Path loss measurements and comparisons of 433 MHz, 869 MHz and 1249 MHz within multi-floored buildings

Abstract

In this paper, an extensive set of propagation path loss measurements within multi-floored buildings at 433 MHz, 869 MHz and 1249 MHz are presented. Parameter for use in two indoor path loss prediction models, Distance-Dependant Model (DD) and Floor Attenuation Floor Model (FAF), are derived from measurement data of three multi-floored buildings. Buildings were chosen with typical features such as rectangle footprint, square footprint and existence of an atrium within the building, respectively. Comparison of model parameters has concluded that higher attenuation is experienced by the signal within a square footprint building than rectangle footprint. Building with an indoor atrium is found to have lower path losses than buildings without atrium, when considering multi-floor transmission. 869 MHz signal attenuated at slowest rate in most of the considered environments. 433 MHz signal is found to have better floor penetration compared to other frequencies. 1249 MHz is found to attenuate at slowest rate within a straight corridor with waveguiding and line-of-sight propagation path between the transmitter and the receiver. Path loss prediction within multi-floored buildings with indoor atrium is refined by considering type of propagation path between trnamsitter and receiver. It is found that path loss of areas with line-of-sight propagation path could be modelled using parameters of same floor environment. An attenuation factor is derived and added for areas with non line-of-sight propagation path. It is shown that using this refinement, better prediction accuracy is obtained. Standard deviations of path loss prediction error are reduced as a result.