PushToTalk

Push-to-Talk (PTT) is a communications method that enables immediate voice transmission by pressing a button. In most systems the talk path is half-duplex: a speaker talks while others listen, then control returns to listening when released. PTT can support one-to-one calls or many-to-many conversations within defined talkgroups or contact lists.

Originating with hardware two-way radios used by public safety, transportation, and industry, PTT has expanded to software-based solutions on smartphones, tablets, and desktops. Modern PTT systems span networks and platforms, enabling instant coordination across organizations without dialing a number.

Operation and features: to transmit, a user holds a PTT control to start a session and releases to stop. A central server manages authentication, talkgroup membership, and session setup. Many systems add priority signaling, emergency alerts, and presence indicators to show who is available.

Technologies and standards: PoC uses IP-based signaling such as SIP to initiate sessions, with media carried over RTP and often SRTP for encryption. Traditional radio standards like TETRA and DMR define PTT within dedicated networks, while consumer and enterprise apps may use proprietary or open protocols for cross-network support.

Applications and considerations: PTT is used in emergency services, logistics, field service, utilities, construction, and large events, as well as in team coordination apps. Benefits include rapid communication and reduced call setup. Drawbacks include network dependence, latency, privacy concerns, and the risk of accidental transmissions; effective use requires policy and training.