D-STAR — Digital Smart Technologies for Amateur Radio
D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol developed by the Japan Amateur Radio League (JARL) and primarily manufactured by Icom. D-STAR provides clear digital voice, slow-speed data alongside voice (callsign, GPS position, and short messages transmitted simultaneously with voice), and a high-speed digital data mode (DD mode) for network applications. D-STAR repeaters are linked into worldwide networks via the internet through a system of reflectors and gateways.
D-STAR modes
D-STAR has three operating modes. DV (Digital Voice) mode is the most common — it transmits AMBE+2 compressed digital voice along with a 950 bps data channel carrying your callsign, the destination callsign, a GPS position if your radio has GPS, and a short message. DR (Digital Radio) mode is the simplified operating mode on newer Icom radios. DD (Digital Data) mode provides 128 kbps data throughput on 1.2 GHz and is used for wireless networking applications.
The D-STAR network
D-STAR repeaters connect to the internet via a gateway — a computer running the IRCDDB or other gateway software. Repeaters can link to reflectors — servers that connect multiple repeaters together into a shared audio stream. The most widely used D-STAR reflector system is the REF (DPlus) network, with REF001C being the most popular English-language reflector. The XRF and XLX systems provide alternative reflector networks. When a repeater is linked to a reflector, your voice is heard on all other repeaters linked to that same reflector simultaneously.
Register your callsign
D-STAR requires callsign registration in the D-STAR gateway database before you can use the network features. Register at dstargateway.org or directly through your local D-STAR gateway. Registration is free and typically takes a day or two. Without registration, you can still use local D-STAR repeaters for simplex-like operation but cannot link to other repeaters or use internet features.
Get a D-STAR capable radio
Icom manufactures the majority of D-STAR radios — the IC-705, IC-9700, ID-52A, ID-51A series, and ID-31A are popular choices. Kenwood and other manufacturers also produce D-STAR compatible equipment. D-STAR radios tend to be more expensive than equivalent DMR radios. The ID-52A and ID-51A Plus series are popular dual-band portables for D-STAR operation.
Programme your radio
Programme local D-STAR repeater frequencies into your radio using Icom's CS programming software or the radio's front panel. D-STAR radios require you to set your callsign in the radio's memory (MY callsign) and the destination callsign (UR callsign — typically CQCQCQ for calling all stations). Programme the RPT1 field with the local repeater callsign and module (e.g., W1ABC B for the 2m module) and RPT2 with the gateway address.
Link to a reflector
To link a D-STAR repeater to a reflector, transmit the link command via DTMF or via the UR callsign field. For example, to link to REF001C, set UR to REF001CL (L for link) and transmit briefly. The gateway processes the link request and connects the repeater to the reflector. Check that the link was successful by listening for the gateway announcement. Different repeaters may have different link procedures — check with your local repeater trustee.
| Feature | D-STAR | DMR | System Fusion |
|---|---|---|---|
| Developer | JARL / Icom | ETSI standard | Yaesu |
| Voice codec | AMBE+2 | AMBE+2 | AMBE+2 |
| Data alongside voice | Yes — 950 bps | Limited | Yes |
| Radio cost (entry) | Higher ($200+) | Lower ($50+) | Medium ($150+) |
| Network | REF/XLX reflectors | BrandMeister/DMR-MARC | Wires-X |
| Repeater count | Moderate | Highest | Moderate |
| Interoperability | D-STAR only | Some via gateways | Fusion only (some via gateways) |
Why do I need to register my callsign for D-STAR?
D-STAR uses callsign routing — the network routes calls based on callsigns rather than numbered IDs (unlike DMR). For this routing to work, the network needs to know which gateway your callsign is registered to so it can route incoming calls to you. Without registration, the gateway cannot direct network traffic to your location.
What is the difference between a D-STAR reflector and a repeater?
A D-STAR repeater is a physical radio station that receives and retransmits your signal locally. A reflector is an internet server that connects multiple repeaters together into a shared audio conference — like a conference bridge. When your local repeater is linked to a reflector, your voice is simultaneously heard on every other repeater connected to that reflector worldwide.
Can I use D-STAR without a repeater?
Yes — D-STAR hotspots like the MMDVM-based hotspots running Pi-Star, the Icom ID-52's built-in hotspot function, and DV4Mini allow direct connection to D-STAR networks from home without a local repeater. These are particularly useful in areas with poor D-STAR repeater coverage.
Is D-STAR compatible with DMR or System Fusion?
D-STAR is not directly compatible with DMR or System Fusion — each uses different digital encoding. However, gateway software like DVSwitch and the YSF/DMR/D-STAR bridges on some servers allow cross-mode linking, so a D-STAR station can sometimes talk to a DMR or Fusion station through a server bridge. This requires specific infrastructure at the gateway level.