First tests and measurements by OFCOM on adaptive antennas

In March 2020, the Federal Department of the Environment, Transport, Energy and Communications (DETEC) tasked OFCOM with conducting tests on adaptive antennas.

The measurements and simulations conducted in the course of this task revealed that

  • the average level of exposure from adaptive antennas is significantly lower than from classic antennas;
  • Conventional antennas transmit mainly to the centre of their coverage area. The further the user is from this central part, the lower the transmission quality. Adaptive antennas, on the other hand, send data specifically to the end device, regardless of its position in the coverage area. The communication maintains the same quality and speed, even at the edge of the area.
  • the "power-lock" function (automatic power limiter), which has to be integrated into each adaptive antenna, ensure that emission limit values are respected by limiting transmission power to a mean value.

The report on "Testkonzession und Messungen adaptive Antennen" dated 24.09.2020 brings together the results of measurements carried out in the summer of 2020 on two base stations equipped with 5G technology and computer simulations carried out to validate these measurements. Complementary simulations were used to visualise the exposure to non-ionising radiation (NIR) when the same antenna serves one or more users, taking into account the many possible configurations.

The supplementary report on "Testkonzession und Messungen adaptive Antennen Nachtrag" dated 8.2.2021 confirms the measurements and simulations of the first report and attests to the reliability of the power-lock function, which is used as an automatic mechanism to limit the transmission power of adaptive antennas to a mean value.

These two reports show that the method used to assess the exposure level generated by a conventional antenna cannot be applied in the same manner as it is to adaptive antennas. Indeed, this method of calculation clearly overestimates the real average exposure generated by adaptive antennas. The guidance on adaptive antennas therefore introduces a correction factor that ensures that both types of antenna are treated equally while guaranteeing compliance with the emission limit values specified in the Ordinance on Protection against Non-Ionising Radiation (ORNI, RS 814.710).

The results of the tests and measurements carried out by OFCOM made an important contribution to the development of guidance on adaptive antennas issued by the Federal Office for the Environment.

Last modification 27.04.2021

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