Disclosure Wikia

Quantum Correlated Communication Devices (QCCDs) “use quantum entanglement of something like isotopes inside the communication devices that have been entangled with other devices so no matter where in time/space/reality each communicator is, they can speak and video share. They can tell if you are a percent out of phase time/space wise by the reception on the home end's calculation devices.

They are supposed to be able to track and calculate exactly when/where you are once a signal re-establishes the natural quantum entanglement (There may now be a difference that is used to do the calculating before they naturally recalibrate) vibration and over quick increments of time shift back into harmony or alignment. 

This is a secure P2P communication which is encrypted as it is being sent through the QCCD and cannot be hacked or tapped into by other beings or AIs.

These were both handheld devices and devices integrated into the systems of larger and smaller craft that would operate in displays on a workstation or in the smart helmets of pilots.”[1]