Airtel mobile operation is the best mobile service in India. presently it is the only company owns the all India spectrum for all 2g, 3g & 4g Networks. From the beginning I am using Airtel Mobile, never faced any out of coverage or call drop problem in my city, as well as rural areas too, excepting some minor cases. The network coverage is too good in all over country.
Data speed is also remarkable. Only the charges according the service is high. Special rate packs never makes any sense while the pack is costlier at its own. Only valuable for those who are making more and more calls than internet browsing or keeping idle.