diff --git a/tools/cooja/java/se/sics/cooja/interfaces/NoiseSourceRadio.java b/tools/cooja/java/se/sics/cooja/interfaces/NoiseSourceRadio.java
index 8200d6bc4..0648ce02a 100644
--- a/tools/cooja/java/se/sics/cooja/interfaces/NoiseSourceRadio.java
+++ b/tools/cooja/java/se/sics/cooja/interfaces/NoiseSourceRadio.java
@@ -29,7 +29,10 @@
 package se.sics.cooja.interfaces;
 
 /**
- * Noise source radio. 
+ * The noise source radio is used to simulate ambient background noise or 
+ * point-sources of external interference (e.g. Wifi basestations).
+ * 
+ * COOJA's radio mediums may or may not choose to respect noise source radios.
  * 
  * @see MRM
  * @author Fredrik Osterlind