Here in Japan, A career only supports VoLTE because it stopped CDMA2000 3G network for obvious reason. An other career don't support 3G WCDMA network on 5G plan

Here in Japan, A career only supports VoLTE because it stopped CDMA2000 3G network for obvious reason. An other career don't support 3G WCDMA network on 5G plans because it's inefficient and LTE coverage is good enough. An other career only have 4G/5G network because it started recently. 2G network is completely gone a decade ago because no one use GSM.