Lorenz Cuno Klopfenstein

Implementing Energetically Sustainable Routing Algorithms for Autonomous WSNs

Energy harvesting technologies make it possible to exploit environmental power to realize autonomous wireless sensor networks with unlimited lifetime. However, the actual autonomy of a wireless network depends on the energetic sustainability of its workload that depends, on its turn, on the algorithms adopted to route packets from the sensor nodes to the sink. A theoretical framework for assessing and optimizing the energetic sustainability of routing algorithms has been recently proposed. In this paper we discuss the actual applicability of optimal energetically sustainable routing algorithms and the issues raised by non-stationary environmental conditions. Furthermore, we present a distributed algorithm, running on sensor nodes, that is able to re-compute optimal routing tables on the field in order to adapt to the actual distribution of environmental power.

Geospatial data aggregation and reduction in vehicular sensing applications: The case of road surface monitoring

Mobile devices present several features which make them attractive as enabling technology for crowdsensing systems. In particular, their spectrum of sensing capabilities, together with consolidated diffusion and ease of use contribute to an increasing adoption in different mobility-based sensing scenarios. On the other hand, the availability of massive volumes of geospatial data provided by large-scale distributed sensing systems prompts the need for innovative approaches to efficient data gathering and processing. Data reduction strategies are often necessary in order to cope with challenges posed by these volumes, for instance when dealing with real-time visualization of query results. In this paper we present a data reduction and aggregation approach for mitigating the impact of data size in a vehicular sensing application aimed at monitoring the roughness of road surfaces. Data collected by smartphones on board of vehicles is progressively thinned at different levels of the proposed architecture through sampling and spatial/temporal aggregation. Preliminary results show that the proposed methodology provides substantial benefits in terms of reduced impact of data while, at the same time, it enables full exploitation of statistical error compensation.

Multicast TV Channels over Wireless Neutral Access Networks

IP Television (IPTV) is commonly considered to be the killer application for next-generation networks (NGNs). There is, however, a chicken and egg situation between the deployment of broadband access networks and the diffusion of high quality multimedia services, such as high definition television, which actually impairs the development of NGNs. As a matter of fact, most existing access infrastructures are still under-provisioned and they provide no suitable support to the widespread diffusion of global Internet TV channels, while wireless access networks are sprouting worldwide to provide nomadic connectivity and to bridge digital divide in sparsely populated regions. In this scenario, IPTV services are delivered only within the walled gardens of biggest wireline operators and they are far away from reaching the critical mass required to attract investments in NGNs. This paper proposes technological and architectural solutions which enable the widespread diffusion of Internet TV channels over existing wireless access networks, thus overcoming the deadlock between services and infrastructures and paving the way to NGNs. In particular, the paper addresses both technological and market issues and presents the results of a real-world experiment conducted within the wireless campus of the University of Urbino.

Demo: Mobile Crowdsensing of Road Surface Roughness

The roughness of the road surface affects driving safety and comfort. Having complete and up to date information on the state of the road network is essential for maintenance planning, but it entails time consuming and costly monitoring activities. As a matter of fact, maintenance interventions are mainly based on the results of case by case inspections prompted by drivers’ reports. Moreover, qualitative observations are seldom supported by objective measures, making it difficult for administrators to collect data providing a clear perception of the actual priorities. Recent studies have shown that it is possible to exploit the triaxial accelerometers with which smartphones are equipped to obtain a sound indicator of road surface roughness [1, 2]. A crowdsensing system, called SmartRoadSense [3], has been developed to allow any driver to contribute with his/her smartphone in monitoring the status of the roads he/she travels by car. As shown in Fig. 1, Smartroadsense is composed of: a mobile application, a cloud-based backend, and a web portal. The application runs in background on any car-mounted Android smartphone, reads the accelerometer data at a fre-

Gamification for crowdsourced data collection in mobile usability field studies

Larger smartphones have become increasingly commonplace, sometimes blurring the boundaries between phones and tablets. Most UI guidelines and usability studies are rarely updated and are still based on smaller screens or one-handed operations, which can be tiresome on large devices that may require different, or even two-handed postures. Past usability studies have successfully proposed crowd-sourced data collection systems, using mobile applications published on app stores. This work aims to investigate how similar systems can benefit from gamification elements in order to accelerate data collection and to produce accurate results over relatively short periods. An Android game is presented, which challenges users in short 30-second games, collecting performance of users operating the touchscreen using different device grips and postures. The preliminary analysis of the first 60.000 touch interactions is discussed and shown to be coherent with expected results.

Code Hunting Games: A Mixed Reality Multiplayer Treasure Hunt Through a Conversational Interface

In this paper, we describe an online multi-player game that challenges players with abstract coding puzzles that are tied to a geographical location. The proposed system transposes the classical scheme of “treasure hunt” games into a mixed-reality game, where players must physically move in order to advance in the game, while at the same time interacting with a chatbot through an online messaging system. The implementation of the online game is described in detail and an overview of different deployments of the system is given, including a large-scale deployment during the European CodeWeek 2017. We discuss details of the proposed system, including lessons learned during the development and operation of the game. We also argue that mobile games like the one proposed can be successfully adopted for many different purposes, from entertainment to education.

Extensible Immersive Virtual Environments for Large Tiled Video Walls

The intent of the work is to present an Immersive Virtual Environment (IVE) as a new abstracted management layer on top of the Scalable Adaptive Graphics Environment (SAGE) system, allowing the simplified management and linear scaling of multiple SAGE-driven video walls, and the creation and control of simple interactive scenarios. The framework exposes evolved Application Programming Interfaces (APIs) that are detached from the underlying system and can be used by mobile clients as well. Primitives offered to developers and content creators allow the definition of immersive cinematographic experiences using basic commands, which are synchronized on the whole IVE environment. A complete implementation of the system is described and then evaluated with the specific case of one physical installation.

Designing a Trust-Based Virtual Currency System for User-Centric Networks: The ULOOP Case

The functioning of mobile networks, and especially mobile ad-hoc networks (MANETs), is based on the assumption that a subset of the nodes that compose the network are able and willing to cooperate, for instance forwarding packets on the behalf of others. In particular, in user-centric networks based on local-loop forwarding, where resources might be constrained, there is no direct gain in altruistic behavior. Incentives are needed to overcome the selfishness of every participant of the network. The ULOOP project envisions a user-centric network system where nodes are persuaded into cooperation by the presence of both trust-based and monetary incentives. The transfer of monetary units in exchange for resources requires a credit interchange protocol between nodes that satisfies the particular criteria of an ULOOP network. Such a protocol is presented in the following paper and is then discussed and evaluated on its particular properties and constraints.