U-NII

The Unlicensed National Information Infrastructure (U-NII) radio band is part of the radio frequency spectrum used by IEEE-802.11a devices and by many wireless ISPs. It operates over three ranges:

• U-NII Low: 5.15-5.25 GHz. Regulations require use of an integrated antenna. Power limited to 50mW^[1]
• U-NII Mid: 5.25-5.35 GHz. Regulations allow for a user-installable antenna, subject to Dynamic Frequency Selection (DFS, or radar avoidance)^[2]. Power limited to 250mW^[1]
• U-NII Worldwide: 5.47-5.725 GHz. Both outdoor and indoor use, subject to Dynamic Frequency Selection (DFS, or radar avoidance)^[2]. Power limited to 250mW^[1]. This spectrum was added by the FCC in 2003 to "align the frequency bands used by U-NII devices in the United States with bands in other parts of the world"^[2].
• U-NII Upper: 5.725 to 5.825 GHz. Sometimes referred to as U-NII / ISM due to overlap with the ISM band. Regulations allow for a user-installable antenna. Power limited to 1W^[1]

Wireless ISPs generally use 5.725-5.825 GHz.

U-NII is an FCC regulatory domain for 5- GHz wireless devices. U-NII power limits are defined by the United States CFR Title 47 (Telecommunication), Part 15 - Radio Frequency Devices, Subpart E - Unlicensed National Information Infrastructure Devices, Paragraph 15.407 - General technical requirements. Regulatory use in individual countries may differ.

The European HiperLAN standard operates in the U-NII band.

Sources

• 15.07.2005, Heise: 5 GHz WLAN to be available all over Europe Citat: "...Today, the European Commission resolved in Brussels to regulate two blocks in the 5 GHz range (5150-5350 MHz and 5470-5725 MHz) for all of Europe..."
• Cisco: Glossary

See also

• Part 15 (FCC rules)
• ISM band
• 802.11

References

External links

• In the USA, CFR Title 47 Part 15 (revised in 2005) describes the regulation of the U-NII bands.