Service providers like Reliance Communications and Vodafone met the call drop rate threshold.
"In the last 8-9 months we have increased frequency and coverage of test drives. Today we are launching Delhi's results," TRAI Chairman R.S. Sharma told reporters at a press meet.
The test drive was done in Delhi between May 3-6. The test route covered a distance of around 600 km.
There are a few parameters on which the report was based. "Improvement for most on call setup success rate and quality but degradation on call drop rate (CDR) compared to previous independent drive tests of January 2016. Most operators fall below the 2 percent CDR threshold," the report stated.
The independent test drive was carried out by Phistream.
The drive test was done on a total of 12,300 calls, made for six 2G networks, five 3G networks and three CDMA networks covering eight operators during those four days.
The call drop issue has been keeping the government and the telecom regulator busy for quite some time now.
Communications Minister Ravi Shankar Prasad recently said the Department of Telecom and the TRAI are looking into the call drop issue seriously. Around one lakh new sites (telecom towers) have been added in the country, of them 6,000 in Delhi itself.
The Supreme Court recently scrapped the watchdog's order to the telecom operators on compensating subscribers for call drops. But the government assured mobile phone users that it will keep a check on service quality.
The TRAI officials on Wednesday said they are planning to write to the government seeking amendments in the TRAI Act to address deficiencies.
Talking about penalties, one of the officials said: "We should be empowered to impose penalty."