Because 5G is an entirely new technology that operates on new frequencies and systems, 4G-only phones are incompatible ... been used for years by 2G, 3G, and 4G/LTE networks.

Although wireless standards like 3G, 4G, and 5G are mostly associated with ... called VoLTE (voice-over-LTE). Even so, a particular phone can choose to use a 4G modem, yet still use 3G-style ...