I would have to agree with Andy's observation that the 1 baud mode is as good as using JT65a With the advantage of being able to send more text in one transmission. It is a very slow throughput though. Very 73, Glenn (WB2LMV)
________________________________ From: Howard Brown <k...@yahoo.com> To: digitalradio@yahoogroups.com Sent: Mon, February 22, 2010 9:55:11 AM Subject: Re: [digitalradio] ROS Advantage? Aside from the legal aspect, does anyone have an opinion as to whether the limited hopping (within the 3khz that it hops) helps the robustness of the waveform? If it makes a tremendous difference, maybe we should all work to get it accepted. Howard K5HB ________________________________ From: J. Moen <j...@jwmoen.com> To: digitalradio@ yahoogroups. com Sent: Sun, February 21, 2010 9:13:50 PM Subject: Re: [digitalradio] FCC Technology Jail: ROS Dead on HF for USA Hams Bonnie's note describes the US/FCC regulations issues regarding ROS and SS really well. It's the best description of the US problem I've seen on this reflector. After reading what seems like hundreds of notes, I now agree that if ROS uses FHSS techniques, as its author says it does (and none of us has seen the code), then even though it 1) uses less 3 kHz bandwidth, 2) does not appear to do any more harm than a SSB signal and 3) is similar to other FSK modes, it is not legal in FCC jurisdictions. As Bonnie points out, ROS "doesn't hop the VFO frequency," but within the 2.5 bandwidth, it technically is SS. This would be true if ROS used 300 Hz bandwidth instead of 2.5 kHz, but hopped about using FHSS within the 300 Hz bandwidth. So I have to agree the FCC regs are not well written in this case. Regarding the corollary issue of US/FCC regulations focused on content instead of bandwidth, I'm not competent to comment. Jim - K6JM ----- Original Message ----- >From: expeditionradio >To: digitalradio@ yahoogroups. com >Sent: Sunday, February 21, 2010 5:09 PM >Subject: [digitalradio] FCC Technology Jail: ROS Dead on HF for USA Hams > > >Given the fact that ROS Modem has been advertised as Frequency Hopping Spread >Spectrum (FHSS), it may be quite difficult for USA amateur radio operators to >obtain a positive interpretation of rules by FCC to allow use of ROS on HF >without some type of experimental license or waiver. Otherwise, hams will need >an amendment of FCC rules to use it in USA. > >Sadly, this may lead to the early death of ROS among USA hams. > >If ROS Modem had simply provided the technical specifications of the emission, >and not called it "Spread Spectrum", there would have been a chance for it to >be easily adopted by Ham Radio operators in USA. > >But, the ROS modem designer is rightfully proud of the design, and he lives in >a country that is not bound by FCC rules, and probably had little or no >knowledge of how his advertising might prevent thousands of hams from using it >in USA. > >But, as they say, "You cannot un-ring a bell, once it has been rung". > >ROS signal can be viewed as a type of FSK, similar to various other types of >n-ary-FSK presently in widespread use by USA hams. The specific algorithms for >signal process and format could simply have been documented without calling it >Frequency Hopping Spread Spectrum (FHSS). Since it is a narrowband signal >(using the FCC and ITU definitions of narrowband emission = less than 3kHz) >within the width of an SSB passband, it does not fit the traditional FHSS >description as a conventional wideband technique. > >It probably would not have been viewed as FHSS under the spirit and intention >of the FCC rules. It doesn't hop the VFO frequency. It simply FSKs according >to a programmable algorithm, and it meets the infamous 1kHz shift 300 baud >rule. >http://www.arrl. org/FandES/ field/regulation s/news/part97/ d-305.html# 307f3 > >This is a typical example of how outdated the present FCC rules are, keeping >USA hams in "TECHNOLOGY JAIL" while the rest of the world's hams move forward >with digital technology. It should come as no surprise that most of the new >ham radio digital modes are not being developed in USA! > >But, for a moment, let's put aside the issue of current FCC "prohibition" >against Spread Spectrum and/or Frequency Hopping Spread Spectrum, and how it >relates to ROS mode. Let's look at "bandwidth". > >There is the other issue of "bandwidth" that some misguided USA hams have >brought up here and in other forums related to ROS. Some superstitious hams >seem to erroneously think that there is an over-reaching "bandwidth limit" in >the FCC rules for data/text modes on HF that might indicate what part of the >ham band to operate it or not operate it. > >FACT: >"There is currently no finite bandwidth limit on HF data/text emission in USA >ham bands, except for the sub-band and band edges." > >FACT: >"FCC data/text HF rules are still mainly based on "content" of the emission, >not bandwidth." > >New SDR radios have the potential to transmit and receive wider bandwidths >than the traditional 3kHz SSB passband. We will see a lot more development in >this area of technology in the future, and a lot more gray areas of 20th >century FCC rules that inhibit innovation and progress for ham radio HF >digital technology in the 21st century. > >Several years ago, there was a proposal to FCC to provide regulation by >bandwidth rather than content. However, it failed to be adopted, and ARRL's >petition to limit bandwidth was withdrawn >http://www.arrl. org/news/ stories/2007/ 04/27/101/ ?nc=1 > >Thus, USA hams will continue to be in Technology Jail without access to many >new modes in the foreseeable future :( > >Best Wishes, >Bonnie Crystal KQ6XA
