On 05/20/2012 06:32 PM, Matthew Pitts wrote:
Bruce,
If we can demonstrate the system by plugging something into their D-Star
transceiver, I think we can get their attention;
Codec2 voice over D-STAR just duplicates what the D-STAR radio already
does, but you have to connect some external device to make your D-STAR
radio do it with Codec2. I don't think this will excite a /lot /of people.
It might excite someone that Codec2 should work over a 1200 Baud KISS
TNC, because the TNC has not done voice before. It might excite someone
that we can do Codec2 over HF, and that (unlike D-STAR or DMR/TRBO) it
is actually legal to use between the U.S. and another country, and that
it is narrower than an SSB channel.
I think we need to be very careful about separating what excites /us
/ffrom what excites the larger ham community. We are excited because our
new development works, it's Free Software / Open Source, you can tweak
it, etc. It is nice that you bought D-STAR and are excited by these
things, but I am not getting the impression that they excite most D-STAR
users. Although we got the Georgia D-STAR folks to give out our
brochures, we did not get invited to speak at their meeting. I stood in
the aisle and put brochures into hundreds of people's hands at
Hamvention, and a number of people told me the project was cool, but
none identified themselves as D-STAR users.
I'm not so sure about the DMR guys, as they have issues with anything that
doesn't have fancy features like text messaging and such included.
My APRS radio has text messaging. Is text messaging what is exciting
about DMR/TRBO? Overall it seems to me to be a loser out of the gate.
Twice the bandwidth of D-STAR, the same dumb proprietary codec, and no
additional advantages. What am I missing? Yaesu claims their major
advantage is that they have half the bandwidth of wideband FM, but
D-STAR has 1/4 by that measure and we could have 1/10.
I also feel that we should design an adaptive system that makes use of GPS data
to regulate power levels and bandwidth (narrow bandwidth and higher power
output farther out and wider bandwidth with lower power closer in or in
situations where traditional radios run into problems). We need to show that we
can design digital modes that can keep the spirit of the rules as well as the
letter. :)
How about adjusting power based upon feedback of RSSI from the other
radio in a point-to-point link? GPS doesn't tell you about trees and
structures between the two stations, RSSI does.
Have we got a documented protocol that we are.going to use yet? I'd like to
start working on the repeater controller code changes soon, among the other
software projects I'm working on.
There is a proposal for a D-STAR-like protocol for VHF/UHF. But our
voice payload is potentially smaller than the overhead in such a
protocol. I think there is room for work on ultra-low-overhead schemes.
Thanks
Bruce
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
Freetel-codec2 mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/freetel-codec2
