Setting Long Distance WiFi Records: Proofing Solutions for Rural Connectivity

802.11 WiFi technology is commonly used for creating wireless networks with a range of about one hundred meters. With careful planning and proper antennas, this same equipment can be used to make point-to-multipoint links of tens of kilometers and point-to-point links of hundreds of kilometers. This paper presents some experiments at distances of up to 382 kilometer  that were performed in Venezuela from April 206 to July 2007, as well as an affordable instrument setup for long distance antenna alignment.La tecnología conocida como WiFi, basada en el estándar 802.11 se usa comúnmente para crear redes inalámbricas con alcance de un centenar de metros. Haciéndole las modificaciones apropiadas y utilizando antenas adecuadas los mismos dispositivos pueden utilizarse  para establecer redes punto-multipunto de decenas de kilómetros y enlaces punto a punto de centenares de kilómetros.  Este artículo presenta algunos experimentos a distancias de hasta 382 kilómetros realizados en Venezuela entre abril del 2006 y julio de 2007, así como una técnica de alineación de antenas para larga distancia utilizando instrumentos de bajo costo

TV White Spaces: A Pragmatic Approach

190 pages The editors and publisher have taken due care in preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information contained herein. Links to websites imply neither responsibility for, nor approval of, the information contained in those other web sites on the part of ICTP. No intellectual property rights are transferred to ICTP via this book, and the authors/readers will be free to use the given material for educational purposes.  e ICTP will not transfer rights to other organizations, nor will it be used for any commercial purposes. ICTP is not to endorse or sponsor any particular commercial product, service or activity mentioned in this book. This book is released under the Attribution-NonCommercial-NoDerivatives ¦.þ International license. For more details regarding your rights to use and redistribute this work, see http://creativecommons.org/licenses/by-nc-nd/4.0/

Energy-efficient Internet of Things monitoring with low-capacity devices

The Internet of Things (IoT) allows users to gather data from the physical environment. While sensors in public spaces are already widely used, users are reluctant to deploy sensors for shared data at their homes. The deployment of IoT nodes at the users premises presents privacy issues regarding who can access to their data once it is sent to the Cloud which the users cannot control. In this paper we present an energy-efficient and low cost solution for environmental monitoring at the users home. Our system is built completely with open source components and is easy to reproduce. We leverage the infrastructure and trust of a community network to store and control the access to the monitored data. We tested our solution during several months on different low-capacity single board computers (SBC) and it showed to be stable. Our results suggest that this solution could become a permanently running service in SBCs at the users homes.Peer ReviewedPostprint (author's final draft

On the design of a sustainable ocean drifter for developing countries

More than fifty low and medium income countries rely on the sea for their economies. Despite its importance, there is a lack of oceanographic scientific data from these countries due to the high cost of equipment and to the running costs of measurement campaigns. In this paper we present a low-cost drifter based on a LoRa communication platform and tested in a coastal area (Gulf of Trieste). The system, built using low-cost off-the-shelf components, has at least the same performances of drifters that costs about three times as much and its operation does not require any recurring costs. The use of a LoRa allows several drifters to operate simultaneously in the same area, providing a rich and homogeneous database for the statistical post processing. The high transmission rate allows an almost instantaneous position determination, facilitating the drifter recovery for successive reuse, which essential in developing countries

Alternative Network Deployments: Taxonomy, Characterization, Technologies, and Architectures

This document presents a taxonomy of a set of "Alternative Network Deployments" that emerged in the last decade with the aim of bringing Internet connectivity to people or providing a local communication infrastructure to serve various complementary needs and objectives. They employ architectures and topologies different from those of mainstream networks and rely on alternative governance and business models. The document also surveys the technologies deployed in these networks, and their differing architectural characteristics, including a set of definitions and shared properties. The classification considers models such as Community Networks, Wireless Internet Service Providers (WISPs), networks owned by individuals but leased out to network operators who use them as a low-cost medium to reach the underserved population, networks that provide connectivity by sharing wireless resources of the users, and rural utility cooperatives

On the Relevance of Using Affordable Tools for White Spaces Identification

It is widely recognized that white spaces identification is an important milestone for the wide deployment of next generation cognitive wireless networks. However, spectrum holes detection tools used for white spaces discovery are still either in the infancy stage or too expensive to enable massive white spaces exploitation. Building upon cheap hardware equipment, this paper presents experiments conducted in the town of Trieste in Italy to sense the environment and find out which frequencies are not being used in a particular place and time-of-the-day. As a first step towards white spaces exploitation, we believe that our experimental frequency exploration is an important milestone upon which white spaces patterns recognition will be built with the aim of using these patterns in wireless network planning and management

An Augmented Virtuality Based Solar Energy Power Calculator in Electrical Engineering

It is becoming increasingly important to include information about power generation from renewable energy sources in the training of electrical engineers. Solar energy is arguably the most common renewable energy source in use today. Providing practical hands-on training on solar energy power generation today requires the use of photovoltaic panel devices which are used for transforming solar energy into electrical energy. In many developing countries, practical hands-on training on solar power generation is limited due to the cost of photovoltaic panel devices and so the training consists of theoretical and tutorial classes sometimes supported by remote and virtual laboratories. This paper presents an augmented virtuality tool where real-time information from a mobile device's sensors is used directly within a virtual or computer generated environment. The tool provides a practical context for hands-on tutorial exercises on solar energy power generation

A Low-Cost and Low-Power Messaging System Based on the LoRa Wireless Technology

[EN] In this paper we describe a low-cost and low-power consumption messaging system based on LoRa technology. More that one billion people worldwide cannot access even the most basic connectivity services. For them even simple messaging services would be of great help, for example to farmers wishing to know the price of goods they want to sell or buy before deciding whether a possibly long, expensive and exhausting trip is undertaken. LoRa networks allow for very long wireless links that can connect villages and towns. This system falls in the category of community networks, where users build their own network where no commercial infrastructure is available. In addition to the simple messaging application, LoRa can be used to distribute sensor information to communities or to provide disaster alerts or meteorological data.Moreno Cardenas, A.; Nakamura Pinto, MK.; Pietrosemoli, E.; Zennaro, M.; Rainone, M.; Manzoni, P. (2020). A Low-Cost and Low-Power Messaging System Based on the LoRa Wireless Technology. Mobile Networks and Applications (Online). 25(3):961-968. https://doi.org/10.1007/s11036-019-01235-5S96196825