TETRA over LTE? Public safety LTE? What do these things really mean?
Ask an engineer for the meaning of TETRA over LTE and they may say something like: "TETRA over LTE is an LTE smart device application and an interface in the TETRA service core to connect from the smart device to TETRA services, using a secured VPN tunnel over LTE data access."
Okay, but what does that mean in everyday terms?