U.S. now allows full 5-GHz Wi-Fi networking: "The FCC added another 255 MHz and 11 channels to the existing 325 MHz and 13 channels available for Wi-Fi in the Unlicensed National Information Infrastructure spectrum. As of Jan. 20, any products that apply for certification in the 5.47-to-5.725-GHz band or in the lower end of the UNII band at 5.25 GHz to 5.35 GHz were required to support dynamic frequency selection (DFS) and transmit power control (TPC) to minimize interference, per a February 2005 FCC order. If you've already got equipment running in the lower band installed, don't worry, you're grandfathered.DFS and TPC are part of 802.11h, the European "flavor" of 802.11a. DFS dynamically instructs a transmitter to switch to another channel under particular conditions, such as the presence of a radar signal.