Radio Channel Modeling in a Ship Hull: Path Loss at 868 MHz and 2.4, 5.25, and 60 GHz

This letter presents the analysis of a channel sounding campaign in the hull of a bulk carrier vessel at sub-6 GHz frequencies 868 MHz and 2.4 and 5.25 GHz as well as millimeter-wave (mmWave) frequency 60.48 GHz. For the sub-6 GHz frequencies, path loss (PL) is measured using omnidirectional antennas. The measured PL is fitted to a one-slope PL model that takes into account attenuation due to engine room floor crossings, obstructions, and walls. The fitted model has a reference PL lower than free space and a PL exponent around 1.2. For mmWave wireless communication, high gain directive antennas are typically used. Therefore, the directive radio channel for line-of-sight (LOS) communication is measured using the Terragraph channel sounder and an antenna beamwidth dependent PL model is created. At mmWave frequencies, LOS PL in the vessel is close to PL in a free-space environment, but angular spread values are lower compared to other indoor scenarios.