Recibir sms en el arduino

#include <SoftwareSerial.h>
SoftwareSerial mySerial(7, 8);

char incoming_char=0;

void setup()
{
  Serial.begin(19200); // for serial monitor
  mySerial.begin(19200); // for GSM shield
 
  mySerial.print("AT+CMGF=1\r");  // set SMS mode to text
  delay(100);
  mySerial.print("AT+CNMI=2,2,0,0,0\r");
  // blurt out contents of new SMS upon receipt to the GSM shield's serial out
  delay(100);
}

void loop()
{
  // Now we simply display any text that the GSM shield sends out on the serial monitor
  if(mySerial.available() >0)
  {
    incoming_char=mySerial.read(); //Get the character from the cellular serial port.
    Serial.print(incoming_char); //Print the incoming character to the terminal.
  }
}