On Fri, Jun 28, 2024 at 4:42?PM Steve Stroh via groups.io
<steve.stroh@...> wrote:
One advantage I see to M17 is that it¡¯s largely a software / protocol specification intended to be implemented by (and take advantage of) modern embedded processors. All the other radios have to be built around a DSP chip with DVSI code embedded into it, with all the compromises that requires. It also handicaps the evolution of those systems to insure backwards compatibility with older radios with older hardware.
K6BP's slideshow indicates that Icom has apparently licensed the code
in newer radios versus actually using a DVSI chip, but your point is
still valid.
I should also note that in the original JARL documentation
() anticipates different
modulations schemes - GMSK, as Icom chose, but also QPSK and 4FSK. I
see nothing there that would allow either identification of the chosen
format (maybe it's enough that the radio understands it or doesn't)
and certainly no method of allowing the different modulation
techniques to work together independent of codec.
Along those lines, there was a TAPR paper by SV9OAN that suggests
using an undefined flag field in the existing D-STAR protocol stream
header to identify the codec in use, suggesting that radios could be
built that use the D-STAR *protocol* but the CODEC2 to encode voice.
Interesting idea.
I like the digital stuff (and am an Icom Fanboy if that isn't obvious)
but do NOT care to use DVSI's patents to do it and really object to
having three different NON-INTEROPERABLE DV systems that all use the
same patents under the hood!
--
Peter Laws | VE[23]UWY / N5UWY | plaws0 gmail com | Travel by Train!
Peter Laws