Abstract-This paper capitalizes on two emerging trends, i.e. the growing use of wireless at the edge of industrial control networks and the growing interest to integrate IP into said networks. This is facilitated by recent design contributions from the IEEE and the IETF, where the former developed a highly efficient deterministic time-frequency scheduled medium access control protocol in form of IEEE 802.15.4e TSCH and the latter IPv6 networking paradigms in form of 6LoWPAN/ROLL, and scheduling approaches in form of 6TiSCH. The focus of the present work is on advancing the state of the art of deterministic 6TiSCH schedules towards more flexible but equally reliable distributed approaches. In addition, this paper aims to introduce the first implementation of 6TiSCH networks for factory automation environments: it outlines the challenges faced to overcome the scalability issues inherent to multi-hop dense low-power networks; the experimental results confirm that the naturally unreliable radio medium can support time-critical and reliable applications. These developments pave the way for wireless industry-grade monitoring approaches.

The Time Slotted Channel Hopping (TSCH) Medium Access Control (MAC) has been introduced in the recent IEEE 802.15.4e amendment to improve energy efficiency and reliability of short range wireless communications in industrial applications. However the joining phase can take very long time due to the operation of TSCH and beside being a problem in the deployment phase it may become a relevant source of energy consumption. To overcome this issue the present contribution investigates the problem of acquiring the first synchronization in a TSCH network from several points of view: (i) two novel mechanisms are proposed and implemented in real motes to speed up joining operations; (ii) for each of them, the average joining time is analytically modeled with closed form expressions as a function of node density, communication reliability, and beacon transmission frequency; (iii) the effectiveness of these novel algorithms and the accuracy of their models are experimentally validated in different scenarios.

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Interoperability, flexibility, and adaptability are key requirements of future internet applications. Convergence of contents, services, things, and networks can be the cornerstone to fulfill these requirements. Such rich and composite sources of data and processing capabilities call for a structured and formal approach that manages and capitalizes heterogeneous information. This paper proposes an approach to the run-time composition of software system architectures, aimed at addressing goals revealed at runtime. The approach is grounded on a graph model characterized by two control levels: a metamodeling and an instantiation level. At metamodeling level, the graph describes facts that may occur in a scenario of interest, processes triggered by facts, and technologies available to execute processes. The actual occurrence of facts, together with the deriving processes and technologies, is managed at instantiation level, with reference to an application-specific model. In particular, the paper proposes an algorithm that determines an optimal way to manage a change in the run-time environment, by finding a minimum cost path in the model. The usefulness of the proposed approach and its applicability to actual scenarios have been validated in an example smart home environment.