rm data.outcomm_type=0loss_model=1for x in  0.4 0.5 0.6 0.7do             pG=0.01	pB=$x	pGG=0.96	pBB=0.94  	ith=20	for xx in $( seq 1 $ith )	do		echo $xx		echo $x      		ns.exe wireless_error.tcl $pGG $pBB $pG $pB $xx $comm_type $loss_model	done	./plot_err.pl test $ith $x	done# ith is the number of iteration# if BSC channel packet loos rate =pG# loss_model: 0 for BSC, 1 for GE model# comm_type: 0 for broacdcast, 1 for unicast