U.S. Non-Federal-Government Allocations
4400 - 4500 MHz

U.S. Federal Government Allocations
4400 - 4940 MHz

ITU Region 1 Allocations
4400 - 4500 MHz

ITU Region 2 Allocations
4400 - 4500 MHz

ITU Region 3 Allocations
4400 - 4500 MHz



5.440A In Region 2 (except Brazil, Cuba, French overseas departments and communities, Guatemala, Paraguay, Uruguay and Venezuela), and in Australia, the band 4400-4940 MHz may be used for aeronautical mobile telemetry for flight testing by aircraft stations (see No. 1.83). Such use shall be in accordance with Resolution 416 (WRC-07) and shall not cause harmful interference to, nor claim protection from, the fixed-satellite and fixed services. Any such use does not preclude the use of this band by other mobile service applications or by other services to which this band is allocated on a co-primary basis and does not establish priority in the Radio Regulations. (WRC-07)

US113 Radio astronomy observations of the formaldehyde line frequencies 4825-4835 MHz and 14.47-14.5 GHz may be made at certain radio astronomy observatories as indicated below:

4 GHz

14 GHz




National Astronomy and Ionosphere Center (NAIC), Arecibo, PR



National Radio Astronomy Observatory (NRAO), Green Bank, WV



NRAO, Socorro, NM



Allen Telescope Array (ATA), Hat Creek, CA



Owens Valley Radio Observatory (OVRO), Big Pine, CA



NRAO’s ten Very Long Baseline Array (VLBA) stations (see US131)



University of Michigan Radio Astronomy Observatory, Stinchfield Woods, MI



Pisgah Astronomical Research Institute, Rosman, NC

Every practicable effort will be made to avoid the assignment of frequencies to stations in the fixed or mobile services in these bands. Should such assignments result in harmful interference to these observations, the situation will be remedied to the extent practicable.

US245 In the bands 3600-3650 MHz (space-to-Earth), 4500-4800 MHz (space-to-Earth), and 5850-5925 MHz (Earth-to-space), the use of the non-Federal fixed-satellite service is limited to international inter-continental systems and is subject to case-by-case electromagnetic compatibility analysis. The FCC's policy for these bands is codified at 47 CFR 2.108.

US342 In making assignments to stations of other services to which the bands:

13360-13410 kHz

42.77-42.87 GHz*

25550-25670 kHz

43.07-43.17 GHz*

37.5-38.25 MHz

43.37-43.47 GHz*

322-328.6 MHz*

48.94-49.04 GHz*

1330-1400 MHz*

76-86 GHz

1610.6-1613.8 MHz*

92-94 GHz

1660-1660.5 MHz*

94.1-100 GHz

1668.4-1670 MHz*

102-109.5 GHz

3260-3267 MHz*

111.8-114.25 GHz

3332-3339 MHz*

128.33-128.59 GHz*

3345.8-3352.5 MHz*

129.23-129.49 GHz*

4825-4835 MHz*

130-134 GHz

4950-4990 MHz

136-148.5 GHz

6650-6675.2 MHz*

151.5-158.5 GHz

14.47-14.5 GHz*

168.59-168.93 GHz*

22.01-22.21 GHz*

171.11-171.45 GHz*

22.21-22.5 GHz

172.31-172.65 GHz*

22.81-22.86 GHz*

173.52-173.85 GHz*

23.07-23.12 GHz*

195.75-196.15 GHz*

31.2-31.3 GHz

209-226 GHz

36.43-36.5 GHz*

241-250 GHz

42.5-43.5 GHz

252-275 GHz

are allocated (*indicates radio astronomy use for spectral line observations), all practicable steps shall be taken to protect the radio astronomy service from harmful interference. Emissions from spaceborne or airborne stations can be particularly serious sources of interference to the radio astronomy service (see ITU Radio Regulations at Nos. 4.5 and 4.6 and Article 29).


4.9 GHz Public Safety Spectrum
Aeronautical Radio Altimeters
Radio Astronomy Formaldehyde (H2CO) Observations

Related Documents, Links, and Multimedia:
FCC Proceeding (2)

Engineering Data

Lower Frequency Center Frequency Upper Frequency
Frequency 4.4 GHz 4.67 GHz 4.94 GHz
Wavelength 6.8 cm 6.4 cm 6.1 cm
Band designator(s) SHF; C-band (IEEE) SHF; C-band (IEEE) SHF; C-band (IEEE)
Isotropic collecting area 3.7 cm2 3.3 cm2 2.9 cm2
Free space loss (1 m) 45.3 dB 45.8 dB 45.5 dB
Free space loss (1 km) 105.3 dB 105.8 dB 105.5 dB
Free space loss (10 km) 125.3 dB 125.8 dB 125.5 dB
Free space loss (100 km) 145.3 dB 145.8 dB 145.5 dB
Free space loss (1000 km) 165.3 dB 165.8 dB 165.5 dB
Free space loss
(35,786 km = GEO orbit)
196.4 dB 196.9 dB 196.6 dB
Free space loss (378,370 km = Moon) 216.9 dB 217.4 dB 217.1 dB