D-Star InformationWebpage





Watch an ICOM D-STAR promotional video 

D-STAR Technology

D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification for amateur radio. The system was developed in the late 1990s by the Japan Amateur Radio League and uses frequency-division multiple access and minimum-shift keying in its packet-based standard. There are newer digital modes (Codec2, for example) that have been adapted for use by amateurs, but D-STAR was the first that was designed specifically for amateur radio 

Several advantages of using digital voice modes are that it uses less bandwidth than older analog voice modes such as amplitude modulation, frequency modulation, and single sideband. The quality of the data received is also better than an analog signal at the same signal strength, as long as the signal is above a minimum threshold, and there is no multipath propagation.  D-STAR compatible radios are manufactured by both Icom and FlexRadio Systems.

The system today is capable of linking repeaters together locally and through the Internet utilizing callsigns 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. The current master gateway in the United States is operated by the K5TIT group in Texas, who were the first to install a D-STAR repeater system in the U.S.

D-STAR transfers both voice and data via digital encoding over the 2 m (VHF), 70 cm (UHF), and 23 cm (1.2 GHz) 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.

Within the D-STAR Digital Voice protocol standards (DV), voice audio is encoded as a 3600 bit/s data stream using proprietary AMBE encoding, with 1200 bit/s FEC, leaving 1200 bit/s for an additional data "path" between radios utilizing DV mode. On air bit rates for DV mode are 4800 bit/s over the 2 m, 70 cm and 23 cm bands.

Listen to a D-STAR digital transmission

In addition to digital voice mode (DV), a Digital Data (DD) mode can be sent at 128 kbit/s only on the 23 cm band. A higher-rate proprietary data protocol, currently believed to be much like ATM, is used in the 10 GHz "link" radios for site-to-site links.

Radios providing DV data service within the low-speed voice protocol variant typically use an RS-232 or USB connection for low speed data (1200 bit/s), while the Icom ID-1 23 cm band radio offers a standard Ethernet connection for high speed (128 kbit/s) connections, to allow easy interfacing with computer equipment.

Gateway Server

The current gateway control software rs-rp2c version 2.0, more commonly called "Gateway 2.0". Though most Linux distributions should be suitable, the recommended configuration uses CentOS Linux 5.1 with the latest updates, typically running (kernel 2.4.20. glibc 2.3.2 and BIND.1 or later). The CPU should be 2.4 GHz or faster and the memory should at least be 512 MB or greater. There should be two network interface cards and at least 10 GB free of hard drive space which includes the OS install. Finally for middleware, Apache 2.0.59, Tomcat 5.5.20, mod_jk2 2.0.4, OpenSSL 0.9.8d, Java SE 5.0 and postgreSQL 8.2.3 are utilized, but these can be different as updates occur. Along with the open-source tools, the Icom proprietary dsipsvd or "D-STAR IP Service Daemon" and a variety of crontab entries utilize a mixture of the local PostgreSQL and BIND servers to look up callsigns and "pcname" fields (stored in BIND) which are mapped to individual 10.x.x.x internal-only addresses for routing of both voice and data traffic between participating gateways. During installation, the Gateway 2.0 software installation script builds most of the Web-based open-source tools from source for standardization purposes, while utilizing some of the packages of the host Linux system, thus making CentOS 5.1 the common way to deploy a system, to keep incompatibilities from occurring in both package versions and configuration.

Additionally, gateways operating on the U.S. trust server are asked during initial setup to install DStarMonitor which is an add-on tool that allows the overall system administrators to see the status of each Gateway's local clock and other processes and PIDs needed for normal system operation, and also sends traffic and other data to servers operated under the domain name of "dstarusers.org". By this means a complete tracking of user behaviour is technically possible. Installation of this software also includes JavaAPRSd, a Java-based APRS interface which is utilized on Gateway 2.0 systems to interface between the Icom/D-STAR GPS tracking system called DPRS to the more widely known and utilized amateur radio APRS system.

How Gateway 2.0 works

Each participating amateur station wanting to use repeaters/gateways attached to a particular trust server domain must "register" with a gateway as their "home" system, which also populates their information into the trust server—a specialized central gateway system—which allows for lookups across a particular trust server domain. Only one "registration" per trust domain is required. Each amateur is set aside eight 10.x.x.x internal IP addresses for use with their callsign or radios, and various naming conventions are available to utilize these addresses if needed for specialized callsign routing. Most amateurs will need only a handful of these "registered" IP addresses, because the system maps these to callsigns, and the callsign can be entered into multiple radios. The gateway machine controls two network interface controllers, the "external" one being on a real 10.x.x.x network behind a router. A router that can perform network address translation on a single public IP address (can be static or dynamic in Gateway 2.0 systems) to a full 10.x.x.x/8 network is required. From there, the Gateway has another NIC connected directly to the D-STAR repeater controller via 10BaseT and the typical configuration is a 172.16.x.x (/24) pair of addresses between the gateway and the controller.

You must Register to use a D-star Repeater Gateway. Once registered you can use any repeaters Gateway or Reflector.

Local Gateway Registration web page 

Icom D-Star Radios

D-Star Repeaters

Listen to a D-Star Repeater QSO

Imagine a world where you can get a VHF and UHF repeater pair. Or where VHF and UHF DX does not require a band opening. Or even a plug and play repeater system that gives you functionality and capabilities that no other radio service in the world can offer!. This dream has become a reality with the introduction of Icom's ID-RP2000V and ID-RP4000V D-STAR Modules!

Whether you are a repeater owner wanting to experiment in the digital world or a club who wants more from their repeater network, D-STAR is definitely the future of Amateur Radio.


With the capability of handling up to four RF modules, ID-RP2C repeater controller is the cornerstone of the D-STAR repeater system. This includes basic in-band as well as crossband operation between any of the four digital voice RF modules. In addition to basic control of the RF modules, the RP2C also provides linking capabilities through the Internet and future 10GHz backbone products.

ID-RP2D (23cm Data)

One of the most powerful functions of D-STAR is the ability to move data. The ID-RP2D provides an access point with a data rate of 128kbps. Depending on the system setup, the 128kbps is perfect for setting up an e-mail and/or file server for EmComm support. It's also perfect for the connecting to the Internet or web applications and support.

Whether you use the 128kbps for e-mail or file servers, connecting to an Internet source via a router will give you the capability of checking out the radar from the National Weather Service or National Hurricane Center.

ID-RP2V (23cm Voice)

Finally a commercially available legal crossband repeater! With proper callsign programming in any D-STAR compatible mobile or portable, the Icom D-STAR repeaters will automatically route your signal to any other RF module connected to a common RP2. With simple repeater commands, you can direct your communications through any of the RF modules.

ID-RP2000V (2M)

This VHF digital voice repeater opens the way to use the D-STAR repeater system in the popular 2m band with the ID-800H, IC-91AD and other D-STAR compatible radios. It also provides cross band operation with 144/440/1200MHz bands.

ID-RP4000V (70cm)

The RP4000V, a UHF digital voice repeater, uses the D-STAR repeater system in 70cm bands. It also provides cross band operations with 144/440/1200MHz bands.

 D-STAR Repeaters


Active Repeaters / Reflectors


Repeater / Reflector

Primary Coverage Area


North /  East / Central

Baltimore County

North East, North Central / Upper  Eastern Shore

Harford County

North Capital / Western to Hagerstown, East to Carrol County

Frederick County

South Capital, South Central, Portions Upper Eastern Shore

Montgomery County

Lower Eastern Shore / Portions Upper Eastern Shore

Wicomico County

Southern / South Capital, Portions Lower Eastern Shore

St. Charles County

State Wide Reflector

Baltimore County


D-Star Reflector Technology

The D-Star Reflectors are a means to set up a conference bridge for D-Star Users. They allow multiple D-Star repeaters and DV Dongle users, from all around the world, to be joined together in one big conference call and whatever information is transmitted from one of the users is repeated across all of the connected repeaters that are linked to the Reflector; a true worldwide conference call. Everyone connected will be part of the conversation; well at least be able to listen in.

There was a World Wide Net set up and the objective was to see how many D-STAR Nodes and DV Dongle Users could connect to a D-STAR Reflector and to gauge what sort of capacity it could take. There were 28 D-STAR Nodes (repeaters) and 18 DV Dongle users connected. The system performed perfectly, and no performance issues were noted.

Reflector Directory Worldwide



 D-Star can be asscesed by Computer or use of the internet and a HT or Dongle


The DV Access Point Dongle connects to your PC or Intel based Mac via a USB port and provides a 2 meter or 70 cm Access Point for use with a D-STAR radio.  Using an Internet connection, a user may connect to and communicate with D-STAR gateways and reflectors around the world.  The DVAPTool application used with the DV Access Point Dongle may be installed and run on Microsoft Windows XP/Vista/7, Mac OS X Leopard/Snow Leopard, or many flavors of Linux. 



The DV Dongle connects to your PC or Apple Mac via a USB port and provides encoding and decoding of compressed audio using the DVSI AMBE2000 full duplex vocoder DSP chip.  AMBE technology is used in all D-Star radios to provide efficient voice transmissions.  It is also used in some HF digital protocols by vendors like AOR.  The DVTool application used with the DV Dongle may be installed and run on Microsoft Windows XP/Vista/7/8/10, Mac OS X, or many flavors of Linux. Simply install the dongle plug in headset log on to gateway and your on D-Star!



These are available from Internet Labs and Star-DV


Raspberry Pi (“RPI”) is a small computer using an ARM processer.  It has 512 MB of RAM, two USB ports, an HDMI port, a component video port, audio out port, Ethernet port and a slot for an SD card.  A picture of this wonderful little device is below.  You can learn more about it at the Raspberry Pi Foundation web site http://www.raspberrypi.org .

Added with a DVAP device a rechargabe battery, WIFI hotspot device and a D-Star HT you can use D-Star anywhere you have a wireless connection


 The D-Star image for rasberry PI for  Maryland is available at W3DHS website.

DVAP setup







Standalone D-Star hotspot




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Last Updated July 2016 (C) N3VBJ

Maintained by Jerry N3VBJ n3vbj1@gmail.com


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