Network connectivity is a must for the device to function well. To fetch the information on the phone a working data connection on the phone is required.
In case of no connectivity features like real-time GPS tracking, 2 way calling & Live streaming won't work. When there is no connectivity, it stores on onboard memory and syncs when connectivity is resumed. So you never lose any information.
As soon as connectivity is established features like real-time GPS tracking, 2 way calling & Live streaming start working equally well.