scholarly journals Wire antenna theory applied to the assessment of the radiation hazard in the vicinity of the GSM base stations

2003 ◽  
Vol 1 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Vesna Roje

Safety aspects of the GSM base station radiation concerning human health have been analyzed. The numerical modeling of the human body was performed by utilizing the antenna theory and BEM numerical procedure. The simplified model of the body represented by thick cylindrical scatterer placed vertically on the perfect conducting ground was used. Measurements of the radiated fields have been done at a few sites, and the results were incorporated in the numerical calculations as an incident field.

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
DEJAN KRSTI Ć ◽  
DARKO ZIGAR ◽  
MILAN JOVANOVIĆ ◽  
VLADIMIR STANKOVIĆ ◽  
NENAD CVETKOVIĆ ◽  
...  

Service technicians on mobile phone base stations systems are exposed to electromagnetic waves in the near field. In this area, the values of electrical and magnetic field can overload maximal exposure limit defined by standards. The subject in this paper is health risk of a service technician. It is important to calculate electrical field in the body of a service technician who moves in the vicinity of base station in order to estimate their health status. Key words: Near electromagnetic field, service technicians, health risk from electromagnetic field.


2005 ◽  
Vol 04 (2) ◽  
pp. 7-29
Author(s):  
A.A. de SALLES ◽  
C.R. FERNÁNDEZ

There has been a dramatic increase in the use of mobile phone technology in the last decades, with widespread benefits in many professional and private activities. In parallel with this, the concern regarding the possibility of adverse health effects due to the absorption of electromagnetic fields by humans also increased. For several years, many research groups in different countries were developing research projects on these subjects in the areas of medicine, biophysics, engineering, etc. Also, the World Health Organization (WHO) has coordinate efforts including many countries to access the existing scientific evidence of harmful health effects of non ionizing radiation (NIR) emitted from different communication equipment, such as the mobile phones and their base stations, with special emphasis to the non-thermal effects. In principle, the base stations radiate more energy. However, their antennas are usually located on the top of elevated towers (or masts) and the radiated energy is mainly concentrated in the horizontal direction. Therefore people are usually far from these antennas, and also in directions reasonably apart from those of maximum radiation. Because the conventional monopole (or whip) antennas being used now in mobile phones typically show a circular radiation pattern in the horizontal plane, they may radiate substantial levels of energy in almost all directions, very close to the body and during considerable time. It is observed that when they are operated very close to the user’s head (e.g., 2,5 cm or less) , most of energy is absorbed in the head tissues (such as the bone, the brain, eye, etc), and less energy is radiated to the nearest base station. This situation is undesirable since quality of communication is worse, and the Specific Absorption Rate (SAR) in the user’s head and the battery drain are increased.


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.


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.


2013 ◽  
Vol 347-350 ◽  
pp. 975-979
Author(s):  
Rong Zhao ◽  
Cai Hong Li ◽  
Yun Jian Tan ◽  
Jun Shi ◽  
Fu Qiang Mu ◽  
...  

This paper presents a Debris Flow Disaster Faster-than-early Forecast System (DFS) with wireless sensor networks. Debris flows carrying saturated solid materials in water flowing downslope often cause severe damage to the lives and properties in their path. Faster-than-early or faster-than-real-time forecasts are imperative to save lives and reduce damage. This paper presents a novel multi-sensor networks for monitoring debris flows. The main idea is to let these sensors drift with the debris flow, to collect flow information as they move along, and to transmit the collected data to base stations in real time. The Raw data are sent to the cloud processing center from the base station. And the processed data and the video of the debris flow are display on the remote PC. The design of the system address many challenging issues, including cost, deployment efforts, and fast reaction.


2021 ◽  
Vol 2 (5) ◽  
pp. 5-11
Author(s):  
G. A. Tashpulatova ◽  
◽  
A. N. Krasavin

This article is about instrumental measurements of the FR EMR energy flux density. The measurement results were analyzed with the division of the data obtained by the purpose of buildings and the height of the antenna equipment placement, a hygienic assessment of the RF EMR levels created by the equipment of base stations of cellular communications, installed on the roofs of residential and public buildings and adjacent territories of Tashkent is given. A proposal is made on the rational placement of radio engineering facilities.Keywords:electromagnetic field; electromagnetic safety; base station for mobile communications; protection of public health; sanitary supervision


2019 ◽  
Vol 9 (4) ◽  
pp. 43-48
Author(s):  
Rizal Aji Istantowi

4G LTE networks in big cities are already well available. Meanwhile, on small to medium-sized cities, the 4G LTE network is not evenly distributed and maximized. This study chooses the variable tilting antenna to the coverage area, because in sending information from a base station using an antenna. The average RSRP value (dBm) of the existing base station in the calculation with a distance of 200 m is -122.90 dBm, a distance of 500 m is -136.79 dBm, and a distance of 1000 m -147.30 dBm. Meanwhile, in the simulation with a distance of 200 m of -108.22 dBm, a distance of 500 m of -121.81 dBm, and a distance of 1000 m of -132.69 dBm. The coverage area value of the existing base station in the calculation is 5.29%, while in the simulation it is 11.18%. The average RSRP value (dBm) at optimal conditions for calculations at a distance of 200 m is -80.13 dBm, at a distance of 500 m is -94.03 dBm and at a distance of 1000 m is -104.56 dBm. Meanwhile, the simulation at a distance of 200 m is -98.09 dBm, at a distance of 500 m is -112.79 dBm and at a distance of 1000 m is -123.31 dBm. The value of the coverage area for the calculation is 20.32%, while for the simulation it is 15.01%. The current need for base stations in Trenggalek District that has been met is 68%.


Author(s):  
Jiun-Ru Chen ◽  
Wei-En Chen ◽  
CH Liu ◽  
Yin-Tien Wang ◽  
CB Lin ◽  
...  

A procedure for inverse kinetic analysis on two hard fingers grasping a hard sphere is proposed in this study. Contact forces may be found for given linear and angular accelerations of a spherical body. Elastic force-displacement relations predicted by Hertz contact theory are used to remove the indeterminancy produced by rigid body modelling. Two types of inverse kinetic analysis may be dealt with. Firstly, as the fingers impose a given tightening displacement on the body, and carry it to move with known accelerations, corresponding grasping forces may be determined by a numerical procedure. In this procedure one contact force may be chosen as the principal unknown, and all other contact forces are expressed in terms of this force. The numerical procedure is hence very efficient since it deals with a problem with only one unknown. The solution procedure eliminates slipping thus only nonslip solutions, if they exist, are found. Secondly, when the body is moving with known accelerations, if the grasping direction of the two fingers is also known, then the minimum tightening displacement required for non-sliding grasping may be obtained in closed form. In short, the proposed technique deals with a grasping system that has accelerations, and in this study the authors show that indeterminancy may be used to reduce the complexity of the problem.


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