2. MTS launches Net-calls scheme for WhatsApp, Viber, Google Chat priced at Rs 499 Sistema Shyam Teleservices (SSTL) that offers mobile phone and internet services under the brand name MTS on Monday announced special tariff plans for phone calls made through internet, at prices as low as 10 paise per minute for domestic or international calls. The special plans are targeted at phone calls using any over-the-top (OTT) voice messaging app services such as WhatsApp, Viber, Google Chat, Facebook Messenger, and Skype amongst others. A 5GB data pack would cost a pre-paid subscriber about Rs 499, which translates into 5,000 minutes of phone calls using internet-based services, Sistema Shyam said in a statement. Similarly, postpaid customers can opt for rental plans starting Rs 599 for 10 GB data, it said.