Rick, I prefaced my comment with " It is my belief that if "voice" of the same bandwidth were allowed everwhere "data" is allowed, the data segments of the bands would be overrun with phone stations using DV."
Perhaps it is not clear what I meant. For example, if someone comes up with a DV of 300 hz bandwidth, it will quickly be widely used anywhere 300 hz bandwidth signals are allowed, and the crush of phone users will leave little space for modes like MFSK16 of the same bandwidth to operate, simply because there will be so many people wanting to use phone instead of another digital mode, like MFSK16, but that is just my personal belief. If there were a DV mode the same width as PSK31, then the same would prove true, except that there are more spaces to use PSK31, because of its narrow bandwidth, than there are digital operators looking for space (right now, but changing). In fact there already is a sort of narrowband "DV" in my DigiTalk program for the blind, which "speaks" the PSK31 text (at 50 wpm text-to-speech), but, because going the other way (speech-to-text), still has a 5% translation error rate at best, "speaking" must still be done by typing, and that is a deterrent to many who might use PSK31 if they could just speak into a mike and have errorless text go out over the air. As you point out, some sort of planned segregation is going to be inevitable on shared bands. With phone and CW, there was a common language for everyone, and sharing was possible by QRL or other Q signals on CW or the equivalent on phone, but that sharing technique is useless when one mode does not hear or understand another. We have yet to experience what it will be like if everyone uses DV, there is not enough space to hold everyone, and someone accidentally starts up on your frequency because propagation was such he thought it was clear and did not happen to choose an alternate clear frequency he could QSY to if he could just understand a request to do so. I believe the thing that makes it possible for PSK31 to have a space, for example, is only that there is no true 31.25 Hz-wide phone mode. Of course, the more narrow the mode, the more stations that will fit in any given slice of spectrum, so it is advantageous to have the most narrow modes possible so there is room for as many stations as possible. At some point, there will be plenty of space, depending upon the demand, even if everyone used a voice mode that is only 31.25 Hz wide. For example, if every RTTY contester only used PSK63, there would probably be more than enough space so that during contests, RTTY stations would not have to spread out so much. There was a psychological experiment some years ago in which scientists set up two cages of rats, one overcrowded and one just at capacity. The rats in the overcrowded cage ate each other until they were no longer overcrowded. Skip KH6TY > It is almost for sure that if the FCC equated DV as being similar to any > other digital mode, that DV would not take over the ever decreasing size > of the text digital portions of the HF bands. There are several reasons: > > - the lower portions of the bands, historically used for the earliest > text digital mode based on wetware decoding will likely see further > reductions in that mode (CW), except during contest periods since almost > no new hams are acquiring even basic CW skills, much less proficiency. > This will allow for more space for text digital, assuming that text > digital will be segregated in that manner. > > - since DV is likely to never be competitive with analog SSB for weak > signals as analog due to the practical limitations of science. > > - if digital modes did increase in popularity, which would primarily be > voice DV, there would be tremendous pressure to segregate digital and > analog modes by a sizable majority of radio amateurs. And it works both > ways, as you well noted, analog SSB is a serious hindrance to digital > modes in general. > > - some phone bands are underutilized now, such as on 80 meters, with few > stations on the lower end of the voice sub bands and yet CW and digital > can be quite crowded in a space that is well under half of what we > previously had. (And I admit was underutilized with that mix too). > > Unless we eventually go to bandwidth based bandplans, and at the same > time do not segregate by mode (especially voice modes, whether analog or > digital), then it would be entirely appropriate for hams to use narrow > voice modes for spectrum conservation and do it in the appropriate > bandwidth areas. Based upon comments made by Dave Sumner in the past, I > am not sure that will be supported by ARRL, since he seems to suggest > that even if we have bandwidth limits, we will not necessarily mix > modes. In fact, it was at that point that I was no longer as supportive > of the withdrawn ARRL proposals, because it will still not allow us the > ability to use voice and data intermixed on the HF bands (even if only > in small areas) which I consider to be one of the most unfortunate > effects of our current rules. > > The best band plans are those that allow for the best use of a shared > resource. If one part of the band is congested and another part is under > utilized, that means the planning is flawed. And since conditions and > events constantly vary, the best regulations are the minimum necessary > to make more efficient use of the bands for the maximum number of shared > resource users. > > 73, > > Rick, KV9U > > > > kh6ty wrote: >> It is my belief that if "voice" of the same bandwidth were allowed >> everwhere >> "data" is allowed, the data segments of the bands would be overrun with >> phone stations using DV. Phone is the easiest to operate and obviously >> the >> preferred mode. During the "bandwidth petition" discussions, it became >> clear >> that the phone people wanted to take over as much space as they could, >> which >> is understandable, since the phone bands are always overcrowded. >> >> I don't pretend to know the real reasoning behind the FCC determination >> that >> DV is phone (just like analog voice), but practically, it currently >> serves >> to protect digital mode operators from being overrun by a multitude of >> phone >> operators. In light of the fact that you can sometimes copy an analog >> phone >> signal through another analog phone signal, but cannot do that with DV, I >> think we are fortunate that the FCC has taken the position they have. >> >> Skip KH6TY >> >> > > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG Free Edition. 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