Tata Telecommunications and Bharti Airtel have emerged the best performers in the national capital and the country's commercial capital, respectively, with the lowest call drop rates of 0.84 per cent and 0.97 per cent, respectively.
Bharti Airtel has emerged as the mobile network with the least number of call drops on Mumbai roads, while in Delhi, Tata (CDMA) tops the list, according to two-day drive tests conducted by the Telecom Regulatory Authority of India (Trai).
Against the maximum permissible limit of less than two per cent for call drop rate fixed by the telecom regulator, the call drop rate registered by Airtel network in Mumbai was 0.97 per cent.
On the other hand, with 5.56 per cent, Idea Cellular had the highest call drop rate. Except for one operator, none met the prescribed benchmark, Trai said.
In Mumbai, the test was carried out between 9 am and 7:30 pm on 23-24 June and covered peak and off-peak hours. About 3,305 calls were made in the networks of all six operators.
On Trai's behalf, TUV SUD conducted the drive test, covering various locations in the south and central parts of the city.
In the national capital, Tata emerged as the best operator, with a call drop rate of only 0.84 per cent. At 17.29 per cent, Reliance Telecommunications' rate was the highest.
Here, the test was carried out on 9-11 July. It covered various locations in south central and west Delhi. The test, carried out between 9 am and 8:30 pm, covered both peak as well as off-peak hours. A total of 3,626 calls were made across six networks.
Trai said the main limitation of a drive test was that it was based on data collected at a specific point. Also, it showed only the network conditions / performance along the route covered by the test vehicle; it didn't reflect the long-term performance of the networks and the network conditions away from the route covered.
The regulator said telecom service providers claimed frequent call drops resulted from limited spectrum; delay in allocation of spectrum; reduction in the 2G frequency band after the spectrum auction; and major changeover of frequencies within and across the 900-MHz and 1,800-MHz bands on the live networks of some players. Poor coverage due to non-availability of sites for base transceiver stations in some areas; and sealing and forced closure of existing sites were also cited.
During the past six months, 801 sites in Mumbai and 523 sites in Delhi were shut due to various reasons. The closure of each site affects three to four neighbouring sites, which might result in increased call drops at these locations.
Trai is weighing the need for a consultation paper on 'regulatory framework on call drops', based on available information, discussions with telecom service providers, independent tests and international best practices.