D-STAR. Under the Covers. D-STAR - Icom Corporation Inc. Copyright 2011 Peter Loveall AE5PL

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Ira Daniel
5 years ago
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2 D-STAR Under the Covers

3 Pete Loveall AE5PL WN0FEW 1971 WB0FEW (Advanced) 1972 RTTY 1972 Packet 1986 APRS 1996 AE5PL (Extra) 2000 Author javaprssrvr 2002 Author DStarMonitor 2005 Author D-PRS 2005

4 D-STAR 101 D-STAR owned by JARL Not owned by vendors Not Public Domain Is Open Protocol Disclaimer Not going to debate what should be or why didn t they

5 D-STAR 101 D-STAR Digital Voice (DV) 3600 bps dedicated to AMBE voice and FEC (72 bit voice frames) 1200 bps designated for synchronization and undefined (24 bit data frames) Icom defines signaling and text services About 900 unprotected bps for radio-defined usage

6 D-STAR 101 D-STAR Digital Data(DD) Ethernet bridge Available only on Icom ID-1 (1.2 GHz) Direct Ethernet 10 base T connection between radio and computer/router Radio does not have an IP address DD Repeater is half-duplex Access Point

7 Bit Stream Format Bit Syn Frame Syn Flag 1 Flag 2 Flag 3 Destination Repeater RPT2 Radio header Departure Repeater RPT1 ID Companion URCALL Own MYCALL Own Ext Voice Frame Data Frame 64 bit 15 bit byte 8 byte 8 byte 8 byte 4 byte 2 byte 72 bit 24 bit byte error correction 660 bits P_FCS Voice Frame data Data Frame Voice Frame Data Frame EOF 72 bit 24 bit 72 bit 48 bit Radio Header Data FCS ID MAC Header Bit Syn Frame Syn Flag 1 Flag 2 Flag 3 Destination Repeater RPT2 Departure Repeater RPT1 Companion URCALL Own MYCALL Own Ext P_FCS E_Len SA DA Type data frame CRC 64 bit 15 bit byte 8 byte 8 byte 8 byte 4 byte 2 byte 2 byte 6 byte 6 byte 2 byte byte 4 byte byte error correction 660 bits

8 RF Header Key Factors Flags indicate type of D-STAR transmission and miscellaneous control information. Own 1 & 2 (extension) must never be modified after transmission. Companion is the station intended to hear the transmission. Companion is used solely for D-STAR routing Departure Repeater is the repeater local to the transmitting station. Destination Repeater is the second repeater the transmission is to pass to/through. This will normally be the local gateway or blank (spaces). No other routing information is contained in the D-STAR protocol. None may be added as any additions would break the existing networks. No modification of the RF header is allowed on RF (repeaters, etc. must leave the header intact).

9 RF Header Protected by FEC and FCS Critical for all routing Defines only the current transmission Sole transmission identification mechanism Non-protocol manipulation breaks protocol

10 Network Definition

11 Routing Key Factors Simplex uses only Own and Companion. The repeater callsigns are set to spaces. CQCQCQ is the universal calling everyone callsign and ID for the Companion only. Local repeater use sets only the Departure Repeater repeater. Destination Repeater is set to spaces. Accessing the gateway requires the local repeater in Departure Repeater and the local gateway in Destination Repeater. Routing outside of the local zone requires programming the radio to access the gateway. Inter-zone and inter-area routing by station callsign and ID requires the radio to be programmed to access the gateway. Inter-zone and inter-area routing using the slash with a repeater callsign and ID requires the radio to be programmed to access the gateway. DD routing based on assigned /8 IP address requires the radio to be programmed to access the gateway. Routing is unidirectional. Responding station(s) must program their radios correctly to reach the calling station. D-STAR routing is not linking, it is routing of the bit stream from source to destination. Responding requires proper configuration of the responding radio.

12 Icom Enhancements FP Messages Front panel display of up to 20 characters can be transmitted to remote radio Front panel message is encoded within DV data frames Front panel message is not available via the radio serial port

13 Icom Enhancements Serial Data Serial data port on all radios (USB on ID-1) Serial data is encoded within DV data frames Serial data uses different encoding from front panel message MAXIMUM throughput approximately 740 bps unprotected (NO FEC/FCS) on the 4800 bps DV bit stream

14 Icom Enhancements GPS (Serial Data) Icom implements GPS capability in VHF and UHF D-STAR radios GPS NMEA strings transmitted with callsign and message GPS & GPS-A encoded within the DV data frames as standard serial data GPS strings and callsign/message lines and GPS-A available on Icom serial port

15 Summary Protocol well-defined Some holes are being addressed by JARL Digital protocol, not data protocol addressing/routing Icom enhancements primarily with DV Icom enhancements do not break protocol High growth, potential for next SSB

16 Q&A Pete Loveall AE5PL

D-STAR System D-mystified. Brian Roode, NJ6N

D-STAR System D-mystified. Brian Roode, NJ6N D-STAR System D-mystified Brian Roode, NJ6N Who Am I? SOARA Repeater Team Unix Systems Programmer D-STAR gateway management team d*chat Author D-Star System Overview Baseband Allocation DV Radios (ID-1,