[pskmail] Re: integrating Winmor TNC
- From: karel Fassotte <karel.fassotte@xxxxxxxxx>
- To: pskmail@xxxxxxxxxxxxx
- Date: Thu, 27 Jan 2011 19:10:39 -0500
Hello John,
I will comment below.
2011/1/27 John Douyere <vk2eta@xxxxxxxxx>
> Hola Karel,
>
> There are three key design objectives in the Pskmail project that
> relate to your questions:
>
> 1. Open source (right its no open source9
>
> 2. Narrow band (less than 500 Hz). (why ?)
>
> 3. Solid link even in the presence of QRM/QRN (NVIS links are very stroung
> little interference)
>
> The Winmor protocol is available as a software TNC (like Fldigi) but
> unfortunately only under Windows. So that excludes for the moment
> having it linked to Pskmail. (right)
>
> On the speed aspect there would be some work required to increase the
> speed further with say 2PSK or 4 PSK (e.g. 2 or 4 PSK500 or PSK500R
> modulations in parallel). That would not be that hard to do in Fldigi,
> but the timing will become more critical in Pskmail as it was more
> designed to accommodate very different (and some slow) digital mode
> timings rather than a fixed and precise timing between client and
> server. (that could be a solution. However I liked the very ffast and
> efficient turn arround of Winmor)
>
> So probably the issue at present is more to understand the need for
> faster speed as the design objectives has served us well until now I
> believe. (yes that might be the case but link build up and conecting speed,
> addaptive is of great advantage for a quick handling of mail. Speed is also
> an issue) A mail of 1KB should be transfered and handled in a minute.
>
> Please note that Pskmail (at least in recent versions) will
> automatically adapt it's speed depending on the conditions, from THOR8
> to PSK500 and in my personal experience has been able to establish
> links several times when I could not with Winmor from my same portable
> setup. (I dont have the same experience. I have no problem linking Winmor
> on my links)
>
> Of course it could be a difference in the server's setup since they
> are separated by several kilometers and don't run the same antennas,
> but that is my experience.(My conexions are NVIS links up to about 1000km)
>
> What happens often is that the link is not symmetric, either because
> the portable station is running low power and/or has compromise
> antennas, or the server (which normally runs high power - say 50 watts
> - and has good antennas) has local QRM. (maybe an item)
>
> That is why Pskmail will TX and RX in different modes and adapt each
> individually to the link quality.(I understands but that takes time and
> time is critical for emergency communications)
>
> I have several time run QRP power (FT-817) with a dipole in NVIS
> conditions (which I believe represents the most common situation for
> disaster conditions) and had very good downlink from the server and
> poor uplink to it, but Pskmail did it's job nicely almost every time. (I
> hope it can be faster and better)
>
> When the link is good the PSK500 modulation will provide an 800 words
> per minute raw speed, and taking into account the compression of text
> messages (about 2 x for text) and the overhead of the Pskmail protocol
> we should see net exchanges of about 200 to 400 words per minute or
> above 70Kb of data per hour. That is a lot of data exchanged I feel. (for
> bigger files I would use another protocol 188-110, this is slower bulding up
> the link but has much faster data troughput uo to 2Kb/s)
>
> In my experience also, the psk modulations (as used in Fldigi and
> Wiinmor) are not the most robust due to phase shifting and selective
> fading that is characteristic of that propagation mode. In that case
> the fsk modes (MFSK and THOR for example) provide much lower error
> rates. (Winmore is fast adaptive and uses 5Khz. bandwith or 1,6Khz.
> Bandwith using multi carriers OFDM PSK)
>
> I have seen many times a slower but more reliable link (in MFSK for
> example) providing a higher net data rate than a fast, lest reliable
> link with many repeats. (Looking for a solution for a good NVIS link, not
> for links wit a lot of QRM, QSB, speed should be maximum 1300b/s)
>
> What format do you expect your emergency network to take: NVIS or long
> distance, what type of stations (fixed, high power, good antennas OR
> portable low power, compromise antennas), how many stations, how many
> messages, of what size, what type of message content (text or binary
> data). (NVIS uo to 1500 km, 50 watts of power 100% duty cycle, a good NVIS
> dipole on several frequencies. About 20 stations, 1K, max. 2KB messages.
> Messages usualy are text based but could contain binary attachments (small)
>
> These are all factors that are important in your selection of the best
> solution.
>
> Hope this helps.
>
> Regards,
>
> John (VK2ETA)
>
Please go on suggesting, I might not the only one thats looking for this
solution.
Greetings
and thanks
Karel (HC1AKP)
>
>
> On Fri, Jan 28, 2011 at 3:03 AM, karel Fassotte
> <karel.fassotte@xxxxxxxxx> wrote:
> > Hello all,
> > I have been investigating for some time now solutions for a emergency
> > network in Ecuador I also have been testing pskmail. I think it is
> allright
> > but I would like to have more and faster modem waveforms included. FLDIGI
> is
> > a nice multiwave form software modem, but for mespeed could be faster. I
> > have been testing the WINMOR TNC of Winlink.
> > My results are that the WINMOR TNC is very adecuate and hast handling
> > maximizing overall troughput. This is of big interest for an emergency
> > network. Many small (1KB) messages should be handled.
> > The RMS message terminal is also very easy to use.
> > This is all closed software, only windows untill now. I am not interested
> in
> > windows, but I am interested in solutions for open code with maximum
> > funcionality and easy use.
> > Can this WINMOR TNC be integrated in pskmail? This would realy be a great
> > improvement over the existing FLDIGI modem.
> > Do exists other soundcard modems that have the same specs as the WINMOR
> TNC?
> > Please let me know.
> > greetings, 73
> > Karel Fassotte
> > HC1AKP
> >
> >
> >
>
>
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