I'd like to see a message type that consisted of a callsign in the current format, and the rest of the bits are in a callsign specific message format. It should be displayed as HEX. There should be a website somewhere where the message format is defined based on the sending callsign. For example, it might be used to report location data from (say) a balloon.

It turns out that a useful message size can actually be fit into the existing 72 bit message (there are, as I recall, around 2^68 code points that are unused -- 28 bits for a callsign + 48 bits for 12 hex characters -- fits easily into the existing format).

Philip

On 07/07/2017 12:55, Black Michael via wsjt-devel wrote:
Consideration may be given to using the 3 bits as an index rather than binary bits. That would give 7 options based on a 3-bit index with 000 meaning no options.

de Mike W9MDB



------------------------------------------------------------------------
*From:* Alexandre Moleiro via wsjt-devel <wsjt-devel@lists.sourceforge.net>
*To:* WSJT software development <wsjt-devel@lists.sourceforge.net>
*Cc:* Alexandre Moleiro <avataranedo...@yahoo.com>
*Sent:* Friday, July 7, 2017 11:49 AM
*Subject:* Re: [wsjt-devel] Suggestions for three extra bits in FT8

Hi!

3 extra bits can potentially create 5 new FT8 "submodes" with just these constraints:
-15 second T/R period
-72 bits of payload each period

This can open a whole new world of qso sequences, multi-pass decoding, TX power adjustment, beaconing, etc.

We can look at "most requested" features (portable and rover operation, complete grids contests, very complex compound callsigns, etc) but we can also begin with a clean sheet of paper and try to take a step into the future.

73 de CT1GVN







On Thursday, July 6, 2017, 2:49:12 PM GMT+1, Bill Somerville <g4...@classdesign.com> wrote:


On 06/07/2017 14:26, James Lemley wrote:
> After discarding the idea of encoding eight humorous messages, and
> without studying the rest of the protocol to see if these are already
> implemented, here are my suggestions for the three extra bits with a
> transmit frame:

HI James,

adding extra ad hoc messages can be easily done by using some of the
unused existing message space. For example the directional CQ messages
were inserted by using the unused callsign series E9xx. These sort of
things require no extra bits, just global agreement.

With respect to your other suggestions, in the protocols as they stand
every standard message except the 73 one expects acknowledgement. The 73
and free text messages do not expect acknowledgement although some free
text messages can be constructed to imply acknowledgement is expected,
"REPORT PSE?" for example. When acknowledgement is not received then
simply repeating the last message until acknowledgement is received is
all that is needed. It is unfortunate that many users wish to shorten
the QSO sequences without regard for the above. There are some cases for
dropping messages like the initial grid reply to a CQ when propagation
is unstable.

I believe you are not thinking far enough outside the box with how an
extra bit may be used. For example the current protocol is partitioned
into two by a single bit. One half encompasses every standard message
and the other half encompasses all the free text messages. A single
extra bit opens up the possibility of a whole new protocol with a
message space as large as the existing protocol. Using one or more extra
bits to add value to the existing protcol would be missing a huge
opportunity.

73
Bill
G4WJS.



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