  Adequate coverage with high gain antennas is key to realizing the full
promise of the bandwidth available at mm/cm wave bands. We report extensive
indoor measurements at 28 GHz (1000 links, 9.9 million individual power
measurements, 10 offices, 2 buildings), with/without line-of-sight (LOS) using
a continuous wave channel sounder, with a 10o spinning horn, capable of
capturing a full azimuth scan every 200 ms, in up to 171 dB path loss to
characterize coverage with 90% confidence level. The environment had prominent
corridors and rooms, as opposed to open/mixed offices in latest 3GPP standards.
Guiding in corridors leads to much lower RMS azimuth spread (7 degree median in
corridor non-LOS vs. 42 degree in 3GPP) and higher penetration loss into rooms
and around corners (30-32 dB, some 12 dB more loss than 3GPP at 20 m non-LOS).
Measured path gain in non-LOS is predicted by a mode-diffusion model with 3.9
dB RMS error. Scattering degraded azimuth gain by up to 4 dB in the corridor
and 7 dB in rooms with 90% probability. Link simulations in a canonical
building indicate every corridor needs an access point to provide 1 Gbps rate
to adjoining rooms within 50 m using 400 MHz of bandwidth.
