What's D-STAR? 2
D-STAR features 3
The D-STAR repeater 4
What can D-STAR do for me? 5
Glossary 6
Technical specs 7
Myths! 8
Figure 1
Figure 2
Figure 3
Figure 4
Figure 6
What is a “Protocol”?
RWP
WM.S
WM
KNAB
TPO
From the Wikipedia (www.wikipedia.org),
"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.
Technical Specifications
*
The following table compares D-STAR capabilities and costs with those of VHF packet for both low-speed and high-speed
systems. (Costs are based on equipment MSRP.) You can see that low-speed D-STAR links, which support simultaneous voice
and data, cost no more than low-speed packet and are cost -competitive with even high-speed packet. High-speed D-STAR
links provide approximately 10 times the performance of high-speed packet at less than three times the price.
D-STAR PACKET
DV:
6 kHz
®
LS: TNC($200) + IC-2200 ($230) = Total $430
HS: TNC ($400) + IC-2200 ($230) = Total $630
None
LS: 1200 bps
HS: 9600 bps
20 kHz
Any VHF/UHF band
VOICE CODEC
DATA SPEED
BANDWIDTH
FREQUENCY
COST*
3600 bps AMBE
1200 bps (net 950 bps)
DV:
DD: 128k bps (net 90k bps)
DD: 150 kHz
Any VHF/UHF band
DV:
DD: 1.2 GHz
IC-V82 or IC-U82 ($230) + UT-118 Module ($200) = Total $430
DV:
or ID-800 ($748)
DD: ID-1 ($1600)
Software and system developers want to know the detailed technical specifications and the following table illustrates the
main points of the D-STAR system.
DV: Digital Voice + Data DD: High Speed Digital Data LS: Low Speed Data HS: High Speed Data
D-STAR PACKET
DATA INTERFACE
DATA FORMAT
AIR LINK
NETWORK & TRANSPORT
DV:
RS-232 or USB 1.0
DD: Ethernet
Same as Ethernet 7-bit ASCII text
D-STAR packet format and 0.5GMSK
modulation
Transparent point-to- point
DV:
DD: TCP/IP
LS: AX.25 using Bell 202 modulation
HS: AX.25 using K9NG Bell 212A
RS-232
AX.25 or TCP/IP
Data interface
For low-speed DV D-STAR links (1200 bps), the data interface to your laptop or terminal is a familiar RS-232, three-wire
connection (Rx data, Tx data, and signal ground) or a USB 1.0 interface, depending on the radio. For high-speed D-STAR
(128k bps), the data interface is an Ethernet connection with the customary RJ-45 jack.
Air link
Over the air, packet signals use FSK protocols originally designed for land-line applications and adapted to amateur radio.
D-STAR uses the up-to-date modulation method of 0.5GMSK--Gaussian Minimum Shift Keying. GMSK provides improved
performance over packet because it is designed for wireless links. Data is sent using the D-STAR packet format, which
includes FEC (Forward Error Correction) and routing information. The data itself is encapsulated within the D-STAR packet
as an Ethernet packet.
Network and transport
Low-speed DV D-STAR data is a “keyboard-to-keyboard” mode. The D-STAR system provides reliable, transparent transport
from user to user by using CRC error detection. High-speed DD D-STAR data appears at the data interface as an Ethernet
packet suitable for encapsulation by the TCP/IP protocol stack. The Ethernet connection is a bridged, point-to-point
connection between static IP addresses so that standard Internet application software can be used to transfer data across
the D-STAR system.
You may download your own copy of the JARL’s D-STAR Technical Specification at www.icomamerica.com/amateur/dstar.
*All information, including pricing, is subject to change without notice or obligation.
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.
Myth #5
“D-STAR is a replacement for broadband home Internet”
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