This probably depends on your particular dongle model. Back in 3G era, some carriers offered USB modems with SMS locked out in the firmware, but you could flash a firmware from a different operator (also install their variant of software, the only difference being the added SMS tab and a different skin) and then you can text and even use USSD! (No calls, though.)
This probably depends on your particular dongle model. Back in 3G era, some carriers offered USB modems with SMS locked out in the firmware, but you could flash a firmware from a different operator (also install their variant of software, the only difference being the added SMS tab and a different skin) and then you can text and even use USSD! (No calls, though.)