Push to Talk Over Cellular

Push-to-talk over cellular definition

Push-to-talk over cellular (PoC) technology uses mobile networks for instant voice transmissions. Unlike walkie-talkies that work only between two people, PoC enables group communication. 

See also: Radio over Internet Protocol, general packet radio service, voice over wireless local area network, VoIP

How push-to-talk over cellular works

1. 1.Initiating a call. When a user presses the push-to-talk (PTT) button on their device, it sends a signal to a PoC server to start a communication session.
2. 2.Connecting to the server. The PoC server authenticates the user, verifies their subscription to the PoC service, and determines the recipient(s) of the call.
3. 3.Transmitting. The user’s device records the voice message and encrypts it to ensure privacy and security before sending it over the cellular network to the PoC server.
4. 4.Routing the data. The PoC server receives the encrypted voice data and routes it to the appropriate recipient. If the recipients are part of a predefined group, the server broadcasts the voice data to all members at the same time.
5. 5.Receiving the message. The recipients’ devices receive the encrypted voice data from the PoC server. They decrypt, decompress, and convert it into audible speech. While it may seem like a lot, the recipients hear the message almost instantly. 
6. 6.Ending the call. When the user releases the PTT button, the device sends another signal to the PoC server to end the transmission.