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LPWAN systems are being deployed in lightly licensed regional bands. For applications with low data rate and low duty cycle, LPWAN extends battery life, reduces cost and offers improved link budgets compared with current cellular formats. Networks often use a star topology around a gateway node. LoRa is a Sub-GHz wireless technology designed for low power, unlicensed, Long Range operations. The communication...
Maintenance strategies based on structural health monitoring are able to provide effective support when it comes to optimizing the scheduled repair of existing structures, enabling their lifetime to be extended. With a particular focus on reinforced concrete (RC) structures, the state of the art seems to still be lacking an efficient and cost-effective technique that is capable of monitoring inner...
Usually energy-detection based spectrum sensing techniques for Cognitive Radios need, as preliminary operation, the spectrum segmentation in smaller sub-bands, in order to apply test statistic over each sub-band rather than over the entire span, resulting in a sensitivity and selectivity improvement of the output. Despite uniform subdivision is the easiest way, the problem resides on the optimal sub-band...
Over the past few years, the scientific community, both in academia and industry, witnessed a continuous and persistent effort in order to close the unexplored portion of the electromagnetic spectrum called THz gap, ranging from 100 GHz to 10 THz. Thanks to its properties, the THz technology finds application in diverse dual-use areas, spanning from chemical to pharmaceutical, biology and environmental...
The paper proposes a distributed architecture to monitor spectrum occupancy status through the use of Software Defined Radios (SDRs). Such a monitoring process is useful in order to fulfill a geolocation database, whose consultation is a mandatory task for license-exempt devices operating under the IEEE 802.22 standard rules. Moreover, the system is thought for a dual use scenarios: it can be enforced...
Drones like helicopters use vertical oriented rotors to lift and navigate forward. Thanks to the use of modern flight controllers, they often can fly autonomously. Namely, the user can mark target points on a map to which the helicopter is driven by the software controller without any other interventions of the user. Once on the target, the helicopter performs the intended task, such as landing, catching...
The paper deals with the problem of designing and implementing a measurement node based on compressive sampling (CS). The considered node is tailored for wide area sensors networks aimed to carry out measurements in frequency domain. To this aim, the node takes advantage from some known or recently proposed CS features in such a way as to outperform the nominal specification of its data acquisition...
Intelligent Transportation Systems (ITS) are fundamental in order to improve safety and road efficiency. In this framework inter-vehicle communications play a primary role. To this aim several vehicle-to-vehicle (V2V) communication standards have been developed. The most important is IEEE 802.11p that operates in ISM band (5.85–5.92) GHz. Unfortunately at these frequencies communication ranges are...
In this paper, a novel measurement data management system, based on cloud technology, is proposed. The system aims at maximizing the potential of the information assets of large electronic manufacturing companies through the collection, management and analysis of the so called Big Data generated by means of test processes, performed during the life-cycle of the products.
The paper deals with the problem of early detecting cracks in composite materials for avionic applications. In particular, the authors present a THz imaging system that exploits compressive sampling (CS) to detect submillimeter cracks with a reduced measurement burden. Traditional methods for THz imaging usually involve raster scan of the issue of interest by means of highly collimated radiations...
The paper deals with the problem of in-service testing of complex systems and apparatuses (in particular, radio frequency ones) for avionic applications. This is a fundamental step when maintenance and/or monitoring of the system or apparatus have to be carried out without stopping its standard operation condition. Traditional approaches usually work by measuring only the signals at the output of...
The growing demand for available frequency bands in contrast to the scarcity of allocated spectrum slots, is promoting the development of smart wireless transmission terminals generally called cognitive radios. These devices are able to select the most suitable operating frequency and modulation scheme in order to minimize the probability of interference with other users operating in the same area...
Generally, the voice quality of a VoIP call can be analyzed through the measurement of suitable metrics at the application layer of the International Organization for Standardization/Open Systems Interconnection (ISO/OSI) protocol stack. However, the peculiarities of such a kind of measurements make very difficult to provide to each user a value representative of the quality of each VoIP call.
Nowadays, radio systems have to use the spectrum resource more intensely than in the past to meet the demanding expectations of the users. Several studies have demonstrated that portions of radio spectrum are not in use for significant periods of time, showing the necessity to design a more flexible way to manage the spectrum resource with respect to the traditional frequency allocation policy.
A new method based on an improved version of the well-known multiple signal classification (MUSIC) algorithm for life signs detection is proposed. With respect to other competitive methods already available in the literature, the proposed method assures higher dynamic range of the estimated spectrum and effective noise/clutter rejection when detecting the respiratory and the cardiac activities from...
Measurement of Internet Protocol Packet Delay Variation (IPDV) is a relevant issue in application involving real time video streaming. Generally, this quantity is compared with predefined thresholds (whose value depends upon the application requirements) to verify the quality of service to the end user. However, the exceeding of this threshold only for short time intervals and with relatively low...
The paper deals with the problem of non intrusive detection of concealed people by means of passive acoustic sensors To this aim, the authors present hereinafter a new method capable of detecting and recognizing vital signs, typical of human beings, thanks to the use of a suitable data acquisition system, based on a geophones network, and a proper digital signal processing algorithm. In particular,...
The paper deals with the implementation of a suitable technological support to improve the success likelihood of Urban Search and Rescue (USAR) missions. In particular, the adoption of an heterogeneous sensors network for situation awareness and security applications is suggested. The sensor network consists of two types of sensor, mandated, respectively, to through-the-wall radar (TTW) imaging and...
Reliable quality of service measurements are crucial issues to monitor and evaluate the performance of computer and communication networks. To these aims, depending on the applications, several figures of merit have to be measured. They mainly concern with: throughput, available bandwidth, packet jitter, one way delay, round trip delay, and packet loss. To estimate these quantities two general classes...
A novel built-in solution for improving the effective number of bits of data acquisition systems (DASs) in presence of band-pass input signals is presented. The proposed solution takes advantage of the processing capabilities of modern DASs. It allows acquiring a seamless data stream with improved resolution, and imposes very little hardware requirements.
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