem, focusing on the use of the methodology as a step towards the resolution.

2 An Animation Tool Based on SDL Models

The animation tool allows to dynamically present different elements of an SDL model (processes, procedures, channels, messages) as graphical objects such as icons, links, sounds, gauges (see figure 1). An animation can evolve step by step or continuously.

Fig 1 Graphical Interface of the Animation Tool.

During the simulation of the underlying SDL model using the ObjectGeode simulator [1], the aspect of the graphical objects evolves according to the model execution. For example:

• a user terminal will be described by different icons depending on its type and its state: fixed, mobile, onhooked, ringing state, conversation, receipt of a message,

• graphical links representing interfaces between objects can be animated when a message occurs and become visible/invisible, blink or appear with a different colour,

• messages received by a terminal can be animated as graphical labels or sounds,

• labels can be displayed and present the value of variables of the model,

• icons representing service constituents can appear, disappear depending on their invocation during the service logic execution.

The animation tool interface allows a user to send requests to the simulator, clicking the icon representing for example a terminal and selecting one of the possible actions at this animation step: offhook, onhook, dialling a number, pushing a button, selecting a text, talking. On the same way, variables of the SDL model can be accessed during the animation and their values can be modified. It is also possible to specify to stop the animation when it reaches a specific state or when a specific message appears. Finally when observers are used during the simulation to verify some specific properties, it is possible to animate them e.g., as lights which become orange when they evolve and red when they reach a success or error state.

The associations between the SDL model elements and the graphical objects are done via configuration files. Different configurations can be created for the same SDL model which allow to animate different aspects of the service model by means of different windows (a userview with terminals, network and protocols aspects, a service logic view by constituent aggregation) without modifying the SDL model.

Scenarios obtained during the animation of the SDL model can be recorded and replayed on a version of the tool independent of the ObjectGeode environment. It is thus easy to show them on a personal computer.

The architecture presented below shows how the tools communicate. The animation tool sends requests to the simulator and receives answers via the tool software bus. The graphical aspect of the animation changes according to the answers and a variable of the SDL model is modified by a request.

Fig 2 The Animation Tool Architecture.

3 Animation of Management Scripts

The animation tool was advantageously used to animate vocal and French Videotexmanagement scripts.

The basic principle of such scripts, more precisely the logic of dialogue sequencing, is quite simple. A script is constituted by different phases, each of them being a sequence of different steps. A step consists in:

• for the vocal services, to play an audio film and the possibility for the user to dial some choice,

• for the French Videotexservices, to display a page and the possible buttons provided to the user.

The result of an action performed by the user will trigger another step.

Scripts themselves are quite complex, due to the great number of possibilities offered to users (nominal and erroneous choices), to the complexity of feedbacks and controls, and to the intrinsic complexity of some service subscriber profiles.

The most common representation of these scripts is the textual form, and reading a complete dialogue often needs to switch from one page to another one, which makes them not so easy to understand.

The use of SDL to model such scripts is really efficient to ease their validation. In fact, only few functionnalities of the SDL language are needed: one step is modelled by one SDL procedure, and service logic is a succession of procedure calls and decisions performed when the procedure returns and corresponding to user choices (see figure 3). Moreover, reuse aspects were introduced,...

Produkt-Details

• Erscheint lt. Verlag: 10.6.1999
• Sprache: englisch
• Themenwelt: Mathematik / Informatik ► Informatik ► Programmiersprachen / -werkzeuge
• Themenwelt: Mathematik / Informatik ► Informatik ► Software Entwicklung
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Nachrichtentechnik
• ISBN-10: 0-08-054080-5 / 0080540805
• ISBN-13: 978-0-08-054080-1 / 9780080540801