BSNL has introduced Special Tariff Vouchers for the prepaid customers. These STVs are the cheapest and the best in market where you can make very cheap calls. The cost of the STVs are a little different in each state. For more information check the particular state bsnl website.
BSNL has a very good network coverage better than Vodafone and Airtel. In Bangalore BSNL is now one of the best network. There is no congestion in network. BSNL has improved a lot. It provides faster and cheaper GPRS than any other operator. By introducing the STVs BSNL has proved that call rates are made more cheaper than any other service provider.
Its our wrong impression that since BSNL is a govt service provider the service shall be bad. But when you go for it you will experience the difference. Dont get cheated by private operators. I have been using Airtel and vodafone and shifted to BSNL and my experience is very good with BSNL.
But the E recharge centers or customer care people doesn’t know much about these STVs. Only you need to do is, e-recharge for the particular denomination mentioned in the STV from a e-recharge shop. The tariff will automatically change.
In Karnataka the STV details can be taken from the link
https://karnataka.bsnl.co.in/offers/STVs.pdf
You can choose two STVs by selecting one as the base tariff and other as the tariff cutter.
For eg if you select STV of Rs 99 all the local and STD calls in home and roaming network is 49ps and it is valid for 365 days. On top of that if you want to go for locall all network calls to 30ps, you have to recharge it with Rs 61 and it is valid for 30days. So now local calls will be 30ps and STD will be 49ps.
Base tariff STVS are available for STV 45(1p/sec, 180 days validity), STV 49(49p/min, 180days validity) and STV 99(49p/min, 365days validity)