Large scale circulation patterns associated to seasonal dry and wet conditions over the Czech Republic

Ponencia presentada en: VIII Congreso de la Asociación Española de Climatología celebrado en Salamanca entre el 25 y el 28 de septiembre de 2012.[ES]Este trabajo analiza la relación entre las condiciones estaciónales extremadamente secas y húmedas en la República Checa y los patrones de circulación de gran escala. El índice estandarizado de precipitación y evapotranspiración (SPEI) se utiliza para cuantificar las condiciones de humedad. El SPEI fue calculado a partir de los registros mensuales de temperatura media y precipitación total de una densa red de 184 estaciones climatológicas para el período 1961-2010 en la escala temporal de un mes.[EN]This paper analyzes the link between the extremely dry and wet conditions over the Czech Republic and the large scale circulation patterns, at seasonal scale. The Standardized Precipitation Evapotranspiration Index (SPEI) is used to quantify the moisture conditions. The SPEI for one month lag was calculated from monthly records of mean air temperature and precipitation totals using a dense network of 184 climatological stations for the period 1961-2010.The research on drought conditions in the Czech Republic was supported by S grant of MSMT CR and projects 6046070901 and OC10010

Priority questions in multidisciplinary drought research

Addressing timely and relevant questions across a multitude of spatio-temporal scales, state-of-the-art interdisciplinary drought research will likely increase in importance under projected climate change. Given the complexity of the various direct and indirect causes and consequences of a drier world, scientific tasks need to be coordinated efficiently. Drought-related research endeavors ranging from individual projects to global initiatives therefore require prioritization. Here, we present 60 priority questions for optimizing future drought research. This topical catalogue reflects the experience of 65 scholars from 21 countries and almost 20 fields of research in both natural sciences and the humanities. The set of drought-related questions primarily covers drought monitoring, impacts, forecasting, climatology, adaptation, as well as planning and policy. The questions highlight the increasingly important role of remote sensing techniques in drought monitoring, importance of drought forecasting and understanding the relationships between drought parameters and drought impacts, but also challenges of drought adaptation and preparedness policies

On the performance of narrow-band internet of things (NB-IoT) for delay-tolerant services

Narrowband IoT (NB-IoT) stands for a radio access technology standardized by the 3GPP organization in Release 13 to enable a large set of use-cases for massive Machine-type Communications (mMTCs). Compared to legacy human-oriented 4G (LTE) communication systems, NB-IoT has game-changing features in terms of extended coverage, enhanced power saving modes, and a reduced set of available functionality. At the end of the day, these features allow for connectivity of devices in challenging positions, enabling long battery life and reducing device complexity. This article addresses the development of the universal testing device for delay-tolerant services allowing for in-depth verification of NB-IoT communication parameters. The presented outputs build upon our long-term cooperation with the Vodafone Czech Republic a.s. company.acceptedVersionPeer reviewe

Pitfalls of LPWA Power Consumption: Hands-On Design of Current Probe

The unique opportunities introduced by the emerging Industrial Internet of Things (IIoT) applications have accelerated the momentum of the massive Machine-Type Communications (mMTC) worldwide. As the number of already deployed Low-Power Wide-Area (LPWA) applications growth exponentially over the last decade, new open challenges started to be discussed across the industry sector. The most critical parameter of the LWPA devices in question is energy efficiency and the overall power consumption of designed end-devices. Therefore, the need for precise measurement of power consumption has attracted engineers’ attention as the unique communication parameters of the LPWA devices form the current consumption measurements challenging task. To facilitate accurate current measurements ranging between hundreds of nA and hundreds of µA, we propose a unique design of the current probe prototype. We then demonstrate the obtained results concerning the accuracy, measurement range switching, and sufficient sampling speed. All the measurements from the designed prototype are further compared with the industry-grade DC power analyzer Agilent N6705B.acceptedVersionPeer reviewe

A perspective on wireless M-bus for smart electricity grids

The Internet of Things (IoT) enables long-range outdoor networks, such as smart grid and municipal lighting, as well as short-range indoor systems for smart homes, residential security, and energy management. Wireless connectivity and standardized communication protocols become an essential technology baseline for these diverse IoT applications. The focus of this work is wireless connectivity for smart metering systems. One of the recent protocols in this field is Wireless M-BUS, which is being widely utilized for remote metering applications across Europe. Therefore, in this paper, we detail a novel multi-platform framework designed to serve as a data generator for the protocol in question. The developed software allows to construct Wireless M-Bus telegrams with a high level of detail according to the EN 13757-4 specification and then schedule them for periodic transmission. The evaluation of the data generator is done in real scenario by using previously developed prototype equipped with IQRF TR72DA communication module acting as a smart meter with implemented software framework. As a result, the evaluation of communication distance between the developed Wireless MBus prototype and commercial gateway was tested in case of indoor scenario at Brno University of Technology, Faculty of Electrical Engineering and Communication.acceptedVersionPeer reviewe

Unifying multi-radio communication technologies to enable mMTC applications in B5G networks

Abstract Even though the wireless communication technologies have evolved significantly in the last decade, the performance requirements of versatile massive Machine-Type Communication (mMTC) use-cases grow at even faster pace. For this reason, the challenge of providing energy-efficient, reliable, secure, and variable devices with ubiquitous connectivity cannot be addressed by any single Radio Access Technology (RAT) available today. Therefore, the concept of multi-RAT devices in the context of next-generation communication technologies (5G and beyond 5G (B5G)) comes into play. In this paper, we investigate the utility of multi-RAT IoT connectivity in practice with respect to a Smart City scenario, in which the location of public transport vehicles e.g., trams and buses is tracked and reported by a device equipped with two Low-Power Wide-Area Network (LPWAN) technologies i.e., Narrowband IoT (3rd Generation Partnership Project (3GPP)) and LoRaWAN (non-3GPP). Both technologies got matured and have shown their momentum in the recent years, and are expected to play the key role also in the future. We first detail the constructed multi-RAT prototype and then report the initial results of its evaluation in a pilot deployment in the city of Brno, Czech Republic. The obtained results illustratively confirm the feasibility of joint usage of two diverse LPWAN RATs while their combination brings higher flexibility, reliability, and improve the overall Quality of Service (QoS) to wireless connectivity

Climate-induced decline in the quality and quantity of European hops calls for immediate adaptation measures

Acknowledgements: This work was supported by the project SustES—Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797) to M.T., the Technology Agency of the Czech Republic (No. SS02030040, SS02030018) to M.M.Funder: Ministry of Education, Youth and Sports of the Czech Republic - project SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions Technology Agency of the Czech Republic - No. SS02030040, SS02030018.A recent rise in the global brewery sector has increased the demand for high-quality, late summer hops. The effects of ongoing and predicted climate change on the yield and aroma of hops, however, remain largely unknown. Here, we combine meteorological measurements and model projections to assess the climate sensitivity of the yield, alpha content and cone development of European hops between 1970 and 2050 CE, when temperature increases by 1.4 °C and precipitation decreases by 24 mm. Accounting for almost 90% of all hop-growing regions, our results from Germany, the Czech Republic and Slovenia show that hop ripening started approximately 20 days earlier, production declined by almost 0.2 t/ha/year, and the alpha content decreased by circa 0.6% when comparing data before and after 1994 CE. A predicted decline in hop yield and alpha content of 4–18% and 20–31% by 2050 CE, respectively, calls for immediate adaptation measures to stabilize an ever-growing global sector

On the performance of multi-gateway LoRaWAN deployments:an experimental study

Abstract A remarkable progress in the Low Power Wide Area Network (LPWAN) technologies over the recent years opens new opportunities for developing versatile massive Internet of Things (IoT) applications. In this paper, we focus on one of the most popular LPWAN technologies operating in the license-exempt frequency bands, named LoRaWAN. The key contribution of this study is our unique set of results obtained during an extensive measurement campaign conducted in the city of Brno, Czech Republic. During a three-months-period, the connectivity of a public Long Range Wide Area Network (LoRaWAN) with more than 20 gateways (GWs) was assessed at 231 test locations. This paper presents an analysis of the obtained results, aimed at capturing the effects related to the spatial diversity of the GW locations and the real-life multi-GW network operation with all its practical features. One of our findings is the fact that only for 47% tested locations the GW featuring the minimum geographical distance demonstrated the highest received signal strength and signal-to-noise ratio (SNR). Also, our results captured and characterized the variations in the received signal strength indicator (RSSI) and SNR as a function of the communication distance in an urban environment, and illustrated the distribution of the spreading factors (SFs) as a result of the adaptive data rate (ADR) algorithm operation in a real-life multi-GW deployment

Communication performance of a real-life wide-area low-power network based on Sigfox technology

Abstract In this paper, we study real-world performance of Sigfox, which is one of the most mature Low-Power Wide-Area Network (LPWAN) technologies that operate in unlicensed frequency bands. During an extensive measurement campaign conducted over three months in the city of Brno, Czech Republic, we assessed the communication performance and the radio channel properties in 311 different test locations. We observed that despite the challenging natural landscape and urban environment of the test area, more than 94% of the packets sent were received successfully, with at least one packet delivered from 297 out of 311 tested locations. Our results also reported experiment-based radio channel and signal-to-noise characterization as well as provided insights into the efficiency of two crucial mechanisms used by Sigfox to improve the packet delivery — packet repetition and multi-gateway reception. Finally, we employed our experimental data to understand the efficiency of two non-fingerprint localization methods based on received signal strength indicator in a practical Sigfox network