Definition: U-NII

(1) (UNique Ingredient Identifier) See healthcare IT.

(2) (Unlicensed-National Information Infrastructure) A part of the national spectrum sanctioned by the FCC in 1997 that does not require a license for short-range wireless use. One of the purposes for U-NII was to enable schools, libraries and healthcare organizations in rural areas to more easily connect to the Internet and private, high-speed networks.

Radar Has Priority
U-NII channels 52 through 140 (5.26-5.7 GHz) require transmitting devices to use dynamic frequency selection (DFS) to avoid conflicts with radar pulses. A DFS frequency must be clear of radar for one minute before using it, and if radar is detected on the current channel, the transmitter must switch to another channel, also free of radar for one minute. See ISM band and WiSA.

 U-NNI BANDS

               Indoor/  Max
 Frequency     Outdoor  Power
 Range (GHz)   Usage    (mW)  DFS?

 5.150-5.250   In       50    no

 5.250-5.350   In/Out  250    yes

 5.470-5.725   In/Out  250    yes

 5.725-5.825   Out    1000    no