Radio channel measurements in off-body communications in a ferry passenger cabin

Abstract

This paper presents an off-body radio channel measurements in a ferry passenger cabin at 2.45 GHz band, for static sleeping scenarios with different body orientation and on-body antennas placements, and also for upper and lower sleeping berths. The measurements have been performed with two types of on-body wearable receiving antennas: FlexPIFA (flexible planar inverted F antenna), and FlexNotch (flexible adhesive-backed notch antenna) and one patch off-body transmitting antenna. The measurement equipment, measurement environment and investigated scenarios are described. A preliminary analysis of the results — the mean value (μ) and standard deviation (σ) — is presented. In general, the propagation path loss mainly depends on the type and location of the receiving antennas, and also on the body orientation during sleeping and surrounding elements of environment. The lowest mean path loss values (both below 56 dB) were obtained for upper sleeping berth and scenario, where receiving FlexPIFA antennas were mounted on chest and back during lying on the left side. In contrast, the highest values (both over 70 dB) were obtained for upper sleeping berth and scenario, where FlexNotch antennas were mounted on chest and right wrist during lying on the left side. Moreover, the standard deviation varies in a range from 3.7 dB up to 8.0 dB for all cases.