Has anyone experienced that RTS/CTS handshaking stops occurring at the client if the the access point enables WMM? Using the carl9170 driver with RTS/CTS handshaking enabled on a USB Ubiquiti SR71-USB (Atheros AR9170 based wireless adapter). RTS/CTS will stop working when WMM is enabled on the WAP. The network is running in 802.11n C-band (5GHz) channels in Infrastructure mode with an Atheros AR9370 based Access Point. We are using RTS/CTS handshaking to reduce “Hidden Node” effects. Other clients in the network require WMM to be enabled. For reasons cited in http://www.smallnetbuilder.com/wireless/wireless-features/30938-dont- mess-with-wmm, WMM should be enabled to support 802.11e, required for 802.11n to use HT (High Throughput) link rates. With the WMM turned OFF at the AP and RTS value = 256 at the Ubiquiti client, the RTS/CTS handshake functions normally. With WMM turned ON at the AP and RTS value = 256 still on at the client no RTS/CTS handshake occurs. The carl9170 client stops sending the RTS, and the carl1970 client ignoring the CTS messages transmitted by the AP, causing collisions because of my “Hidden Node” condition. Had to get scope plots of the RF network traffic between the AP and client to observe this happening. thanks, Eric��.n��������+%������w��{.n�����{���zW����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
