On Mar 19, 1:26 am, John Smith I wrote:
John Smith I wrote:

Over in RRAM there seems to be much debate on the need for HS data
communications, strange ...

Seems like in a REAL disaster, the need to xmit satellite maps of flood
areas, earthquake damage to bridges, structures, fires, hostiles?,
technical docs, medical documents/instructions/directions, signs, plans,
email, web data, etc. would be most appreciated if not desperately needed.


You are overlooking the digital modes already available, for example,
SSTV and Fax for images. Although not fast, how many pictures of the
same item do you really need immediately for example? It is not going
to be a hardship if it takes a couple of minutes for the image to
transfer rather than a couple of seconds.

Text data (documents, instructions, directions, etc) are easily
handled by error correcting modes now available. Granted these modes
aren't used much but all the sender and recipient have to do is agree
on which mode.


While VHF+ (satellite comms would be good!) may be suitable for some
flat terrain and moderate distances, availability of HF communications,
surely, would be a requirement in many situations

A laptop consumes VERY LITTLE power and can turn any xceiver into a VERY
powerful data transmission tool; most today would consider it a
requirement rather than a luxury.


Depends on how hard up for power you are. In some cases, no problem.
In other cases, power will be so limited that you would only send the
most urgent of messages.

However, PSK is highly unsuitable and the development of REAL tools
remains for the future ... new minds with up-to-date technology, methods
and skills will accomplishing this.


There are tools that will meet these needs today. They are not as
fast as you would like them to be but they do work.

The future is coming ... like it or not.

JS

To shape the future, we need to understand the abilities of the
present. I'd suggest getting out there and working SSTV (ATV on UHF),
packet, RTTY, PSK31, AMTOR, PACTOR (I, II, and III), Hellschreiber and
the rest of the myriad "flavors" of digital out there. There is even a
variant of PSK that includes some error checking. Learn first hand
their strengths and weaknesses. Without this background, a developer
will be handicapped in coming up with something better. If he is not
knowledgeable on what is out there, he may end up "re-inventing the
wheel." If he is not knowledgeable about the strengths and weaknesses
of current modes, his new mode may end up having some of the same
issues.

One can't just wave a magic wand and say "let it be so."

Dee, N8UZE