  New spectrum allocations in the 4--8 GHz FR1(C) and 7--24 GHz FR3 mid-band
frequency spectrum are being considered for 5G/6G cellular deployments. This
paper presents results from the world's first comprehensive indoor hotspot
(InH) propagation measurement campaign at 6.75 GHz and 16.95 GHz in the NYU
WIRELESS Research Center using a 1 GHz wideband channel sounder system over
distances from 11 to 97 m in line-of-sight (LOS) and non-LOS (NLOS). Analysis
of directional and omnidirectional path loss (PL) using the close-in free space
1 m reference distance model shows a familiar waveguiding effect in LOS with an
omnidirectional path loss exponent (PLE) of 1.40 at 6.75 GHz and 1.32 at 16.95
GHz. Compared to mmWave frequencies, the directional NLOS PLEs are lower at FR3
and FR1(C), while omnidirectional NLOS PLEs are similar, suggesting better
propagation distances at lower frequencies for links with omnidirectional
antennas at both ends of the links, but also, importantly, showing that higher
gain antennas will offer better coverage at higher frequencies when antenna
apertures are kept same over all frequencies. Comparison of the omnidirectional
and directional RMS delay spread (DS) at FR1(C) and FR3 with mmWave frequencies
indicates a clear decrease with increasing frequency. The mean spatial lobe and
omnidirectional RMS angular spread (AS) is found to be wider at 6.75 GHz
compared to 16.95 GHz indicating more multipath components are found in the
azimuthal spatial domain at lower frequencies.
