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Path Loss at 5 GHz and 31 GHz for Two Distinct Indoor Airport Settings

Vehicular and indoor communications continue to grow. This pertains to applications in aviation as well, which is also experiencing rapid growth. Since a pre-requisite to reliable communication link design is accurate knowledge of the wireless channel, research on channel models for these environments is an active area of study, and this is the topic of this paper. In this work, we report on measurement and model results for propagation path loss in two indoor airport environments, in two frequency bands. The first environment is a typical small terminal building, with characteristics similar to indoor offices, and the second is a more unusual aircraft maintenance hangar. The hangar is a crowded environment with multiple aircraft and metallic objects. Our results are for both the 30 GHz band (specifically 31 GHz), which is being investigated for future 5th generation cellular and other applications, and for the 5 GHz band, for a comparison. Our results show that the airport terminal building exhibits path loss characteristics very similar to those of an indoor office environment, at both frequencies, and this is largely as expected. In contrast, the maintenance hangar path loss is less than that of non-line of sight terminal building regions, somewhat unexpectedly. We attribute this to the highly reflective hangar environment, which serves to compensate for reduced diffraction and increased blockage losses at 31 GHz.