Let's say you're in an office with a good Wi-Fi signal. Joining a BlueJeans meeting from your mobile, the office Wi-Fi will provide a good connection. Now you're heading out to your car. As you enter the fringe area of the Wi-Fi signal, the quality of your audio and video will degrade. Once completely out of the Wi-Fi zone, BlueJeans will switch you over to your cellular signal (assuming cellular data is enabled). You will see a brief "Resolving network issues" message while the switch takes place - you will not have to re-enter the meeting.
If you plan on remaining in the fringe area of the Wi-Fi signal, we suggest turning off your mobile's Wi-Fi so that the stronger cellular signal takes over immediately.