Time-averaged Realistic Maximum Power Levels for Assessment of RF Exposure for 5G Radio Base Stations

2017 · No effect · Low evidence

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No effectLow evidencePaper 2332

Study snapshot

Publicationmanual · 2017

Study typeengineering

Reported directionNo effect

Evidence ratingLow

Abstract

Time-averaged Realistic Maximum Power Levels for Assessment of RF Exposure for 5G Radio Base Stations Thors B, Furuskär A, Colombi D, Törnevik C. Time-averaged Realistic Maximum Power Levels for the Assessment of Radio Frequency Exposure for 5G Radio Base Stations using Massive MIMO. IEEE Access. PP(99), 18 Sep 2017. Abstract In this paper a model for time-averaged realistic maximum power levels for the assessment of radio frequency (RF) electromagnetic field (EMF) exposure for the fifth generation (5G) radio base stations (RBS) employing massive MIMO is presented. The model is based on a statistical approach and developed to provide a realistic conservative RF exposure assessment for a significant proportion of all possible downlink exposure scenarios (95th percentile) in-line with requirements in a recently developed International Electrotechnical Commission (IEC) standard for RF EMF exposure assessments of radio base stations (RBS). Factors such as RBS utilization, time-division duplex (TDD), scheduling time, and spatial distribution of users within a cell are considered. The model is presented in terms of a closed-form equation. For an example scenario corresponding to an expected 5G RBS product, the largest realistic maximum power level was found to be less than 15% of the corresponding theoretical maximum. For far-field exposure scenarios, this corresponds to a reduction in RF EMF limit compliance distance with a factor of about 2.6. Results are given for antenna arrays of different sizes and for scenarios with beamforming in both azimuth and elevation. ieeexplore.ieee.org Excerpt In this paper, a theoretical model was presented to estimate the time-averaged realistic maximum power levels for the assessment of RF EMF exposure for 5G Radio Base Stations using Massive MIMO. The model was based on realistic conservative assumptions of a 5G mobile communication system and made use of a statistical approach to distribute the transmitted energy within the cell to obtain results that may be used in context with the 'actual maximum exposure conditions' in the international RF EMF exposure assessment standard for radio base stations IEC 62232:2017. A key parameter of the model is how the users are assumed to be distributed within the cell. For all UDS considered, the time-averaged realistic maximum power levels was found to be significantly below the theoretical maximum. Even for very large degrees of system utilization, the time-averaged realistic maximum was found to take values between 7% - 22% of the theoretical maximum. This translates to reduced compliance distances and may be used to facilitate installation of 5G RBS products. The obtained results provide valuable input to standardization of RF EMF exposure assessments in the vicinity of RBS.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering

Effect directionno_effect

PopulationNot supplied

Sample sizeNot supplied

ExposureRF · time-averaged

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

A statistical model (closed-form equation) is presented to estimate time-averaged realistic maximum power levels for RF EMF exposure assessment of 5G massive MIMO base stations, targeting the 95th percentile of downlink exposure scenarios per IEC 62232:2017 context. In an example scenario, the largest realistic maximum power level was <15% of the theoretical maximum; across user-distribution scenarios and high utilization, realistic maxima were reported between 7% and 22% of theoretical maximum, corresponding (for far-field scenarios) to an RF EMF limit compliance distance reduction factor of about 2.6.

Outcomes measured

Time-averaged realistic maximum power level (relative to theoretical maximum)
Estimated far-field RF EMF compliance distance reduction factor

Limitations

No specific frequencies, measurement data, or empirical exposure measurements are described in the provided abstract/excerpt.
Results are model-based and depend on assumptions about user spatial distribution, utilization, TDD, scheduling time, and beamforming configuration.

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": "RF",
    "source": "5G radio base station",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "time-averaged"
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Time-averaged realistic maximum power level (relative to theoretical maximum)",
    "Estimated far-field RF EMF compliance distance reduction factor"
  ],
  "main_findings": "A statistical model (closed-form equation) is presented to estimate time-averaged realistic maximum power levels for RF EMF exposure assessment of 5G massive MIMO base stations, targeting the 95th percentile of downlink exposure scenarios per IEC 62232:2017 context. In an example scenario, the largest realistic maximum power level was <15% of the theoretical maximum; across user-distribution scenarios and high utilization, realistic maxima were reported between 7% and 22% of theoretical maximum, corresponding (for far-field scenarios) to an RF EMF limit compliance distance reduction factor of about 2.6.",
  "effect_direction": "no_effect",
  "limitations": [
    "No specific frequencies, measurement data, or empirical exposure measurements are described in the provided abstract/excerpt.",
    "Results are model-based and depend on assumptions about user spatial distribution, utilization, TDD, scheduling time, and beamforming configuration."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "5G",
    "radio base stations",
    "massive MIMO",
    "beamforming",
    "RF EMF exposure assessment",
    "time-averaged power",
    "IEC 62232:2017",
    "TDD",
    "compliance distance",
    "downlink"
  ],
  "suggested_hubs": [
    {
      "slug": "5g-policy",
      "weight": 0.62,
      "reason": "Focuses on 5G base-station exposure assessment and compliance distance implications."
    },
    {
      "slug": "who-icnirp",
      "weight": 0.28,
      "reason": "Addresses RF EMF compliance assessment context (standards/limits), though ICNIRP/WHO are not explicitly mentioned."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

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DOI: Not supplied
PubMed: Not supplied

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