684 research outputs found

    Mobile phones: a trade-off between speech intelligibility and exposure to noise levels and to radio-frequency electromagnetic fields

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    When making phone calls, cellphone and smartphone users are exposed to radio-frequency (RF) electromagnetic fields (EMFs) and sound pressure simultaneously. Speech intelligibility during mobile phone calls is related to the sound pressure level of speech relative to potential background sounds and also to the RF-EMF exposure, since the signal quality is correlated with the RF-EMF strength. Additionally, speech intelligibility, sound pressure level, and exposure to RF-EMFs are dependent on how the call is made (on speaker, held at the ear, or with headsets). The relationship between speech intelligibility, sound exposure, and exposure to RF-EMFs is determined in this study. To this aim, the transmitted RF-EMF power was recorded during phone calls made by 53 subjects in three different, controlled exposure scenarios: calling with the phone at the ear, calling in speaker mode, and calling with a headset. This emitted power is directly proportional to the exposure to RF EMFs and is translated into specific absorption rate using numerical simulations. Simultaneously, sound pressure levels have been recorded and speech intelligibility has been assessed during each phone call. The results show that exposure to RF-EMFs, quantified as the specific absorption in the head, will be reduced when speaker-mode or a headset is used, in comparison to calling next to the ear. Additionally, personal exposure to sound pressure is also found to be highest in the condition where the phone is held next to the ear. On the other hand, speech perception is found to be the best when calling with a phone next to the ear in comparison to the other studied conditions, when background noise is present

    Analysis of Human EMF Exposure in 5G Cellular Systems

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    Increasing concerns of communications at a frequency spectrum higher than 6 GHz have gained international alarm that suggests more research is needed before it is deployed successfully. In this context, in the first part of this thesis, we investigated the human electromagnetic field (EMF) exposure in indoor and outdoor environments from fifth-generation (5G) downlink communications and compared its impacts with the present cellular technologies considering the features that the 5G will likely adopt. The second part focuses on mitigation of human exposure for both indoor and outdoor environments with two different methods adopted. Our simulation results suggest that while the impacts from 5G communications cross the regulatory borders for a very short separation distance between base stations (BSs) and user equipment (UE), the exposure level remains high throughout the network compared to the present systems. This work also highlights the significance of considering SAR for the measurement of exposure compliance in downlinks

    Recent Trend in Electromagnetic Radiation and Compliance Assessments for 5G Communication

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    The deployment of the 5G networks will feature high proliferation of radio base station (RBS) in order to meet the increasing demand for bandwidth and also to provide wider coverage that will support more mobile users and the internet-of-things (IoT). The radio frequency (RF) waves from the large-scale deployment of the RBS and mobile devices will raise concerns on the level of electromagnetic (EM) radiation exposure to the public. Hence, in this paper, we provide an overview of the exposure limits, discuss some of the effects of the EM emission, reduction techniques and compliance assessment for the 5G communication systems. We discuss the open issues and give future directions

    Electromagnetic Assessment of UHF-RFID Devices in Healthcare Environment

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    In this work, the evaluation of electromagnetic effect of Ultra High Frequency Radio Frequency Identification (UHF-RFID) passive tags used in the healthcare environment is presented. In order to evaluate exposure levels caused by EM field (865–868 MHz) of UHF-RFID readers, EM measurements in an anechoic chamber and in a real medical environment (Hospital Universitario de Canarias), as well as simulations by 3D Ray Launching algorithm, and of biophysical exposure effects in human models are presented. The results obtained show that the EM exposure is localized, in close vicinity of RFID reader and inversely proportional to its reading range. The EM exposure levels detected are sufficient to cause EM immunity effects in electronic devices (malfunctions in medical equipment or implants). Moreover, more than negligible direct effects in humans (exceeding relevant SAR values) were found only next to the reader, up to approximately 30% of the reading range. As a consequence, the EM risk could be firstly evaluated based on RFID parameters, but should include an in situ exposure assessment. It requires attention and additional studies, as increased applications of monitoring systems are observed in the healthcare sector—specifically when any system is located close to the workplace that is permanently occupied.This work was supported by Instituto de Salud Carlos III project “Electromagnetic “Characterization in Smart Environments of Healthcare, and their involvement in Personal, Occupational, and Environmental Health” (PI14CIII/00056) https://portalfis.isciii.es/es/Paginas/DetalleProyecto. aspx?idProyecto=PI14CIII%2f00056 (accessed on 24 July 2022), and project “ (PI19CIII/00033) TMPY 508/19 “ Metrics development for electromagnetic safety assessment in healthcare centers in the context of 5G“ https://portalfis.isciii.es/es/Paginas/DetalleProyecto.aspx?idProyecto=PI19 CIII%2f00033, (accessed on 24 July 2022) from Sub-Directorate-General for Research Assessment and Promotion. The results of a research task (II.PB.15) carried out within the National Programme “Improvement of safety and working conditions” partly supported in Poland in 2020-2022-within the scope of research and development-by the National Centre for Research and Development were also included.S

    Electromagnetic assessment of UHF-RFID devices in healthcare environment

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    In this work, the evaluation of electromagnetic effect of Ultra High Frequency Radio Frequency Identification (UHF-RFID) passive tags used in the healthcare environment is presented. In order to evaluate exposure levels caused by EM field (865–868 MHz) of UHF-RFID readers, EM measurements in an anechoic chamber and in a real medical environment (Hospital Universitario de Canarias), as well as simulations by 3D Ray Launching algorithm, and of biophysical exposure effects in human models are presented. The results obtained show that the EM exposure is localized, in close vicinity of RFID reader and inversely proportional to its reading range. The EM exposure levels detected are sufficient to cause EM immunity effects in electronic devices (malfunctions in medical equipment or implants). Moreover, more than negligible direct effects in humans (exceeding relevant SAR values) were found only next to the reader, up to approximately 30% of the reading range. As a consequence, the EM risk could be firstly evaluated based on RFID parameters, but should include an in situ exposure assessment. It requires attention and additional studies, as increased applications of monitoring systems are observed in the healthcare sector—specifically when any system is located close to the workplace that is permanently occupied.This work was supported by Instituto de Salud Carlos III project “Electromagnetic Characterization in Smart Environments of Healthcare, and their involvement in Personal, Occupational, and Environmental Health” (PI14CIII/00056), and project (PI19CIII/00033) TMPY 508/19 “Metrics development for electromagnetic safety assessment in healthcare centers in the context of 5G“ from Sub-Directorate-General for Research Assessment and Promotion. The results of a research task (II.PB.15) carried out within the National Programme “Improvement of safety and working conditions” partly supported in Poland in 2020–2022—within the scope of research and development—by the National Centre for Research and Development were also included

    Analysis of the impact of EMF exposure in 5G deployments

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    Abstract. 5G or fifth-generation mobile network is being developed to meet the massive increase in data and connectivity, and it connects billions of devices via the internet of things. A significant advantage of 5G is the fast response time, also known as latency, which is delivered by faster connections and greater capacity. As 5G is using high frequencies such as above 6GHz, people are concerned about this electromagnetic field (EMF) exposure because it uses a large number of transmitters. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) issued guidelines to protect humans and the environment from radio frequency electro magnetic field (RF-EMF) exposure in the frequency range of 100kHz-300GHz. These constraints are expressed in terms of specific absorption rate (SAR), electric and magnetic field strength, and power density. The goal of this thesis is to analyse the impact of EMF exposure in 5G deployment. The first step was to examine the EMF and its characteristics in general and in 5G in particular. Characteristics of 5G which are relevant to the electromagnetic field were then analyzed. The regulations related to human exposure to EMF were investigated globally, regionally, and in selected countries and compared with the key parameters including incident electric field strength, incident magnetic field strength, and incident power strength. To analyze the impact of the EMF in 5G two methods were used to assess EMF exposure: calculating the minimum distance and assessing the power density. Power density assessments were done for three different frequency bands (700MHz,1800MHz, and 3.5GHz), five different environmental scenarios (indoor hotspot, dense urban, rural, urban macro massive machine-type communications (mMTC), urban micro ultra-reliable low-latency communications (URLLC), and four different scenarios of a typical 5G network (indoor hotspot, dense urban, micro, micro remote radio head (RRH)), and by co-locating the three transmitters in the frequency bands 700MHz,1800MHz and 3.5GHz. The results of the power density assessment in frequency bands 700MHz,1800Mhz, and 3.5GHz show that there is no EMF exposure near the transmitters. However, with the simulation results, we can see that there is an EMF exposure near the transmitter when considering various scenarios such as dense urban, rural, urban macro mMTC, urban micro URLLC, micro and micro remote radio head (RRH). With the simulation results of co-locating transmitters also we can see that there is also EMF exposure close to the transmitters. So, when deploying the 5G network in these environmental conditions, EMF regulations and limitations should be taken into greater account and deployment should be carried out to minimize this exposure. Thus, when planning the 5G network this exposed area should be included as a restricted area that the general public cannot access
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