D-Star

What is D-STAR?
D-STAR is a new ham radio standard which, when made into a system, offers both digital voice and data communication. It connects repeater sites over microwave links and the Internet and forms a wide area ham radio network. The DSTAR system provides a new capability and functionality to the ham radio world and increases the efficiency of emergency communications.

What can the D-STAR system do?
128kbps digital data and 4.8kbps digital voice communication!
The D-STAR system provides not only digital voice (DV mode) communication but also digital data transmission (DD mode). It can exchange various data files such as graphics, images, etc, at 128kbps.  Multiple repeater links by radio and the Internet provide long distance communication to virtually anywhere.

Many Internet applications are available
The D-STAR system uses the TCP/IP protocol, so when it is connected with a PC, web, e-mail and other Internet applications are available.

Wireless Internet Access
No matter where you travel with the DSTAR network, you can access the web, e-mail, text messages and multimedia messages.  It works even when “the net is down” and normal Internet communications are not working.
The D-Star standard, first published four years ago, resulted from government-funded research in Japan administered by the Japan Amateur Radio League (JARL) to investigate Amateur Radio digital technologies. D-Star is an open protocol that’s available for implementation by anyone.

“Amateur Radio is again out there in the forefront of technology,” saiys Ray Novak of Icom America, one of the companies manufacturing D-Star equipment. Although he concedes there’s a steep learning curve ahead, he predicts Amateur Radio users will invent new ways to put D-Star technology to work as they get better acquainted with its possibilities.

At this stage, the ARRL HQ in Newington, CT has a D-Star 23-cm repeater is up and running in digital voice mode, and W1AW Station Manager Joe Carcia, NJ1Q, and ARRL Web and Software Development Manager Jon Bloom, KE3Z, have enjoyed contacts through the repeater. In the meantime, Bloom has been working to interface the D-Star system with a Linux server, which will serve as an Internet gateway, to check out that aspect of the system.  It is a new technology and still being created.

The digital voice stream can simultaneously handle voice at 3600 bps with error correction and data at up to 1200 bps. Since a D-Star voice signal occupies only 6.25 kHz the potential is there to make more efficient use of available spectrum on 2 meters by squeezing up to four D-Star repeaters into the same space as two analog channels.
Working through a D-Star repeater is a bit different than using an analog repeater. While the basic “repeater” concept is the same, some aspects are altogether new. Your call sign is the key to a D-Star system since it’s incorporated into every transmission you make. Because of D-Star’s call sign-routed system, registered users are able to cross-communicate with stations registered on another network’s D-Star repeater, wherever it may be.
 
This means that if a user calls a station registered elsewhere, the voice transmission would be routed to the appropriate repeater where it would be heard just as though both stations were using the same repeater.

The 1.2 GHz D-Star system’s high-speed data capability is another exciting feature. The high-speed data stream has a data rate of 128 kbps and a maximum occupied bandwidth of 130 kHz. With the Ethernet jack on the transceiver, you now have the functionality of an ISDN (integrated services digital network) line available in your vehicle.
“We’ll have to find new ways of using this technology,” Novak said. “That will be where ham radio changes. This opens up an unbelievable array of features for repeater systems–including graphics, schedules, tables, photos, you name it!”

The D-Star discussion forum at dstar_digital@yahoogroups.com is the place where the latest developments, applications and uses are appearing almost daily with this new technology.
John Webb of Whiskey 7 Media interviewed some Washington State hams about it.