30. The system of claim 27 , wherein each of the terminal devices is further configured to transmit a respective acknowledgement message indicating that the message was successfully received by the terminal device.
30. The system of claim 27 , wherein each of the terminal devices is further configured to transmit a respective acknowledgement message indicating that the message was successfully received by the terminal device. 31. The system of claim 30 , wherein the server is further configured to: determine for each of the terminal devices whether a respective indication of verbal confirmation has been received; determine for each of the terminal devices whether a respective acknowledgement message has been received; and display a respective message status for each of the terminal devices indicating whether the message was at least one of received or understood.