how can send long sms

#!/bin/sh
# Example of sending long SMS by OpenVox GSM card.

#####################################################
# The following parameters should be input to yours!
#####################################################

# SMS Content(s)
SMS_CONTENTS="123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890"

# SPAN Number(s)
SPAN=1

# Destination Number(s)
NUMBER=15623841257

# SMS Center Number.
#SMSC= 1380075500 #Shenzhen China

#Sending MODE: pdu or text
MODE=text

######################################################
# The following should not be edited by users!!!
######################################################


# Set up sending methods
if [ $MODE = text ];then

# Defaut length of TEXT mode
LIMIT=140
asterisk -rx "gsm set send sms mode text"
else

# Default length of PDU mode
LIMIT=70
asterisk -rx "gsm set send sms mode pdu"
fi

# Count the length of whole SMS
LENGTH=${#SMS_CONTENTS}

# Groups of sending time(s)
TIMES=$(($LENGTH / $LIMIT))

# The remaining length of SMS
LAST=$(($LENGTH % $LIMIT))

if [ $LAST -eq 0 ];then
# Notes
SEND_TIMES=$TIMES
else
SEND_TIMES=$(($TIMES+1))
fi


echo -----------------------------------------------------------------------
echo "Please note: Your SMS will be separted to $SEND_TIMES section(s) to send!"
echo -----------------------------------------------------------------------

for((i=0; i<$TIMES; i++)) do

	S=$(($i*$LIMIT))
	REAL_CONTENT=${SMS_CONTENTS:$S:$LIMIT}
	asterisk -rx "gsm send sms $SPAN $NUMBER \"$REAL_CONTENT\""
	echo $(($i + 1))

done

if [ $LAST -ne 0 ]; then
	S=$(($LENGTH - $LAST))
	REAL_CONTENT=${SMS_CONTENTS:$S:$LAST}
    	asterisk -rx "gsm send sms $SPAN $NUMBER \"$REAL_CONTENT\""
	echo $(($TIMES + 1))

fi