Patrick Lieser

Electricity-Metering in a Connected World: Virtual Sensors for Estimating the Electricity Consumption of IoT Appliances

Due to rising electricity prices, there is an increasing incentive to save energy. Therefore, more and more large organizations intend to reduce their energy consumption. Often, their plans cannot be realized due to missing insights into the causes energy consumption. Centralized energy meters provide no information at which appliances the energy is spent and the installation of thousands of distributed meters is often not feasible from an economic point of view. To simplify the energy metering in large scale, we propose to make Internet of Things (IoT) appliances aware of their own electricity consumption using on software based virtual energy sensors. We demonstrate how to automatically generate those energy models for nearly arbitrary networked devices with a high accuracy. Our purely software based energy metering solution approximates the energy consumption of common office equipment with an error between 2.19% and 10.8%. Using our approach, IoT appliances become aware of their own energy expenditure. This greatly simplifies energy metering on device level granularity, giving appropriate user feedback and developing more energy-efficient appliances. All these benefits are achieved without the need for installing additional hardware sensors.

Adaptive Decision Making Based on Temporal Information Dynamics

To increase road safety and efficiency, connected vehicles rely on the exchange of information. On each vehicle, a decision-making algorithm processes the received information and determines the actions that are to be taken. State-of-the-art decision approaches focus on static information and ignore the temporal dynamics of the environment, which is characterized by high change rates in a vehicular scenario. Hence, they keep outdated information longer than necessary and miss optimization potential. To address this problem, we propose a quality of information (QoI) weight based on a Hidden Markov Model for each information type, e.g., a road congestion state. Using this weight in the decision process allows us to combine detection accuracy of the sensor and the information lifetime in the decision-making, and, consequently, adapt to environmental changes significantly faster. We evaluate our approach for the scenario of traffic jam detection and avoidance, showing that it reduces the costs of false decisions by up to 25% compared to existing approaches.

Conducting a Large-scale Field Test of a Smartphone-based Communication Network for Emergency Response

Smartphone-based communication networks form a basis for services in emergency response scenarios, where communication infrastructure is impaired or overloaded. Still, their design and evaluation are largely based on simulations that rely on generic mobility models and weak assumptions regarding user behavior. For a realistic assessment, scenario-specific models are essential. To this end, we conducted a large-scale field test of a set of emergency services that relied solely on ad hoc communication. Over the course of one day, we gathered data from smartphones distributed to 125 participants in a scripted disaster event. In this paper, we present the scenario, measurement methodology, and a first analysis of the data. Our work provides the first trace combining user interaction, mobility, and additional sensor readings of a large-scale emergency response scenario, facilitating future research.

Ad-Hoc-Kommunikation – Gesellschaftlich wünschenswert, rechtlich ungeregelt

Bei einem Ad-hoc-Kommunikationsnetzwerk auf Peer-to-Peer-Basis ist rechtlich gesehen jede Nutzerin und jeder Nutzer zugleich Anbieter. Dieser hat aber keinerlei Moglichkeit, auf die Technik selbst Einfluss zu nehmen und verfugt auch uber keine vollstandigen Informationen uber das Netzwerk. Sogar die Gesamtzahl der Teilnehmerinnen und Teilnehmer ist der einzelnen Nutzerin oder dem einzelnen Nutzer in der Regel unbekannt. Dadurch ist es ihm unmoglich, seine datenschutzrechtlichen Pflichten zu erfullen. Als Losungsansatz bietet sich hier die Verpflichtung des App-Anbieters an. Hierzu bedarf es spezieller gesetzlicher Regelungen fur diese Kommunikationsnetzwerke, damit diese ihren gesellschaftlich wunschenswerten Effekt auch verwirklichen konnen.