Wideband measurements of channel characteristics at 2.4 and 5.8 GHz in underground mining environments

This paper analyzes the results of wideband radio channel measurements conducted in an underground mining environment at center frequencies of 2.4 GHz and 5.8 GHz using a vector network analyzer. Relevant impulse response parameters such as the rms delay spread and the relative multipath total power are presented and compared for the two bands. The measurements suggest that in such an underground gallery and in the two frequency bands, random reflections have the effect of flattening the relationship between the rms delay spread and distance. In the 2.4 GHz band, the rms delay spread is less than or equal to 6.34 nanoseconds for 50% of all measurement locations. The corresponding value for the 5.8 GHz band is 4.98 nanoseconds. In general, it has been observed that underground radio channel characteristics are influenced by the configuration of this peculiar environment.