Interfacing Telephone Network with UV5R

[Lightspeed]

The mobile phone system is full duplex ( meaning it can play a received message at the same time as it transmits) This id the main difference between telephones and radios, which are simplex ( meaning they only play received messages or transmit, transmit or receive, not both at the same time)

We've decided that the message received from the mobile phone will transmit via the Repeater UV5R using VOX to open and close transmit function .
This will re-transmit the telephone message in real time from the UV5R to a remote receiving radio.

If the remote receiving radio transmits back to the Repeater UV5R, the Repeater UV5R will output that reply over its loudspeaker. If the audio signal from the loudspeaker on the Repeater UV5R is connected to the mike in on the mobile phone, the reply received from the remote receiving radio will be transmitted by the mobile phone.

In effect the mobile phone will then be operating in a simplex mode. You are correct in assuming that "over" will be a good way to identify when its the correspondent party's turn to speak.

In this scenario, the call will only be able to be initiated and terminated by the person calling the mobile phone.