FCC Rules
In general, the U.S. FCC does not require users to license wireless LAN products, assuming that
the user does not exceed certain emission limits. The FCC uses Effective Isotropic Radiated Power
(EIRP) as a factor for determining whether a wireless LAN is in compliance with regulatory rules.
EIRP equals the transmit power (in dBm) minus cable and connector losses (in dB) and plus the
antenna gain (in dB). For 802.11b/g access points and radio cards, the EIRP can be up to 36 dBm,
which includes a transmit power up to 30 dBm (4 watts) and 6-dBi antenna gain.
In addition, the user must obtain FCC licensing for the wireless LAN solution when using
antennas or amplifiers that are not part of the access point vendor’s products certified with the
FCC. This is necessary to ensure that the proposed wireless system will not interfere with existing
systems at the location of operation. Regulatory agencies in other countries have similar rules, but
they differ slightly depending on the country. As mentioned earlier, research your country’s rules
and deploy your systems based on them.