If you want to know the current expected time of arrival or departure of any Indian Train at any station in India, you can know this by sending SMS to 139 following message -
< AD Train-Number STD-Code >
Suppose you are in Delhi (STD code 011), and before going to railway station you want to know the current status of expected time of arrival of train (suppose) Paschim Express (train number- 2926). To know this through your mobile, just send SMS-
AD 2926 011 to 139.
There are many time in which you will not be able to call Indian railway station enquiry counter to know the current expected time of Arrival or Departure of any train. Many time you may not know the contact number of station enquiry counter.
If you know the status of train (expected arrival or departure time) at your desired station, you can save a lot of your time, as most of the train arrive station with lot of delay.