On 11/28/2024 12:31 PM, N9PNO via groups.io wrote:
Hi Steve
Congratulations on all the work you’re doing. I do follow you closely and
find your work most interesting. I want to ask if you know anything about
robust packet?
Hello
George Kirn had contact with this data.
I have played with it briefly.
Robust packet is a higher-performance proprietary replacement for classic HF AX.25 packet created by the German company SCS <> ? It uses 8 OFDM audio subcarriers in a 500 Hz bandwidth. The extensive forward-error correction built-in tremendously reduces the NAKs and retries of conventional AX.25 packet on HF.?? Details are in the attached document *Advanced_Protocol_Robust-Packet.pdf*.
It was first embodied exclusively in their expensive (USD $500 and up) Pactor 4 hardware radio modems. ? Although these were hardware-based devices, internally both modes used DSP audio processing similar to most "digi-modes" used today on computer sound cards.? The SCS Pactor III and 4 modems were and are widely used for the WinLink radio email system by boaters on the high seas.
Neither mode was ever offered as a soundcard app to run on PCs, or licensed to other hardware mfrs. ? Later, SCS offered a lower-cost (around USD $300)? robust-packet-mode-only "TNC" that was a more-or-less direct drop-in for a classic hardware TNC like a TNC-2, Kantronics, etc.? (It could do classic AX.25 packet as well as the vastly-superior robust mode.? This device also had a NMEA GPS input that could originate APRS-format position beacons without external programs. ? This device saw significant uptake among yachters and EMcomms types.
The network you link above is based primarily on this device. The network is almost exclusively in Europe and the UK, and some in Australia/New Zealand.
When SCS discontinued the robust-packet modem hardware in 2020, a Windows soundcard-based version of robust packet was released. Technically a beta program, no full version 1.0 was ever released. ? You can download the final version 0.752 here:
<>
The program presents a KISS-over-IP link that can link to any APRS client program that can use KISS interfaces.? It has a TNC-2-like command language that presents a converse-vs-command mode OR a KISS interface as needed.
There are some similarities between robust packet and VARA. Both are advanced DSP-based digi-modes that are VASTLY superior to classic 300-baud HF AX.25 packet, due to aggressive built-in forward error correction. Both can operate in a 500 Hz bandwidth; i.e. you can run them through a 500-Hz CW receive filter on HF. Both have incredible weak-signal capabilities.
??? --BUT-- VARA is adaptive and can achieve far higher throughput speeds on strong signals.?? With a decent signal, it can achieve data speeds higher than 1200 baud VHF packet in only a 500 Hz bandwidth.? It can increase speed to best 9600-baud VHF packet in a 2300 Hz SSB bandwidth on HF.?? It is now seeing rapid uptake on the WinLink radio email system as an? alternative to the pricey SCS Pactor Modems. (The basic version of VARA is free. The highspeed version is a USD $70 license fee.
I have installed and tried the WinRPR program, monitoring the announced robust packet frequencies on 30 meters here from central Michigan for a couple of weeks. I heard a grand total of 3 stations beaconing in North America and no conversations or traffic. ? Perhaps it's different in Europe or ANZ.???? Even at this early point in uptake, I'm seeing far more traffic on VARA VarAC Chat and on APRS-over-VARA which I have been proselytizing for on 30M APRS for a couple of years now.
I distribute a "Ham Software MegaPack" on 32-GB flash drives at ham fests and radio club meetings.? It includes a folder for Robust Packet. Here is the --ReadMe__ file for that folder:
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***? This is a compilation of info about "Robust Packet" gleaned from various sparse resources around the Internet.?? ***
"Robust Packet" is an enhanced more error-free packet mode, based on 8 OFDM audio subcarriers in a 500 Hz bandwidth instead of the traditional two-tone AFSK used by classic packet.? Unlike conventional HF packet, robust packet contains built-in forward error correction (FEC). This guarantees a much higher percent of successful receives of packets on the first try in HF noise and multipath. The large number of NAKs and retries experienced with conventional packet on HF is avoided.
Robust Packet is a proprietary "digi mode" traditionally generated exclusively by the very expensive hardware-based SCS Systems PACTOR 4 modems.? These modems were/are widely used for Winlink radio email and APRS tracking by boats on the high seas starting in the early 2000s.?? When SCS discontinued the lower-priced Tracker-1 robust packet TNC, they released a free Windows soundcard "digimode" application that emulates the hardware modem in software.? When linked to external applications such as WinLink radio email or an APRS app, this program "looks like" a TNC2-type hardware TNC to programs, even though the transmitted waveform is completely different.
Note that technically, this is a "beta" application -- YMMV! Program tested and verified to work on Win 7, 8, and 11.
The main repositories of information and software for this mode is the Virginia Packet Network website at:
<>
and
<>
Main published operating frequencies ("dial frequencies")? for robust packet (mainly non-connected APRS) are:
??? 10.147.30 USB? (World-wide)???? (Actually seems to be 10.147.60 , at least in North America... )
????? 3.610.00 USB? (Night)
?????? 7.047.30 USB (Rarely)
???? 14.102.00 USB (Europe heard on this freq)
???? 14.103.50 USB (Nothing heard on this freq)
Virginia Packet Network (robust packet & conventional HF AX.25 packet - mostly connected & BBS operation)
???? 3.598 MHz (dial) USB
NOTES:
You may need to edit the file? "WinRPR_Config.txt"? located in the program's install folder to configure.? Note this is "WinRPR_Config.txt" - not .ini or .cfg !? In the [TNC] paragraph of?? "WinRPR_Config.txt"? you can place numerous TNC2-type commands to be executed at startup.? Or they can be typed into the "Terminal Input" window while the program is running. (The "Terminal Input" window is disabled during KISS operation.)? A list of some of the commands is in the document "WinRPR-TNC-Commands" in this folder.
This modem program links to a packet or APRS program that will use it,? via either a KISS-over-serial port connection,? or a KISS-over-IP interface.? For APRS, the serial port link will be needed for UIview.?? Other APRS applications such as PinPoint, APRS-IS32 or YAAC can use the KISS-over-IP interface.
You will need to install/configure a serial-COM-port bridging tool such as "com0com" or "VSPE" to connect the Robust Packet modem to a real or virtual com port on the external program.??? These tools create a virtual "null modem" (two cross-connected serial ports). In turn, these tools allow two programs that each want to communicate via a serial COM port,? to talk to each other.
??? "VSPE" configured as a "connector" (null modem with the SAME COM number on both ends) works very well -- it can be used wherever other documentation refers to using "com0com" for this purpose, and saves using a second COM number in systems crowded with other COM numbers.
Net result is that you will be dealing with TWO comports, physical or virtual.? One for the KISS data stream if you use serial KISS, and one for the RTS or DTR transmit PTT keying unless you use a tone-activated interface like a SignalLink or WA8LMF's tone-key designs.
Finally, the transmit audio tone level is determined within the program - system-level audio controls in Win 7 and later seem to have no effect on the TX tone level.
??? You need to edit the? "set transmit level" item in "WinRPR_Config.txt" to change it.? Edits are also required to make the chosen audio TX and RX device "stick" between sessions, and to determine the IP ports used.
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Stephen H. Smith??? wa8lmf (at) aol.com
Skype:??????? WA8LMF
EchoLink:? Node #? 14400? [Think bottom of the 2-meter band]
Home Page:
APRS-over-VARA igates now operating on 30 & 60 meters
<>
"Studio B" Ham Shack on Wheels
<>
-- APRS over VARA? --
<.>
N9PNO