Forum Discussion

djrichard's avatar
djrichard
Network Novice
9 months ago

VoLTE in Japan?

GSM-phones built for the US (and GSM) aren’t compatible with 2G in Japan which is based on CDMA.  So I’d like to know can I use VoLTE in Japan when roaming using Tmobile’s roaming agreements with the carriers in Japan?   And if so, does that work for txt messaging as well?

If VoLTE is a no go should I be prepared to use VoIP alternatives (I.e. with a different phone number)?

Thanks!

  • David
  • gramps28's avatar
    gramps28
    Router Royalty

    You will need to check the Japanese mobile network your roaming on to see if it's compatible with your phone by entering your imei#.

  • djrichard's avatar
    djrichard
    Network Novice

    I've already done that using the kimovil website. For the iPhone 13 mini

    - 2G is 0 for 2

    - 4G is 10 of 12 depending on carrier.

    Otherwise I know the iPhone 13 mini supports VoLTE. But VoLTE depends on the roaming agreements that T-Mobile has in place with the Japanese carriers.  I suspect T-Mobile doesn't have such agreements with them.  Looking for somebody to confirm. 

     Thanks! 

  • gramps28's avatar
    gramps28
    Router Royalty

    VoLte depends on if the other carrier supports it. There's phones out there thar have VoLte but it doesn't meet Tmobiles standards.

  • djrichard's avatar
    djrichard
    Network Novice

    I know the carriers in Japan support VoLTE.  In fact a US competitor to T-mobile announced that their roaming agreements with one of the carriers in Japan included support for VoLTE.  I didn’t see a similar announcement by T-mobile which makes me think it doesn’t have a similar agreement with carriers in Japan.