More wall penetration is not the solution. 900 MHz is the outcome of what you seek. It’s unlicensed so it’s filled with noise. And the noise carries far thanks

More wall penetration is not the solution. 900 MHz is the outcome of what you seek. It’s unlicensed so it’s filled with noise. And the noise carries far thanks to the low frequency. The entire band is only 28 MHz wide. “DECT 6.0” cordless phones use a 1.9 GHz band that is only 10 MHz wide.