Monday, May 6, 2019

Interested in D-Star?

D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification for amateur radio was developed by the JARL and was the first digital radio system designed specifically for Amateur Radio. The D-Star system was in the development stages in the late 1990s before its release in 2004. At the Dayton Hamvention (2004) there were demonstrations of D-Star and the AOR 9000 Digital voice system used on HF.

The advantage of D-Star, like all of the other Digital modes, is that it utilizes less bandwidth and the quality of audio is better than an analog signal at the same signal strength provided that the signal is above the minimum threshold. D-Star has the advantage of a number of years development over the newer Yaesu Fusion System.  
D-Star is capable of linking repeaters together locally and through the Internet utilizing call signs for routing of traffic. Servers are linked via TCP/IP utilizing proprietary "gateway" software, available from Icom. This allows amateur radio operators to talk to any other amateurs participating in a particular gateway "trust" environment.    

D-STAR transfers both voice and data via digital encoding over the 2 m (VHF), 70 cm (UHF), and 23 cm (1.2 G)Hz) amateur radio bands. There is also an interlinking radio system for creating links between systems in a local area on 10 GHz, which is valuable to allow emergency communications oriented networks to continue to link in the event of Internet access failure or overload.  

What is available - a picture is worth a thousand words

D-Star transfers voice and data by digital encoding over the 2m, 70cm, and 1.2 GHz amateur bands. There is an interlinking radio system for creating links between systems in a local area on 10 GHz which would allow emergency communications oriented systems to continue to link in the event of Internet access failure or overload. See below

1) Digital Voice Mode through Repeaters and Gateways Internet Access
2) Short Data Message whilst in Digital Voice mode
3) GPS tracking mode whilst in Digital Voice Mode
4) Digital Data Mode via the Internet
5) I.P. camera in Digital Data Mode - watch digital images sent in real-time
6) Point to point direct Digital Voice mode
7) Analog operation direct or via Analog Repeaters or Gateway

Most D-Star operation results from users talking over links to other users connected to reflectors. Reflectors are conference servers. Many Repeaters may be connected to a particular conference server. A transmission on any one of the connected systems is repeated on all of them. There are actually more operators to talk to than just those connected to within the RF distance of ones own local repeater.

Getting Started 
It is necessary to register for the D-Star Network. This is simple enough as it is possible to register via Icom UK. Send the following: Name, Call sign, Postcode or location, and email address, to This is probably the easiest way. It is also possible to do it yourself via by Googling D-Star registration. This can have its own problems! Once Registration is complete, it is possible to use the facilities D-Star has to offer.   

Setting up the Radio

As with most radios, it is necessary to set up the date, time, and add your call sign. The GPS may be left on to send out position information but, if it is not required, turn it off so save the battery. Select the desired mode - either analog or DV.

 Simplex Operation

Local Repeater Call

Gateway Repeater Call

 Calling Via a Reflector

Linking to Reflectors

There are a couple of  systems available:

D-PLUS has probably caused the most significant D-Star growth around the world. D-PLUS reflectors are designated REF###x as in REF001C etc.

Two other linking systems have since been written:

DExtra creates XRF reflectors and DCS creates DCS reflectors. They all operate in a similar way.

Linking is relatively easy. Most D-Star Repeaters allow registered users to issue Link and Unlink commands over RF. These commands need to be inserted into the URCall of the radio and then press the PTT. An Example of a Link command to REF001C as follows -- "Place REF001CL" in URCall. Note the first 6 positions are for the name of the reflector as in REF001, the 7th  position is the Band Module, normally A, B, C, D, E,   and the 8th position is the D-Plus command. L is the link command and U is the unlink command. Is is common practice to program the a couple of memories with these commands.

Practical Use of D-Star
Most D-Star Repeaters are connected to Reflectors. Any Radio Operator registered with D-Star can connect with another Radio Operator beyond the coverage of the local Repeater. Connection to any part of the world is possible with a relatively simple combination of button presses.

D-Star can be used with Digital Access points such as the DVAP, Openspot and DVmega etc.

One of the outstanding features of D-Star is the ability to call another operator without knowing their current location or on which Repeater or Gateway they are located. If an operator has used a Repeater of Gateway in the UK, it is possible to connect to their call sign via one's own Repeater/Gateway and D-Star will automatically route to the last known destination. If should move to another area and use D-Star it will automatically route to the new location.

Facilties Available in Galway

D-Star has been implemented on the Galway Multi-Mode Digital Gateway on 144.850 MHz. Aengus, EI4ABB, has a D-Star Gateway which may be pressed into service on the 70cm band at some future point in time. 

In Conclusion

D-Star has been around since 2004 and many modifications to the system have been made to the operation. D-Star is a System designed specifically for Amateur Radio use and is quite complex as a result. APRS and Digital messaging are possible whilst in QSO and are transmitted simultaneously.

It is not easy to use equipment straight out of the box and reading the manual is essential to derive the best possible use. The basic ID-51E Plus2 manual is 90 pages long and explains the use of the system very well. The advanced D-Star Manual for the ID-51E Plus2 Handheld is literally 400+ pages long and is useful for reference purposes. It would take some time and patience, which we as amateurs don't have, to wade through this manual. We are, however adaptable!

The Nifty E-Z guide to D-Star Operation by Bernie Lafreniere, N6FN, gives an easier tour of the facilities with comprehensive explanations. The Nifty Mini-Manual is also a superb source of reference. In addition, D-Star is well documented on the Internet so there are plenty of resources should difficulties be encountered.

There are over 50,000 D-Star operators so there is no shortage of people to chat with. A number of Worldwide D-Star nets are held and they are well populated. As a starting point, try REF 001C where there is an abundance of activity. Reflector  DCS 049 I will yeild activity from all over Ireland both North and South and REF005C for the London area.

D-Star operation is possible on most amateur bands from 80 metres to 10 GHz

Voice quality is excellent and especially somewhat enhanced since the AMBE+2 chip has been implemented.

Verdict - A steep learning curve but once mastered it becomes second nature.