Hi Rick, At 08:26 PM 12/26/2007, you wrote: >Hi Steve, > >I agree that it is a type of protectionism.
Which in my opinion is a worst case issue for the Amateur Radio Service (ARS) than the technical challenges being presented. > I did not view it that way >as much until we really started seeing a lot of new modes and how poorly >they cooperated with each other. Especially with the main change over >the years which is ... inability to intercommunicate. The best we can do >is to try not to interfere with each other. The narrow modes do a far >better job of this because of a practical reason. They do not need as >much real estate to operate in what is often a VERY limited shared >resource. I noticed this time and again when I tried to pick out a place >to operate 2K MT-63 or wide Olivia. It is very hard to do without >stepping on someone else. As I have stated before what is needed within the ARS is segregation of narrow vs. wide digital modes. The approach taken should be to split in half the digital sub bands so that the bottom half is used for emissions below 500hz and the 2nd half for emissions greater than 500hz, regardless of automated operations or not. I agree that we have too little frequency allocation on most bands, period, not just when it comes to digital sub bands, personally I would like to see a 500Khz wide band for each segment below 10 meters, but that's a dream, we come close to that on 15m, a bit less so on 20m ( and about the same for 40m in North America ) and we hit the mark on 80/75m but elsewhere we are no where near being close. With or without 500Khz bands I see no reason why each band allocated to the ARS could not be split 50/50 between Digital and Voice, I actually see no reason why that should not be the case with the allocations already in place personally. I would also like to see the availability of stations involved in the support of Emergency Communications, during such an event allowed to work multi-mode Voice/Digital in the Voice segments and not have to move off frequency. >Another thing that I have noticed is that the digital and analog modes >really do not work well in the same area. SSB voice just tears up such a >large part of the band and you can not filter it out. This is the >historical reason that CW and RTTY were kept separate from voice modes. Well the problem with a large segment of AM/SSB stations is that they are over driven and splatter, those driving QRO level amplifiers make the situation even worst during their on-the-air pursuits. Its not like AFSK digital mode stations are immune from this either, I see a number of PSK-x stations and others over driven as well. >Now that we have digital modes that may even sound somewhat the same, >(OFDM for example), but may carry totally different payloads, e.g., >voice, text data, image data, etc. we have to be very careful how we >intermix them (the modes, not the content). They have no way of >intercommunication unless you do what used to be a mandatory requirement >of providing at least some kind of CW ID. So absent that idea, some kind >of segregation is needed. Again, I am all for segregation of narrow vs. wide digital modes on a normal basis. >There are some new technologies that may have some advantages, but >usually there is a tradeoff. Digital voice is not competitive with SSB >voice since it is technologically inferior on a shared resource like the >ham bands. Can it ever overcome these limits? Maybe some day, but very >unlikely. Just because something is older does not mean it is obsolete. Don't take your Amateur Radio Digital Voice experience to heart and tell Government and Military users that, they will laugh at you. We Radio Amateurs are slapping together various equipments for digital voice operations that are either firmware/hardware digital voice modems or Software/PC OS based modems with common Amateur Radio SSB transceivers, change that paradigm to the use of full up 3Khz radios and Vocoder modems designed for the task and the results are quite different. >I used to think that we were maybe being held back by old rules that >were not necessary, but that kind of thinking can be shortsighted >because after serious discussion with other active hams who are also >technologically knowledgeable, we don't really have many limits. You have to be kidding? >For example, your agenda, promoting ALE and high speed modems on HF is >not being held back at all by the rules. Rick I have NO agenda as you state, I am NOT promoting anything, do you really think that? All my software development which I am involved that has to do with digital waveforms and data link protocols are in support of the MARS program. I am directly associated with G4GUO as my efforts with MARS-ALE is based on his efforts with PC-ALE and he asked that I update aspects of PC-ALE that have to do with Radio Control and interfacing, but I do not do any development of that tool with respect to the digital data operations. > As you know, I have submitted >questions to the FCC on this very subject and am waiting on a return >response. Good luck and don't be to surprised when/if you get one as to what it will contain. >Your fellow promoter of ALE, Bonnie, KQ6XA, was livid that I >even dared ask these questions and yet the amateur community has a right >to know how the rules should be properly interpreted. If you have issues with Bonnie, take them up with her. >And a major one is whether we can operate certain kinds of modes on the >high speed portions of the HF bands, otherwise known as the voice/image >portions. Maybe they will stretch the rules to allow use of mixed image >and text, maybe they won't, but I want to know what we can and can not >do. I am convinced that the FCC will support the use of ALE modes, >including the very modes you mention below providing that that content >is image/fax. I personally have sent many faxes over the years that >don't even have one picture in them and were all "text." Even if they >say we can not send a pdf, or a doc or an xls, we can still send jpg and >jp2 files as the WinDRM folks actively do ever day for real world >testing. And we can coordinate this with SSB voice too. Something we can >not do in the text data portions of the bands. Unfortunately for U.S. based Amateurs the use of serial tone modem waveforms and others that are specified in MIL-STD-188-110x and various NATO STANAG standards exceed both the symbol rate and bandwidth under the current FCC Part 97 Rules for data transmissions in the current digital sub bands. I have yet to fully form an opinion regarding the sending of image files as attachments using said modems within the Voice/Image sub bands, taking into account other recent developments in that arena, such as WinDRM, it would appear that such use is acceptable, but I will refrain from doing so until I am sure. >Although I did ask the FCC about the single tone MILSTD/FEDSTD/STANAG >modem use in the text data portions of the bands, they would have to >make changes to the rules to allow such use. I agree. > My preference is to keep >the narrow modes in the text digital area, and rename this the narrow >areas and then allow us to use the wide modes in the voice/image areas. That approach if I read you correct is a mixed Voice/Data multi-mode concept where you are stating that all wide mode digital regardless of Text or Image base you would rather see in the Voice sub bands. I too would like to see such on an ECOM event basis, however I don't think such on a daily basis would go over well with the ARS on a whole or for that matter with the FCC. The better approach I feel is to split the digital sub band in to 2 parts as I detailed earlier. >But here is the rub. We can do that any time we want now ... right? All >you have to do is make it an image and you have no limits on the baud >rate, even 2400 baud ... right? Ask the FCC. >And I have asked this question many times on these groups. No one even >wants to try it? Why is that? Is it possible that you have tried it or >others have tried it with poor results? The professional contacts I have >in the business of emergency/military communication tell me that these >modes don't work all that well, even on dedicated channels. Something we >don't have in the amateur shared frequency bands. Really? Again, go tell that to the Government/Military users of MIL-STD modems, start with the manufacturers with your Q&A. >When I asked the ARRL, Paul Rinaldo, W4RI, he felt that the reason we >don't use the single tone modems may be due to the need for increased >computing power to make it work. Either way, why is no one working on >this now? It does not add up. To implement such modems as software based PC OS modems there is a huge increase in CPU processing required verses an 2FSK+ MFSK modems, no question about it! However, that computing power is readily available to most any Radio Amateur today that is interested in the pursuit vs. the purchase of an expensive hardware based modem that has many limitations compared to software based modems. >Why do we need wider modes? The reality is that HF is a terribly >difficult place to get high speeds with weak signals. The wider modes >tend to work less well than the narrow modes in most cases. Even Pactor >3 drops to way under 1,000 Hz and only 2 tones when conditions get >really difficult. The wide 8FSK125 ALE mode at around 2000 Hz wide >compares very poorly with the narrow 8FSK50 mode at only 400 Hz when it >comes to sensitivity. It is very difficult to find 2000 Hz of clear >frequency to even operate such a mode and yet 400 Hz is much more useful >and ham friendly. 3000 Hz or more is even more than a communications >quality voice bandwidth and is a step backward in technological >achievement with shared bandwidth services such as we have with amateur >radio. Narrow modes are fine for the average Radio Amateur in pursuit of daily ragchew's or DX, I highly recommend that such pursuits be contained to modes less than 500hz. However for station-to-station message traffic handling or remote-to-automated station traffic automation in support of moving book message traffic with or without file attachments in support of various Amateur Radio communications, especially Health/Welfare and ECOM, the throughput offered by 500hz and less waveforms is inferior to wider band width, higher symbol and data rate protocols. Its that simple, it should be obvious to you or anyone else without a just plain old anti-wide mode agenda. >For those hams who are not aware, the ham who convinced the FCC (over >the objections by the ARRL) to allow image/FAX to be used in the text >data portions of the bands, which some have tried to lobby for more than >20 years, was Mark Miller, N5RFX. > >Ask yourself why did the FCC go along with this reasonable idea at the >maximum 500 Hz bandwidth? Why not make it 1000 Hz or 2000 Hz, etc. The >answer has to be that they really expect the lower portions of the bands >to move to narrow bandwidths. The answer actually has to be that it was a reasonable thing to allow and that it served the best interests of the Amateur Radio Service and those that the ARS serve, especially in times when the ARS is on the front lines providing Emergency Communications if you want my opinion. >Take a look at the new IARU Region 2 Bandplan that was promulgated >primarily by ARRL leadership at the IARU conference. Note that there is >no wider bandwidth than 500 Hz in the 80 meter band below 3600. Same >below 7040, 14100, etc. Those are all fine break points for 500hz, now what is needed is 3600-3700, 7040-7080 and 14100-14200 configured for nothing but 500hz and greater band widths and we will be on our way to a vast improvement for the future of HF digital communications within the Amateur Radio Service on those bands. /s/ Steve, N2CKH >73, > >Rick, KV9U
