Telecom Regulatory Authority of India (TRAI) has made it mandatory for telecom providers to let the phone call ring for 30 seconds on mobiles, in case the call is not answered or rejected by the subscriber. Landline phone calls require 60 seconds of ring time, TRAI notes.

Till now, there were no such limits for calls in India.

"The time duration of alert for an incoming voice call, which is neither answered nor rejected by the called party, shall be thirty seconds for Cellular Mobile Telephone Service," the Telecom Regulatory Authority of India.

TRAI notes that the new regulation would be effective "after 15 days from the date of publication in the Official Gazette," reports said.