D–STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification developed as the result of research by the Japan Amateur Radio League to investigate digital technologies for amateur radio.
What is D-Star?
D-STAR (Digital Smart Technologies for Amateur Radio) is a radio system which offers digital voice and data communication. Repeater sites are pre-dominantly connected over the Internet and form a wide area amateur radio network as a result that can span states, countries, continents or the entire world.
The following video gives you some insights into the system.
Thanks go to Duffy WB8NUT (http://wb8nut.com/dstar/ ) for allowing us to re-produce the following information from his page.
Facilities D-Star Provides
128kbps digital data (on 1.2GHz) and 4.8kbps digital voice communication
D-Star offers digital voice as well as slow and high-speed data communications. Slow-speed digital voice and data are transported at 4800 bps, of which 3600 bps is used for voice transmission and the remaining 1200 bps is used for syncronization and general use. Of that 1200 bps, around 900 bps is available for the transmission of data.
High-Speed digital data communication is transported at 128kpbs and is capable of supporting Ethernet packets and also is fast enough to use for Internet applications such as displaying web pages. In order to send and receive greater volumes of data and large files, D-Star has the “DD Mode” or Digital Data Mode. The DD mode is only supported on the 1.2Ghz amateur band and is capable of sending a receiving data at a 128kbps rate.
There are several software applications to use for data exchange, See the Favourites page for links.
Increase efficiency and availability of emergency communications
Out in the field, fast emergency information is the key. Send pictures and weather charts to or from a remote location with a data capable radio such as the Icom ID-1. “A picture is worth a thousand words”, and efficient send/receive opens up your repeater for other emergency communications. In DD mode, the Icom ID-1 can transfer data directly with another ID-1 without the use of a repeater which is useful for establishing a simple network where a D-Star repeater does not exist or D-Star services are not required.
Routing and linking options within or between repeaters
Due to the data component of D-Star, you can dial up your friend directly simply by putting in his/her callsign into your radio without knowing his or her current location or what D-Star repeater they are currently using. Repeaters can also be linked to together as needed by operators on air to form a wider area conference or system administrators can link repeater gateways together to link all voice & data from multiple repeaters together. Operators can also talk in to a repeater via one band and be cross banded out another band on the same repeater.
Internet facilitated Wide area multi-linked repeater systems
Repeater systems can be interconnected via “reflectors” which are essentially servers on the Internet with appropriate capacity behind broadband Internet links that interconnect many repeaters together.
Internet facilitated PC connectivity to D-Star
The DV-Dongle connects to a Personal Computer which needs to be connected to the Internet with a broadband connection. Then with a standard computer audio headset with microphone and headphones, the DV Dongle allows the user to connect to D-Star reflectors on the network and carry on conversations with other DV Dongle users or radio users through the repeaters connected to the various reflectors! This allows every ham, no matter how they are housing and antenna restricted, to again communicate with hams around the world.
Another device, the DVAP can do two things. First, if you have a D-Star radio but no local repeaters, it allows you to use your radio to connect to any reflector in the D-Star network. How? The DVAP is actually a D-Star voice encoder/decoder coupled with a micro transceiver that can be set to any frequency in either the 2 meter or 70cm amateur band (there is a model for each band). Let’s say in your area no one typically uses the 146.46 simplex frequency. So you set the DVAP frequency to 146.46 and you then connect the DVAP to the D-Star network and desired reflector with the provided software. Now you set your D-Star transceiver or handheld to 146.46 simplex using the Digital Voice or DV setting. Now start talking! You control the DVAP with the same commands that you would use for D-Star repeaters. This allows you to unlink and link different reflectors from your radio.
“Simplex” repeater connectivity to the D-Star network
Hotspots are very similar to the DVAP outlined above. The DVAP’s low power limits its use to around the house, or maybe a few blocks if connected to an outside antenna.
A Hotspot on the other hand is usually connected to a higher power standard analog VHF or UHF radio (with a 9600 baud packet port) and therefore has a lot more flexibility and range. With a sufficiently high antenna connected to a radio with a Hotspot interface, you can actually create what some might call a simplex repeater. Like the DVAP, the Hotspot is connected to an Internet enabled computer and the radio via the 9600 baud packet port. The radio is set to a D-Star simplex frequency and you and your friends can talk all around the world from another hand-held or mobile radio.
A Typical D-Star System
The D-Star repeater system is typically composed of a repeater controller, 1.2GHz, 70cm and 2mtr digital voice repeater, digital data repeater and the Internet gateway PC (Some might use a 10GHz relay). The D-STAR system repeater can perform multiple relay functions as shown in the diagram below.
The D-Star repeater operates similar to existing analog repeater. That is a simple relay of transmit and receive communication within or across the 2m, 70cm or 23cm bands.
When D-Star repeaters are connected with the Internet gateway, the D-Star system relays the received data over the Internet. Your message will get through virtually to anywhere in the D-Star system.
D*STAR in Australia
In 2006, the Wireless Institute of Australia teamed up with ICOM Australia to kick start the use of digital voice modes within the Amateur Service in Australia. The original WIA concept was to establish a network of repeaters, one in each capital city, that were all networked sowing the seeds for the nascent digital voice modes in Amateur Radio to grow.
The AREG took up the challenge of establishing the system in Adelaide, South Australia and thus VK5RWN was born.
For more information about VK5RWN contact Ben VK5BB.