-Thanks for sharing this Mark Andy
-- In digitalradio@yahoogroups.com, Mark Miller <[EMAIL PROTECTED]> wrote: > > Forwarded with the permission of G3PLX > > > >Subject: Your excellent petition > >Date: Wed, 26 Dec 2007 20:37:30 -0000 > >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 > > > >Mark: > > > >I hope I have the right email address.... > > > >This is just a note to offer my congratulations and express my > >admiration for the work you have put in to your petition to FCC, > >which I have only just seen as a result of various people drawing my > >attention to it in the last few days. > > > >You may know that I was the only non-U.S. citizen to be invited to > >serve on the ARRL Digital Communications Committee when it was > >considering what should be the response of the ARRL to the moves in > >Europe towards "separation by emission width", which are now built > >into the IARU region 1 bandplan. It was me that first proposed the > >change from "segregation by mode" to "segregation by emission width" > >within IARU region 1. The ARRL committee subsequently reported back > >to the ARRL board, and you will be well aware of the result. I > >resigned from that committee before it reported, because it was > >clear to me that the committee was dominated by a small group whose > >sole aim was to gain additional spectrum for voice-band unattended > >digital traffic-handling. They were simply hijacking the "separation > >by emission width" debate to further this aim. The result was a > >disaster, and it's down to people like yourself to sort out the mess! > > > >While I was on the committee, however, I tabled arguments almost > >exactly identical to those you have outlined in your petition, > >drawing attention to the inappropriate use of ARQ techniques (not > >just Pactor 3) in the amateur service. The use of ARQ in a congested > >band is counter-productive, since in the face of co-channel > >interference (which results from congestion), it INCREASES the > >amount of time-bandwidth it uses, thus making the congestion worse. > > > >I went on to generalise this discussion. To be able to survive > >congestion in an unregulated band, there must be a mechanism that > >causes individual transmitting stations to REDUCE their output (in > >time-bandwidth terms) when faced with undesirable congestion. The > >AX25 protocol, much maligned for HF use, did achieve this. I will > >come back to this, but it's also self-evident that all traditional > >one-to-one amateur operation has this desirable feedback mechanism - > >an operator faced with QRM due to congestion will shorten his > >transmissions or close down, thus reducing the congestion, or at > >least he will do so if he doesn't have any important traffic to pass. > > > >This leads to an important conclusion about amateur radio in an > >unregulated environment where the level of activity is > >congestion-limited. It will ONLY be stable and self-limiting if > >there are enough people on the air who are just there for fun, and > >who will QRT if/when it stops being fun. If we ever got to the > >situation where a significant fraction of the activity was by people > >who needed to be on the air for a purpose, then there will be an > >increasing tendency for congested bands to exhibit 'grid-lock' behaviour. > > > >We don't have a big problem over here in Europe. For a start, the > >use of amateur radio for third-party traffic is illegal everywhere > >except the USA, so virtually all amateur activity is of the > >recreastional (fun) type. But I can see it becoming a real problem > >in USA, and especially if ARQ modes like Pactor become a dominant > >fraction of the total. When we were discussing "emission width > >segregation" in Europe, it became clear that although disparity in > >emission widths was the most significant source of conflict between > >operators of different modes, it wasn't the only source of conflict. > >We identified "unattended operation" as another major source. With > >this in mind we created, within the bandplan, segments for this type > >of operation. This is working well. There is no longer a > >significant level of complaint by one-to-one operators from unattended systems. > > > >I said I would come back to AX25. The fact that AX25 'backed off' in > >the face of errors (which could be due to congestion) meant that > >multiple AX25 links could share a channel in a stable way. Pactor > >has no such characteristic. Co-channel QRM between two Pactor links > >results in neither link passing any traffic until one link aborts. > >The logistic consequence of this is that Winlink sysops will always > >choose to operate on a channel on which they can be sure no other > >Pactor link will take place. They will always prefer to be subjected > >to random QRM from another service than to be subjected to QRM from > >another Pactor link. > > > >This unfortunate characteristic has meant that the interference from > >Pactor to other services is maximised rather than minimised, and it > >also means that the Winlink organisers complain bitterly that there > >is insufficient space within the designated automatic sub-bands. The > >total volume of traffic handled by these unattended stations could > >easily be passed within the automatic sub-band limits, given a > >mechanism by which the stations involved could co-ordinate their > >activity. However, it cannot be done with Pactor or Winlink in their > >present forms, and while these stations are free to roam the bands, > >there will be no incentive to improve their channel utilisation. > > > >In theory at least, the same arguments for segregating unattended > >ARQ stations applies to ALL amateur activity which has a purpose > >other than recreation. Only truly recreational activity is > >self-limiting without regulation. Any other activity in which > >amateur radio performs a service to a third party, will be > >vulnerable to grid-lock in the face of band congestion in an > >unregulated channel structure. To be truly a service to the > >community, these activities should have their own channels. This > >would be worth exploring. There are huge tracts of the marine and > >aviation bands lying vacant now. > > > >These thoughts go far beyond your present petition, but I hope I > >haven't bored you by expounding them to you. I hope you have a good > >result with your petition, but even if you don't succeed, I hope > >your actions will be enough to kickstart the debate about how > >amateur radio can simultaneously (a) survive in a deregulated world, > >and (b) provide a service to the community. I don't think it can do > >both without changes to the rules such as you are proposing. > > > >73 > >Peter G3PLX > > > > >
