Index: mac/wireless-phyExt.h
--- mac/wireless-phyExt.h.orig
+++ mac/wireless-phyExt.h
@@ -211,7 +211,7 @@ class WirelessPhyExt : public WirelessPhy { (private)
 	double SINR_Th_RX; //SINR threshold for decode data according to the modulation scheme
 	double power_RX;
 
-	void log(char * event, char* additional); // print out state informration
+	void log(const char * event, const char* additional); // print out state informration
 	double SINR_Th(int modulationScheme);
 	inline int initialized() {
 		return (node_ && uptarget_ && downtarget_ && propagation_);