Document changes to YansWifiPhy defaults

CHANGES.html

@@ -43,6 +43,24 @@ the cracks, unfortunately.  If you, as a user, can suggest improvements
 to this file based on your experience, please contribute a patch or drop
 us a note on ns-developers mailing list.  </p>
 
+<hr>
+<h1>Changes from ns-3.6 to ns-3.7</h1>
+
+<h2>Changes to build system:</h2>
+
+<h2>New API:</h2>
+
+<h2>Changes to existing API:</h2>
+
+<h2>Changed behavior:</h2>
+<ul>
+<li> Changed default value of YansWifiPhy::EnergyDetectionThreshold from
+-140.0 dBm to -96.0 dBm.  Changed default value of 
+YansWifiPhy::CcaModelThreshold from -140.0 dBm to -99.0 dBm.  Rationale
+can be found <a href="http://www.nsnam.org/bugzilla/show_bug.cgi?id=689"> 
+here</a>.
+</ul>
+
 <hr>
 <h1>Changes from ns-3.5 to ns-3.6</h1>