Mumbai: Telecom operators in Mumbai have once again failed to keep the call drop rate below the maximum limit. While the accepted level is below 2% of the total calls made, the city witnessed a call drop rate ranging from 2.6% to as high as 5.5%. This was revealed in a survey conducted by the Telecom Regulatory Authority of India ( TRAI ) during the August-September quarter among six leading telecom operators in the city. Mobile users agreed that calls dropped at least three to five times a day, which was frustrating. Sources said TRAI officials conducted an independent drive across a 300km route of Mumbai, covering most parts of the island city and suburbs. The survey report said: “We had laid down the benchmark for call drop rate at less than 2%. But six operators in Mumbai exceeded this limit and none met the prescribed benchmark.” Accessibility—a user’s ability to obtain the required service from a network—is monitored (by TRAI) by measuring the call setup success rate (CSSR). The CSSR is defined as the ratio of established calls to the number of call attempts. In the September drive, the CSSR was a poor 92.6% for one of the operators while, for the remaining five, it was around 95.37% to 97.39%—the benchmark being 95% and above. In other words, most operators reported improved call accessibility. For measuring voice quality, TRAI had set down norms requiring connections with good voice quality to be 95% or above. Barring one operator, five had scores below 95%, in the the range of 91.3% to 94.1%. Compared wth the drive in the previous April-June quarter, though, there was an improvement in scores, said sources. “But call drop is a major issue for Mumbai and we receive regular complaints,” said an operator. “Removal of cell towers from certain parts has also added to the call drops.” In the past, when the BMC had stopped accepting applications for cell towers, a source from Cellular Operators Association of India had warned of call drops. The source had said there was “no health hazard from the towers and they were following norms which were ten times more stringent than global standards”. Anti-radiation activist Prakash Munshi, who has filed a PIL, said he was not against towers “but they should not come up in gardens, schools and hospitals.”