Investigation of the influence of surfaces between basic stations and satisfactory recognition on the accuracy of coordinating definitions

Author(s):  
Natalia Neizvestna ◽  
◽  
Anna Khomiak ◽  
Sibilla Omelchuk ◽  
Marya Malko ◽  
...  

The distance between different base stations and the mobile receiver, as well as errors of coordinate definitions at different distances between the base station and the mobile receiver are investigated. For realization of the set tasks the following methods of research were applied: field measurements, mathematical modeling method and methods of mathematical statistics for the processing of experimental data. The degree of influence of distances between the base station and the satellite receiver on accuracy of coordinate definitions in RTK-mode is established.

2020 ◽  
Vol 192 (1) ◽  
pp. 1-13
Author(s):  
Sajedeh Keshmiri ◽  
Neda Gholampour ◽  
Vahid Mohtashami

Abstract This paper presents a series of electromagnetic field measurements performed on the campus of Ferdowsi University of Mashhad in order to assess the compliance of radiation levels of cellular base stations and WiFi access points with international guidelines. A calibrated, broadband and isotropic probe is used and recommendations of International Telecommunication Union (ITU) are followed up throughout measurements. More than 300 outdoor and indoor locations have been systematically chosen for measurements. The recorded data are post-processed and compared with the guideline of International Commission on Non-Ionizing Radiation Protection (ICNIRP). Measured power densities of WiFi access points are low and do not exceed 1% of the level allowed by ICNIRP. For cellular base stations, measured power density is usually low outdoors, but reaches up to 16% of the allowed radiation level in publicly accessible indoor locations. Comprehensive exposure assessment, as recommended by ITU, has been performed to estimate the maximum possible radiation of one indoor base station. It is concluded that precautionary actions have to be taken by university authorities to limit the presence of students in close proximity to specific indoor antennas. Moreover, comprehensive exposure assessment is more likely necessary for indoor base stations whereas such assessment is not usually required outdoors.


Author(s):  
Natalya Ivanovna Shaposhnikova ◽  
Alexander Aleksandrovich Sorokin

The article consideres the problems of determining the need to modernize the base stations of the cellular network based on the mathematical apparatus of the theory of fuzzy sets. To improve the quality of telecommunications services the operators should send significant funding for upgrading the equipment of base stations. Modernization can improve and extend the functions of base stations to provide cellular communication, increase the reliability of the base station in operation and the functionality of its individual elements, and reduce the cost of maintenance and repair when working on a cellular network. The complexity in collecting information about the equipment condition is determined by a large number of factors that affect its operation, as well as the imperfection of obtaining and processing the information received. For a comprehensive assessment of the need for modernization, it is necessary to take into account a number of indicators. In the structure of indicators of the need for modernization, there were introduced the parameters reflecting both the degree of aging and obsolescence(the technical gap and the backlog in connection with the emergence of new technologies and standards). In the process of a problem solving, the basic stages of decision-making on modernization have been allocated. Decision-making on the need for modernization is based not only on measuring information that takes into account the decision-makers, but also on linguistic and verbal information. Therefore, to determine the need for upgrading the base stations, the theory of fuzzy sets is used, with the help of which experts can be attracted to this issue. They will be able to formulate additional fuzzy judgments that help to take into account not only measuring characteristics, but also poorly formalized fuzzy information. To do this, the main indicators of the modernization need have been defined, and fuzzy estimates of the need for modernization for all indicators and a set of indicators reflecting the need for upgrading the base stations have been formulated.


Author(s):  
V. Lyandres

Introduction:Effective synthesis of а mobile communication network includes joint optimisation of two processes: placement of base stations and frequency assignment. In real environments, the well-known cellular concept fails due to some reasons, such as not homogeneous traffic and non-isotropic wave propagation in the service area.Purpose:Looking for the universal method of finding a network structure close to the optimal.Results:The proposed approach is based on the idea of adaptive vector quantization of the network service area. As a result, it is reduced to a 2D discrete map split into zones with approximately equal number of service requests. In each zone, the algorithm finds such coordinates of its base station that provide the shortest average distance to all subscribers. This method takes into account the shortage of the a priory information about the current traffic, ensures maximum coverage of the service area, and what is not less important, significantly simplifies the process of frequency assignment.


1977 ◽  
Vol 12 (1) ◽  
pp. 51-76
Author(s):  
B. Bobée ◽  
D. Cluis ◽  
A. Tessier

Abstract A water quality sampling programme for James Bay territory established in a previous study has been carried out for the Department of Natural Resources of the Province of Quebec. The network is composed of 5 base-stations, sampled every fortnight to determine the variability with time of the parameters and 16 satellite-stations, sampled five times yearly with a view to determine the spatial variability. The data (major ions and certain nutrients) gathered during the 1974–1975 field survey are subjected to an analysis by a multivariate technique (correspondence analysis) in addition to certain classical statistical methods. The latter have shown that the mean values obtained at satellite stations were representative of the annual mean. In addition, the results permit the determination for a given parameter, of the relationship between stations and, for a given station, the relationship between parameters. In both cases, the formulation of predictive equations was attempted. An overall evaluation of the data by correspondence analysis has permitted: - a more precise definition of the qualitative behaviour of the different sub-basins of the James Bay territory and characterization of their waters;- a proof of the existence of gradual concentration changes in both East-West and North-South directions. Within the original objectives of the network, the results of the study have led to the following recommendations: - to continue synchronised samplings;- to transform a base station with a low information content into a satellite station;- to create a new base station in the eastern part of the territory.


2016 ◽  
Vol 11 (1) ◽  
pp. 53-59
Author(s):  
A.S. Topolnikov

The paper presents results of modeling of periodical regime of oil well for the purpose of monitoring and optimization of its operation. To describe non-stationary flow in the reservoir a planar-radial model of filtration is employed. The flow of multiphase flux in the well elements (casing, tubing, annulus) is described by 1D Navier-Stoks equations. The pump work is modelled by specification of its rate-head curve. To estimate the typical time duration of the processes in the well and in the reservoir a solution of a model problem for cylindrical tube is given. Through the examples a solution of a problem of optimization of periodical regime of oil wells is demonstrated. The comparison with field measurements is presented.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3584
Author(s):  
Milembolo Miantezila Junior ◽  
Bin Guo ◽  
Chenjie Zhang ◽  
Xuemei Bai

Cellular network operators are predicting an increase in space of more than 200 percent to carry the move and tremendous increase of total users in data traffic. The growing of investments in infrastructure such as a large number of small cells, particularly the technologies such as LTE-Advanced and 6G Technology, can assist in mitigating this challenge moderately. In this paper, we suggest a projection study in spectrum sharing of radar multi-input and multi-output, and mobile LTE multi-input multi-output communication systems near m base stations (BS). The radar multi-input multi-output and mobile LTE communication systems split different interference channels. The new approach based on radar projection signal detection has been proposed for free interference disturbance channel with radar multi-input multi-output and mobile LTE multi-input multi-output by using a new proposed interference cancellation algorithm. We chose the channel of interference with the best free channel, and the detected signal of radar was projected to null space. The goal is to remove all interferences from the radar multi-input multi-output and to cancel any disturbance sources from a chosen mobile Communication Base Station. The experimental results showed that the new approach performs very well and can optimize Spectrum Access.


Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 23
Author(s):  
Ioannis Gkiougkis ◽  
Christos Pouliaris ◽  
Fotios-Konstantinos Pliakas ◽  
Ioannis Diamantis ◽  
Andreas Kallioras

In this paper, the development of the conceptual and groundwater flow model for the coastal aquifer system of the alluvial plain of River Nestos (N. Greece), that suffers from seawater intrusion due to over-pumping for irrigation, is analyzed. The study area is a typical semi-arid hydrogeologic environment, composed of a multi-layer granular aquifers that covers the eastern coastal delta system of R. Nestos. This study demonstrates the results of a series of field measurements (such as geophysical surveys, hydrochemical and isotopical measurements, hydro-meteorological data, land use, irrigation schemes) that were conducted during the period 2009 to 2014. The synthesis of the above resulted in the development of the conceptual model for this aquifer system, that formed the basis for the application of the mathematical model for simulating groundwater flow. The mathematical modeling was achieved using the finite difference method after the application of the USGS code MODFLOW-2005.


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