802.11h

The h in 802.11h stands for HiperLan, a competing WLAN standard in Europe. In many European countries, radar and satellite services operate near the 5 GHz band, and without modification 802.11a systems could possibly interfere with them.802.11h is a supplement to the 802.11 MAC layer, specifically for 802.11a, so that it can operate in the 5 GHz band in Europe in compliance with EU regulations. The addition of 802.11h should facilitate adoption of 802.11a by European users.