Steve and group, The part of ALE that has this ARQ mode sounds pretty good. Is it fair to say that the 8 tone modulation is actually closer to what Pactor 3 uses? The speed is a bit fast for many HF conditions but it has FEC as well as ARQ so like Pactor, is that why it tends to overcome some of the ISI issues?
Can you just use the PC-ALE program and connect to another station for an ARQ transfer of data or even a keyboard connection? If this mode is this good, what is the possibility of adapting it for a high speed digital sound card mode and have it incorporated into the multimode sound card programs? How can this mode handle ARQ with sound card/computer timing constraits? Some of us in the amateur digital community have been hoping for some kind of ARQ sound card mode. Are we overlooking an already invented sound card protocol as Bonnie had mentioned last summer, except that ideally it would scale down in baud rate if conditions require it? I tried to find more information on the specifications but did not find any. I would not consider this mode to be legal on amateur radio frequencies until it has an easy to access specification as required by the FCC. This really should be detailed on the ARRL web site along with the many other digital specs, don't you think? 73, Rick, KV9U Steve Hajducek wrote: >Hi Andy, > >A system that implemented the ALE Data Block Message (DBM) ARQ >protocol using the PC Sound Device Modem (PCSDM) which at a raw 125 >baud with its deep interleaving providing a full 3x throughput on a >good circuit where no ACK/NAK failures occurred would be much better. >GTOR which blows away PACTOR I is blown away by ALE DBM and best of >all it can be easily implemented on the PCSDM as the ACK/NAK >is variable in seconds and not milliseconds. In MARS we sending >messages using DBM ARQ and FTP on channels where GTOR and PACTOR I >are failing, its really something to see for yourself. The DBM >protocol is extremely robust and it supports bidirectional messaging >as well which is an interesting twist when two stations are attended. > >/s/ Steve, N2CKH > > >
