The pros and cons of using SDL for creation of distributed services

In a competitive market for the creation of complex distributed services, time to market, development cost, maintenance and flexibility are key issues. Optimizing the development process is very much a matter of optimizing the technologies used during service creation. This paper reports on the experience gained in the Service Creation projects SCREEN and TOSCA on use of the language SDL for efficient service creation

Automatic synthesis of SDL from MSC and its applications in forward and reverse engineering

Abstract Wider adoption of formal specification languages in industry is impeded by the lack of support for early development phases and for integration with older, legacy software. Methodology aimed at improving this situation is presented. The methodology uses Message Sequence Charts (MSC) as a "front-end" specification language and systematically applies an automatic synthesis technique to produce executable specifications in the telecommunications standard Specification and Description Language (SDL). Applications of the automatic synthesis technique for both forward and reverse engineering are demonstrated

Métodos y Herramientas para el Diseño y Verificación de Sistemas de Comunicaciones Móviles

El objetivo de esta Tesis ha sido la consecución de tecnología para el diseño y mantenimiento eficientes, en coste temporal y económico, de Sistemas de Pruebas para equipos de comunicaciones inalámbricas. El proceso de diseño elaborado se ha basado en un conjunto de principios básicos: uso de lenguajes y notaciones ITU, independencia de la plataforma de ejecución y uso de herramientas comerciales. En esta Tesis se describe: a) Una arquitectura genérica para Sistemas de Pruebas. b) Una Metodología de Diseño de Sistemas de Pruebas. c) Un conjunto de herramientas de soporte. d) Una propuesta de metodología para el modelado con SDL. e) La aplicación a Sistemas de Pruebas de capa física de la arquitectura, métodos y herramientas utilizados en el área de protocolos. f) Un conjunto de implementaciones que validan las aportaciones anteriores

Load balancing approach for wireless IEEE 802.11 QoS enhancement

Abstract. In the few last years, the deployment of IEEE 802.11 WLAN in hotspots environment had becoming a useful solution providing practical and attractive communication characteristics. However the problem of user bandwidth availability arises as one of the most limit of this solution. In fact, the IEEE 802.11 standards do not provide any mechanism of loading distribution among different Access Points of the network. Then an AP can be heavily overloaded leading to station throughput degradation. This paper deals with this problem. It focuses on the presentation of QoS (Quality of Service) management solution for wireless communication system. It, mainly, presents a protocol structure between mobile and AP. This protocol is intended to provide best resources allocation and efficiency on communication metrics. An SDL description and MSC simulation is provided as a first step in the development of this protocol

State abstraction in SDL

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

CABS: a case-based and graphical requirements capture, formalisation and verification system

The use of formal specifications based on varieties of mathematical logic is becoming common in the process of designing and implementing safety critical systems and practices for hardware design. Formal methods are usually intended to include in the specification, all the important details of the final system in the specification, with the aim of proving that the specification possesses certain properties and lacks other unwanted properties. In large, complex systems, this task requires sophisticated theorem proving, which can be difficult and complicated. Telecommunications systems are large and complex, making detailed formal specification impractical given current technology. However, formal “sketches” of the behaviours the services provide can be produced, and these can be very helpful in locating which service might be relevant to a given problem.This thesis describes CABS, a case-based approach that uses coarse-grained graphical requirements specification sketches, to outline the basic behaviour of the system's func­tional modules (called services), thereby allowing us to identify, re-use and adapt re­quirements (from cases stored in a library), to construct new cases. The matching algorithm identifies similar behaviour between the input examples and the cases stored in the case library. By using cases that have already been tested, integrated and im ­plemented, less effort is needed to produce requirements specifications on a large scale. Using a hypothetical telecommunications system as an example, it will be shown that a comparatively simple logic can be used to capture coarse-grained behaviour and how a case-based approach benefits from this. The input from the examples is used both to identify the cases whose behaviour corresponds most closely to the designer's intentions, and also in the process of adapting, validating and, finally, verifying the proposed solution against the examples