[aprssig] 9600 Baud Packet Network?

vk4tec at tech-software.net vk4tec at tech-software.net
Sun Jun 12 12:47:56 CDT 2016


Why don't you use PPM pulse position modulation at 1 MHz

Like the big boys use

-----Original Message-----
From: aprssig [mailto:aprssig-bounces at tapr.org] On Behalf Of Stephen H. Smith via aprssig
Sent: Sunday, 12 June 2016 10:53 PM
To: Robert Bruninga <bruninga at usna.edu>; TAPR APRS Mailing List <aprssig at tapr.org>
Subject: Re: [aprssig] 9600 Baud Packet Network?

On 6/12/2016 3:57 AM, Robert Bruninga via aprssig wrote:
> We are not using our 9600 Baud Radios well!
>
> What kind of external processor could we plug into the back of a 9600 
> baud APRS radio with built-in TNC to make it function as a NETROM node?

Not very practical.  The internal TNC would have to operate in KISS mode to allow an external processor get at the raw packets. Given the notorious unreliability of the KISS mode in many APRS radios, this is dubious at best.

>
> What could we do with it?  All I remember about NETROMS were something like this:
> 1) You could connect to any node and see what it could connect to.
> 2) Then you could connect to anyone in the net
> 3) Such as their PBBS

Except for a few DX packet clusters, There is virtually no packet 
infrastructure left.  Conventional connected packet (and BBS systems) were 
killed off by Internet email in the 1990s, cellular  text messaging in the 
2000s, and full internet access on cell phones in the late 2000s/early 2010s.

Remember, it was all those abandoned TNCs, left over when the connected packet 
era of the '80s died, that were the foundation of APRS........

> 4) where you could see their message list
> 5) And then read any of their messages.
>
> 6) Could a message be a FILE???
> 7) And a file could be a small picture?
>
> 8) And JPG cameras now cost peanuts

These cheap cameras are USB-based and require massive software stacks provided 
by real operating systems like Windows, Linux, iOS or Android.   Not something 
you are going to run on a PIC-class controller.

> 9) THey could plug into the same extrnal processor!

Which is now going to have to be essentially a "real" PC with a real operating 
system.

> 10) Now I can see what you are seeing!

Even a small JPG image file is HUGE (i.e. 10s or 100s of K) compared to the 
bare ASCII text files of the packet messaging heydays that were at most a few 
hundred bytes.

I once tried transferring a 320x240 SSTV-like image over packet.  With all the 
back and forth transmit-ack-transmit-ack hand-shaking on each few hundred 
bytes, it took over 15 minutes to send one image.  And that was direct 
radio-to-radio without the overhead of digipeaters, nodes, etc.

>
> We have the radios, we have the sites,

What sites???


> but we are not using our 9600 baud
> capabilties at all.
>
> I'm thinking it does need to be seamless with the existing NETROM, THENET, KA
> node archetecture for the long haul links so we can use a lot of our existing
> stuff.

What "existing stuff".   Classic packet is dead - the infrastructure isn't 
there anymore....

>
> Hummh...
> Bob, WB4APR
>



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