A LoRa-based protocol for connecting IoT edge computing nodes to provide small-data-based services

Data is becoming increasingly personal. Individuals regularly interact with a variety of structured data, ranging from SQLite databases on the phone to personal sensors and open government data. The “digital traces left by individuals through these interactions” are sometimes referred to as “small data”. Examples of “small data” include driving records, biometric measurements, search histories, weather forecasts and usage alerts. In this paper, we present a flexible protocol called LoRaCTP, which is based on LoRa technology that allows data “chunks” to be transferred over large distances with very low energy expenditure. LoRaCTP provides all the mechanisms necessary to make LoRa transfer reliable by introducing a lightweight connection setup and allowing the ideal sending of an as-long-as necessary data message. We designed this protocol as communication support for small-data edge-based IoT solutions, given its stability, low power usage, and the possibility to cover long distances. We evaluated our protocol using various data content sizes and communication distances to demonstrate its performance and reliability.     

New Routes and Airport Connectivity

This paper shows how module identification techniques can help airports evaluate the impact of new routes on their network connectivity. Although only carriers can choose whether to open a new route, this research is also of interest to airports and regional governments, who can offer incentives for new connections to desirable destinations. The analysis employs simulated annealing to verify the existence of highly interconnected subsystems, or modules, within the European aviation network. A module is a group of airports with very strong internal links in terms of exchanged seats, but weak connections to the rest of the network. From the standpoint of improving connectivity, we expect that new routes towards large airports belonging to other modules are the most desirable. We also find that the lower the interchange between the modules to be connected, the higher the connectivity gain. We test this hypothesis on all 467 European airports with at least one scheduled flight in autumn 2007.     

Energy-accuracy trade-offs for hybrid localization using RSS and inertial measurements in wireless sensor networks

This paper presents a framework for optimizing the trade-off between energy consumption and localization accuracy in hybrid localization systems combining Received Signal Strength (RSS) measurements with inertial ones. The proposed framework aims at finding the optimal operation point that minimizes the radio energy consumption for a desired target accuracy, or equivalently, the one that maximizes the localization accuracy for a given energy budget. To this end, the proposed approach considers the joint optimization of the localization frequency and number of RSS measurements used at each localization round and leverages practical models to predict the energy consumption and the localization accuracy for combined RSS-inertial localization systems. Simulations and real-field experiments are used to demonstrate that, for a given target accuracy, the proposed strategy entails a lower energy consumption than state-of-the-art methods available in the literature.     

An integrated system based on wireless sensor networks for patient monitoring,localization and tracking

This works describes the system LAURA which provides patient localization, tracking and monitoring services within nursing institutes through a wireless sensor network. The system is composed of three functional blocks: a localization and tracking engine which performs localization out of samples of the received signal strength and tracking through a particle filter; a personal monitoring module based on bi-axial accelerometers which classifies the movements of the patients eventually detecting hazardous situations, and a wireless communication infrastructure to deliver the information remotely. The paper comments on the design and dimensioning of the building blocks. Two approaches are proposed to the implementation of the localization and tracking engine: a centralized implementation where localization is executed centrally out of information collected locally, and a distributed solution where the localization is performed at the mobile nodes and the outcome is delivered to the central controller. Strengths and weaknesses of the two solutions are highlighted from a system’s perspective in terms of localization accuracy, energy efficiency and traffic loads. LAURA modules are finally tested in a real environment using commercial hardware. The main outcomes are an average localization error lower than 2 m in 80% of the cases and a movements classification accuracy as high as 90%.     

Integrators’ Air Transport Networks in Europe

Integrators are shipping carriers that control complete air and road delivery networks and offer a wide range of package delivery services. Despite the increasing relevance of small package delivery services in the European air transport market, very little has been written on integrated carriers’ air transport networks on the Old Continent. In this paper we examine the network configurations of DHL, FedEx, TNT, and UPS in terms of hubs, spokes, and market shares. Our results show that integrators operate hub-and-spoke networks. Network indices and centrality measures confirm that their network structures are more similar to those of full-service passenger carriers rather than those of low-cost carriers. However, the nature of their hub-and-spoke systems is different because freight tons, as compared to passengers, are more easily flown along multiple-stop and circular routes. As a consequence, FedEx, TNT, and UPS operate non-pure star networks with a dominant central hub and a set of intermediate airports acting as stops between the central hub and (usually) one “external airport”. DHL operates a multi-hub architecture, with a main dominant hub in Leipzig and a set of “secondary hubs” that provide several connections to other network nodes. Furthermore, we provide evidence of the most important intra-Europe and long-haul routes for each integrator, showing that DHL seems to have a more developed Europe-Asia connection, and is the only integrator to connect Europe to Sub-Saharan Africa. Finally, we show the high degree of complementarity existing between FedEx and TNT networks and that such complementarity is confirmed also by an analysis of their market shares in the different European sub-markets. Despite the significant level of market concentration, our analysis shows that the recent merger between FedEx and TNT is not expected to significantly modify market equilibrium in Europe.