An Evaluation of Mid-Band Signal Level Variability with 4G and 5G Phones

This study evaluates the use of reference signal measurements from 4G and 5G phones to estimate outdoor signal level variability for empirical propagation modeling. Commercial-off-the-shelf (COTS) mobile phones continuously measure and report Reference Signal Received Power (RSRP), making them an effortless source for crowdsourcing empirical propagation measurements. This study details an extensive measurement campaign with nine phone models used to capture over 350000 RSRP measurements from 4G and 5G mid-band spectrum: band $2(1900 \mathrm{MHz})$, bands 41 and $n 41(2500 \mathrm{MHz})$, and band $66(2100 \mathrm{MHz})$. This study shows that a single COTS mobile phone can measure the location variability of transmission loss with $\pm \mathbf{1. 9} \mathbf{~ d B}$ accuracy for distances up to one kilometer. Further, this study extends historical location variability studies and shows that crowdsourcing with mobile phones is a practical method of acquiring empirical propagation data in previously unmeasured environments.