Is the random or pseudo-random manner of generating the tones or carriers an
essential element of spread-spectrum? If so, and if the aim of using such a
method is not to obfuscate the message but only to provide better immunity to
interference and path variations, would you be any worse off
The difference between spread spectrum and other systems is the
pseudo-random generating of the frequencies and not frequencies
determined by the data. It was originally done to prevent decoding
without the synchronization code. It is only disallowed under FCC
regulations on that basis. SSB
Excactly!. But this also is an inherent possiblility/advantage running PACTOR
1, in FSK mode both ARQ and PACTOR FEC mode.
And the Fec mode, defaulted with 2 repeats, can at the cost of speed be
increased to 5 to increase robustnes.
An extra advantage is fully 8bit information both in ARQ and
Mode is not equivalent to emission type,
Phone is not a mode.
Phone is not an emission type.
Content is what the emission contains or what
is carried by the emission.
Content can often be part of the emission type,
but not always.
Sub-bands are demarcated primarily by content,
not
Another survey of RS ID usage, this time on 80M. This was unattended
monitoring, I suspect the RS IDs were not from numerous stations.
14 MT63-500-LG
13 BPSK250
4OLIVIA-8-500
2OLIVIA-4-500
1BPSK31
Ideally, it would be useful to know how may transmissions were made
that did not
Julian,
By definition, it is SS if the pattern is independently generated from
the data. The original intent of FHSS was to make third-party decoding
impossible without knowledge of the code that generated the tones or
carriers. FCC rules disallow encryption because we are required to
police
Skip.
Thank you for the comprehensive explanation. I understand why ROS is illegal
under your rules.
The point of my question was, if FHSS is illegal, why not simply modify the
mode (which after all is experimental and does not have a large number of
users) to use a non random way of
He did, I guess, when he added a 500Hz-wide mode. The footprint of that
mode indicates it is probably FSK as he tried to claim for the 2200
Hz-wide mode. He says he submitted a technical description to the FCC
but will not release it until he gets an OK. Don't know what to believe
from him
El 10/03/2010 7:57, g4ilo escribió:
What does ROS gain by using SS over another mode that carries the same amount
of data at the same speed using the same bandwidth and the same number of
tones but uses an entirely predictable method of modulation?
Processing gain. Signals correlated with
Jose,
If you were going to design a mode that filled 2200 Hz, but did not use
SS, and was as sensitive as possible in that bandwidth, how would you do
it? It would have to be highly resistant to fast Doppler shift also, but
minimum S/N would be the most important parameter, as it would be
El 10/03/2010 10:51, KH6TY escribió:
Jose,
If you were going to design a mode that filled 2200 Hz, but did not
use SS, and was as sensitive as possible in that bandwidth, how would
you do it?
Tough question. I believe that on HF the best solution so far is Pactor-III
It would have to be
--- In digitalradio@yahoogroups.com, Jose A. Amador ama...@... wrote:
El 10/03/2010 7:57, g4ilo escribió:
What does ROS gain by using SS over another mode that carries the same
amount of data at the same speed using the same bandwidth and the same
number of tones but uses an entirely
Off the top of my head - you'll be needing a SDR transceiver for that mode Sir?
Simon Brown, HB9DRV
http://sdr-radio.com
-Original Message-
From: digitalradio@yahoogroups.com
[mailto:digitalra...@yahoogroups.com] On Behalf Of Trevor .
3 kHz Bandwidth - 16000 bits per second
24
I'll preface this by saying that I'm not trying to defend or crucify
ROS. But when we are dealing with definitions the FCC, it's very
important we be clear accurate on our definitions.
KH6TY wrote:
By definition, it is SS if the pattern is independently generated
from the data.
One test, but
Jose A. Amador wrote:
It does not mean that SS is not a predictable modulation method, you
just need to know the key, in the USA, the key must be one of a few
specific codes, and if you don't have the key, security by obscurity
applies.
And the FCC does not consider a code used to
Alan, though we may disagree as to the amount or nature of FHSS in ROS,
the bottom line is that the FCC engineers, as well as the ARRL
engineers, reviewed both the documentation and the signal footprint, and
have concluded it is FHSS. While their opinion might be changed through
dialog, that
--- On Wed, 10/3/10, KH6TY kh...@comcast.net wrote:
Alan, though we may disagree as to the amount or nature of FHSS in ROS,
the bottom line is that the FCC engineers, as well as the ARRL engineers,
reviewed both the documentation and the signal footprint, and have
concluded it is FHSS.
Who
Engineers that work for the FCC, of course. Their names are not
ordinarily revealed and the mouthpiece of the FCC is a customer service
agent (and for some amateur matters, the ARRL, who relays information
from the FCC offices). This structure should be fairly obvious to anyone
with experience
Trevor, I might add that it is often the practice in this country for a
higher court just to either reaffirm or remand a lower court decision,
instead of issuing a differing decision itself. I am sure that the FCC,
as a government body, also adheres to this practice. That is why the
original
KH6TY wrote:
Alan, though we may disagree as to the amount or nature of FHSS in ROS,
Actually, I think we agree, just for different reasons. I really don't
care about ROS. But do care about dangerous precedents. :-)
the bottom line is that the FCC engineers, as well as the ARRL
engineers,
8P9RY comments below
From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com] On
Behalf Of Trevor .
Sent: Wednesday, March 10, 2010 3:21 PM
To: digitalradio@yahoogroups.com
Subject: Re: [digitalradio] SS definitions
--- On Wed, 10/3/10, KH6TY kh...@comcast.net
Alan, please carry on the debate with someone else. I have spent a huge
amount of time on this issue, trying to help in whatever way I can,
although I do not have all the answers, obviously. I need to do
something other than sit in front of this computer all day!
Have fun,
73 - Skip KH6TY
Well ROS is going to ruin digital operation if it catches on. It has already
ruined Olivia on 20m. Just one transmission using this selfish wideband mode
wipes out three frequencies that were used by Olivia. It is causing
interference to packet networks as well. And, if the number of members of
- Original Message
From: rein...@ix.netcom.com rein...@ix.netcom.com
To: digitalradio@yahoogroups.com
Sent: Tue, March 9, 2010 11:51:52 PM
Subject: Re: [digitalradio] Re: Question for experts
Hi Ralph,
You got me again. Indeed the Commission requires that it has to be intelligent
Bonjour,
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Andy K3Uk
2010/3/10 morgane d morgane-d-bij...@orange.fr
Bonjour,
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