Reliance Jio on Tuesday launched VoLTE-based inbound international roaming services between India and Japan, based on services.Jio is the first Indian telecom operator to provide international roaming services based on Voice Over LTE in the country."Japan-based KDDI Corporation is the first international mobile service provider to avail of Jio's VoLTE calling and LTE data international roaming service which provides international travellers with access to high-speed data and voice services on Jio's all-IP, 4G-exclusive network," Jio said in a statement.It further said that the arrangement would help international travellers to experience Jio's all-IP network.Jio is the ninth largest mobile operator in the world with over 252 million subscribers so far, it said.