I have a SIM-free Galaxy S9+ (SM-G965F/DS) model. And in my home country (India) VoLTE works fine on it. I'm moving to Japan soon and was thinking of getting a Japanese SIM (The name of the carrier is au) . But I have read many posts about peoples phone not working with au VoLTE service (voice+sms service not working).

Is it possible that different countries use different VoLTE standards and my phone might not support au VoLTE?

  • Yes due to the bandwidth variation
    – Izhan Ali
    Feb 12, 2020 at 9:08


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