| 1. |
- Ahmed, Mobyen Uddin, 1976-, et al.
(författare)
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Run-Time Assurance for the E-care@home System
- 2018
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Ingår i: Part of the Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering book series (LNICST, volume 225). - Cham : Springer International Publishing. - 9783319762128 - 9783319762135 ; , s. 107-110
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Konferensbidrag (refereegranskat)abstract
- This paper presents the design and implementation of the software for a run-time assurance infrastructure in the E-care@home system. An experimental evaluation is conducted to verify that the run-time assurance infrastructure is functioning correctly, and to enable detecting performance degradation in experimental IoT network deployments within the context of E-care@home. © 2018, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.
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| 2. |
- Alirezaie, Marjan, 1980-, et al.
(författare)
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An ontology-based context-aware system for smart homes : E-care@home
- 2017
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Ingår i: Sensors. - Basel : MDPI AG. - 1424-8220. ; 17:7
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Tidskriftsartikel (refereegranskat)abstract
- Smart home environments have a significant potential to provide for long-term monitoring of users with special needs in order to promote the possibility to age at home. Such environments are typically equipped with a number of heterogeneous sensors that monitor both health and environmental parameters. This paper presents a framework called E-care@home, consisting of an IoT infrastructure, which provides information with an unambiguous, shared meaning across IoT devices, end-users, relatives, health and care professionals and organizations. We focus on integrating measurements gathered from heterogeneous sources by using ontologies in order to enable semantic interpretation of events and context awareness. Activities are deduced using an incremental answer set solver for stream reasoning. The paper demonstrates the proposed framework using an instantiation of a smart environment that is able to perform context recognition based on the activities and the events occurring in the home.
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| 5. |
- Boano, Carlo Alberto, et al.
(författare)
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Making Sensornet MAC Protocols Robust Against Interference
- 2010. - 10
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Konferensbidrag (refereegranskat)abstract
- Radio interference may lead to packet losses, thus negatively affecting the performance of sensornet applications. In this paper, we experimentally assess the impact of external interference on state-of-the-art sensornet MAC protocols. Our experiments illustrate that specific features of existing protocols, e.g., hand-shaking schemes preceding the actual data transmission, play a critical role in this setting. We leverage these results by identifying mechanisms to improve the robustness of existing MAC protocols under interference. These mechanisms include the use of multiple hand-shaking attempts coupled with packet trains and suitable congestion backoff schemes to better tolerate interference. We embed these mechanisms within an existing X-MAC implementation and show that they considerably improve the packet delivery rate while keeping the power consumption at a moderate level.
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| 7. |
- Boano, Carlo Alberto, et al.
(författare)
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Mitigating the Adverse Effects of Temperature on Low-Power Wireless Protocols
- 2014. - 7
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Konferensbidrag (refereegranskat)abstract
- Research and industrial installations have shown that the on-board temperature of wireless sensor nodes deployed outdoors can experience high fluctuations over time with a large variability across the network. These variations can have a strong impact on the efficiency of low-power radios and can significantly affect the operation of communication protocols, often compromising network connectivity. In this paper, we show the adverse effects of temperature on communication protocols and propose techniques to increase their resilience. First, we experimentally show that fluctuations of the on-board temperature of sensor nodes reduce the efficiency of data link layer protocols, leading to a substantial decrease in packet reception rate and to a considerable increase in energy consumption. Second, we investigate the reasons for such performance degradation, and show that high on-board temperatures reduce the effectiveness of clear channel assessment, compromising the ability of a node to avoid collisions and to successfully wake-up from low-power mode. After modelling the behaviour of radio transceivers as a function of temperature, we propose two mechanisms to dynamically adapt the clear channel assessment threshold to temperature changes, thus making data link layer protocols temperature-aware. An extensive experimental evaluation shows that our approaches considerably increase the performance of a network in the presence of temperature variations commonly found in real-world outdoor deployments, with up to 42% lower radio duty-cycle and 87% higher packet reception rate.
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| 10. |
- Brown, James, et al.
(författare)
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Demo Abstract: How Temperature Affects IoT Communication
- 2014. - 9
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Konferensbidrag (refereegranskat)abstract
- In the future we will rely on applications built on top of the Internet of Things (IoT). Example applications are smart cities, smart grids and smart healthcare. These IoT applications require a reliable service with predictable quality, and that sensor data and actuator commands are delivered reliably and timely. Unfortunately, IoT performance is highly affected by environmental conditions, especially by ambient temperature. It is therefore necessary to configure an IoT system such that sufficient application performance is provided under all environmental conditions that may be encountered. In this demonstration, we show how ambient temperature affects the performance of an IoT application. Specifically, we connect remotely to a large-scale temperature-controlled testbed and show how temperature affects the operation of a state-of-the- art routing protocol. Using a local setup, we further demonstrate how the impact of temperature on communication links can be easily captured and modelled in order to inform the design of communication protocols robust to high temperature fluctuations.
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