The issue is control over the operating system's scheduling
decisions. There are real-time versions of Linux that are comparable
in this dimension to the firmware running in a TNC; given sufficient
CPU horsepower, a Pactor-2 or Pactor-3 implementation on realtime
Linux is feasible.
The
The documentation in http://hflink.com/ recommends that a station
transmit a 20-30 second sounding hourly on each frequency.
Below, Bonnie says In amateur radio ALE, there is only one pilot
channel per ham band where repetitive sounding (station ID) happens
on a regular basis.
How many
There are variants of Linux with pre-emptive scheduling; this enables
guaranteed real-time response. Linux-based cellphones use this
approach, for example.
See http://en.wikipedia.org/wiki/Hard_real-time
Dave, AA6YQ
--- In digitalradio@yahoogroups.com, Chris Jewell ae6vw-
[EMAIL
GM Dave,
Yes, a technical item up for discussion.
I must assume that you have never done any Near Real Time Systems
development such as ATE or Industrial Control applications under MS-Windows?
I on the other hand have and the WIN32 API beginning all the way back
with Windows NT implemented a
Hi Dave,
At 10:53 PM 8/27/2006, you wrote:
Does ALE provide some means of reducing contention?
I recommend that to answer all of your technical questions on subject
ALE that you refer the actual Federal, Military and STANAG Standards
which you can find on the Internet quite easily. You can
Several key points on Bonnie's comments:
1) RTTY contests are human operating events. There is no automatic RTTY
that I am aware of. Big difference! It is one thing to find an apparent
hole to TX into, but are able to back off if it is busy. ALE would
be nearly inoperative during a contest if
Since I am not a programmer, other than taking some rudimentary courses,
reading some of Don Lancaster's books, and knowing that it is not
something I could ever do very well, something still doesn't seem right
to me when it comes to the claim that computers just can not meet the
timing
Chris,
What is your view on using pipelined programming such as what was used
in the SCAMP mode to get around this issue with moving the ACK to the
next packet. The main penalty is latency for the user, but it seems
manageable.
73,
Rick, KV9U
Chris Jewell wrote:
Suppose you're using your
--- In digitalradio@yahoogroups.com, KV9U [EMAIL PROTECTED] wrote:
Since I am not a programmer, other than taking some rudimentary
courses,
reading some of Don Lancaster's books, and knowing that it is not
something I could ever do very well, something still doesn't seem
right
to me when
Precise timing isn't the issue, Steve. WinWarbler originally used
GetTickCount() and QueryPerformanceCounter() in its CW generation
code, but a high-resolution timer using the multimedia library is
sufficiently accurate and more convenient. The problem is thread
scheduling. WinWarbler uses
Steve, I asked a few simple questions about the amateur
implementation of ALE; these questions were not focused on
politeness, but rather on understanding how many ALE users can be
simultaneously QRV if there's one pilot channel per amateur band.
Bonnie claimed 1000, but two multiplications
Yes! Just select a calling frequency. Then move off.
From: kd4e [EMAIL PROTECTED]
Reply-To: digitalradio@yahoogroups.com
To: digitalradio@yahoogroups.com
Subject: Re: [digitalradio] ALE QRM
Date: Sun, 27 Aug 2006 23:32:12 +0800
Someone somewhere will *have* to sound* else no one
anywhere will
Ahhh...we're a tiny minority. Most Hams know only SSB and CW.
Besides, most of the new digital modes seems to come out of Europe!
From: Dave Bernstein [EMAIL PROTECTED]
Reply-To: digitalradio@yahoogroups.com
To: digitalradio@yahoogroups.com
Subject: [digitalradio] Re: Can You Call Another Ham
One of the main interests that I have in digital modes is getting a
message through the most difficult conditions, completely intact as
sent, and as fast as possible. I was looking at the STANAG 5066
specifications and test results, (Steve has some below), and quite
frankly I am concerned that
New/updated Routing Information...station availibility, frequency changes, etc?
Currently in NTS called net bulletins.
73...K5YFW
-Original Message-
...under what circumstances would a message transport layer
require one-to-many transmission?
73,
Dave, AA6YQ
Need a
Hi Dave,
At 10:46 AM 8/28/2006, you wrote:
I have reviewed enough of the military documentation to understand
that they employ dedicated ALE transceivers capable of much faster
scanning rates.
Really? Please enlighten me, I was under the impression that the ALE
scan rates of 1, 2 and 5
Hello Bonnie - what is ALE please? - 73 Bruce.
72/73 - Bruce ve5rc/ve5qrp - QRP-C#1, QRP-L#886, A1 Operator
Enter QRP-Canada's RUN with RAC contest -
details - http://www.qrp-canada.com
Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org
Hi Dave,
I mentioned AMTOR as its timing is more robust that PACTOR I.
As I have stated to the MARS-ALE users, the future version of that
tool when PACTOR I support is added ont he PCSDM will pretty much own
the OS, not a problem for our purposes as that one program running is
our only
To use your example, Rick, if Windows introduces a 10 ms delay from
the time when you strike a button to initiate transmission in
MultiPSK until the point where Commander sends a CI-V Transmit!
command to your 756 Pro2, you'd never notice. However, such a delay
in confirming reception of a
Those are all low-occurrence events that could be implemented with
one-to-one messages with no significant performance degradation.
One-to-one messaging with ARQ would seem optimal. KISS, remember?
73,
Dave, AA6YQ
--- In digitalradio@yahoogroups.com, DuBose Walt Civ AETC CONS/LGCA
Hi Rick,
Just time for a quick comment.
Don't confuse STANAG 5066 Data Link Protocol (DLP) as covered in
MIL-STD-188-141B which is a Data Link Protocol at the Physical Layer
with STANAG 5066 which is a network protocol at the Link Layer.
Basically and DLP with the need ARQ support and speed
AA6YQ comments below
--- In digitalradio@yahoogroups.com, Steve Hajducek [EMAIL PROTECTED]
wrote:
snip
I have reviewed enough of the military documentation to understand
that they employ dedicated ALE transceivers capable of much faster
scanning rates.
Really? Please enlighten me, I was
Agreed, there's no problem if you can own the OS; but on an end-
user's Windows PC, you can't do that.
73,
Dave, AA6YQ
--- In digitalradio@yahoogroups.com, Steve Hajducek [EMAIL PROTECTED]
wrote:
Hi Dave,
I mentioned AMTOR as its timing is more robust that PACTOR I.
As I
Chas, the term modem is a contraction of modulator
and demodulator; it purpose is the bidirectional conversion of
digital signals to analog signals. There are many different kinds of
modems, employing different modulation techniques to achieve
different speeds and error rates over different
KV9U writes:
Chris,
What is your view on using pipelined programming such as what was used
in the SCAMP mode to get around this issue with moving the ACK to the
next packet. The main penalty is latency for the user, but it seems
manageable.
I haven't read any detailed specs of the
I'm willing to believe that the timing tolerances in -tor modes
are so tight that ordinary PC operating systems cannot cope with
them the way a dedicated processor can. What I don't understand
is why the tolerances need to be so tight. The transmitter sends
a packet and then listens for an ACK
jhaynesatalumni writes:
I'm willing to believe that the timing tolerances in -tor modes
are so tight that ordinary PC operating systems cannot cope with
them the way a dedicated processor can. What I don't understand
is why the tolerances need to be so tight. The transmitter sends
a
Hello Rick,
An additive remark to Dave. In Multispk, I have added Pactor 1 (RX/TX) but only
in FEC. I would have liked to propose an ARQ Pactor1 but it is impossible. A
bit in Pactor1 lasts 10 ms or 5 ms (200 bauds). This obliges to have a
precision of at least 2 ms, which would be easy under
In the case of Pactor-2 and Pactor-3, the developers knew they were
running on dedicated processors with complete control over scheduling,
so there was no reason to reduce performance by unnecessarily extending
turnaround time or pipelining control messages (which extends recovery
when an
Back in the late 80's when Mil-STD-188-110 was still in development, a Harris
RF Comm Gp engineer/programmer recommended that you send a frame with X number
of numbered packets with a CRC. The receiving station would only NAK the
packets it didn't receive. The transmitting stations would
At 11:41 AM 8/28/2006, you wrote:
I'm willing to believe that the timing tolerances in -tor modes
are so tight that ordinary PC operating systems cannot cope with
them the way a dedicated processor can. What I don't understand
is why the tolerances need to be so tight. The transmitter sends
a
Hi Chris,
Take a look at DBM ARQ in
http://www.n2ckh.com/MARS_ALE_FORUM/MIL-STD-188-141B.pdf starting on
page 178, it really lends itself to the PCSDM and its works
fantastic, I love GTOR, more so than PACTOR I since the day I bought
my first KAM Plus (I like my KAM XL a bit better though)
Why? Because your digital voice QSO sounds like noise to SSBers?
From: John Becker [EMAIL PROTECTED]
Reply-To: digitalradio@yahoogroups.com
To: digitalradio@yahoogroups.com
Subject: RE: [digitalradio] The digital throughput challenge on HF
Date: Sun, 27 Aug 2006 20:29:05 -0500
You should try
An Article on the HFLINK.COM website explains ALE for amateur radio
operators. The PCALE software to run ALE on your ham transceiver is
also available for download on HFLINK.COM website.
ALE on HF in the Amateur Radio Service
Selective Calling and Automatic Linking for Voice, Text, Image, CW,
Thank you Bonnie - 73 Bruce.
72/73 - Bruce ve5rc/ve5qrp - QRP-C#1, QRP-L#886, A1 Operator
Enter QRP-Canada's RUN with RAC contest -
details - http://www.qrp-canada.com
Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org
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