--- a/src/wifi/model/cara-wifi-manager.cc	Sat Sep 05 13:37:30 2015 +0200
+++ b/src/wifi/model/cara-wifi-manager.cc	Sat Sep 05 15:53:37 2015 +0200
@@ -184,7 +184,7 @@
   NS_LOG_FUNCTION (this << st << size);
   CaraWifiRemoteStation *station = (CaraWifiRemoteStation *) st;
   uint32_t channelWidth = GetChannelWidth (station);
-  if (channelWidth >= 40)
+  if (channelWidth > 20 && channelWidth != 22)
     {
       //avoid to use legacy rate adaptation algorithms for IEEE 802.11n/ac
       channelWidth = 20;
@@ -200,7 +200,7 @@
   /// \todo we could/should implement the Arf algorithm for
   /// RTS only by picking a single rate within the BasicRateSet.
   uint32_t channelWidth = GetChannelWidth (station);
-  if (channelWidth >= 40)
+  if (channelWidth > 20 && channelWidth != 22)
     {
       //avoid to use legacy rate adaptation algorithms for IEEE 802.11n/ac
       channelWidth = 20;