Interesting idea, a couple of thoughts come to mind (not that you haven't already considered them):
When you are only listening, you have a good idea of who else is transmitting when/where, but as soon as you start transmitting, you lose visibilty into your timeslot. I use a combination of visual inspection and a Python program that grinds through the last couple of minutes of ALL.TXT to pick an empty transmit frequency, and while it works, it's a bit of a kludge. There's no good answer to "How wide is someone else's rx bandwidth?". While some have fancy SDR rigs with 5KHz or more, others have voice rigs (or don't know how to set their filters), so attempting a QSO at 200Hz or 4KHz is only going to work for some random subset of operators. 73, Willie N1JBJ > On Aug 27, 2021, at 3:48 PM, Phil Karn via wsjt-devel > <wsjt-devel@lists.sourceforge.net> wrote: > > While composing another message I had an idea that might help reduce > FT-8 congestion. > > Every FT-8 receiver listens to an entire "band" (approximately 1 SSB > bandwidth) and it will hear and decode every station transmitting > anywhere in it. This makes each station's exact transmit frequency > unimportant. So for some time I've felt that FT-8 transmissions should > be randomized in frequency to avoid repeated collisions, as most WSPR > stations already do. But the transmit frequency need not be truly > random; if it is based on a hash function, then other stations can know > the frequency on which you will (or would) transmit during any given > 15-second slot. > > So here's my idea. Divide the FT-8 "band" into slots, each wide enough > to take one signal. Set your transmit frequency "slot" based on a hash > of the transmitting station's callsign, perturbed by the time of day in > 15 second increments. This sets up the frequency hopping. It is backward > compatible with current operation. > > Everyone monitors everyone else's protocol exchanges so they are aware > of the active callsigns and their current QSO exchange states. If your > hash happens to match that of a station expected to transmit, either > inhibit transmission or choose from a small set of secondary "overflow" > slots unprotected against a collision. > > I just had this idea so it is far from fully formed. Nor can it be > perfect because, if nothing else, you are unable to monitor > transmissions while you yourself are transmitting. But I wanted to see > if anyone else had any comments on it, or if it has been suggested before. > > 73, Phil > > > > > > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
