Dear amigos:
I am really concerned about the damage to the amateur radio hobby generated by
a NON AMATEUR in Spain that wrote a software program for a new digital
mode that very clearly to me, without any doubts , is a FHSS communications
mode.
I wrote e-mail messages to this person, and received some very aggressive
replies from him... he even used several " bad words" in his messages that show
that besides his very primitive knowledge of the English language _ ( he can
not communicate effectively using English, as he has demonstrated many times
with this very poorly written postings ) he lacks the most basic education and
ethics.
The topic we are dealing now is not, in my humble opinion, if ROS is or is not
FHSS, it this person sent messages explaining or attempting to explain the
nature
of the ROS software, and then when faced with clear evidence that part of the
"market" , and a signficant one indeed , to which he was aiming, could not
make use of the ROS software.
Now we are seeing on the 20 meters band, under better propagation conditions due
to the so far sustained increase in solar activity, that Olivia users are
facing
interference from ROS users, caused by the ignorance of the Spanish "inventor"
about amateur radio.
He replied to a senior Cuban professor, a very prestigious telecommunications
expert, using what could be described as "foul" language, an indication that
confirmed
that he was not only answering to my advice in such a disrespectful language.
Just to add one more element... when I asked him about the possibility of
writing
the ROS software for LINUX users, his answer was also a clear demonstration
of his ignorance about today's world.
So, amigos at "digital radio ", my advise , and that's what I am going to do,
is to
alert ROS users of the possibility that the author of the software may even be
attempting to use it for other purposes that are not related to amateur radio...
After all, once you load a program of which you don't known the source code,
into your computer, you are at the mercy of those who wrote the computer code...
73 and DX
Arnie Coro
CO2KK
IARU Region II Area C
Emergency Coordinator
--- On Sat, 3/6/10, John B. Stephensen <kd6...@comcast.net> wrote:
From: John B. Stephensen <kd6...@comcast.net>
Subject: Re: [digitalradio] What is SS?
To: digitalradio@yahoogroups.com
Date: Saturday, March 6, 2010, 4:00 AM
The document that the author of ROS
originally published, "Introduction to ROS: The Spread
Spectrum", contains a good description of frequency-hopping
spread-spectrum (FHSS) techniques. Section 4 describes taking a
250 Hz wide mode (MFSK16) and spreading it over 2 kHz by shifting the
center frequency in a pseuorandom sequence. The receiver changes frequencies in
the same sequence and the logic used to detect a special
tone sequence to obtain synchronization is described in section 5. The
amount of spectrum occupied increases by a factor of 8. FHSS is one way to
minimize the effects of multipath spread but there are also other techniques
that occupy less spectrum.
Note that the author of ROS published a second
doucument,"ROS Technical Description" , that contains elements of the
original but does not mention FHSS and omits any description of how data
is mapped to tones. Users comparing the original and later versions of
the code haven't seen a difference in the transmitted spectrum.
73,
John
KD6OZH
----- Original Message -----
From:
Rein A
To: digitalradio@ yahoogroups. com
Sent: Friday, March 05, 2010 19:16
UTC
Subject: [digitalradio] What is SS?
Here is a reprint that for my limited
mental capacities defines
the core quite well.
I have asked Mike the
author for some references, no lack of
trust
though.
------------ --------- --------- --------- --------- ---------
>
-----Original Message-----
> >From: n4qlb <n4...@...>
>
>Sent: Mar 5, 2010 1:15 PM
> >To: ROSDIGITALMODEMGROU p...@yahoogroups. com
>
>Subject: [ROSDIGITALMODEMGRO UP] Re: How do you like ROS Now?
>
>
> >Thank You for your comments Sig. Let me explain what SS is.
Spread spectrum is a method by which a bank of channels (Frequencies) are
designated between a Transmitter and Receiver and are shared or (Frequency
Hopped) to facilitate a clear Transmisson. The Transmitter actually signals
the Receiver to Hop from one frequency to another. A good example is a 900mhz
digital cordless telephone or a 800Mhz digital radio truncking system.
(Motorla Astro). A frequency in Ham radio consist of a 3kh wide channel. Ros
does not signal a receiver to hop outside of that channel (3 Khz) therefore
it
is not SS and is just like anyother FSK mode used in the amatuer radio
service. The ease of obtaining a License in the U.S. by people that are not
technically qualified to hold one is the main culprit regarding the
controversy over new modes such as ROS. I am confident that all variations of
ROS are perfectly legal in the U.S.
> >
>
