Antennas, Antenna Cables, Wireless Products: Technical Articles
Legal & Illegal Frequencies & Channels In the United States
Table of Contents
LEGAL & ILLEGAL Frequencies 4.9GHz to 5.825
(United States only)
The following table lists legal and illegal operating channels in the 4.9–5.825 GHz frequency range for use within the United States.
| Channel | Frequency | United States |
| (MHz) | 40/20 MHz | |
| 183 | 4915 | ILLEGAL |
| 184 | 4920 | ILLEGAL |
| 185 | 4925 | ILLEGAL |
| 187 | 4935 | ILLEGAL |
| 188 | 4940 | ILLEGAL |
| 189 | 4945 | ILLEGAL |
| 192 | 4960 | ILLEGAL |
| 196 | 4980 | ILLEGAL |
| 7 | 5035 | ILLEGAL |
| 8 | 5040 | ILLEGAL |
| 9 | 5045 | ILLEGAL |
| 11 | 5055 | ILLEGAL |
| 12 | 5060 | ILLEGAL |
| 16 | 5080 | ILLEGAL |
| 34 | 5170 | ILLEGAL |
| 36 | 5180 | LEGAL |
| 38 | 5190 | ILLEGAL |
| 40 | 5200 | LEGAL |
| 42 | 5210 | ILLEGAL |
| 44 | 5220 | LEGAL |
| 46 | 5230 | ILLEGAL |
| 48 | 5240 | LEGAL |
| 52 | 5260 | LEGAL |
| 56 | 5280 | LEGAL |
| 60 | 5300 | LEGAL |
| 64 | 5320 | LEGAL |
| 100 | 5500 | LEGAL |
| 104 | 5520 | LEGAL |
| 108 | 5540 | LEGAL |
| 112 | LEGAL | |
| 116 | 5580 | LEGAL |
| 120 | 5600 | ILLEGAL |
| 124 | 5620 | ILLEGAL |
| 128 | 5640 | ILLEGAL |
| 132 | 5660 | ILLEGAL |
| 136 | 5680 | LEGAL |
| 140 | 5700 | LEGAL |
| 149 | 5745 | LEGAL |
| 153 | 5765 | LEGAL |
| 157 | 5785 | LEGAL |
| 161 | 5805 | LEGAL |
| 165 | 5825 | LEGAL |
2.4 GHz Band (802.11b/g/n)
The 2.4 GHz band is legal in all countries; however, please note the following for the United States:
- Channels 1-12 are legal in the United States
- Channels 13-14 are illegal to use in the United States
3.65 GHz Band
The 3.65 GHz band operates under a registration system.
The application fee for a nationwide 3.65 GHz license is less than $300
The 3.65 GHz band is non-exclusive and, therefore, interference is a concern, but it is not an unlicensed band in the true meaning of the word, since licensing and registration is required to use 3.65. Once a license is obtained, every base station operating under that license must be registered in a national database. This encourages coordination among operators to reduce interference.
4.9 GHz Band
The 4.9 GHz band is reserved for public safety applications.
NOTICE FOR CUSTOMERS
IMPORTANT: Purchasing Equipment with 5GHz capabilities
Customer agrees to, and assumes responsibility for, use of only legal bandwidth frequencies. Please review this page of frequencies that are legal and illegal in the United States, in the range of 4.9 to 5.85GHz.
Ubiquiti 5GHz equipment (M5 / AirMax): Starting in May 2011, Ubiquiti is designating two versions, each with different firmware US and World. The part# ends with either "US" or "World." The US version firmware will have restrictions to use only in the legal frequency bands/channels.
Customers who purchase for use in the United States:
- We strongly recommend and encourage you to buy only the US versions, which have firmware programmed to work only on the legal frequencies.
- If you buy the World version for use in the United States: The act of your purchase is your acknowledgement of your agreement and intention to use only legal frequency bands.
Conclusion
Operating wireless equipment in the 4.9–5.825 GHz range in the United States requires careful attention to FCC regulations. While some channels are legal for unlicensed or lightly licensed use, many frequencies are restricted, reserved, or outright illegal for general operation. Using equipment configured outside of approved bands can result in harmful interference, service disruption, and regulatory penalties. Customers are responsible for ensuring that their devices, firmware, and configurations comply with U.S. frequency rules. When in doubt, always select U.S.-locked equipment and operate only within clearly authorized channels to ensure legal, reliable, and interference-free deployments.
FAQs
Which 5 GHz frequencies are legal to use in the United States?
Only specific channels within the 4.9–5.825 GHz range are legal for general wireless use in the U.S. Many frequencies—especially below 5.15 GHz and certain mid-band channels—are restricted or illegal. Always verify that your equipment is operating only on FCC-approved channels listed as legal.
Why are some 5 GHz channels marked illegal?
Some frequencies are reserved for public safety, government, radar (DFS), or other protected services. Using these channels without authorization can cause harmful interference and violates FCC regulations, even if the hardware is technically capable of transmitting on them.
Is the 4.9 GHz band legal for Wi-Fi or wireless data links?
No. The 4.9 GHz band is reserved exclusively for public safety applications in the United States and is not legal for commercial, consumer, or private wireless networking use.
What is the 3.65 GHz band and how is it regulated?
The 3.65 GHz band is not unlicensed. It operates under a registration and licensing system. A nationwide license costs less than $300, and each base station must be registered in a national database to promote coordination and reduce interference.
Should I buy “US” or “World” version 5 GHz wireless equipment?
If you are operating in the United States, you should only purchase the US version. US firmware restricts operation to legal frequency bands. Purchasing a World version places full responsibility on the user to ensure operation only on legal channels, and misuse can result in regulatory violations.