The Next Generation In Digital Amateur Radio
D-STAR Logo
What is D-Star?

The D-STAR system provides digitally modulated voice/data communication and high-speed data access over the air. This project has been developed in collaboration with JARL (Japan Amateur Radio League) and is supported by the Japanese Telecommunications Administration.

D-STAR is an exciting new form of Amateur Radio that compliments other parts of the hobby including VHF, HF operation, Contesting and Satellite communications etc. Utilising digital communication and the Internet, D-STAR allows you to communicate worldwide with other operators who are connected to D-STAR repeaters.

D-STAR Diagram

An Overview

D-STAR, a standard published in 2001, is the result of years of research funded by the Japanese government and administered by the JARL to investigate digital technologies for amateur radio. D-STAR is an open protocol - published by JARL, it is available to be implemented by anyone. Whilst 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.

In a D-STAR system, the air link portion of the protocol applies to signals travelling directly between radios or between radios via 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. D-STAR also specifies how a voice signal is converted to and from the stream of digital data. The D-STAR codec is known as AMBE® (Advanced Multiband Excitation) and the voice signal is transmitted in the D-STAR system at 3600 bits/second (3.6 kbps).

D-Star Features

D-Star is constantly developing and lends itself to continual improvement both in the ability to display information from over the Internet and in the control of the radios connected to the system. We have only scratched the surface with what has currently been provided. D-Star is capable of carrying both digital voice and data. Already there has been developed a number of utilities, a mail client that uses the data messaging for the mail messages, a statistical program for showing current users, GPS positioning and many more. To find out more of the features of this exciting new protocol click the links below.

How D-Star will operate in the UK

D-Star repeaters can be operated in the same way as existing repeaters except that they communicate using a digital transmission from the transmitting radio through to the receiving radio. Unlike other systems that have been developed that use the internet for linking distant stations together, D-Star treats all repeaters in exactly the same way. A local repeater is no different to a repeater 3000 miles away, you just have to route your call to the distant repeater. You can connect to a local repeater and a repeater across the internet and all participants will be treated as though they are on the same repeater.

D-Star FAQ's

From 'Who can use D-STAR equipment?' to 'Can I make a call with foreign countries?', find answers to some of the most commonly asked questions about D-Star.

Q: What does D-Star stand for?

D-STAR stands for Digital Smart Technologies for Amateur Radio.

Q: D-STAR only works on 1.2 GHz?

Low-speed DV D-STAR voice and data works just fine at 144 and 430-440 MHz. 1.2 GHz supports the bandwidth needs of high-speed DD data. Choose the technology that satisfies your needs.

Q: There's no difference between D-STAR and packet?

Even D-STAR's lowest speed is competitive with the highest-performance packet systems available today. D-STAR's simultaneous digital voice and data at 4800 bps is beyond the capability of any packet technology. High-speed D-STAR systems are ten times faster than the highest packet speeds.

Q: D-STAR is no different from IRLP or Echolink?

VOIP systems like IRLP and Echolink® are only capable of routing voice signals. They don't support data exchange at any speed. Calls targeted to a specific user are not possible by any amateur technology except for D-STAR.

Q: D-STAR is just a digital party line!

The ability of D-STAR repeaters to route data and digitized voice worldwide sets it far apart from a simple party line. Sophisticated D-STAR controllers and gateways implement modern telecommunications functions in an amateur package.

Q: Will I be locked into Icom equipment forever?

While Icom is the first manufacturer to support D-STAR, any manufacturer or amateur can use the JARL standards to create equipment - transceivers, repeaters, and gateways - compatible with the D-STAR system. As the D-STAR system grows, look for other manufacturers to join the fun.

Q: What can I do with the D-STAR radio?

4.8kbps digital voice (DV) mode and 128kbps data* (DD) mode communications are available. When using DD mode with a PC and the D-STAR radio, high speed data communication is possible. * DD mode is available with ID-1 only.

Q: Can I send data with a voice transmission?

Yes, you can. In DV mode operation, you can simultaneously send up to 950bps of data, such as call sign, short data message or GPS position with a voice transmission.

Q: Can I use the D-STAR repeater without connecting to the Internet?

Yes, you can use a D-STAR repeater as a local repeater. You can also communicate with other D-STAR radios directly.

Q: Can I make a call with foreign countries?

Yes, you can*. The Internet gateway allows you to relay your call to a remote D-STAR repeater over the Internet. The D-STAR repeater call sign and IP address must be registered to the gateway server. * Some restrictions may apply depending on specific countries’ regulations.

Q: Can I receive a call only when the call is intended for me?

Yes, you can. The call sign squelch function opens the squelch only when your call sign is received.

Q: How do I set a repeater call sign when I make a call to desired station?

When you communicate with other D-STAR stations using a D-STAR repeater, it is necessary to set the repeater's call sign in RPT1/RPT2 as well as the desired station call sign and your own call sign. For example, when you make a call in the same zone (without using the Internet gateway), set the uplink repeater call sign in RPT1 and the downlink repeater call sign in RPT2. Set "CQCQCQ" for the desired station call sign, when you make a CQ call. When you make a call in another zone using the Internet gateway, set the uplink repeater call sign in RPT1 and the gateway call sign in RPT2. The gateway repeater has "G" setting for the 8th-digit. Set "/" plus downlink repeater call sign at the desired station call sign, when you make a CQ call.

Q: What range will the system offer?

Range always varies due to terrain and antenna height, but 20-40 miles* from the repeater is normal. Due to digital technology, benefits of up to 20% have been experienced over comparable analogue systems. *20-40 miles is a best case measurement, distances will vary based on frequency used and other terrain obstacles. 23cm can easily be only 2-3 miles based on topography.

Q: What is Protocol?

"In computing, a protocol is a convention or standard that controls or enables the connection, communication, and data transfer between two computing endpoints." Essentially, protocols are the "rules of engagement" between two devices that allow them to connect to each other and exchange data. Protocols don’t guarantee that the data exchanged is correct or has meaning, they just describe how the data gets from one point to another. There are two D-STAR protocols; one for the air link that controls over-the-air transmissions and one that controls how information is exchanged between gateways. If you can create a radio or a program that plays by those rules, you can connect to the D-STAR world. Because D-STAR is an open protocol, all of the necessary information to play by those rules is publicly available.

 
 
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