Telecom Regulatory Authority of India has received 1,165 service related complaints against leading telecom operator Bharti Airtel, followed by 654 for Vodafone and 647 against Reliance," Minister of State for Communications and IT Milind Deora informed the parliament of Friday.

He said that a total of 4,133 service related complaints were received by the regulator in 2011-12.

There were 466 and 165 complaints against state run BSNL and MTNL, respectively. Besides, Tata had 438 complaints and Idea Cellular, 326, the Minister added.

Deora said for basic telephone service (wireline), non compliance with the Quality of Service (QoS) benchmarks included fault repair, metering and billing and response time to the consumer for assistance.

In case of mobile telephone service, non-compliance included call drops, network congestion and operator response within 60 seconds.

As per the licence conditions, telecom operators are responsible for maintaining the performance and the QoS.