Keep in mind that the Droid X is a phone from 2010, and Droid is a nickname for Android. It isn't actively sold by Verizon and is not a 4G (LTE) handset. A more modern version I can suggest is the Motorola Bionic (Android device). The mobile hotspot feature works like a mobile router using the data connection on the phone. With the Droid X, you cannot maintain a data connection while on a phone call. You can verify data usage using the "My Verizon" tool in the phone, check your online account or call customer service.