D-STAR
D-Star information
Digital Smart Technology for Amateur Radio
D-Star Radio is a digital HAM radio. D-Star HAM radio lets you talk to people much like a walkie-talkie but with more power and frequencies. In addition to the power of D-Star HAM radio there are repeaters that bounce the signal even further.
D-STAR is an open protocol although it is published by JARL, it is available to be implemented by anyone. While Icom is the only company to date that manufactures D-STAR-compatible radios, any equipment or software that supports the D-STAR protocol will work with a D-STAR system. D-STAR systems can be built using both commercial and homebrew equipment and software. In a D-STAR system, the air link portion of the protocol applies to signals travelling between radios or between a radio and a repeater. D-STAR radios can talk directly to each other without any intermediate equipment or through a repeater using D-STAR voice or data transceivers. The gateway portion of the protocol applies to the digital interface between D-STAR repeaters (see figure 1). D-STAR also specifies how a voice signal is converted to and from streams of digital data, a function called a codec. The D-STAR codec is known as AMBE® (Advanced Multi-Band Excitation) and the voice signal is transmitted in the D-STAR system at 3600 bits/second (3.6 kbps). http://www.icomamerica.com/amateur/dstar/dstar2.asp
D-Star like cellphones uses digital voice technology, which allows you to talk further away. This is much better than analog that has difficulties when parts of the analog signal is lost.
D-Star allows you to connect your laptop to your D-Star compliant radio and talk to other D-Star complaint radios with a program like telnet. One of the D-Star compliant radios will need to act as a server for this to work.
D-Star further information
Some radios with D-Star have a pager feature that lets someone page you with their radio. This is great because we aren't always at our radio. The ICOM D-Star compliant radio, ID-800H has this feature.
D-Star radios have a feature that lets you send digital messages to one another. No other radio known by this author has this feature. A digital message can be programmed into the radio so that you can send your message while driving. This is great for the HAM community in those cases when the traffic is bad.
"It’s only natural that D-Star’s digital voice capabilities will be linked up with the most popular repeater sharing applications, EchoLink® and IRLP. Since your voice is already digitized within the D-STAR system, third party bridges and converters to and from other digital voice systems an obvious and expected future addition." http://www.icomamerica.com/amateur/dstar/dstar5.asp
D-Star history
D-STAR, a standard published in 2001, is the result of three years of research funded by the Japanese government and administered by the JARL to investigate digital technologies for amateur radio. The research involved Japanese radio manufacturers and other observers. Icom provided the equipment used for development and testing. D-STAR radios and repeaters have been tested extensively and are now ready for public use.