Mobile network operator (MNO) XL Axiata has announced plans to test voice-over-LTE (VoLTE) this year, with company director Yessie D Yosetya noting that on the current XL network, packet switched rather than circuit switched technology dominates voice call traffic. According to the official, 60% of regular customers are making calls using apps such as WhatsApp, and the introduction of higher quality VoLTE will only serve to improve call quality, he said. XL’s support of VoLTE has been mirrored by Imam Nashiruddin, Commissioner of the Indonesian Telecommunication Regulatory Body (BRTI), who suggested that to achieve the best results, VoLTE trials should be conducted by operators on a cross-network basis.
Source: https://www.telegeography.com/products/commsupdate/articles/2017/06/30/xl-axiata-to-test-volte/