Phones that were released or bought before Reliance Jio had come, were mostly 4G / 3G enabled phones without Voice Over LTE (Long Term Evolution / 4G) support. Reliance Jio's Free Calls offer forced many customers to buy new phones with VoLTE support right out the box. Reliance LYF phones are still Value For Money phones with 4G VoLTE support. LYF phones enable customers to make calls directly using its default dialer without installing any App. Phone directly converts voice encoded data to VoLTE packets to transfer digitally.
Phones without VoLTE support can not directly make VoLTE calls. Reliance Jio answers this problem with its App Jio4GVoice. This App enables even 2G, 3G and Non VoLTE 4G phones to make Voice and Video Calls seamlessly. Customers buying Jio SIM need not worry about their phone now. This app also supports messaging service. You can send and receive SMS without any problem. After setting the Jio4GVoice app the default calling app, you can directly call a number from dialpad without opening the app.
Reliance Jio is planning to release entry level feature phones with VoLTE support so that the customer can happily use its Unlimited Calls offer. After 31 March 2017, Jio customers have to subscribe to monthly voice / data packs.