Not all frequency bands are supported worldwide. In the USA, however, some providers should work, AT&T and T-Mobile are mentioned for 4G LTE. The device supports the following:
800 MHz , 850 MHz , 900 MHz , 1800 MHz , 1900 MHz , 2100 MHz , 2300 MHz , 2600 MHz
and here are the matching providers in the US for 3G and 4G:
https://www.signalbooster.com/pages...
What this doesn't quite clarify is where (regionally) these providers transmit in what frequency, so despite compatibility you may not have coverage in a working frequency everywhere (because AT&T, for example, also operates in frequencies that the device does not support).