Sec. 15.407  General technical requirements.

    (a) Power limits:
    (1) For the band 5.15-5.25 GHz, the peak transmit power over the 
frequency band of operation shall not exceed 50 mW. In addition, the 
peak power spectral density shall not exceed 2.5 mW/MHz. If transmitting 
antennas of directional gain greater than 6 dBi are used, both the peak 
transmit power and the peak power spectral density shall be reduced by 
the amount in dB that the directional gain of the antenna exceeds 6 dBi.
    (2) For the band 5.25-5.35 GHz, the peak transmit power over the 
frequency band of operation shall not exceed 250 mW. In addition, the 
peak power spectral density shall not exceed 12.5 mW/MHz. If 
transmitting antennas of directional gain greater than 6 dBi are used, 
both the peak transmit power and the peak power spectral density shall 
be reduced by the amount in dB that the directional gain of the antenna 
exceeds 6 dBi.
    (3) For the band 5.725-5.825 GHz, the peak transmit power over the 
frequency band of operation shall not exceed 1 W. In addition, the peak 
power spectral density shall not exceed 50 mW/MHz. If transmitting 
antennas of directional gain greater than 6 dBi are used, both the peak 
transmit power and the peak power spectral density shall be reduced by 
the amount in dB that the directional gain of the antenna exceeds 6 dBi.
    (4) The peak transmit power must be measured over any interval of 
continuous transmission using instrumentation calibrated in terms of an 
rms-equivalent voltage. The measurement results shall be properly 
adjusted for any instrument limitations, such as detector response 
times, limited resolution bandwidth capability when compared to the 
emission bandwidth, sensitivity, etc., so as to obtain a true peak 
measurement for the emission in question over the full bandwidth of the 
channel.
    (5) The peak power spectral density is measured as a conducted 
emission by direct connection of a calibrated test instrument to the 
equipment under test. Measurements are made using a resolution bandwidth 
of 1 MHz. If the device can not be connected directly, alternative 
techniques acceptable to the Commission may be used.
    (b) The peak levels of emissions outside of the frequency band of 
operation shall be attenuated below the maximum peak power spectral 
density contained within the band of operation in accordance with the 
following limits:
    (1) For transmitters operating in the band 5.15-5.25 GHz: all 
emissions within the frequency range 5.14-5.15 GHz and 5.35-5.36 GHz 
must be attenuated by a factor of at least 27 dB; within the frequency 
range outside these bands by a factor of at least 37 dB.
    (2) For transmitters operating in the 5.25-5.35 GHz band: all 
emissions within the frequency range from the band edge to 10 MHz above 
or below the band edge must be attenuated by a factor of at least 34 dB; 
for frequencies 10 MHz or greater above or below the band edge by a 
factor of at least 44 dB.
    (3) For transmitters operating in the 5.725-5.825 GHz band: all 
emissions within the frequency range from the band edge to 10 MHz above 
or below the band edge must be attenuated by a factor of at least 40 dB; 
for frequencies 10 MHz or greater above or below the band edge by a 
factor of at least 50 dB.
    (4) The above emission measurements shall be performed using a 
minimum resolution bandwidth of 1 MHz. A lower resolution bandwidth may 
be employed near the band edge, when necessary, provided the measured 
energy is integrated to show the total power over 1 MHz. Regardless of 
the attenuation levels shown above, emissions outside the frequency 
range of operation do not need to be attenuated below the general 
radiated emission limits in Sec. 15.209.
    (5) Unwanted emissions must comply with the general field strength 
limits set forth in Sec. 15.209. Further, any U-NII devices using an AC 
power line are required to comply also with the conducted limits set 
forth in Sec. 15.207.
    (6) The provisions of Sec. 15.205 of this part apply to intentional 
radiators operating under this section.

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    (7) When measuring the emission limits, the nominal carrier 
frequency shall be adjusted as close to the upper and lower frequency 
block edges as the design of the equipment permits.
    (c) The device shall automatically discontinue transmission in case 
of either absence of information to transmit or operational failure. 
These provisions are not intended to preclude the transmission of 
control or signalling information or the use of repetitive codes used by 
certain digital technologies to complete frame or burst intervals.
    (d) Any U-NII device that operates in the 5.15-5.25 GHz band shall 
use a transmitting antenna that is an integral part of the device.
    (e) Within the 5.15-5.25 GHz band, U-NII devices will be restricted 
to indoor operations to reduce any potential for harmful interference to 
co-channel MSS operations.
    (f) U-NII devices are subject to the radio frequency radiation 
exposure requirements specified in Secs. 1.1307(b), 2.1091 and 2.1093 of 
this chapter, as appropriate. All equipment shall be considered to 
operate in a ``general population/uncontrolled'' environment. 
Applications for equipment authorization of devices operating under this 
section must contain a statement confirming compliance with these 
requirements for both fundamental emissions and unwanted emissions. 
Technical information showing the basis for this statement must be 
submitted to the Commission upon request.
    (g) The frequency stability of the carrier frequency of an 
intentional radiator operating under this section shall be #10 ppm over 
10 milliseconds. The frequency stability shall be maintained over a 
temperature variation of -20 degrees to +50 degrees Celsius at normal 
supply voltage, and over a variation in the primary supply voltage of 85 
percent to 115 percent of the rated supply voltage at a temperature of 
+20 degrees Celsius. For equipment that is capable of operating only 
from a battery, the frequency stability tests shall be performed using a 
new battery without any further requirement to vary supply voltage.