Abstract. As embedded systems must constantly integrate new functionalities, their developement cycles must be based on high-level abstractions, making the software design more flexible. CBSE provides an approach to these new requirements. However, low-level services provided by operating systems are an integral part of embedded applications, furthermore deployed on resource-limited devices. Therefore, the expected benefits of CBSE must not impact on the constraints imposed by the targetted domain, such as memory footprint, energy consumption, and execution time. In this paper, we present the componentization of a legacy industry-established Real-Time Operating System, and how componentbased applications are built on top of it. We use the Think framework that allows to produce flexible systems while paying for flexibility only where desired. Performed experimentions show that the induced overhead is negligeable.

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Wormhole attacks enable an attacker with limited resources and no cryptographic material to disrupt wireless networks. In a wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them (possibly selectively) to another location and retransmits them there into the network. In this paper, we present an algorithm for detecting and thus defending against wormhole attacks in wireless multihop networks. This algorithm uses only local and neighborhood information without requiring clock synchronization, location information or dedicated hardware. Moreover, the algorithm is independent of wireless communication models. We present simulation results for grid-like topologies and for random topologies and show that the algorithm is able to detect wormhole attacks in all cases whereas the number of false alarms (false detections) decreases rapidly if the network is sufficiently dense.

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As functionalities required by embedded systems increase, higher levels of abstraction become necessary to fulfill development exigences. At the same time, traditional physical and economical constraints such as size, memory usage and energy consumption subsist, making embedded systems development even more complex as it must face two contradictory requirements. In this paper, we expose how a component-based development framework is able to support these two conflicting demands. We follow a component-based approach to benefit from reusability and separation of concerns at design-time, producing flexible systems. We propose a set of flexibility-oriented properties allowing architects to generate, for a same architecture, a set of systems with different flexibility capabilities; these optimization techniques allow developers to pay for flexibility only where it is actually desired. Experiments conducted on several use-cases confirm the effectiveness of our approach.