Back to basics to try and send SMS with TC35i GSM

I have the following code for the Arduino Uno, it sends the simple command ‘AT’ over (TX) and should get response over (RS).
When AT, what should come back is ‘OK’, however I get nothing.

Very basic code am I missing anything obivous?

#include <SoftwareSerial.h>

void setup() 
  Serial.begin(9600);     // Baud set to 9600 (TC35 is autobaud)

  void loop() 
  delay(2000);   // Delay to view transmission      
  Serial.print("AT"); // Test command