>>The FCC regulation on technical descriptions, ยง 97.309(a)(4), reads: >> >> (4) An amateur station transmitting a RTTY or data emission using a >> digital code specified in this paragraph may use any technique whose >> technical characteristics have been documented publicly, such as >> CLOVER, G-TOR, or PacTOR, for the purpose of facilitating >> communications. >> >>ARRL further states: >> >>"Documentation should be adequate to (a) recognize the technique or >>protocol when observed on the air, (b) determine call signs of stations >>in communication and read the content of the transmissions." >> >>Clearly, Pactor 2 and 3 and probably Clover II, do not completely >>fulfill these requirements. Since they have been used for many years >>now, it is probably too late to do much about it and I doubt that the >>ARRL Directors would take any action. However, one could mention it to >>their director and see what response they get. >> >> > >Laughter would probably be a good start for an appropriate response. > >http://www.arrl.org/FandES/field/regulations/techchar/PACTOR.html >http://www.arrl.org/FandES/field/regulations/techchar/PACTOR-II.html >http://www.arrl.org/FandES/field/regulations/techchar/PACTOR-III.html > >http://ecjones.org/pactor.html >http://ecjones.org/PT-III.pdf > >http://people.uncw.edu/youngb/research/nwc.pdf >http://www.rmsinst.com/dt3.htm > >http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6518330597 > >Your technical inability to implement the documented protocols does not >constitute a Part 97 rule violation on the part of those using PACTOR >modes, nor should it. > >
Is that the extent of the documentation? After a quick scan, the Pactor I documentation seems like it might have enough detail, but the Pactor III documentation seems very scattered, or perhaps even incomplete. It's certainly very light for what appears to be a complex and rich protocol. One example: the Pactor III documentation identifies one compression scheme as "a slightly modified approach which we called Pseudo-Markov Compression (PMC), because it can be considered as a hybrid between Markov- and Huffman encoding". It goes on to mention two different tables for English and German texts, but doesn't publish them (is that the English table in the Pactor I documentation? Not sure...). That is more marketing hype than technical detail. Just saying that it's a hybrid between Markov and Huffman doesn't really say much. Where are the details? It's basically an undocumented code. I for one wouldn't want to implement Pactor III. It will need very extensive research to make up for the limited documentation, and perhaps some serious reverse engineering. It may meet the letter of the law, but it's barely a start for someone trying to implement it. I don't think it achieves the spirit of amateur radio: to spread knowledge and goodwill. BTW: I've implemented several communications protocols professionally. Some recognized standards, some proprietary. The last one I did had to be compatible with a proprietary protocol that was almost entirely undocumented. Glad I was being paid to do that one... Later, Artie Lekstutis KC2MFS [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Check out the new improvements in Yahoo! Groups email. http://us.click.yahoo.com/6pRQfA/fOaOAA/yQLSAA/ELTolB/TM --------------------------------------------------------------------~-> Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
