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Model-checkers are powerful tools that can find individual traces through models to satisfy desired properties. These traces provide solutions to a number of problems. Instead of individual traces, software testing needs sets of traces that satisfy coverage criteria. Finding a trace set in a large model is difficult because model checkers generate single traces and use a lot of memory. Space and time requirements of modelchecking algorithms grow exponentially with respect to the number of variables and parallel automata of the model being analyzed. We present a method that generates a set of traces by iteratively invoking a model checker. The method mitigates the memory consumption problem by dynamically building partitions along the traces. This method was applied to a testability case study, and it generated the complete trace set, while ordinary model-checking could only generate 26%.

We present experiences from a case study where a model-based approach to black-box testing is applied to verify that a Wireless Application Protocol (WAP) gateway conforms to its specification. The WAP gateway is developed by Ericsson and used in mobile telephone networks to connect mobile phones with the Internet. We focus on testing the software implementing the session (WSP) and transaction (WTP) layers of the WAP protocol. These layers, and their surrounding environment, are described as a network of timed automata. To model the many sequence numbers (from a large domain) used in the protocol, we introduce an abstraction technique. We believe the suggested abstraction technique will prove useful to model and analyse other similar protocols with sequence numbers, in particular in the context of model-based testing.

A complete test bed is presented, which includes generation and execution of test cases. It takes as input a model and a coverage criterion expressed as an observer, and returns a verdict for each test case. The test bed includes existing tools from Ericsson for test-case execution. To generate test suites, we use our own tool CO[sic]ER- a new test-case generation tool based on the real-time model-checker UPPAAL.

We describe a partial order reduction technique for a real-time component model. Components are described as timed automata with data ports, which can be composed in static structures of unidirectional control and data flow. Compositions can be encapsulated as components and used in other compositions to form hierarchical models. The proposed partial order reduction technique uses a local time semantics for timed automata, in which time may progress independently in parallel automata which are resynchronized when needed. To increase the number of independent transitions and to reduce the problem of re-synchronizing parallel automata we propose, and show how, to use information derived from the composition structure of an analyzed model. Based on these ideas, we present a reachability analysis algorithm that uses an ample set construction to select which symbolic transitions to explore. The algorithm has been implemented as a prototype extension of the real-time model-checker Uppaal. We report from experiments with the tool that indicate that the technique can achieve substantial reduction in the time and memory needed to analyze a real-time system described in the studied component model.

The component-based strategy aims at managing complexity, shortening time-to-market, and reducing maintenance requirements by building systems with existing components. The full potential of this strategy has not yet been demonstrated for embedded software, mainly because of specific requirements in the domain, e.g., those related to timing, dependability, and resource consumption.

We present SaveCCT – a component technology intended for vehicular systems, show the applicability of SaveCCT in the engineering process, and demonstrate its suitability for vehicular systems in an industrial case-study. Our experiments indicate that SaveCCT provides appropriate expressiveness, resource efficiency, analysis and verification support for component-based development of vehicular software.

The project consists of ten fourth-year computer science students at Uppsala University developing an A-GPS (Assisted-GPS) system. During the fall term of 2005 the students have developed a module for GPS-calculations in a GSM-network and an application that demonstrates a possible way of using the calculations module. This paper describes the design, the development process and the results of the project.