D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification for amateur radio. The system was developed in the late 1990s by the Japan Amateur Radio League and uses frequency-division multiple access and minimum-shift keying in its packet-based standard. There are newer digital modes (Codec2,
for example) that have been adapted for use by amateurs, but D-STAR was
the first that was designed specifically for amateur radio. Several
advantages of using digital voice modes are that it uses less bandwidth than older analog voice modes such as amplitude modulation, frequency modulation, and single sideband. The quality of the data received is also better than an analog signal at the same signal strength, as long as the signal is above a minimum threshold and as long as there is no multipath propagation. D-STAR compatible radios are available for HF, VHF, UHF,
and microwave amateur radio bands. In addition to the over-the-air
protocol, D-STAR also provides specifications for network connectivity,
enabling D-STAR radios to be connected to the Internet or other
networks, allowing streams of voice or packet data to be routed via
amateur radio. D-STAR compatible radios are manufactured by Icom, Kenwood, and FlexRadio Systems
