Hi Warren,
I do not know of any way to change bandwidth in ROS. My observations
with ROS is that another ROS station on the same frequency will make ROS
stop decoding the first station and start decoding the next. I don't
know if it is a matter of strength, but I guess it is. The reason for
this is that if the second station is weaker than the first, the first
will continue decoding and I will not know there is another signal on
the frequency, until one or the other fades. Any wideband signal, like
Pactor, covering about the upper forth of the ROS signal also stops
decoding.
Olivia is much more narrow than ROS, so the chances of QRM to ROS are
much greater, and harder to get away from, since ROS is so wide.
Jose admits that QRM from wideband signals cannot be tolerated, but
narrowband signals (like PSK31) can be, and I can understand that, but
ROS is still a wideband signal, even if the tones are randomly spaced
and separated a lot, and you can see what happens when one ROS signal
comes on the frequency used by another ROS signal just by monitoring a
popular ROS frequency. 14.101 is particularly bad for Pactor QRM, both
from Pactor I, Pactor-II and Pactor-III.
I don't use Olivia enough on HF to know how it handles same-frequency
interference. I use Olivia daily only on UHF, where it works as well as
SSB phone, or sometimes a little better, under severe Doppler flutter
and QSB on 70cm DX. I am hoping that ROS will do even better. I think
the 1 baud mode may be very good for "real time" VHF DX or EME QSO's.
Unfortunately, we can only use ROS above 222, so 2m EME is not possible
yet for us using ROS. I hope some day it will be.
73 - Skip KH6TY
Warren Moxley wrote:
Hi Skip,
Does ROS have any flexibility like Olivia where you can change the
Bandwidth? I am thinking it must not. SS modes that we all have
experience with ( Cells, WiFi, etc ) seem to work well on top of each
other and seem not to interfere with each other (for the most part). I
was wondering if several hams using ROS that are one top of each
other, does it work better than say, Olivia?
Warren - K5WGM
--- On *Fri, 2/26/10, KH6TY /<kh...@comcast.net>/* wrote:
From: KH6TY <kh...@comcast.net>
Subject: Re: [digitalradio] ROS carrier pattern when idle
To: digitalradio@yahoogroups.com
Date: Friday, February 26, 2010, 8:27 AM
Hi Warren,
I have already captured a spectrum of Olivia 32-100 (i.e., FSK32)
and posted it in a reply, but glad do it again.. You can see the
fixed frequencies at idle and then the new frequencies added when
data is sent (in the "seared" middle part). I have not combined
that on one uploaded page with the ROS spectrum analysis, but you
can easily compare the two yourself, using the ROS spectral
analysys with MFSK16. I wanted to confirm that both MFSK16 and
Olivia 32-100 had the same signature of FSK, and they do, which is
far different from the signature of ROS. It is very clear that ROS
is using Frequency Hopping, as the frequencies are not a function
of the data, and that is a unique characteristic of frequency
hopping, at least according to everything I could find.
Olivia 32-1000: http://home. comcast.net/ ~hteller/ OLIVIA32- 1000.JPG
73 - Skip KH6TY
Warren Moxley wrote:
Skip, can you show some more spectral comparison examples? This
time add the widest Olivia mode and other very wide modes.
Thanks in advance,
Warren - K5WGM
--- On *Fri, 2/26/10, KH6TY /<kh...@comcast. net>/* wrote:
From: KH6TY <kh...@comcast. net>
Subject: Re: [digitalradio] ROS carrier pattern when idle
To: digitalradio@ yahoogroups. com
Date: Friday, February 26, 2010, 8:11 AM
Jose, my attempted help is to let you understand that the FCC
believed you when you said ROS is FHSS, so you will fail in
any attempt to reclassify ROS as just FKS144. The FCC will
not believe you. What will probably succeed is for you to
continue to describe ROS as FHSS and let the FCC permit it in
the USA as long as it can be monitored, the bandwidth does
not exceed the wide of a SSB phone signal, and it is not used
in either the phone bands (data is illegal there anyway) or
in the band segments where narrow modes, such as PSK31 are
used because it is as wide as the entire PSK31 activity area.
Look at the spectral comparison http://home. comcast.net/
~hteller/ SPECTRUM. JPG. In the middle, I am sending data by
MFSK16 (the letters "N"), and you can see that the
frequencies are being determined by the data, which means it
is not FHSS. But, in the middle of the ROS spectral display,
I am doing the same thing, and there is no change to the
frequencies being transmitted, obviously because the
frequencies are independent of the data, which is requirement
#2 in the ROS documentation for FHSS. This definitely implies
ROS is FHSS.
If you really want ROS to be legal here, just support a
petition to the FCC to allow it.
73 - Skip KH6TY
jose alberto nieto ros wrote:
If you are waste time in try demostrate ROS is a SS, i think
you are not trying help.
------------------------------------------------------------------------
*De:* KH6TY <kh...@comcast. net>
*Para:* digitalradio@ yahoogroups. com
*Enviado:* vie,26 febrero, 2010 14:36
*Asunto:* Re: [digitalradio] ROS carrier pattern when idle
> jose alberto nieto ros wrote:
> I propose to moderator you will be banned if you continue
saying stupid things in this group.
Moderated for stupidity? Now that will be a first!
Good luck with trying to fool the FCC. Spectral analysis
suggests ROS really is FHSS, no matter what you now try to
claim.
This picture does not lie: http://home. comcast.net/
~hteller/ SPECTRUM. JPG
Too bad - ROS is a fun mode and I cannot use it in USA
except on UHF.
I have only tried to help find a way for US hams to use ROS.
It will be an honor to be banned for my stupidity! :-)
Please go ahead as you wish.
73, Skip KH6TY SK
jose alberto nieto ros wrote:
My friend, one thing is what i wrote, and other different
is what ROS is.
If recommend you waste your time in doing something by Ham
Radio, instead of criticism ROS.
I propose to moderator you will be banned if you continue
saying stupid things in this group.
------------------------------------------------------------------------
*De:* KH6TY <kh...@comcast. net>
*Para:* digitalradio@ yahoogroups. com
*Enviado:* vie,26 febrero, 2010 13:18
*Asunto:* Re: [digitalradio] ROS carrier pattern when idle
> If MFSK16 was randomized would it magically become
spread-spectrum?
Alan, sorry I forgot to reply to this question.
The answer is yes, but only if the following three
conditions are ALL met (from the ROS documentation) :
1. The signal occupies a bandwidth much in excess of the
minimum bandwidth necessary to send the information.
2. Spreading is accomplished by means of a spreading
signal, often called a code signal, which is independent of
the data.
3. At the receiver, despreading (recovering the original
data) is accomplished by the correlation of the received
spread signal with a synchronized replica of the spreading
signal used to spread the information.
Standard modulation schemes as frequency modulation and
pulse code modulation also spread the spectrum of an
information signal, but they do not qualify as
spread-spectrum systems since they do not satisfy all the
conditions outlined above.
Looking at the comparison between ROS and MFSK16,
http://home. comcast.net/ ~hteller/ SPECTRUM. JPG, it is
easy to see that MFSK16 is not FHSS, but ROS definitely is.
Another thing that a petition should include is a
requirement that ROS only be used BELOW the phone segments
and ABOVE the narrowband data segments. On 20m, that means
only between 14.1 and 14.225, because ROS is so wide.
BTW, this same issue came up during the "regulation by
bandwidth" debate when the ARRL HSMM (High Speed
MultiMedia) proponents wanted to allow wideband, short
timespan, signals everywhere with the argument that they
last such a short time on any given frequency that they do
not interfere, but the fallacy to that argument is that
when you get a multitude of HSMM signals on at the same
time, all together they can ruin communication for narrow
modes, like PSK31.
The other problem is that SHARING of frequencies requires
that users of one mode be able to communicate with users of
another mode in the same space so QRL or QSY can be used.
It was realized that only CW used by both parties would
make this possible. ROS does not work well in a crowded
environment or with wideband QRM, so it must find a home
relatively clear of other mode QRM. This is just another
job the FCC must do in order to be sure a new mode does not
create chaos. It has already been shown that leaving that
up just to hams does not work, and the strongest try to
take over the frequencies.
upper
73 - Skip KH6TY
Alan Barrow wrote:
If MFSK16 was randomized would it magically become
spread-spectrum?
