5.338A In the frequency bands 1 350-1 400 MHz, 1 427-1 452 MHz, 22.55-23.55 GHz, 24.25-27.5 GHz, 30-31.3 GHz, 49.7 50.2 GHz, 50.4-50.9 GHz, 51.4-52.4 GHz, 52.4-52.6 GHz, 81-86 GHz and 92-94 GHz, Resolution 750 (Rev.WRC 19) applies. (WRC 19)
5.532AA The allocation to the fixed service in the frequency band 24.25-25.25 GHz is identified for use in Region 2 by high-altitude platform stations (HAPS). This identification does not preclude the use of this frequency band by other fixed-service applications or by other services to which this frequency band is allocated on a co-primary basis, and does not establish priority in the Radio Regulations. Such use of the fixed-service allocation by HAPS is limited to the HAPS-to-ground direction and shall be in accordance with the provisions of Resolution 166 (WRC 19). (WRC 19)
5.532AB The frequency band 24.25-27.5 GHz is identified for use by administrations wishing to implement the terrestrial component of International Mobile Telecommunications (IMT). This identification does not preclude the use of this frequency band by any application of the services to which it is allocated and does not establish priority in the Radio Regulations. Resolution 242 (WRC 19) applies. (WRC 19)
5.533 The inter-satellite service shall not claim protection from harmful interference from airport surface detection equipment stations of the radionavigation service.

Wiki entries

Possible MSS Allocations (WRC-15 Agenda Item 1.10)

Proposed Use 22–26 GHz Possible MSS allocations (WRC-15 agenda item 1.10)

Agenda item 1.10 of the 2015 World Radiocommunication Conference:

"to consider spectrum requirements and possible additional spectrum allocations for the mobile-satellite service in the Earth-to-space and space-to-Earth directions, including the satellite component for broadband applications, including International Mobile Telecommunications (IMT), within the frequency range 22 GHz to 26 GHz, in accordance with Resolution 234 (WRC-12)"

Unlicensed Level Probing Radars

Proposed Use 24.05–29 GHz

The FCC has released a Notice of Proposed Rule Making that would allow downward-pointing, unlicensed level probing radars, for use both in tanks and outdoors, at 5.925-7.250, 24.05-29, and 75-85 GHz.

Proposed EIRP boresight emissions limits are:

5.925-7.250 GHz: -33 dBm/MHz average and +7 dBm across 50 MHz.
24.05-29 GHz: -14 dBm/MHz average and +26 dBm across 50 MHz
75-85 GHz: -3 dBm/MHz average and +34 dBm across 50 MHz

Proposed average emissions limits to the sides and upward are:

5.925-7.250 GHz: -55 dBm/MHz
24.05-29 GHz: -41.3 dBm/MHz
75-85 GHz: -41.3 dBm/MHz

Airport Body Scanners

Current Use 24.25–30 GHz Airport body scanners

Under an FCC waiver (link below) issued to SafeView, Inc., since acquired by L-3 Security & Detection Systems, full-body airport scanners can use repeated sweeps over the range 24.25-30 GHz to detect objects hidden underneath clothes. These units are referred to as millimeter wave scanners by the U.S. Transportation Security Administration (TSA), but don't actually operate in the millimeter wave band (30-300 GHz).

Quoting from the FCC waiver: "The SafeView SafeScout imaging device is a security portal that uses imaging technology to detect weapons or contraband carried on an individual’s person, including non-metallic objects or explosives, which might otherwise require intrusive manual searches or be missed entirely by existing metal detectors. A person to be scanned by the SafeView device steps briefly into a transparent, upright cylinder seven feet high by four feet in diameter. Two vertical antenna masts rotate around the person over a 2-second interval. Each antenna element in turn sweeps from 24.25 to 30 GHz, operating for approximately six microseconds per sweep. The device measures reflections of the radio signals from the subject and calculates an image that shows hidden objects."