Two weeks ago we explained (translated version here) how to disable the auto-spotting feature in the ROS digital communication software. Its creator, José Alberto Nieto Ros, contacted us shortly afterwards to dispute the usefulness of this operation, arguing that the DX-cluster saturation issue has been resolved. We then thought about interviewing José to get to know him better and give him the chance to reply to criticism on his software.
This is an exclusive interview made by DxCoffee.com. Please link this article if you want share this news!
What’s your current occupation?
I’m a telecommunication engineer and I’m currently working as a consultant in the field of digital transmissions.
When did you start working on ROS? And why?
Actually, I started working in something similar to ROS when I was studying in the University, 12 years ago. I produced an HF communications software that used the Serial Port, in a way similar to HamComm but far more robust. It ran from 50 to 1500 bauds with AM Rigs.
Last year (2009) I decided continue with the experiments, but in this case, I decided to upload the project to the Internet for Ham Radio use because ROS offers improvements over others weak signal modes. As you can see by simply viewing the PSK-Reporter website, usage has been widely taken up by the Ham community.
Of particular note, ROS is not a time-locked mode, thus it doesn’t need a precise clock synchronization between computers, as opposed to other weak-signal modes such as WSPR. This, combined with superior data-rates and interactivity (TX and RX timing are managed by the user and it’s practical to have live-keyboard conversation just like BPSK31), would allow a DX’pedition to work in remote locations without needing accurate clock synchronization via Internet or GPS.
Are you interested at all in other means of radio-communication? Do you plan to get an amateur radio license?
I expect get a license soon. I am interested in QRP. Also and military data com, Slow scan digital TV, DSP, in general.
How do you develop ROS? How do you test it?
Having previously produced a working data system, I set about improving the system making use of modern techniques, this gave me a clear objective for the ROS project, to create a mode efficient in power.
Initial testing was done with CO2DC over 7 MHz band.
Is it true that ROS is all developed in Visual Basic? Will you consider porting ROS to other operating systems?
Yes, it’s true, and not at the moment. Perhaps in a future.
How about ROS MF?
ROS MF is a mode that I created for request of Graham, G0NBD and others enthusiasts of LF and MF bands and has established itself as the mode of choice for data MF live QSOs and reactive beacons linking back to the reporting network.
It is a narrow band mode that occupies only 100 Hz according band-plans of many countries. It uses two symbol-rates, 0.8 bauds (ROS MF1) for use in Beacon Mode mainly, but is a live keyboard mode as is 7 bauds (ROS MF7) for keyboard to keyboard communications to 130 characters/minute.
Which are the most interesting DX QSOs made with ROS that you are aware of?
Probably across USA from Canada to Cuba with 25 mW at 150 characters/minute. A lot of Great QSOs are published in ROS website, as low power MF7 QSOs into Europe using the 500 kHz band.
What’s your recommended setup (RX/TX, antenna, computer) to make ROS contacts?
Any modern SSB radio, IF filtering is not a requirement as ROS has adaptive filtering that is matched to the mode in use, AGC may be disabled, taking care not to overload the soundcard, of course.
Narrow IF filtering will degrade the system performance. ROS has been developed to run within the limitations of a simple HF transceiver.
Any antenna is suited, but with the enhanced S/N capability of over 10 dB over the most popular data modes and its inherent insensitivity to phase distortion over the polar paths, any simple array is capable of excellent results. Power levels of 5 to 20 Watts are being reported as quite sufficient, the software also provides instant S/N and fade margin reading, enabling the user to evaluate the path and power levels during the QSO, or simply by monitoring the traffic.
Computer clock must be over 1Ghz (PIII 1.2 GHz not fast enough), older PCs can have problems using ROS. The ROS system is leading-edge technology and it follows that demands are placed on the computer and soundcard. You don’t need any special soundcard, though.
Will you release full ROS specifications so that it could be implemented in other multi-mode programmes such as fldigi and MixW?
…………….$64,000Â question. Not at the moment, as ROS is under constant development, so it’s pointless to try and implement it elsewhere. ROS is freely available and fully web-integrated, so its not a detrimental situation.
There has been lots of criticism over the auto-spotting feature in the ROS programme, what did you do to improve it?
Many people publish articles on the internet about ROS, without knowing how ROS actually works, which in turn have produced erroneous technical discussions and some quite bizarre actions by people otherwise considered quite sane.
There was a bug in the auto-spotting on the 15 m band, but it has been corrected quickly with the release of a new version of the software. The auto-spotting is regulated by two algorithms that compare decoded calls with the DX-cluster spots and their purpose is to limit the number of spots sent to the DX-cluster itself:
- 20 metres algorithm. It allows one ROS spot every 10 “non-ROS” spots on this band. The spot is first subjected to a “draw” among all ROS stations active on the band and with auto-spotting enabled according to three priorities:
HIGH – QRB > 4000 km
MEDIUM – call is spotted on 14.078, 14.079 or 12.112 MHz
LOW – call is spotted on 14.103 MHz
- 15 and 40 metres algorithm. It allows one ROS spot every 10 “non-ROS” spots on the sum of all bands. The “draw” is present but there are no priorities.
In the rest of bands there is not any algorithm. Spots are sent directly because activity is very low. This promotes the possibility of doing a QSO in bands like 80 metres or 10 metres where activity is very low. Algorithms can change with new versions, according the increase of ROS users in unusual bands.
It is for there reasons that I discourage to disable the auto-spotting. Now, look the DX-cluster, count the number of spots and tell me if actually ROS is saturating the DX-cluster.
11) Could you tell us what has happened in the USA with the ARRL?
USA Ham community has a “local” problem, in that, the FCC has a clause in the licence preventing spread spectrum communication below 220 MHz.
ROS is not a “SS” mode. In fact, ROS7/100 occupies 100 Hz, ten times less the Olivia32/1000 and transmits at the same rate. So, if ROS7/100 is defined as SS, then Olivia and most of the other soundcard-based data modes should be classified as SS too, or is this just “sour grapes’” as ROS was invented outside the USA?
Totally lost in a modern sea of technicalities, the representatives of USA hams, instead of trying to amend the situation, are blindly following a minority opinion and are trying convince “all” USA Hams that all the ROS modes HF/EME/MF ROS/100 Hz are illegal and cause interferences, but Olivia 2000 Hz and other modes are legal, that’s something that I think, nobody can believe.
To state that ROS is a narrow-band SS. It is the first time that I heard that a SS mode can occupy less bandwidth than others modes that the FCC says are not SS, like Olivia, MT63, MFSK, Chirp and the new super wideband ALE networks that now use the HAM bands for private e-mail exchange. It’s perhaps very clear that the ARRL doesn’t defend the interest of USA Hams. Checking PSK- Reporter for ROS activity shows my mode to be in constant use, fromVHF EME contacts, through HF, to setting distance records on the LF bands, while only one user shows in the USA.
USA Hams that do not agree with ARRL should not pay the ARRL fees, as even China is free to use ROS!
As of today, the situation remains, with only one license toallow the use of the ROS mode issued by the FCC to WE9XLQ, a sort of cross between Eliot Ness and the Lone Ranger.
