Home // SnT // Research // SIGCOM // Projects // SAFER

SAFER: Demonstration of SAFE electromagnetic Radiation emitted by 5G active antennas systems

Funding Source: SMC – Service des Médias et des Communications, Luxembourg

Team: Prof. Symeon Chatzinotas (PI), Dr. Jorge QUEROL (VPI), Dr. Sumit KUMAR (Lab Coord.), Dr. Chandan Sheemar, Dr. Juan MERLANO DUNCAN, Dr. Konstantinos NTONTIN, Dr. Mahdi AZARI, Dr. Sourabh SOLANKI, Dr. Jorge Luis GONZALEZ RIOS, Dr. Oltjon KODHELI, Abdelrahman ABDALLA, Mohammad GHOLAMIAN

Starting date / Duration: 08/2021, 9 months

Summary

The project “Demonstration of safe electromagnetic radiation emitted by 5G active antennas systems” (SAFER) aims to showcase the benefits of 5G from a scientific point of view and to expose some of the misconceptions related to the active antenna systems technology. In particular, the project focuses on demonstrating the radiation levels from beamforming is even lower as compared to traditional systems through specific and easy-to-understand hardware setups. The project SAFER extends the objectives of the IRANATA project in terms of openness and mmWave bands, and it adds the important component of communicating and showcasing the obtained results to the general non-trained audience.

Download the SAFER project Flyer here: Flyer_SAFER

Objectives

The objectives of the project are:

Showcase to the general public how 5G base stations are reducing the amount of electromagnetic radiation emitted to the environment, contrary to the common misconception. This will be divided into two demos in October 2021 and March 2022. The specific topics to be covered by the 2 demos are:
- How steerable active antennas use more efficiently the energy thanks to their increased directivity (keeping signal-to-noise ratio constant),
- How increased frequency bands in the mmWave range help to miniaturize, distribute and deploy smaller low-power coverage cells,
- How the signal power emitted by the base station has a lower magnitude than the one generated by the user terminal, and
- How new waveforms and duplexing schemes (FDD vs TDD) decrease the exposure to radiation concerning previous generations of cellular technology.
- Define a methodology to evaluate objectively, efficiently, and accurately the level of electromagnetic radiation emitted by 5G active antennas systems. This topic will be addressed in March 2022 workshop. The main open issues to be addressed are:
  - how to account for the spatial dynamics of the antenna radiation pattern,
  - how to account for the temporal dynamics of the measurement scenario, and
  - contribute to the standardization of the measurement methodology.

The project aims to contribute to the international standards, such as IEC 62232 edition 3, helping to address some of the open questions for the proper measurement of the exposure to 5G RF-EMF.

Some of the open issues due to the 5G transmitting environment complexity are:

Active vs. passive antenna
Space dynamics (beamforming antennas)
Time dynamics (Time Division Duplex & Scheduling)
MIMO setup (4x4, 64x64, mMIMO, etc.)
or not, can software upgrades to existing antennas make beamforming possible,
PBCH vs PDSCH beamforming
PBCH allocated frequency

Expected Outcomes

Demonstrate with 2 simplified demos to the general public that 5G radiation is safe.
Increase the acceptance of the 5G (and beyond) technology to the general public.
Introduce to the general public the concept of mmWave and small cells, since these are new concepts of currently deployed networks all over the world.
Foster the collaboration among national entities (research institutes, network operators, ILR, ITM, Administration de l’Environnement, etc) involved in the regulatory aspects of the electromagnetic radiation of 5G base stations with 1 joint workshop.
Contribute to the standardization of the radiation measurement methodology at the national and international level together with the relevant actors with press releases and scientific publications.

The contribution of the public co-funding is crucial for the development of this activity. The project has an educational vocation for people without expertise in the field. This is not the classical audience targeted by a usual research project, and we believe this funding instrument is the correct vehicle for this project proposal.

Experimental Set-ups

Four different experimental setups have been planned to illustrate how electromagnetic radiation emitted by 5G active antenna systems is SAFER than pre-5G technology.

Fig-1: Commercial base-station radiation measurement setup

Figure 1 shows the first test setup to be used as a reference using the 5G base-stations (gNB) deployed by the network operators. We will monitor the radiation of 5G waveforms at C-band and use them as reference values for the rest of the demo cases. Another aspect to be shown with this setup is how the radiation of the UEs is more powerful than the radiation coming from the gNB itself.

Fig-2: Pre-5G passive antenna setup

Figure 2 illustrates the second test set up to show the electromagnetic field strength of a conventional patch antenna while transmitting and receiving 5G NR waveforms. In this set-up we will use, a 5G NR waveform generator (gNB) the output of which is connected to a C-band patch antenna. This is illustrating a pre-5G (e.g. 4G) antenna setup with low directivity and fixed beam pattern. On the receiver side, we have used a 5G NR signal analyser (UE) which get its input from a similar C-band patch antenna. Once the connection is established between gNB and UE, we measure the electromagnetic radiation and power strength from the antenna at both sides. Results will be compared to the previous case.

Fig-3: High-directive antenna setup mimicking 5G Active Antenna Arrays

Figure 3 illustrates the third test set up to show the electromagnetic field strength of the horn antenna while transmitting and receiving 5G NR waveforms. In contrast to the patch antenna as shown in Figure 2, the horn antenna generates narrower transmit and receive beams. Their narrower beamwidth (in the range of 15 degrees) mimics accurately the beams generated by the commercial active antenna systems. In this set-up we have used, a 5G NR waveform generator (gNB) the output of which is attached to a C-band horn antenna. On the receiver side, we have used a 5G NR signal analyser (UE) which gets input from a similar C-band horn antenna. The main purpose of this setup is to show that the same quality of the signal can be obtained with less radiated power (thus more efficient) by creating a narrower beam between transmitter and receiver instead of using a low-directive antenna.

Fig-4: 5G mmWave Active Antenna Array setup

Eventually, Figure 4 illustrates our fourth test set up in the mmWave band. In this case, we use a mmWave antenna array enabling 5G small cells. The signal output from the 5G NR signal generator is fed to a mmWave up-converter where the incoming signal is mixed with a LO generated by mmWave Analog Signal Generator. The receiver side performs a similar operation of down-conversion before feeding the received signal from mmWave antenna array to the signal analyser. The main reason for this test is to show that at mmWave, which native support beamforming through compact antenna arrays, better performance can be achieved via beam-based operation, however, spreading less amount of radiation. Moreover, the attenuation by free-space propagation loss is proportional to the carrier frequency which also contributes to reduce the amount of total radiation received by people. Eventually, the more compact antennas at this frequency band enable to build of smaller form-factor base stations.

Demo at 5G Connecting Tomorrow Conference 2021, Luxembourg

A demo of test setups as described above was conducted at 5G Conference, Luxembourg 5-7 Oct, 2021. During the demo, an audience from a multitude of background visited our booth and awareness of the functionality of beamforming, radiation measurement, 5G active antenna system. A workshop titled: “Exposure to Electromagnetic Fields and Interference Management in 5G Network Planning” was also conducted during the conference in collaboration with the Luxembourg Institute of Science and Technology (LIST). There are still many factors to consider that may limit the deployment and adoption of 5G technologies. This workshop focused specifically on exposure to electromagnetic fields (EMF) and intended to discuss the role of research and innovation, in addition to presenting the views of various stakeholders in Luxembourg.

SnT booth at 5G Connecting Tomorrow

The following videos were recorded during the 5G Connecting Tomorrow conference showing the difference in the over-the-air measured radiated electromagnetic field (V/m) between a 5G-like directive antenna (~19 dBi) implemented with a horn antenna for simplicity, and a Pre-5G-like sectorial antenna (~9 dBi). The target of this simplified, but representative, demonstration experiment was the general public audience with limited technical knowledge of radio communications.

EMF (V/m) emitted by a 4G-like sectorial antenna (~9 dBi)

EMF (V/m) emitted by a 5G-like sectorial antenna (~19 dBi)

Workshop and Demo at SnT Kirchberg

The workshop along with the final demo was held in March 2022 at SnT, Kirchberg campus of the University of Luxembourg. The workshop covered technical aspects such as relevant concepts and motivation of the SAFER project (interference, coexistence, radiation), a review of the current measurement standard (IEC 62232), and technical gap identification and future proposals. This was followed by a hardware demo showing dedicated experiments such as 4G vs 5G antennas, downlink vs uplink radiation, and frequency-selective vs code-selective measurements. Relevant national stakeholders from the 5G ecosystem (SMC, ILR, Proximus, Post, DAC, LIST) were present during the workshop and demonstration, also participating in the final round-table discussions.