RF-EMF Exposure Measurement for 5G over mm-Wave Base Station with MIMO Antenna

Abstract

RF-EMF Exposure Measurement for 5G over mm-Wave Base Station with MIMO Antenna S. Q. Wali, A. Sali, J. K. Allami, A. F. Osman. RF-EMF Exposure Measurement for 5G over mm-Wave Base Station with MIMO Antenna. IEEE Access. 2022. doi: 10.1109/ACCESS.2022.3143805. Abstract The fifth-generation (5G) technology offers more capacity and data rates than the previous generations. It provides ultra-low latency and ultra-high dependability, allowing for efficient services in many industries. Using radiofrequency electromagnetic fields (RF-EMF) above 6 GHz in 5G millimeter Wave(mm-Wave) base stations has concerned many people due to the potential health risks caused by EMF exposure. This study aims to measure the maximum exposure emitted by a 5G mm-Wave base station by utilizing international standards in both its assessment methodology and exposure limits. In this study, the R&S®TSMA6 scanner, R&S®ROMES4 software, and R&S®TSME30DC down converter have been used for the measurement campaign; in addition to the user equipment device (UE), GPS, and an omnidirectional antenna. The investigation is based on a code selective method due to the radiated power fluctuations over time with data traffic. To conduct the measurement, six tests are taken based on three different time frames, antenna directions, and user equipment device (UE) to investigate the RF-EMF exposure. The maximum and average exposure from the 5G mm-Wave base station are calculated and compared with the ICNIRP standard. The maximum exposure from the 29.5 GHz base station is found to be 5.71 V/m, and the highest amount of average exposure is 2.02V/m. In this study, it was found that the maximum and average exposure (RF-EMF) produced from a single 5G mm-Wave base station are well within the allowed RF-EMF standard limit. Excerpts This section presents the methodology used in performing this work. To conduct the measurement at the base station, different scenarios and tests were chosen. Choosing a location to take the measurement was the second step. After going around the area for a few hours, the location was chosen based on getting the highest received power. The measurement was conducted in the car park of Rekascape Cyberjaya, Selangor at a 5G mm-Wave base station, the distances between the transmitter and receiver were 22 m that the highest amount of power was received. The scenario had been selected in the line of sight (LOS) location; six different tests were selected one of them was measured without connecting the UE device to the base station, while, in the other five tests, the UE device was connected to the base station. The measurement in the LOS scenario had been taken in three different standard times to know when the maximum exposure will be recorded and to illustrate the time effect on the exposure level. Measurement was conducted at 1 minute as a default time, 6 minutes based on the ICNIRP [53]standard, and 30 minutes depending on the IEEE [54] and ICNIRP [55] standard. To analyze the Electrical field strength per channel [V/m] and Electrical field of the 5G mm-Wave base station, the data was extracted from the scanner. Then, the data was sorted in an excel sheet based on the top (n) to normal sorting where every signal synchronization block (SSB) had a fixed column to analyze the electrical field per channel in 5G base station. The maximum electric field strength (Emax) and the average electric-field strength (Avg) were analyzed. Finally, the maximum exposure and average exposure will be compared to ICNIRP [50] standard to ensure the safety of deploying 5G mm-Wave in Malaysia.... In this paper, the RF-EMF exposure for 5G over the mm-Wave base station with a MIMO antenna was investigated. From the literature, no study has been carried out analyzing the exact level of exposure from mmWave base station making it the first of its kind in Malaysia. This study investigated and elaborated on how to take the measurement, sort, extract, and calculate the data. Besides, the effect of time duration on the amount of exposure, various antenna directions, and using UE devices on six different tests was elaborated. For all the tests, the distance between the 5G mm-Wave base station (Tx) and the receiver (Rx) was the same, and the location was chosen based on getting the maximum power. It can be noticed from the data that there is a slight difference in the amount of produced exposure between the first test which is without UE, and the other tests that the UE device was connected to the BS, so the UE does not have a noticeable impact on the measurement results. The experimental results ensure that the time has a modest impact on the level of exposure, in the three-time frames. A high level of Emax from the 5G mm-Wave base station was recorded in the second, third, and fourth tests. The maximum exposure called the worst-case scenario is much higher than the average exposure emitted at the 5G mm-Wave base station. The maximum exposure at the base station among all the tests is 5.71V/m, which is recorded in video streaming from YouTube, and this value is significantly lower than the ICNIRP standard accepted limit of exposure, which is 61V/m [50]. The highest average exposure, which is 2.02V/m at the video call test, is well below the accepted RF-EMF exposure by the ICNIRP standard at the same time, it was found that the level of exposure at the mm-Wave base station is not zero. It was found that the Emax and Eavg from 5G mm-Wave selected base station in this work, are within the limits, indicating that it does not have effects on human health. Nevertheless, there is a need for further investigations on the RF- EMF exposure from 5G mm-Wave in areas that are surrounded by many mm-Wave base stations and for a longer measurement time duration. ieeexplore.ieee.org

AI evidence extraction

Main findings

Field measurements near a 29.5 GHz 5G mm-wave base station (LOS, 22 m) found a maximum exposure of 5.71 V/m and a highest average exposure of 2.02 V/m across six tests. Reported maximum and average exposures were stated to be well within the ICNIRP limit (61 V/m).

Outcomes measured

• Electric field strength (V/m): maximum (Emax) and average (Eavg) exposure
• Comparison to ICNIRP exposure limits

Limitations

• Single base station/location (Malaysia; car park, LOS at 22 m)
• Exposure metrics limited to measured electric field strength; no health outcomes assessed
• Six test scenarios only; authors note need for longer measurement durations and areas with many mm-wave base stations

Suggested hubs

• 5g-policy (0.6)
  Measures RF-EMF exposure from a 5G mm-wave base station and discusses compliance with standards.
• who-icnirp (0.85)
  Exposure results are explicitly compared against ICNIRP limits and measurement averaging times.

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        "source": "5G base station",
        "frequency_mhz": 29500,
        "sar_wkg": null,
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    "outcomes": [
        "Electric field strength (V/m): maximum (Emax) and average (Eavg) exposure",
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    ],
    "main_findings": "Field measurements near a 29.5 GHz 5G mm-wave base station (LOS, 22 m) found a maximum exposure of 5.71 V/m and a highest average exposure of 2.02 V/m across six tests. Reported maximum and average exposures were stated to be well within the ICNIRP limit (61 V/m).",
    "effect_direction": "no_effect",
    "limitations": [
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        "Exposure metrics limited to measured electric field strength; no health outcomes assessed",
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    ],
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        "SSB"
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