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1
Content available remote Dwupasmowa stacja bazowa oparta na technice SDR przeznaczona do pracy w systemach opomiarowania zużycia
Worek Cezary, Krzak Łukasz, Gajoch Grzegorz, Witkowski Janusz
Przegląd Elektrotechniczny
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2022
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R. 98, nr 1
131--134
PL
W artykule zaprezentowano prototyp dwuzakresowej, wieloprotokołowej stacji bazowej do zastosowań w systemach inteligentnego opomiarowania zużycia mediów. Wykorzystując takie techniki jak: automatyczna adaptacja warstwy fizycznej, wielopasmowość (169 MHz i 868 MHz), technikę SDR oraz autorski, wąskopasmowy protokół transmisji danych, uzyskano poprawienie zasięgu łącza radiowego bez zwiększenia kosztów liczników mediów. Dzięki autonomicznemu systemowi odczytu możliwy jest ciągły monitoring zużycia mediów oraz instalacji do ich przesyłu.
EN
This paper presents a designed prototype of a two-band multi-protocol base station for smart-metering applications. Using such techniques as the automatic physical layer adaptation, multi band design (169 MHz and 868 MHz), SDR technique and custom radio protocol, we have increased radio coverage without increasing cost of smart meters. Thanks to the autonomous readouts, constant monitoring of smart-metering system is allowed.
2
Content available An Optimized Propagation Model based on Measurement Data for Indoor Environments
Morocho-Yaguana M., Ludeňa-González P., Sandoval F., Poma-Vélez B., Erreyes-Dota A.
Journal of Telecommunications and Information Technology
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2018
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nr 2
69--75
EN
Propagation is an essential factor ensuring good coverage of wireless communications systems. Propagation models are used to predict losses in the path between transmitter and receiver nodes. They are usually defined for general conditions. Therefore, their results are not always adapted to the behavior of real signals in a specific environment. The main goal of this work is to propose a new model adjusting the loss coefficients based on empirical data, which can be applied in an indoor university campus environment. The Oneslope, Log-distance and ITU models are described to provide a mathematical base. An extensive measurement campaign is performed based on a strict methodology considering different cases in typical indoor scenarios. New loss parameter values are defined to adjust the mathematical model to the behavior of real signals in the campus environment. The experimental results show that the model proposed offers an attenuation average error of 2.5% with respect to the losses measured. In addition, comparison of the proposed model with existing solutions shows that it decreases the average error significantly for all scenarios under evaluation.
3
Wpływ warunków propagacyjnych na działanie systemu LTE
Ludwig A., Wągrowski M., Sitarz P.
Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
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2016
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nr 6
325--328, CD
PL
W artykule przedstawiono metodologię i wyniki pomiarów wybranych parametrów sygnału radiowego w systemie LTE dla różnych warunków propagacyjnych. Przetestowano wpływ szumu AWGN, zaników wielodrogowych o różnych profilach opóźnień oraz efektu Dopplera.
EN
This article presents the methodology and selected measurement results of the LTE radio signal quality indicators for different propagation conditions. Described tests include the impact of noise (AWGN), multipath fading for distinct delay profiles and the Doppler effect.
4
Content available remote Atmospheric influences on satellite communications
Zubair M., Haider Z., Khan S., Nasir J.
Przegląd Elektrotechniczny
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2011
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R. 87, nr 5
261-264
EN
Among other atmospheric regions, ionosphere, which is ionized region of the atmosphere, is considered to impose serious limitations on satellite communication. At higher frequencies, radio waves pass through the ionosphere and are attenuated due to the free electrons present in ionosphere. This paper discusses atmospheric effects on high frequency radio waves illustrating the attenuation and losses it may come across like attenuation due to atmospheric gases, rain, clouds, beam spreading loss and noise temperature. Data used to summarize the influence of atmospheric phenomena is obtained from ITU-R models and processed using MATLAB.
PL
Spośród różnych warstw atmosfery szczególnie jonosfera wpływa niekorzystnie na komunikację za pośrednictwem satelitów. Przy wyższych częstotliwościach fale radiowe są silnie tłumione w jonosferze. Artykuł przedstawia analizę wpływu czynników atmosferycznych w jonosferze na tłumienie i straty w radiowej komunikacji wysokoczęstotliwościowej.
5
Content available Analysis and simulation of wireless signal propagation applying geostatistical interpolation techniques
Kolyaie S., Yaghooti M., Majidi G.
Archiwum Fotogrametrii, Kartografii i Teledetekcji
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2011
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Vol. 22
261--270
EN
This paper is a part of an ongoing research to examine the capability of geostatistical analysis for mobile networks coverage prediction, simulation and tuning. Mobile network coverage predictions are used to find network coverage gaps and areas with poor serviceability. They are essential data for engineering and management in order to make better decision regarding rollout, planning and optimisation of mobile networks.The objective of this research is to evaluate different interpolation techniques in coverage prediction. In method presented here, raw data collected from drive testing a sample of roads in study area is analysed and various continuous surfaces are created using different interpolation methods. Two general interpolation methods are used in this paper with different variables; first, Inverse Distance Weighting (IDW) with various powers and number of neighbours and second, ordinary kriging with Gaussian, spherical, circular and exponential semivariogram models with different number of neighbours. For the result comparison, we have used check points coming from the same drive test data. Prediction values for check points are extracted from each surface and the differences with actual value are computed.The output of this research helps finding an optimised and accurate model for coverage prediction.
6
Content available Propagation Path Loss Modeling in Container Terminal Environment
Katulski R. J., Stefański J., Sadowski J.
Journal of Telecommunications and Information Technology
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2009
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nr 3
38-42
EN
This paper describes novel method of path loss modeling for radio communication channels in container port area. Multi-variate empirical model is presented, based on multidimensional regression analysis of real path loss measurements from container terminal environment. The measurement instruments used in propagation studies in port area are also described.
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