rule in Sections 15.33(a)(1) through (a)(3), or the range applicable to the digital
device, as shown in Section 15.33(b)(1), whichever is the higher frequency
range of investigation. When testing the host product, all the transmitters must
be operating. The transmitters can be enabled by using publicly available
drivers and turned on, so the transmitters are active. In certain conditions it
might be appropriate to use a technology-specific call box (test set) where
accessory devices or drivers are not available. When testing for emissions
from the unintentional radiator, the transmitter shall be placed in the receive
mode or idle mode, if possible. If receive mode only is not possible then, the
radio shall be passive (preferred) and/or active scanning. In these cases, this
would need to enable activity on the communication BUS (i.e., PCIe, SDIO,
USB) to ensure the unintentional radiator circuitry is enabled. Testing
laboratories may need to add attenuation or filters depending on the signal
strength of any active beacons (if applicable) from the enabled radio(s). See
ANSI C63.4, ANSI C63.10 and ANSI C63.26 for further general testing details.
