Roy’s Two-Way Radios

Digital two way radios may communicate text from computer-aided dispatch. For example, a display in a tow truck may give a textual location for a call and any related details. The tow truck driver may press an acknowledge button, sending data in the opposite direction and flagging the call as received by the driver. They can be used for analog telemetry systems, such as livestock tank levels, as described above. Analog conditions are translated into data words. Some systems send radio paging messages which can either: 1) beep a paging receiver, 2) send a numeric message, or 3) send a text message.

Digital systems typically use data rates in the 1,200-19,200 kilobit-per-second rates and may employ modulation schemes such as frequency shift keying, audio frequency shift keying, or quadrature phase shift keying to encode characters. Modern equipment have the same capabilities to carry data as are found in Internet Protocol. Working within the system’s protocol constraints, virtually anything can be sent or received.