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ABSTRACT: This work illustrates the methodological approach followed in the Province of Orellana, Eastern Ecuador, for the realization of a telecommunication network infrastructure between the capital of the Province, the city of Puerto Francisco de Orellana (also known as El Coca), and some peripheral communities located in the surrounding of the tropical moist forest. The project has been implemented in one of the poorest countries of Latin America, in a remote and disadvantaged area where the lack of communication infrastructures and the absence of almost all public services generates a strong migration towards the capital. In this context, in 2008, it was conceived a project for the development of a communication system that allows the provisioning of basic intranet services for distance learning, telemedicine and internet connectivity. The main scope of the project was the development of an approach focused on the technological transfer to the local population, to start a reduction process of the digital gap in the area. The aim of the project has been achieved thanks to the direct enrolment of local municipalities, small entrepreneurs, communities and local NGO. The technological transfer to local players and the choice of a suitable platform, designed for a simplified, low cost management, guarantee the sustainability and scalability of the project. The declaration of interest in the infrastructure by the Municipality enables the economic sustainability of the project.
Kaleidoscope: Beyond the Internet? - Innovations for Future Networks and Services, 2010 ITU-T; 01/2011
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ABSTRACT: In the last decades the most advantageous opportunity to improve data rate and transport capacity over wireless connections has been made available by a progressive upper-shift of the frequency of the carrier. As a matter of fact, increasing the carrier frequency, channel allocation and modulation bandwidth can be increased. Unfortunately, in parallel, path losses augment, and obstacles, humidity and weather affect more negatively radio-transmissions. To face propagation losses, the number of installations is increased and the service area reduced, allowing the frequency reuse, but generating also an exponential raise of hardware costs. As a consequence, this strategy is unsuitable in developing countries. Inverting the trend, this paper presents a study carried out by means of several simulations, to evaluate coverage opportunities and cost impact by reducing the radiofrequency carrier, without varying any base-band characteristic of the communication platform. To this purpose, as an application example, low cost IP-based wireless cards implementing OFDM modulation were considered, at progressively lower frequencies, from 5.5 GHz down to 180 MHz. The comparison was run in real contexts, and applied to the region of El Carmen, Guayas, in Ecuador and the region, of Antsirabe Rural, Antananarivo, in Madagascar. In the first one, a proper network will be implemented by the end of 2009, in the framework of the ldquoInnovation for Development Programrdquo of the InterAmerican Development Bank.
Innovations for Digital Inclusions, 2009. K-IDI 2009. ITU-T Kaleidoscope:; 10/2009
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ABSTRACT: The paper presents preliminary results obtained during an experimental activity carried out to evaluate the applicability of wireless sensor networks in underground water pipes. For this purpose, a wireless sensor, connected to a dedicated acoustic interface, was waterproofed, to allow its insertion within pipes filled with water. The microwave components were designed to optimize the transmission towards the ground surface, while the form of the radome was chosen to avoid unwanted rotations of the antenna, and consequently link degradations. The introduced technological solution was experimentally validated In a controlled scenario, an ldquoad-hocrdquo wireless sensor network was designed and tested, performing analyses on water pipes of different dimensions at a varying depths in the ground, down to 2.5 meters. Results show excellent performance and reliability.
Microwave Symposium Digest, 2009. MTT '09. IEEE MTT-S International; 07/2009
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ABSTRACT: Wireless sensor networks (WSNs) represent a key point of application and research in the next future. WSNs are applied in many technological areas, including environment and habitat monitoring, healthcare applications, home automation, traffic control, industrial automation, industrial production management, logistics, e.g. the work published by Xu et al. (2004). Many researchers are developing studies to analyze the use of WSNs for an increasing number of applications, looking for optimized solutions in terms of power consumption, available bandwidth, sensor dimensions, computational speed, realization costs (Manges, 1999). Compared to analogous solutions, WSNs are particularly efficient and interesting, if exploited in complex scenarios, where wired sensors cannot be used, or the sensor itself is a moveable one, e.g., the application proposed in the work of Wark et al. (2007). In this framework, a mobile wireless technological solution for leakage monitoring in water pipes, based on the use of acoustic sensors, has been recently introduced (Trinchero et al., 2009).
Antennas and Propagation Society International Symposium, 2009. APSURSI '09. IEEE; 07/2009
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ABSTRACT: The present paper analyses the applicability of the method proposed in D. Trinchero et al. (2009) to exposure assessment issues, and introduces some preliminary results that demonstrate its reliability and usability for base transceiver station (BTS) antennas.
Antennas and Propagation Society International Symposium, 2009. APSURSI '09. IEEE; 07/2009
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ABSTRACT: In this paper the possibility to construct wireless sensor networks buried in the terrain is discussed. Advantages and drawbacks are pointed out, and an analysis of the most efficient method to evaluate the effect of radio-link parameters on radio propagation is provided. As it is unsuitable for fixed monitoring applications, because of the need to power the equipment, this technological solution may become effectively convenient, when the sensor is mobile and its permanence in the ground is time-limited. For all these reasons, the solution becomes attractive, applied to detect breaks and reveal unknown tracks in water distribution networks, monitoring the pressure of the fluid flowing in the pipe and tracking the path of the sensor through the conduits.
Wireless and Microwave Technology Conference, 2009. WAMICON '09. IEEE 10th Annual; 05/2009
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ABSTRACT: The paper presents an hardware solution for the realization of wireless sensors able to flow, without any anchorage, through the pipes used for fluid transportation, located on the terrain, but also under the ground surface. The designed sensors do not need any direct connection to the surface, communicate via wireless channels towards fixed stations positioned out of the ground, and provide a complete analysis of fluid pipes, in terms of survey, path identifications, damage recognition and leakage prevention. The electromagnetic components, particularly the antenna, are chosen in order to optimize the data transmission towards the surface. Antenna design and channel propagation modeling are based on a dedicated full-wave solution of the problem. To validate the introduced technological solution, an ldquoad-hocrdquo wireless sensor network has been designed and tested, thanks to the collaboration of the aqueduct company ldquoAcquedotto del Monferratordquo. In a dedicated test space, analyses were performed on water pipes of different dimensions at varying depths in the ground, up to 2.5 meters. Results show excellent performance and reliability.
Sensors Applications Symposium, 2009. SAS 2009. IEEE; 03/2009
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ABSTRACT: Field probes have been widely used, in the literature, for electromagnetic compatibility measurements and electromagnetic interference estimation. In the last two decades, these instruments have been exploited for open-space electric field exposure assessment, thanks to their ergonomics and capability to adapt to any scenario. This paper analyses the behaviour of field probes, in presence of digital spread-spectrum signals: OFDM (802.11a, 802.11g, 802.16x, DVB-x), W-CDMA (UMTS), DSSS (802.11b). The experiment was set-up in controlled environments, and the results were compared to referenced one, measured by means of bolometers or vector signal analysers. Some structural drawbacks were identified. Consequently, some conclusions about calibration needs were introduced.
Electromagnetic Compatibility, 2009 20th International Zurich Symposium on; 02/2009
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ABSTRACT: The letter focuses on a simplified and conservative method for the assessment of the electromagnetic exposure in proximity of a radiator. The method allows the use of the Fraunhofer antenna pattern to estimate the electromagnetic field radiated in the Fresnel region of base transceiver station (BTS) antennas. The proposed approach is introduced from a theoretical point of view and validated with simulations and measurements on linear and planar array systems. For its application, a specific description of the boundaries of the Fresnel region for a generic antenna of parallelepipedal shape, which takes into account the dependency from the direction of observation, is introduced. The method provides a rapid and simple solution of assessment issues in relation to the electromagnetic fields exposure limits.
IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
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D. Trinchero,
R. Stefanelli,
F. Longobardi,
A. Galardini, B. Fiorelli,
G. d'Amore,
L. Anglesio,
A. Benedetto,
S. Trinchero,
M. Borsero,
G. Vizio
[show abstract]
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ABSTRACT: This letter describes results obtained from an experimental evaluation of field probes used to assess digitally modulated electromagnetic fields. Making use of an experimental setup specifically developed, a large number of devices with different characteristics were analyzed in the presence of three different spread-spectrum schemes: wideband code division multiple access [(W)CDMA], direct sequence spread spectrum (DSSS), and orthogonal frequency division multiplexing (OFDM). The measurement error caused by the modulation was investigated as a function of its main parameters: signal power, time variation, and occupied bandwidth.
IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
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D. Trinchero,
R. Stefanelli,
F. Longobardi,
A. Galardini, B. Fiorelli,
G. d'Amore,
L. Anglesio,
A. Benedetto,
S. Trinchero,
M. Borsero,
G. Vizio
[show abstract]
[hide abstract]
ABSTRACT: Field probes are widely used for radio-frequency electromagnetic-field exposure assessment. Nevertheless, several authors point out measurement uncertainties when the signal under test is digitally modulated. In this letter, the main drawbacks emerging from the use of probes to measure complex modulations are analyzed and discussed. Consequently, an experimental setup is introduced and investigated to verify probes performance and to allow an easy and usable evaluation of the uncertainty.
IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
