The new mode uses spread spectrum technology at 1 or 16 Baud signalling rates, and is designed to cope with disturbances, low level signals, meteor scatter and moon bounce says José. José claims that receiving signals down to -35 dB (!) with 1 Bd signalling rate and -30 dB (!) with 16 Bd are possible.
But we have a problem here in the US. ROS is a spread spectrum mode and US hams are not allowed to use SS modes below 222 MHz by FCC regulation. Another problem is that hams in other portions of the world are using this 2.2 kHz bandwidth mode in the portion of the ham bands reserved for narrowband comms. Again not a good thing.
On March 4, 2010 the following was posted to the ARRL website:
In mid-February, European amateurs first used a new, experimental digital mode known as ROS. On February 23, 2010 -- after FCC review of the original documents provided from the developer's Web site -- the FCC made the following statements on ROS:
"Section 97.305 is the rule that specifies where different emission types are allowed to be transmitted on different bands. 'ROS' is viewed as 'spread spectrum,' and the creator of the system describes it as that. We assume that he knows what he created. [Section] 97.305 authorizes spread spectrum emission types (defined in Section 97.3) to be transmitted by FCC licensed amateur stations at places we regulate communications only on 222-225 MHz and higher frequency amateur bands. European telecommunication regulatory authorities may authorize amateur stations in Europe to use SS on the HF bands, but this is of no concern to us. The Commission does not determine if a particular mode 'truly' represents spread spectrum as it is defined in the rules. The licensee of the station transmitting the emission is responsible for determining that the operation of the station complies with the rules. This would include determining the type of emission the station is transmitting and that the frequencies being used are authorized for that type of emission."
Since that initial FCC review, several Internet sites have reported a claim -- attributed to the FCC -- that the original statements made had been reconsidered and that the FCC view was now that "ROS cannot be viewed as Spread Spectrum and it would be encompassed within Section 97.309 (RTTY and data emissions codes)."
When queried about this new statement, the FCC's Consumer Assistance Office stated that "[T]he information contained on the ROS Web site was not provided by the FCC." They then reaffirmed the original statements that originated from the FCC's Wireless Bureau, which handles Amateur Radio rules for the US.
The ARRL supports -- as one of the basic purposes of Amateur Radio -- the experimentation and advancing the technical skills of operators. The development and use of any new mode is exciting to many amateurs, and the League encourage amateurs to experiment within the parameters of the rules; however, the ARRL also reminds US licensees that according to Section 97.307, spread spectrum communications are only permissible in the US on frequencies above 222 MHz.
Of course, the debate raged on the various newsgroups about the pros and cons, but soon the conversation slowly died off, until this week. Earlier in the week the conversation cranked up in earnest again about the legally of using ROS in the US on the 30MDG newsgroup. This was due to this post by José on his ROS website:
Instead of investigating the details of the post, a flame war erupted, and is still raging strong even this morning. So now I'm now waiting for the aluminum foil hats (or hard kats with rubber ducks in the middle) to come out and aliens to land in BTown.
Yes, José's choice of a headline was poor "The FCC allows ROS to be used in the USA," since it makes it sound like the FCC has cleared and approved the mode for general hams ops in the US. But the details are in the body of the post:
Instead of taking a pause and looking into the callsign on the FCC website which would have been the prudent thing to do, some gents blew up the situation into a full blown flame war. Theese folks should have their keyboards disabled and given a time out in one corner of their shacks. ;-)))
Now the real truth, WE8XLQ is a newly issued FCC experimental license issued to Reindert A Smit in Alta Loma, CA, to test the ROS mode in the HF spectrum. The license is valid from 8/1/2010 to 1/31/2011.
In the "Explanation" section of the license it states:
Like to use ROS Modem digital mode in Amateur Radio Service. Questions exist about the legality of this mode on frequencies below 225 MHz.
In the "Purpose of Operation" section of the license it states:
Experiment with this mode and research capabilities of this mode under weak signal conditions and make comparisons against other digital modes such as WSJT and PSK31
Complete details are available at the link below: https://fjallfoss.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=initial&application_seq=45235
So it will be interesting to see how all of this washes out. Personally other than the wideband nature of ROS being used in the narrowband section of the various bands, I don't see why the ARRL and FCC should have opposed the mode in the first place. There is a mode called Chip64/128 which is also described as spread spectrum (full details at http://xoomer.virgilio.it/aporcino/Chip64/index.htm) being used in the HF spectrum. I haven't seen anything being done to ban this mode on the HF spectrum by the FCC. It has been around since 2007.
Not sure why all the fuss over ROS and not CHIP64/128 by the FCC. I look forward to seeing the test results of the ROS mode from WE9XLQ early next year.
In the meantime, here is your caveat. Using the ROS mode on HF by US hams other than Reindert A Smit, WE9XLQ, is illegal. If you use it, you may lose it (your license that is).