A radio is a communication device that can be used to send and receive messages. A portable radio is a digital two-way radio that can be carried around and does not need to be attached or permanently installed to a station. A typical two-way radio system allows people to speak over a radio channel, but only one user can transmit at a time so users must take turns talking. When the radio is in receive mode the user can hear the transmissions on the channel, and when the user wishes to communicate, they press the “push-to-talk” button on the device.