The current lack of reference datasets of road traffic mobility for network simulation jeopardizes the reliability and reproducibility of vehicular networking research. We contribute to the ongoing effort to develop dependable and publicly available mobility traces through the following: (1) implementing an original version of the Simulation of Urban Mobility (SUMO) road network conversion tool that allows importing OpenStreetMap (OSM) data in a neat automated fashion; (2) generating an original dataset of road traffic in Bologna, Italy; and (3) providing a novel validation methodology that builds on open data provided by navigation service, which we leverage to assess the quality of the proposed Bologna dataset. These three contributions are expected to benefit the whole research community, since they not only provide a new ready-to-use realistic dataset that can be input to network simulators but ease the generation and validation of further vehicular mobility traces for networking research as well.

Internet-of-Things (IoT) and sensor technologies have enabled the collection of data in a distributed fashion for analysis and evidence-based decision making. However, security concerns regarding the source, confidentiality and integrity of the data arise. The most common method of protecting data transmission in sensor systems is Transport Layer Security (TLS) or its datagram counterpart (DTLS) today, but exist an alternative option based on Distributed Ledger Technology (DLT) that promise strong security, ease of use and potential for large scale integration of heterogeneous sensor systems. A DLT such as the IOTA Tangle offers great potential to improve sensor data exchange. This paper presents L2Sec, a cryptographic protocol which is able to secure data exchanged over the IOTA Tangle. This protocol is suitable for implementation on constrained devices, such as common IoT devices, leading to greater scalability. The first experimental results evidence the effectiveness of the approach and advocate for the integration of an hardware secure element to improve the overall security of the protocol. The L2Sec source code is released as open source repository on GitHub.

Many cooperative applications designed to improve road safety rely on the frequent exchange of awareness messages among vehicles. Therefore, under high vehicle density, the channel medium is expected to get congested. To tackle this situation, the European Telecommunications Standards Institute (ETSI) specified a set of Decentralized Congestion Control (DCC) mechanisms that adapt the transmission parameters based on channel load measures. Due to some concerns about its effectiveness and stability, DCC and its overall philosophy are currently being revised and extended: all in all, DCC deserves additional investigations. For this purpose, in this paper a simulation analysis is presented, aiming at enriching the insight into the DCC behaviour, under a variety of channel load conditions and through the definition of both link- and application-layer performance metrics. Achieved results show that the DCC techniques are not really effective with the currently specified parameters settings; hence some hints are given to improve their performance.

In urban contexts, the increasing density of electronic devices equipped with Global Navigation Satellite System (GNSS) receivers and complementary positioning technologies is attracting research and development efforts devoted to an improvement of the quality of life towards the smart city paradigm. Vehicular and pedestrian positioning and navigation capabilities are among the major drivers for innovation in this process. Ultra-low-cost electronics such as smartphones and Internet of Things (IoT) sensors aim at providing accurate and reliable positioning solutions through a set of promising solutions. Among these, snapshot positioning allows to remotely perform the post-processing of GNSS signals in IoT sensor networks while Wi-Fi™ ranging and cooperative positioning provide auxiliary anchors of opportunity to enhance indoor/outdoor positioning capabilities. This paper presents an innovative platform to perform a centralised testing and assessment of such positioning and navigation technologies along with a set of results obtained in the context of the European project HANSEL, by relying on current network technologies and infrastructures (i.e., Wi-Fi™ and cellular connectivity).