Its a good news for IRCTC users that they will now get their confirmed PNR status SMS on  their mobile and you don’t have to worry about your ticket that it got confirmed or not.
As soon as your wait-listed ticket gets confirmed you will receive a SMS from IRCTC about your details of seat and coach.

As you all know that each wait-listed person has to check their PNR status and its not only one time but you have to check again and again as you don’t know whether your ticket got confirmed or not. Many people use net to check their status and many usually SMS to 139 or call that number.
Others get to know the status of their tickets only after reaching stations.

“Once the SMS-based service is operational, passengers will get the updated status of their waitlisted tickets automatically,” the official said, adding “only those passengers will get the message whose tickets get confirmed.” CRIS, the technological arm of Railways, is making the software for the SMS-based service.
IRCTC has already launched a system for booking tickets using mobile phones. Check your PNR Status from here too!