My Rockwell ARC-190 v8 HF radio and a Rockwell Q9600 modem at "the office" into the SCOPE Command network works very well for e-mail INTERNET access but I do have access to 3khz wide channels. This is military hardware (spelled expensive!!) but it does work and I have seen 8 kbps out of a theoretical 9.6 kbps max running the STANAG 4539 single tone protocol. I have seen it hang in there at maybe 300 bps as low as -4 db SNR but no lower - it just falls apart after that. Thus, it does work for some of us and these terms are Google-able if you want more information.
Rick - KH2DF _____ From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Rick Sent: Wednesday, June 20, 2007 8:59 AM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] A.L.E., VHS and Betamax I doesn't sound like this mode would require much change in software, but if you have a rig with some kind of unchangeable firmware, I can see where AQC would not work. If we ever did get ALE placed in amateur rigs, it would be wise to have it in a flash eeprom form that can be updated with new technology. ALE is very unlikely to have a large following with radio amateurs because we don't tend to operate by calling specific stations, but I can see the potential for certain kinds of net operation. Even better would be some kind of store and forward or at least BBS type system to shift away from real time interfacing that we typically must do with nets. In fact, the main reason that I reduced my activity with NTS nets was not only the lack of traffic, but the requirement to meet at a specific time and day, which was not acceptable to me. I realize that part of the attraction of nets is the human social function and machine connections are not the same thing and that is probably why other BBS systems did not stay in the forefront over the years. If I understand your comments, you are saying that it is only a theoretical thing that we could run Amtor/Pactor/ and other high speed switching protocols with existing Operating Systems. I guess I look at all of this as to what can we do with what we have in place now and are likely to have in place for the foreseeable future and any kind of RTOS seems unlikely. The main development of new, and yet practical technology has come from Patrick's FAE mode. As I often point out, we have the pieces already developed, to wit: - very high speed modes that work with very good signals (> 10 dB S/N) and modest baud rates that are legal here in the U.S. - software frameworks such as Multipsk and possibly DM780 that handle the rig control through an auxiliary program such as DXLab Commander and Ham Radio Deluxe - no longer having a need for fast switching due to being able to pipeline data into a background thread to be processed while a new packet is incoming - busy frequency detection The main missing piece is being able to automatically switch between a suite of modes and negotiate the best mode for the current conditions. I'm still very skeptical of the utility of very high baud rate single tone modems for moderate to weak signals that are well below the MUF, but I am keeping an open mind on this and keep looking for some real world testing results that would compare various modes. The earlier document I mentioned suggests to me that these modes may not work well below 10 dB S/N and that is often what we radio amateurs must work with. Lately, there have been more comments about HF e-mail and ALE. What is currently available other than PSKmail for Linux OS that permits anyone to set up servers to route the traffic into the internet? 73, Rick, KV9U Steve Hajducek wrote: > GM Rick, > > Alternate Link Call (AQC) ALE is basically 2G Plus ALE in that its an > advanced 8FSK form of ALE where most all of the un-necessary overhead > of ALE has been removed and new capabilities have been added, to > include a PSK burst mode. The linking time to setup is must faster > with AQC-ALE and the ability to achieve a linked state in the face of > poor channel conditions is hugely improved. > > Remember this, ALE is the great facilitator of follow on traffic, be > it data or voice ( analog or digital) or remote signaling for command > and control and where the data may be of any format and not just 8FSK > ALE or other MIL-STD protocols, there are no limitations to what > follows after the ALE Link Quality Analysis (LQA) has been used to > select the best channel from those provided to work with. > > GTOR and PACTOR I are a challenge within the frame work on an event > driven OS to implement, if you take control of the OS and limit the > interrupts to a point of which the application is in control of > environment, which would for the most part preclude the multi-tasking > 3rd party application aspect of the OS to point where only the > digital communications application is running, then it even these > fast timing ACK/NAK protocols would work, even AMTOR ARQ which is > even a worst case than PACTOR I timing. As to the new PACTOR x and > CLOVER modes, they do not have the same short turn around timing, > PACTOR III is basically modeled after the newer Military waveforms > which run on the MIL-STD-188-110x modem. > > The work that Patrick has done with FAE ARQ to date is the best > example of an FSK ARQ protocol for Amateur Radio designed for the PC > Sound Device Modem (PCSDM) in my opinion, it provides the best > aspects of the MIL-STD ALE DBM ARQ protocol ( developed from the > MIL-STD's which Kantronics also worked up GTOR from) and PAX/PAX2 > into a new protocol that I find to be perfect for Amateur Radio at > keyboard to keyboard, file transfer and HF e-mail needs. What the > Amateur Radio Service will see come along on the PCSDM in the way of > a high speed PSK modem waveform that provides all the desired > features and is legal in all countries for use is yet to be seen. Its > obvious to me that the MIL-STD-188-110x modem with one of a number of > DLP waveforms are contenders, timing is not an issue as far as the OS > is concerned and the speed is certainly there, just as fast and even > faster and as and more robust than is PACTOR III which the ham world > uses as the yard stick for some reason, tailoring down of the PSK > carrier and symbol rate for less than 3Khz signal BW is doable, some > hardware modems support it and I did in MARS-ALE, but its still to > much under current FCC rules for Amateur Radio here in the U.S., so > stay tuned for more developments to come is what I say and for now > embrace the legal FSK ARQ waveforms on the PCSDM. > > /s/ Steve, N2CKH > >
