"The TERM cells (field unit of DoT) have been asked to take up the special audit to assess the coverage/quality of service in metro/capital cities of all mobile operators network in order to assess the gravity of problem of call drops," Telecom Minister Ravi Shankar Prasad said in a written reply to the Rajya Sabha today.
In reply to a query as to whether the government has ordered special audit of mobile operators on call drops, he said "yes".
The main reasons behind call drops are poor radio coverage, radio interference due to unauthorised use of repeaters or wi-max frequencies at international borders, loading of available spectrum, inadequate investment in network and change in pattern of traffic, he said.
Telecom Secretary Rakesh Garg undertook a meeting with mobile operators in April to review the issues related to quality of service in telecom networks across the country.
Issues raised during the meeting involved call drops and non-transparency in billing by telcos among others.

A recent report by TRAI has said most of the telecom operators in Delhi and Mumbai are not meeting the prescribed standards regarding call drops.
DoT had also asked the operators to submit the action taken report on call drops by July 31.
In reply to a separate query, Prasad said an independent drive test was conducted by TUV SUD on June 23-24 in Mumbai and July 9-11 in Delhi which revealed that only Tata (CDMA) in Delhi and Airtel in Mumbai were meeting the benchmark prescribed for call drops.