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- LoRa connectivity analysis for urban coverage in real mobile environmentsPublication . Oliveira, Rui; Luís, Miguel; Sargento, SusanaFor the last few years, LoRa technology has been affirming itself as one of the most prominent and widely adopted low power wide area technologies. Very compatible with Internet of Things (IoT) applications and urban environments, this technology is capable of long range communications although with small bandwidths, and consequently, low data rates. Nevertheless, the quality of LoRa communications, like many other wireless technologies, are highly dependent on the transmission's context. In this work, we evaluate the performance of LoRa communications in a mobile sensing scenario, and study its capability to give wireless coverage to a small-size city. Experimental results show that velocity has a consistent and increasing impact on the packet delivery ratio, and that the coverage capability is much more dependent on the terrain distribution and Line-of-Sight (LoS), than on the distance between the mobile node and the gateway.
- Forwarding in energy-constrained wireless information centric networksPublication . Marques, Daniel; Senna, Carlos; Luís, MiguelInformation Centric Networks (ICNs) have been considered one of the most promising candidates to overcome the disadvantages of host-centric architectures when applied to IoT networks, having the potential to address the challenges of a smart city. One of the foundations of a smart city is its sensory capacity, which is obtained through devices associated with the IoT concept. The more sensors spread out, the greater the ability to sense the city. However, such a scale demands high energy requirements and an effective improvement in the energy management is unavoidable. To improve the energy management, we are proposing an efficient forwarding scheme in energy-constrained wireless ICNs. To achieve this goal, we consider the type of devices, their internal energy and the network context, among other parameters. The proposed forwarding strategy extends and adapts concepts of ICNs, by means of packet domain analysis, neighbourhood evaluation and node sleeping and waking strategies. The proposed solution takes advantage of the neighbourhood to be aware of the moments to listen and forward packets in order to consistently address mobility, improving the quality of content delivery. The evaluation is performed by simulation with real datasets of urban mobility, one from the lagoon of “Ria de Aveiro” and the other from a vehicular network in the city of Porto. The results show that the proposed forwarding scheme resulted in significant improvements in network content availability, in the overall energy saving and, consequently, in the network lifetime.
- MobiWise: eco-routing decision support leveraging the internet of thingsPublication . Aguiar, Ana; Fernandes, Paulo; Guerreiro, Andreia P.; Tomás, Ricardo; Agnelo, João; Santos, José Luís; Araújo, Filipe; Coelho, Margarida C.; Fonseca, Carlos M.; D'Orey, Pedro; Luís, Miguel; Sargento, SusanaEco-routing distributes traffic in cities to improve mobility sustainability. The implementation of eco-routing in real-life requires a diverse set of information, including different kinds of sensors. These sensors are often already integrated in city infrastructure, some are technologically outdated, and are often operated by multiple entities. In this work, we provide a use case-oriented system design for an eco-routing service leveraging Internet-of-Things (IoT) technologies. The methodology involves six phases: (1) defining an eco-routing use case for a vehicle fleet; (2) formulating a routing problem as a multi-objective optimisation to divert traffic at a relevant hub facility; (3) identifying data sources and processing required information; (4) proposing a microservice-based architecture leveraging IoT technologies adequate to a multi-stakeholder scenario; (5) applying a microscopic traffic simulator as a digital twin to deal with data sparsity; and (6) visually illustrating eco-routing trade-offs to support decision making. We built a proof-of-concept for a mid-sized European city. Using real data and a calibrated digital twin, we would achieve hourly total emissions reductions up to 2.1%, when applied in a car fleet composed of 5% of eco-routing vehicles. This traffic diversion would allow annual carbon dioxide and nitrogen oxides savings of 400 tons and 1.2 tons, respectively.