NYU Wireless has just reported on 14,000 tests using 28 GHz and 73 GHz indoors. The paper isn't online yet so I put the abstract below. Professor Ted Rappaport believes, "These high frequencies will be an effective substitute when today's Wi-Fi frequencies get crowded."

The FCC is about to set aside some high frequencies for telco use. My opinion, not Ted's is that monopoly spectrum is obsolete. Wi-Fi is proving sharing is possible and productive.  Some monopoly spectrum is needed where reliability is important, but the 100 MHz Sprint, AT&T and Verizon each have is plenty.

Ted makes an important point.  "I think the FCC would do well to also authorize unlicensed bands in the near vicinity of that new mmWave spectrum.

This would relieve the design burden on chip makers, and provide greater bandwidth pipes. As we stated in our FCC comments, we hope that the FCC will open up giant swaths of unlicensed spectrum above 100 GHz, like it opened up the ISM bands in the early 1980s to usher in the Wi-Fi revolution." 

His comments are from an interview I did for the Marconi Society, now being edited. 

Indoor Office Wideband Millimeter-Wave Propagation Measurements and Channel Models at 28 GHz and 73 GHz for Ultra-Dense 5G Wireless

George R. MacCartney, Jr., Student Member, IEEE, Theodore S. Rappaport, Fellow, IEEE, Shu Sun, Student Member, IEEE, Sijia Deng, Student Member, IEEE

Abstract—Ultra-wideband millimeter-wave (mmWave) propagation measurements were conducted in the 28 GHz and 73 GHz frequency bands in a typical indoor office environment in downtown Brooklyn, New York on the campus of NYU.

The measurements provide large-scale path loss and temporal statistics that will be useful for ultra-dense indoor wireless networks for future mmWave bands. This paper presents details of measurements that employed a 400 megachips-per-second broadband sliding correlator channel sounder, using rotatable highly-directional horn antennas for both co- and cross-polarized antenna configurations. The measurement environment was a closed-plan in-building scenario that included line-of-sight and non-line-of-sight corridor, hallway, cubicle-farm, and adjacent-room communication links. Well-known and new single frequency and multi-frequency directional and omnidirectional large-scale path loss models are presented and evaluated based on more than 14,000 directional power delay profiles acquired from unique transmitter and receiver antenna pointing angle combinations.

Omnidirectional path loss models, synthesized from the directional measurements, are provided for the case of arbitrary polarization coupling, as well as for the specific cases of co- and cross-polarized antenna orientations. The results show that novel large-scale path loss models provided here are simpler and more physically-based compared to previous 3GPP and ITU indoor propagation models that require more model parameters, yet offer very little additional accuracy and lack a physical basis. Multipath time dispersion statistics for mmWave systems using directional antennas are presented for co-, cross-, and combined-polarization scenarios, and show that the multipath root mean square delay spread can be reduced when using transmitter and receiver antenna pointing angles that result in the strongest received power.

Abstract—Ultra-wideband millimeter-wave (mmWave) prop-agation measurements were conducted in the 28 GHz and 73
GHz frequency bands in a typical indoor office environment
in downtown Brooklyn, New York on the campus of NYU.
The measurements provide large-scale path loss and temporal
statistics that will be useful for ultra-dense indoor wireless
networks for future mmWave bands. This paper presents details
of measurements that employed a 400 megachips-per-second
broadband sliding correlator channel sounder, using rotatable
highly-directional horn antennas for both co- and cross-polarized
antenna configurations. The measurement environment was a
closed-plan in-building scenario that included line-of-sight and
non-line-of-sight corridor, hallway, cubicle-farm, and adjacent-room communication links. Well-known and new single frequency
and multi-frequency directional and omnidirectional large-scale
path loss models are presented and evaluated based on more
than 14,000 directional power delay profiles acquired from unique
transmitter and receiver antenna pointing angle combinations.
Omnidirectional path loss models, synthesized from the directional
measurements, are provided for the case of arbitrary polarization
coupling, as well as for the specific cases of co- and cross-polarized
antenna orientations. The results show that novel large-scale path
loss models provided here are simpler and more physically-based
compared to previous 3GPP and ITU indoor propagation models
that require more model parameters, yet offer very little additional
accuracy and lack a physical basis. Multipath time dispersion
statistics for mmWave systems using directional antennas are
presented for co-, cross-, and combined-polarization scenarios,
and show that the multipath root mean square delay spread can
be reduced when using transmitter and receiver antenna pointing
angles that result in the strongest received power.